Editor’s Choice Articles

Editor’s Choice articles are based on recommendations by the scientific editors of MDPI journals from around the world. Editors select a small number of articles recently published in the journal that they believe will be particularly interesting to readers, or important in the respective research area. The aim is to provide a snapshot of some of the most exciting work published in the various research areas of the journal.

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Article

14 pages, 4490 KiB  
Article
Sea Urchin-like Si@MnO2@rGO as Anodes for High-Performance Lithium-Ion Batteries
by Jiajun Liu, Meng Wang, Qi Wang, Xishan Zhao, Yutong Song, Tianming Zhao and Jing Sun
Nanomaterials 2022, 12(2), 285; https://doi.org/10.3390/nano12020285 - 17 Jan 2022
Cited by 10 | Viewed by 2945
Abstract
Si is a promising material for applications as a high-capacity anode material of lithium-ion batteries. However, volume expansion, poor electrical conductivity, and a short cycle life during the charging/discharging process limit the commercial use. In this paper, new ternary composites of sea urchin-like [...] Read more.
Si is a promising material for applications as a high-capacity anode material of lithium-ion batteries. However, volume expansion, poor electrical conductivity, and a short cycle life during the charging/discharging process limit the commercial use. In this paper, new ternary composites of sea urchin-like Si@MnO2@reduced graphene oxide (rGO) prepared by a simple, low-cost chemical method are presented. These can effectively reduce the volume change of Si, extend the cycle life, and increase the lithium-ion battery capacity due to the dual protection of MnO2 and rGO. The sea urchin-like Si@MnO2@rGO anode shows a discharge specific capacity of 1282.72 mAh g−1 under a test current of 1 A g−1 after 1000 cycles and excellent chemical performance at different current densities. Moreover, the volume expansion of sea urchin-like Si@MnO2@rGO anode material is ~50% after 150 cycles, which is much less than the volume expansion of Si (300%). This anode material is economical and environmentally friendly and this work made efforts to develop efficient methods to store clean energy and achieve carbon neutrality. Full article
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15 pages, 3756 KiB  
Article
Influence of POSS Type on the Space Environment Durability of Epoxy-POSS Nanocomposites
by Avraham I. Bram, Irina Gouzman, Asaf Bolker, Nurit Atar, Noam Eliaz and Ronen Verker
Nanomaterials 2022, 12(2), 257; https://doi.org/10.3390/nano12020257 - 14 Jan 2022
Cited by 2 | Viewed by 1855
Abstract
In order to use polymers at low Earth orbit (LEO) environment, they must be protected against atomic oxygen (AO) erosion. A promising protection strategy is to incorporate polyhedral oligomeric silsesquioxane (POSS) molecules into the polymer backbone. In this study, the space durability of [...] Read more.
In order to use polymers at low Earth orbit (LEO) environment, they must be protected against atomic oxygen (AO) erosion. A promising protection strategy is to incorporate polyhedral oligomeric silsesquioxane (POSS) molecules into the polymer backbone. In this study, the space durability of epoxy-POSS (EPOSS) nanocomposites was investigated. Two types of POSS molecules were incorporated separately—amine-based and epoxy-based. The outgassing properties of the EPOSS, in terms of total mass loss, collected volatile condensable material, and water vapor regain were measured as a function of POSS type and content. The AO durability was studied using a ground-based AO simulation system. Surface compositions of EPOSS were studied using high-resolution scanning electron microscopy and X-ray photoelectron spectroscopy. It was found that with respect to the outgassing properties, only some of the EPOSS compositions were suitable for the ultrahigh vacuum space environment, and that the POSS type and content had a strong effect on their outgassing properties. Regardless of the POSS type being used, the AO durability improved significantly. This improvement is attributed to the formation of a self-passivated AO durable SiO2 layer, and demonstrates the potential use of EPOSS as a qualified nanocomposite for space applications. Full article
(This article belongs to the Special Issue Nanomaterials for Potential Uses in Extraterrestrial Environments)
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15 pages, 9451 KiB  
Article
Comparison of Plasma Deposition of Carbon Nanomaterials Using Various Polymer Materials as a Carbon Atom Source
by Alenka Vesel, Rok Zaplotnik, Gregor Primc, Domen Paul and Miran Mozetič
Nanomaterials 2022, 12(2), 246; https://doi.org/10.3390/nano12020246 - 13 Jan 2022
Cited by 3 | Viewed by 1314
Abstract
Carbon nanowalls are promising materials for various electrochemical devices due to their chemical inertness, desirable electrical conductivity, and excellent surface-to-mass ratio. Standard techniques, often based on plasma-assisted deposition using gaseous precursors, enable the synthesis of top-quality carbon nanowalls, but require long deposition times [...] Read more.
Carbon nanowalls are promising materials for various electrochemical devices due to their chemical inertness, desirable electrical conductivity, and excellent surface-to-mass ratio. Standard techniques, often based on plasma-assisted deposition using gaseous precursors, enable the synthesis of top-quality carbon nanowalls, but require long deposition times which represents a serious obstacle for mass applications. Here, an alternative deposition technique is presented. The carbon nanowalls were synthesized on titanium substrates using various polymers as solid precursors. A solid precursor and the substrate were mounted into a low-pressure plasma reactor. Plasma was sustained by an inductively coupled radiofrequency discharge in the H-mode at the power of 500 W. Spontaneous growth of carbon nanomaterials was observed for a variety of polymer precursors. The best quality of carbon nanowalls was obtained using aliphatic polyolefins. The highest growth rate of a thin film of carbon nanowalls of about 200 nm/s was observed. The results were explained by different degradation mechanisms of polymers upon plasma treatment and the surface kinetics. Full article
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9 pages, 1862 KiB  
Article
Defect-Induced π-Magnetism into Non-Benzenoid Nanographenes
by Kalyan Biswas, Lin Yang, Ji Ma, Ana Sánchez-Grande, Qifan Chen, Koen Lauwaet, José M. Gallego, Rodolfo Miranda, David Écija, Pavel Jelínek, Xinliang Feng and José I. Urgel
Nanomaterials 2022, 12(2), 224; https://doi.org/10.3390/nano12020224 - 11 Jan 2022
Cited by 6 | Viewed by 3276
Abstract
The synthesis of nanographenes (NGs) with open-shell ground states have recently attained increasing attention in view of their interesting physicochemical properties and great prospects in manifold applications as suitable materials within the rising field of carbon-based magnetism. A potential route to induce magnetism [...] Read more.
The synthesis of nanographenes (NGs) with open-shell ground states have recently attained increasing attention in view of their interesting physicochemical properties and great prospects in manifold applications as suitable materials within the rising field of carbon-based magnetism. A potential route to induce magnetism in NGs is the introduction of structural defects, for instance non-benzenoid rings, in their honeycomb lattice. Here, we report the on-surface synthesis of three open-shell non-benzenoid NGs (A1, A2 and A3) on the Au(111) surface. A1 and A2 contain two five- and one seven-membered rings within their benzenoid backbone, while A3 incorporates one five-membered ring. Their structures and electronic properties have been investigated by means of scanning tunneling microscopy, noncontact atomic force microscopy and scanning tunneling spectroscopy complemented with theoretical calculations. Our results provide access to open-shell NGs with a combination of non-benzenoid topologies previously precluded by conventional synthetic procedures. Full article
(This article belongs to the Special Issue On-Surface Synthesis of Low-Dimensional Organic Nanostructures)
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26 pages, 63495 KiB  
Article
Improving the Performance of BaMnO3 Perovskite as Soot Oxidation Catalyst Using Carbon Black during Sol-Gel Synthesis
by Verónica Torregrosa-Rivero, María-Salvadora Sánchez-Adsuar and María-José Illán-Gómez
Nanomaterials 2022, 12(2), 219; https://doi.org/10.3390/nano12020219 - 10 Jan 2022
Cited by 9 | Viewed by 2036
Abstract
A series of BaMnO3 solids (BM-CX) were prepared by a modified sol-gel method in which a carbon black (VULCAN XC-72R), and different calcination temperatures (600–850 °C) were used. The fresh and used catalysts were characterized by ICP-OES, XRD, XPS, FESEM, TEM, O [...] Read more.
A series of BaMnO3 solids (BM-CX) were prepared by a modified sol-gel method in which a carbon black (VULCAN XC-72R), and different calcination temperatures (600–850 °C) were used. The fresh and used catalysts were characterized by ICP-OES, XRD, XPS, FESEM, TEM, O2-TPD and H2- TPR-. The characterization results indicate that the use of low calcination temperatures in the presence of carbon black allows decreasing the sintering effects and achieving some improvements regarding BM reference catalyst: (i) smaller average crystal and particles size, (ii) a slight increase in the BET surface area, (iii) a decrease in the macropores diameter range and, (iv) a lower temperature for the reduction of manganese. The hydrogen consumption confirms Mn(III) and Mn(IV) are presented in the samples, Mn(III) being the main oxidation state. The BM-CX catalysts series shows an improved catalytic performance regarding BM reference catalyst for oxidation processes (NO to NO2 and NO2-assisted soot oxidation), promoting higher stability and higher CO2 selectivity. BM-C700 shows the best catalytic performance, i.e., the highest thermal stability and a high initial soot oxidation rate, which decreases the accumulation of soot during the soot oxidation and, consequently, minimizes the catalyst deactivation. Full article
(This article belongs to the Special Issue Synthesis and Applications of Nanomaterials Based on Perovskites)
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13 pages, 5387 KiB  
Article
Simultaneous Extraction of the Grain Size, Single-Crystalline Grain Sheet Resistance, and Grain Boundary Resistivity of Polycrystalline Monolayer Graphene
by Honghwi Park, Junyeong Lee, Chang-Ju Lee, Jaewoon Kang, Jiyeong Yun, Hyowoong Noh, Minsu Park, Jonghyung Lee, Youngjin Park, Jonghoo Park, Muhan Choi, Sunghwan Lee and Hongsik Park
Nanomaterials 2022, 12(2), 206; https://doi.org/10.3390/nano12020206 - 09 Jan 2022
Cited by 5 | Viewed by 2108
Abstract
The electrical properties of polycrystalline graphene grown by chemical vapor deposition (CVD) are determined by grain-related parameters—average grain size, single-crystalline grain sheet resistance, and grain boundary (GB) resistivity. However, extracting these parameters still remains challenging because of the difficulty in observing graphene GBs [...] Read more.
The electrical properties of polycrystalline graphene grown by chemical vapor deposition (CVD) are determined by grain-related parameters—average grain size, single-crystalline grain sheet resistance, and grain boundary (GB) resistivity. However, extracting these parameters still remains challenging because of the difficulty in observing graphene GBs and decoupling the grain sheet resistance and GB resistivity. In this work, we developed an electrical characterization method that can extract the average grain size, single-crystalline grain sheet resistance, and GB resistivity simultaneously. We observed that the material property, graphene sheet resistance, could depend on the device dimension and developed an analytical resistance model based on the cumulative distribution function of the gamma distribution, explaining the effect of the GB density and distribution in the graphene channel. We applied this model to CVD-grown monolayer graphene by characterizing transmission-line model patterns and simultaneously extracted the average grain size (~5.95 μm), single-crystalline grain sheet resistance (~321 Ω/sq), and GB resistivity (~18.16 kΩ-μm) of the CVD-graphene layer. The extracted values agreed well with those obtained from scanning electron microscopy images of ultraviolet/ozone-treated GBs and the electrical characterization of graphene devices with sub-micrometer channel lengths. Full article
(This article belongs to the Special Issue Graphene for Electronics)
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18 pages, 2780 KiB  
Article
Double-Layer Fatty Acid Nanoparticles as a Multiplatform for Diagnostics and Therapy
by María Salvador, José Luis Marqués-Fernández, José Carlos Martínez-García, Dino Fiorani, Paolo Arosio, Matteo Avolio, Francesca Brero, Florica Balanean, Andrea Guerrini, Claudio Sangregorio, Vlad Socoliuc, Ladislau Vekas, Davide Peddis and Montserrat Rivas
Nanomaterials 2022, 12(2), 205; https://doi.org/10.3390/nano12020205 - 08 Jan 2022
Cited by 10 | Viewed by 2234
Abstract
Today, public health is one of the most important challenges in society. Cancer is the leading cause of death, so early diagnosis and localized treatments that minimize side effects are a priority. Magnetic nanoparticles have shown great potential as magnetic resonance imaging contrast [...] Read more.
Today, public health is one of the most important challenges in society. Cancer is the leading cause of death, so early diagnosis and localized treatments that minimize side effects are a priority. Magnetic nanoparticles have shown great potential as magnetic resonance imaging contrast agents, detection tags for in vitro biosensing, and mediators of heating in magnetic hyperthermia. One of the critical characteristics of nanoparticles to adjust to the biomedical needs of each application is their polymeric coating. Fatty acid coatings are known to contribute to colloidal stability and good surface crystalline quality. While monolayer coatings make the particles hydrophobic, a fatty acid double-layer renders them hydrophilic, and therefore suitable for use in body fluids. In addition, they provide the particles with functional chemical groups that allow their bioconjugation. This work analyzes three types of self-assembled bilayer fatty acid coatings of superparamagnetic iron oxide nanoparticles: oleic, lauric, and myristic acids. We characterize the particles magnetically and structurally and study their potential for resonance imaging, magnetic hyperthermia, and labeling for biosensing in lateral flow immunoassays. We found that the myristic acid sample reported a large r2 relaxivity, superior to existing iron-based commercial agents. For magnetic hyperthermia, a significant specific absorption rate value was obtained for the oleic sample. Finally, the lauric acid sample showed promising results for nanolabeling. Full article
(This article belongs to the Special Issue Functional Nanomaterials for Sensor Applications)
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11 pages, 6138 KiB  
Article
Effect of the Dopant Configuration on the Electronic Transport Properties of Nitrogen-Doped Carbon Nanotubes
by Kim Eklund and Antti J. Karttunen
Nanomaterials 2022, 12(2), 199; https://doi.org/10.3390/nano12020199 - 07 Jan 2022
Cited by 8 | Viewed by 2343
Abstract
Nitrogen-doped carbon nanotubes (N-CNTs) show promise in several applications related to catalysis and electrochemistry. In particular, N-CNTs with a single nitrogen dopant in the unit cell have been extensively studied computationally, but the structure-property correlations between the relative positions of several nitrogen dopants [...] Read more.
Nitrogen-doped carbon nanotubes (N-CNTs) show promise in several applications related to catalysis and electrochemistry. In particular, N-CNTs with a single nitrogen dopant in the unit cell have been extensively studied computationally, but the structure-property correlations between the relative positions of several nitrogen dopants and the electronic transport properties of N-CNTs have not been systematically investigated with accurate hybrid density functional methods. We use hybrid density functional theory and semiclassical Boltzmann transport theory to systematically investigate the effect of different substitutional nitrogen doping configurations on the electrical conductivity of N-CNTs. Our results indicate significant variation in the electrical conductivity and the relative energies of the different dopant configurations. The findings can be utilized in the optimization of electrical transport properties of N-CNTs. Full article
(This article belongs to the Special Issue Theoretical Calculation and Molecular Modeling of Nanomaterials)
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13 pages, 8345 KiB  
Article
Ethanol Solvothermal Treatment on Graphitic Carbon Nitride Materials for Enhancing Photocatalytic Hydrogen Evolution Performance
by Phuong Anh Nguyen, Thi Kim Anh Nguyen, Duc Quang Dao and Eun Woo Shin
Nanomaterials 2022, 12(2), 179; https://doi.org/10.3390/nano12020179 - 06 Jan 2022
Cited by 15 | Viewed by 2497
Abstract
Recently, Pt-loaded graphic carbon nitride (g-C3N4) materials have attracted great attention as a photocatalyst for hydrogen evolution from water. The simple surface modification of g-C3N4 by hydrothermal methods improves photocatalytic performance. In this study, ethanol is [...] Read more.
Recently, Pt-loaded graphic carbon nitride (g-C3N4) materials have attracted great attention as a photocatalyst for hydrogen evolution from water. The simple surface modification of g-C3N4 by hydrothermal methods improves photocatalytic performance. In this study, ethanol is used as a solvothermal solvent to modify the surface properties of g-C3N4 for the first time. The g-C3N4 is thermally treated in ethanol at different temperatures (T = 140 °C, 160 °C, 180 °C, and 220 °C), and the Pt co-catalyst is subsequently deposited on the g-C3N4 via a photodeposition method. Elemental analysis and XPS O 1s data confirm that the ethanol solvothermal treatment increased the contents of the oxygen-containing functional groups on the g-C3N4 and were proportional to the treatment temperatures. However, the XPS Pt 4f data show that the Pt2+/Pt0 value for the Pt/g-C3N4 treated at ethanol solvothermal temperature of 160 °C (Pt/CN-160) is the highest at 7.03, implying the highest hydrogen production rate of Pt/CN-160 is at 492.3 μmol g−1 h−1 because the PtO phase is favorable for the water adsorption and hydrogen desorption in the hydrogen evolution process. In addition, the electrochemical impedance spectroscopy data and the photoluminescence spectra emission peak intensify reflect that the Pt/CN-160 had a more efficient charge separation process that also enhanced the photocatalytic activity. Full article
(This article belongs to the Special Issue Performance of Nanocomposite for Optoelectronic Applications)
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14 pages, 15216 KiB  
Article
Facile Synthesis of Silver Nanoparticles and Preparation of Conductive Ink
by Gui Bing Hong, Yi Hua Luo, Kai Jen Chuang, Hsiu Yueh Cheng, Kai Chau Chang and Chih Ming Ma
Nanomaterials 2022, 12(1), 171; https://doi.org/10.3390/nano12010171 - 05 Jan 2022
Cited by 14 | Viewed by 2707
Abstract
In the scientific industry, sustainable nanotechnology has attracted great attention and has been successful in facilitating solutions to challenges presented in various fields. For the present work, silver nanoparticles (AgNPs) were prepared using a chemical reduction synthesis method. Then, a low-temperature sintering process [...] Read more.
In the scientific industry, sustainable nanotechnology has attracted great attention and has been successful in facilitating solutions to challenges presented in various fields. For the present work, silver nanoparticles (AgNPs) were prepared using a chemical reduction synthesis method. Then, a low-temperature sintering process was deployed to obtain an Ag-conductive ink preparation which could be applied to a flexible substrate. The size and shape of the AgNPs were characterized by ultraviolet–visible spectrophotometry (UV-Vis) and transmission electron microscopy (TEM). The experiments indicated that the size and agglomeration of the AgNPs could be well controlled by varying the reaction time, reaction temperature, and pH value. The rate of nanoparticle generation was the highest when the reaction temperature was 100 °C within the 40 min reaction time, achieving the most satisfactorily dispersed nanoparticles and nanoballs with an average size of 60.25 nm at a pH value of 8. Moreover, the electrical resistivity of the obtained Ag-conductive ink is controllable, under the optimal sintering temperature and time (85 °C for 5 min), leading to an optimal electrical resistivity of 9.9 × 10−6 Ω cm. The results obtained in this study, considering AgNPs and Ag-conductive ink, may also be extended to other metals in future research. Full article
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15 pages, 2188 KiB  
Article
Artificial Neural Network Modelling for Optimizing the Optical Parameters of Plasmonic Paired Nanostructures
by Sneha Verma, Sunny Chugh, Souvik Ghosh and B. M. Azizur Rahman
Nanomaterials 2022, 12(1), 170; https://doi.org/10.3390/nano12010170 - 04 Jan 2022
Cited by 10 | Viewed by 2486
Abstract
The Artificial Neural Network (ANN) has become an attractive approach in Machine Learning (ML) to analyze a complex data-driven problem. Due to its time efficient findings, it has became popular in many scientific fields such as physics, optics, and material science. This paper [...] Read more.
The Artificial Neural Network (ANN) has become an attractive approach in Machine Learning (ML) to analyze a complex data-driven problem. Due to its time efficient findings, it has became popular in many scientific fields such as physics, optics, and material science. This paper presents a new approach to design and optimize the electromagnetic plasmonic nanostructures using a computationally efficient method based on the ANN. In this work, the nanostructures have been simulated by using a Finite Element Method (FEM), then Artificial Intelligence (AI) is used for making predictions of associated sensitivity (S), Full Width Half Maximum (FWHM), Figure of Merit (FOM), and Plasmonic Wavelength (PW) for different paired nanostructures. At first, the computational model is developed by using a Finite Element Method (FEM) to prepare the dataset. The input parameters were considered as the Major axis, a, the Minor axis, b, and the separation gap, g, which have been used to calculate the corresponding sensitivity (nm/RIU), FWHM (nm), FOM, and plasmonic wavelength (nm) to prepare the dataset. Secondly, the neural network has been designed where the number of hidden layers and neurons were optimized as part of a comprehensive analysis to improve the efficiency of ML model. After successfully optimizing the neural network, this model is used to make predictions for specific inputs and its corresponding outputs. This article also compares the error between the predicted and simulated results. This approach outperforms the direct numerical simulation methods for predicting output for various input device parameters. Full article
(This article belongs to the Special Issue Nanosensors)
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12 pages, 31423 KiB  
Article
Solution-Processed Smooth Copper Thiocyanate Layer with Improved Hole Injection Ability for the Fabrication of Quantum Dot Light-Emitting Diodes
by Ming-Ru Wen, Sheng-Hsiung Yang and Wei-Sheng Chen
Nanomaterials 2022, 12(1), 154; https://doi.org/10.3390/nano12010154 - 01 Jan 2022
Cited by 1 | Viewed by 2352
Abstract
Copper thiocyanate (CuSCN) has been gradually utilized as the hole injection layer (HIL) within optoelectronic devices, owing to its high transparency in the visible range, moderate hole mobility, and desirable environmental stability. In this research, we demonstrate quantum dot light-emitting diodes (QLEDs) with [...] Read more.
Copper thiocyanate (CuSCN) has been gradually utilized as the hole injection layer (HIL) within optoelectronic devices, owing to its high transparency in the visible range, moderate hole mobility, and desirable environmental stability. In this research, we demonstrate quantum dot light-emitting diodes (QLEDs) with high brightness and current efficiency by doping 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F4TCNQ) in CuSCN as the HIL. The experimental results indicated a smoother surface of CuSCN upon F4TCNQ doping. The augmentation in hole mobility of CuSCN and carrier injection to reach balanced charge transport in QLEDs were confirmed. A maximum brightness of 169,230 cd m−2 and a current efficiency of 35.1 cd A−1 from the optimized device were received by adding 0.02 wt% of F4TCNQ in CuSCN, revealing promising use in light-emitting applications. Full article
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15 pages, 3351 KiB  
Article
Tailoring the Nonlinear Optical Response of Some Graphene Derivatives by Ultraviolet (UV) Irradiation
by Aristeidis Stathis, Zoi Bouza, Ioannis Papadakis and Stelios Couris
Nanomaterials 2022, 12(1), 152; https://doi.org/10.3390/nano12010152 - 01 Jan 2022
Cited by 5 | Viewed by 2321
Abstract
In the present work the impact of in situ photoreduction, by means of ultraviolet (UV) irradiation, on the nonlinear optical response (NLO) of some graphene oxide (GO), fluorographene (GF), hydrogenated fluorographene (GFH) and graphene (G) dispersions is studied. In situ UV photoreduction allowed [...] Read more.
In the present work the impact of in situ photoreduction, by means of ultraviolet (UV) irradiation, on the nonlinear optical response (NLO) of some graphene oxide (GO), fluorographene (GF), hydrogenated fluorographene (GFH) and graphene (G) dispersions is studied. In situ UV photoreduction allowed for the extended modification of the degree of functionalization (i.e., oxidization, fluorination and hydrogenation), leading to the effective tuning of the corresponding sp2/sp3 hybridization ratios. The nonlinear optical properties of the studied samples prior to and after UV irradiation were determined by means of the Z-scan technique using visible (532 nm), 4 ns laser excitation, and were found to change significantly. More specifically, while GO’s nonlinear optical response increases with irradiation time, GF and GFH present a monotonic decrease. The graphene dispersions’ nonlinear optical response remains unaffected after prolonged UV irradiation for more than an hour. The present findings demonstrate that UV photoreduction can be an effective and simple strategy for tuning the nonlinear optical response of these graphene derivatives in a controllable way, resulting in derivatives with custom-made responses, thus more suitable for different photonic and optoelectronic applications. Full article
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12 pages, 3291 KiB  
Article
Broadband Optical Constants and Nonlinear Properties of SnS2 and SnSe2
by Georgy A. Ermolaev, Dmitry I. Yakubovsky, Marwa A. El-Sayed, Mikhail K. Tatmyshevskiy, Arslan B. Mazitov, Anna A. Popkova, Ilya M. Antropov, Vladimir O. Bessonov, Aleksandr S. Slavich, Gleb I. Tselikov, Ivan A. Kruglov, Sergey M. Novikov, Andrey A. Vyshnevyy, Andrey A. Fedyanin, Aleksey V. Arsenin and Valentyn S. Volkov
Nanomaterials 2022, 12(1), 141; https://doi.org/10.3390/nano12010141 - 31 Dec 2021
Cited by 13 | Viewed by 3414
Abstract
SnS2 and SnSe2 have recently been shown to have a wide range of applications in photonic and optoelectronic devices. However, because of incomplete knowledge about their optical characteristics, the use of SnS2 and SnSe2 in optical engineering remains challenging. [...] Read more.
SnS2 and SnSe2 have recently been shown to have a wide range of applications in photonic and optoelectronic devices. However, because of incomplete knowledge about their optical characteristics, the use of SnS2 and SnSe2 in optical engineering remains challenging. Here, we addressed this problem by establishing SnS2 and SnSe2 linear and nonlinear optical properties in the broad (300–3300 nm) spectral range. Coupled with the first-principle calculations, our experimental study unveiled the full dielectric tensor of SnS2 and SnSe2. Furthermore, we established that SnS2 is a promising material for visible high refractive index nanophotonics. Meanwhile, SnSe2 demonstrates a stronger nonlinear response compared with SnS2. Our results create a solid ground for current and next-generation SnS2- and SnSe2-based devices. Full article
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17 pages, 2668 KiB  
Article
Rod–Coil Block Copolymer: Fullerene Blend Water-Processable Nanoparticles: How Molecular Structure Addresses Morphology and Efficiency in NP-OPVs
by Anna Maria Ferretti, Marianna Diterlizzi, William Porzio, Umberto Giovanella, Lucia Ganzer, Tersilla Virgili, Varun Vohra, Eduardo Arias, Ivana Moggio, Guido Scavia, Silvia Destri and Stefania Zappia
Nanomaterials 2022, 12(1), 84; https://doi.org/10.3390/nano12010084 - 29 Dec 2021
Cited by 4 | Viewed by 1712
Abstract
The use of water-processable nanoparticles (WPNPs) is an emerging strategy for the processing of organic semiconducting materials into aqueous medium, dramatically reducing the use of chlorinated solvents and enabling the control of the nanomorphology in OPV active layers. We studied amphiphilic rod-coil block [...] Read more.
The use of water-processable nanoparticles (WPNPs) is an emerging strategy for the processing of organic semiconducting materials into aqueous medium, dramatically reducing the use of chlorinated solvents and enabling the control of the nanomorphology in OPV active layers. We studied amphiphilic rod-coil block copolymers (BCPs) with a different chemical structure and length of the hydrophilic coil blocks. Using the BCPs blended with a fullerene acceptor material, we fabricated NP-OPV devices with a sustainable approach. The goal of this work is to clarify how the morphology of the nanodomains of the two active materials is addressed by the hydrophilic coil molecular structures, and in turn how the design of the materials affects the device performances. Exploiting a peculiar application of TEM, EFTEM microscopy on WPNPs, with the contribution of AFM and spectroscopic techniques, we correlate the coil structure with the device performances, demonstrating the pivotal influence of the chemical design over material properties. BCP5, bearing a coil block of five repeating units of 4-vinilpyridine (4VP), leads to working devices with efficiency comparable to the solution-processed ones for the multiple PCBM-rich cores morphology displayed by the blend WPNPs. Otherwise, BCP2 and BCP15, with 2 and 15 repeating units of 4VP, respectively, show a single large PCBM-rich core; the insertion of styrene units into the coil block of BCP100 is detrimental for the device efficiency, even if it produces an intermixed structure. Full article
(This article belongs to the Section Solar Energy and Solar Cells)
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18 pages, 4083 KiB  
Article
Quantification of STEM Images in High Resolution SEM for Segmented and Pixelated Detectors
by Ivo Konvalina, Aleš Paták, Martin Zouhar, Ilona Müllerová, Tomáš Fořt, Marek Unčovský and Eliška Materna Mikmeková
Nanomaterials 2022, 12(1), 71; https://doi.org/10.3390/nano12010071 - 28 Dec 2021
Viewed by 2026
Abstract
The segmented semiconductor detectors for transmitted electrons in ultrahigh resolution scanning electron microscopes allow observing samples in various imaging modes. Typically, two standard modes of objective lens, with and without a magnetic field, differ by their resolution. If the beam deceleration mode is [...] Read more.
The segmented semiconductor detectors for transmitted electrons in ultrahigh resolution scanning electron microscopes allow observing samples in various imaging modes. Typically, two standard modes of objective lens, with and without a magnetic field, differ by their resolution. If the beam deceleration mode is selected, then an electrostatic field around the sample is added. The trajectories of transmitted electrons are influenced by the fields below the sample. The goal of this paper is a quantification of measured images and theoretical study of the capability of the detector to collect signal electrons by its individual segments. Comparison of measured and ray-traced simulated data were difficult in the past. This motivated us to present a new method that enables better comparison of the two datasets at the cost of additional measurements, so-called calibration curves. Furthermore, we also analyze the measurements acquired using 2D pixel array detector (PAD) that provide a more detailed angular profile. We demonstrate that the radial profiles of STEM and/or 2D-PAD data are sensitive to material composition. Moreover, scattering processes are affected by thickness of the sample as well. Hence, comparing the two experimental and simulation data can help to estimate composition or the thickness of the sample. Full article
(This article belongs to the Topic Advances and Applications of 2D Materials)
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20 pages, 6341 KiB  
Article
Structural and Parametric Identification of Knowm Memristors
by Valerii Ostrovskii, Petr Fedoseev, Yulia Bobrova and Denis Butusov
Nanomaterials 2022, 12(1), 63; https://doi.org/10.3390/nano12010063 - 27 Dec 2021
Cited by 24 | Viewed by 3169
Abstract
This paper proposes a novel identification method for memristive devices using Knowm memristors as an example. The suggested identification method is presented as a generalized process for a wide range of memristive elements. An experimental setup was created to obtain a set of [...] Read more.
This paper proposes a novel identification method for memristive devices using Knowm memristors as an example. The suggested identification method is presented as a generalized process for a wide range of memristive elements. An experimental setup was created to obtain a set of intrinsic I–V curves for Knowm memristors. Using the acquired measurements data and proposed identification technique, we developed a new mathematical model that considers low-current effects and cycle-to-cycle variability. The process of parametric identification for the proposed model is described. The obtained memristor model represents the switching threshold as a function of the state variables vector, making it possible to account for snapforward or snapback effects, frequency properties, and switching variability. Several tools for the visual presentation of the identification results are considered, and some limitations of the proposed model are discussed. Full article
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23 pages, 11133 KiB  
Article
Neurobehavioral and Ultrastructural Changes Induced by Phytosynthesized Silver-Nanoparticle Toxicity in an In Vivo Rat Model
by Razvan Vlad Opris, Vlad Toma, Alina Mihaela Baciu, Remus Moldovan, Bogdan Dume, Alexandra Berghian-Sevastre, Bianca Moldovan, Simona Clichici, Luminita David, Gabriela Adriana Filip and Adrian Florea
Nanomaterials 2022, 12(1), 58; https://doi.org/10.3390/nano12010058 - 26 Dec 2021
Cited by 9 | Viewed by 2567
Abstract
(1) Background: The study aimed to assess neurobehavioral, ultrastructural, and biochemical changes induced by silver nanoparticles synthesized with Cornus mas L. extract (AgNPs-CM) in rat brains. (2) Methods: The study included 36 male adult rats divided into three groups. Over a period of [...] Read more.
(1) Background: The study aimed to assess neurobehavioral, ultrastructural, and biochemical changes induced by silver nanoparticles synthesized with Cornus mas L. extract (AgNPs-CM) in rat brains. (2) Methods: The study included 36 male adult rats divided into three groups. Over a period of 45 days, AgNPs-CM (0.8 and 1.5 mg/kg b.w.) were administered daily by gavage to two of the groups, while the control group received the vehicle used for AgNP. After treatment, OFT and EPM tests were conducted in order to assess neurobehavioral changes. Six of the animals from each group were sacrificed immediately after completion of treatment, while the remaining six were allowed to recuperate for an additional 15 days. Transmission electron microscopy (TEM), GFAP immunohistochemistry, and evaluation of TNFα, IL-6, MDA, and CAT activity were performed on the frontal cortex and hippocampus. (3) Results: Treated animals displayed a dose- and time-dependent increase in anxiety-like behavior and severe ultrastructural changes in neurons, astrocytes, and capillaries in both brain regions. Immunohistochemistry displayed astrogliosis with altered cell morphology. TNFα, IL-6, MDA, and CAT activity were significantly altered, depending on brain region and time post exposure. (4) Conclusions: AgNPs-CM induced neurobehavioral changes and severe cell lesions that continued to escalate after cessation of exposure. Full article
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9 pages, 2242 KiB  
Article
Giving Penetrable Remote-Control Ability to Thermoresponsive Fibrous Composite Actuator with Fast Response Induced by Alternative Magnetic Field
by Li Liu, Wenjing Song, Shaohua Jiang, Gaigai Duan and Xiaohong Qin
Nanomaterials 2022, 12(1), 53; https://doi.org/10.3390/nano12010053 - 25 Dec 2021
Cited by 6 | Viewed by 2460
Abstract
An alternative magnetic field (AMF)-induced electrospun fibrous thermoresponsive composite actuator showing penetrable remote-control ability with fast response is shown here for the first time. The built-in heater of magnetothermal Fe3O4 nanoparticles in the actuator and the porous structure of the [...] Read more.
An alternative magnetic field (AMF)-induced electrospun fibrous thermoresponsive composite actuator showing penetrable remote-control ability with fast response is shown here for the first time. The built-in heater of magnetothermal Fe3O4 nanoparticles in the actuator and the porous structure of the fibrous layer contribute to a fast actuation with a curvature of 0.4 mm−1 in 2 s. The higher loading amount of the Fe3O4 nanoparticles and higher magnetic field strength result in a faster actuation. Interestingly, the composite actuator showed a similar actuation even when it was covered by a piece of Polytetrafluoroethylene (PTFE) film, which shows a penetrable remote-control ability. Full article
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12 pages, 3807 KiB  
Article
Effect of Amorphous Crosslinker on Phase Behavior and Electro-Optic Response of Polymer-Stabilized Blue Phase Liquid Crystals
by Kyung Min Lee, Urice Tohgha, Timothy J. Bunning, Michael E. McConney and Nicholas P. Godman
Nanomaterials 2022, 12(1), 48; https://doi.org/10.3390/nano12010048 - 24 Dec 2021
Cited by 6 | Viewed by 2347
Abstract
Blue phase liquid crystals (BPLCs) composed of double-twisted cholesteric helices are promising materials for use in next-generation displays, optical components, and photonics applications. However, BPLCs are only observed in a narrow temperature range of 0.5–3 °C and must be stabilized with a polymer [...] Read more.
Blue phase liquid crystals (BPLCs) composed of double-twisted cholesteric helices are promising materials for use in next-generation displays, optical components, and photonics applications. However, BPLCs are only observed in a narrow temperature range of 0.5–3 °C and must be stabilized with a polymer network. Here, we report on controlling the phase behavior of BPLCs by varying the concentration of an amorphous crosslinker (pentaerythritol triacrylate (PETA)). LC mixtures without amorphous crosslinker display narrow phase transition temperatures from isotropic to the blue phase-II (BP-II), blue phase-I (BP-I), and cholesteric phases, but the addition of PETA stabilizes the BP-I phase. A PETA content above 3 wt% prevents the formation of the simple cubic BP-II phase and induces a direct transition from the isotropic to the BP-I phase. PETA widens the temperature window of BP-I from ~6.8 °C for BPLC without PETA to ~15 °C for BPLC with 4 wt% PETA. The BPLCs with 3 and 4 wt% PETA are stabilized using polymer networks via in situ photopolymerization. Polymer-stabilized BPLC with 3 wt% PETA showed switching between reflective to transparent states with response times of 400–500 μs when an AC field was applied, whereas the application of a DC field induced a large color change from green to red. Full article
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18 pages, 1404 KiB  
Article
Cobalt Ferrite Nanoparticles for Tumor Therapy: Effective Heating versus Possible Toxicity
by Anastasiia S. Garanina, Alexey A. Nikitin, Tatiana O. Abakumova, Alevtina S. Semkina, Alexandra O. Prelovskaya, Victor A. Naumenko, Alexander S. Erofeev, Peter V. Gorelkin, Alexander G. Majouga, Maxim A. Abakumov and Ulf Wiedwald
Nanomaterials 2022, 12(1), 38; https://doi.org/10.3390/nano12010038 - 23 Dec 2021
Cited by 18 | Viewed by 3088
Abstract
Magnetic nanoparticles (MNPs) are widely considered for cancer treatment, in particular for magnetic hyperthermia (MHT). Thereby, MNPs are still being optimized for lowest possible toxicity on organisms while the magnetic properties are matched for best heating capabilities. In this study, the biocompatibility of [...] Read more.
Magnetic nanoparticles (MNPs) are widely considered for cancer treatment, in particular for magnetic hyperthermia (MHT). Thereby, MNPs are still being optimized for lowest possible toxicity on organisms while the magnetic properties are matched for best heating capabilities. In this study, the biocompatibility of 12 nm cobalt ferrite MNPs, functionalized with citrate ions, in different dosages on mice and rats of both sexes was investigated for 30 days after intraperitoneal injection. The animals’ weight, behavior, and blood cells changes, as well as blood biochemical parameters are correlated to histological examination of organs revealing that cobalt ferrite MNPs do not have toxic effects at concentrations close to those used previously for efficient MHT. Moreover, these MNPs demonstrated high specific loss power (SLP) of about 400 W g−1. Importantly the MNPs retained their magnetic properties inside tumor tissue after intratumoral administration for several MHT cycles within three days. Thus, cobalt ferrite MNPs represent a perspective platform for tumor therapy by MHT due to their ability to provide effective heating without exerting a toxic effect on the organism. This opens up new avenues for smaller MNPs sizes while their heating efficiency is maintained. Full article
(This article belongs to the Special Issue Novel Magnetic Nanoparticles: Synthesis and Biomedical Applications)
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11 pages, 4127 KiB  
Article
Boron Nitride Nanotube-Based Separator for High-Performance Lithium-Sulfur Batteries
by Hong-Sik Kim, Hui-Ju Kang, Hongjin Lim, Hyun Jin Hwang, Jae-Woo Park, Tae-Gyu Lee, Sung Yong Cho, Se Gyu Jang and Young-Si Jun
Nanomaterials 2022, 12(1), 11; https://doi.org/10.3390/nano12010011 - 21 Dec 2021
Cited by 20 | Viewed by 4546
Abstract
To prevent global warming, ESS development is in progress along with the development of electric vehicles and renewable energy. However, the state-of-the-art technology, i.e., lithium-ion batteries, has reached its limitation, and thus the need for high-performance batteries with improved energy and power density [...] Read more.
To prevent global warming, ESS development is in progress along with the development of electric vehicles and renewable energy. However, the state-of-the-art technology, i.e., lithium-ion batteries, has reached its limitation, and thus the need for high-performance batteries with improved energy and power density is increasing. Lithium-sulfur batteries (LSBs) are attracting enormous attention because of their high theoretical energy density. However, there are technical barriers to its commercialization such as the formation of dendrites on the anode and the shuttle effect of the cathode. To resolve these issues, a boron nitride nanotube (BNNT)-based separator is developed. The BNNT is physically purified so that the purified BNNT (p−BNNT) has a homogeneous pore structure because of random stacking and partial charge on the surface due to the difference of electronegativity between B and N. Compared to the conventional polypropylene (PP) separator, the p−BNNT loaded PP separator prevents the dendrite formation on the Li metal anode, facilitates the ion transfer through the separator, and alleviates the shuttle effect at the cathode. With these effects, the p−BNNT loaded PP separators enable the LSB cells to achieve a specific capacity of 1429 mAh/g, and long-term stability over 200 cycles. Full article
(This article belongs to the Special Issue Emerging Nanomaterials for Lithium-Sulfur Batteries and Beyond II)
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11 pages, 3915 KiB  
Article
Scintillation Response Enhancement in Nanocrystalline Lead Halide Perovskite Thin Films on Scintillating Wafers
by Kateřina Děcká, Jan Král, František Hájek, Petr Průša, Vladimir Babin, Eva Mihóková and Václav Čuba
Nanomaterials 2022, 12(1), 14; https://doi.org/10.3390/nano12010014 - 21 Dec 2021
Cited by 16 | Viewed by 5547
Abstract
Lead halide perovskite nanocrystals of the formula CsPbBr3 have recently been identified as potential time taggers in scintillating heterostructures for time-of-flight positron emission tomography (TOF-PET) imaging thanks to their ultrafast decay kinetics. This study investigates the potential of this material experimentally. We [...] Read more.
Lead halide perovskite nanocrystals of the formula CsPbBr3 have recently been identified as potential time taggers in scintillating heterostructures for time-of-flight positron emission tomography (TOF-PET) imaging thanks to their ultrafast decay kinetics. This study investigates the potential of this material experimentally. We fabricated CsPbBr3 thin films on scintillating GGAG:Ce (Gd2.985Ce0.015Ga2.7Al2.3O12) wafer as a model structure for the future sampling detector geometry. We focused this study on the radioluminescence (RL) response of this composite material. We compare the results of two spin-coating methods, namely the static and the dynamic process, for the thin film preparation. We demonstrated enhanced RL intensity of both CsPbBr3 and GGAG:Ce scintillating constituents of a composite material. This synergic effect arises in both the RL spectra and decays, including decays in the short time window (50 ns). Consequently, this study confirms the applicability of CsPbBr3 nanocrystals as efficient time taggers for ultrafast timing applications, such as TOF-PET. Full article
(This article belongs to the Special Issue Thin Films Based on Nanocomposites)
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11 pages, 980 KiB  
Article
Crystallization in Zirconia Film Nano-Layered with Silica
by Brecken Larsen, Christopher Ausbeck, Timothy F. Bennet, Gilberto DeSalvo, Riccardo DeSalvo, Tugdual LeBohec, Seth Linker, Marina Mondin and Joshua Neilson
Nanomaterials 2021, 11(12), 3444; https://doi.org/10.3390/nano11123444 - 19 Dec 2021
Cited by 4 | Viewed by 2361
Abstract
Gravitational waves are detected using resonant optical cavity interferometers. The mirror coatings’ inherent thermal noise and photon scattering limit sensitivity. Crystals within the reflective coating may be responsible for either or both noise sources. In this study, we explored crystallization reduction in zirconia [...] Read more.
Gravitational waves are detected using resonant optical cavity interferometers. The mirror coatings’ inherent thermal noise and photon scattering limit sensitivity. Crystals within the reflective coating may be responsible for either or both noise sources. In this study, we explored crystallization reduction in zirconia through nano-layering with silica. We used X-ray diffraction (XRD) to monitor crystal growth between successive annealing cycles. We observed crystal formation at higher temperatures in thinner zirconia layers, indicating that silica is a successful inhibitor of crystal growth. However, the thinnest barriers break down at high temperatures, thus allowing crystal growth beyond each nano-layer. In addition, in samples with thicker zirconia layers, we observe that crystallization saturates with a significant portion of amorphous material remaining. Full article
(This article belongs to the Special Issue Metallic Oxide Nanostructures)
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17 pages, 5973 KiB  
Article
The Effects of the Binder and Buffering Matrix on InSb-Based Anodes for High-Performance Rechargeable Li-Ion Batteries
by Vo Pham Hoang Huy, Il Tae Kim and Jaehyun Hur
Nanomaterials 2021, 11(12), 3420; https://doi.org/10.3390/nano11123420 - 17 Dec 2021
Cited by 8 | Viewed by 2398
Abstract
C-decorated intermetallic InSb (InSb–C) was developed as a novel high-performance anode material for lithium-ion batteries (LIBs). InSb nanoparticles synthesized via a mechanochemical reaction were characterized using X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and [...] Read more.
C-decorated intermetallic InSb (InSb–C) was developed as a novel high-performance anode material for lithium-ion batteries (LIBs). InSb nanoparticles synthesized via a mechanochemical reaction were characterized using X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and energy-dispersive X-ray spectroscopy (EDX). The effects of the binder and buffering matrix on the active InSb were investigated. Poly(acrylic acid) (PAA) was found to significantly improve the cycling stability owing to its strong hydrogen bonding. The addition of amorphous C to InSb further enhanced mechanical stability and electronic conductivity. As a result, InSb–C demonstrated good electrochemical Li-ion storage performance: a high reversible specific capacity (878 mAh·g−1 at 100 mA·g−1 after 140 cycles) and good rate capability (capacity retention of 98% at 10 A·g−1 as compared to 0.1 A·g−1). The effects of PAA and C were comprehensively studied using cyclic voltammetry, differential capacity plots, ex-situ SEM, and electrochemical impedance spectroscopy (EIS). In addition, the electrochemical reaction mechanism of InSb was revealed using ex-situ XRD. InSb–C exhibited a better performance than many recently reported Sb-based electrodes; thus, it can be considered as a potential anode material in LIBs. Full article
(This article belongs to the Special Issue Nanomaterials for Ion Battery Applications)
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19 pages, 3496 KiB  
Article
Preparation and Characterization of Photocatalytically Active Antibacterial Surfaces Covered with Acrylic Matrix Embedded Nano-ZnO and Nano-ZnO/Ag
by Merilin Rosenberg, Meeri Visnapuu, Kristjan Saal, Dmytro Danilian, Rainer Pärna, Angela Ivask and Vambola Kisand
Nanomaterials 2021, 11(12), 3384; https://doi.org/10.3390/nano11123384 - 14 Dec 2021
Cited by 6 | Viewed by 2520
Abstract
In the context of healthcare-acquired infections, microbial cross-contamination and the spread of antibiotic resistance, additional passive measures to prevent pathogen carryover are urgently needed. Antimicrobial high-touch surfaces that kill microbes on contact or prevent their adhesion could be considered to mitigate the spread. [...] Read more.
In the context of healthcare-acquired infections, microbial cross-contamination and the spread of antibiotic resistance, additional passive measures to prevent pathogen carryover are urgently needed. Antimicrobial high-touch surfaces that kill microbes on contact or prevent their adhesion could be considered to mitigate the spread. Here, we demonstrate that photocatalytic nano-ZnO- and nano-ZnO/Ag-based antibacterial surfaces with efficacy of at least a 2.7-log reduction in Escherichia coli and Staphylococcus aureus viability in 2 h can be produced by simple measures using a commercial acrylic topcoat for wood surfaces. We characterize the surfaces taking into account cyclic wear and variable environmental conditions. The light-induced antibacterial and photocatalytic activities of the surfaces are enhanced by short-term cyclic wear, indicating their potential for prolonged effectivity in long-term use. As the produced surfaces are generally more effective at higher relative air humidity and silver-containing surfaces lost their contact-killing properties in dry conditions, it is important to critically evaluate the end-use conditions of materials and surfaces to be tested and select application-appropriate methods for their efficacy assessment. Full article
(This article belongs to the Special Issue Antimicrobial Nano Coatings)
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11 pages, 3073 KiB  
Article
The Sensitization of Scintillation in Polymeric Composites Based on Fluorescent Nanocomplexes
by Irene Villa, Beatriz Santiago Gonzalez, Matteo Orfano, Francesca Cova, Valeria Secchi, Camilla Colombo, Juraj Páterek, Romana Kučerková, Vladimir Babin, Michele Mauri, Martin Nikl and Angelo Monguzzi
Nanomaterials 2021, 11(12), 3387; https://doi.org/10.3390/nano11123387 - 14 Dec 2021
Cited by 4 | Viewed by 2060
Abstract
The sensitization of scintillation was investigated in crosslinked polymeric composite materials loaded with luminescent gold clusters aggregates acting as sensitizers, and with organic dye rhodamine 6G as the emitting species. The evolution in time of the excited states population in the systems is [...] Read more.
The sensitization of scintillation was investigated in crosslinked polymeric composite materials loaded with luminescent gold clusters aggregates acting as sensitizers, and with organic dye rhodamine 6G as the emitting species. The evolution in time of the excited states population in the systems is described by a set of coupled rate equations, in which steady state solution allowed obtainment of an expression of the sensitization efficacy as a function of the characteristic parameters of the employed luminescent systems. The results obtained indicate that the realization of sensitizer/emitter scintillating complexes is the strategy that must be pursued to maximize the sensitization effect in composite materials. Full article
(This article belongs to the Special Issue Advanced Nanomaterials for Radiation Applications)
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11 pages, 577 KiB  
Article
Analytical Performance and Validation of a Reliable Method Based on Graphite Furnace Atomic Absorption Spectrometry for the Determination of Gold Nanoparticles in Biological Tissues
by Oana Cadar, Teodora Mocan, Cecilia Roman and Marin Senila
Nanomaterials 2021, 11(12), 3370; https://doi.org/10.3390/nano11123370 - 12 Dec 2021
Cited by 5 | Viewed by 2351
Abstract
Gold nanoparticles (AuNPs) have a wide-ranging application and are widespread in samples with complex matrices; thus, efficient analytical procedures are necessary to identify and characterize this analyte. A sensitive analytical method for determination of AuNPs content in biological tissues, based on microwave-assisted acid [...] Read more.
Gold nanoparticles (AuNPs) have a wide-ranging application and are widespread in samples with complex matrices; thus, efficient analytical procedures are necessary to identify and characterize this analyte. A sensitive analytical method for determination of AuNPs content in biological tissues, based on microwave-assisted acid wet digestion and graphite furnace atomic absorption spectrometry (GFAAS) validated in accordance with the requirements of Eurachem guideline and ISO 17025 standard, is presented in this study. The digestion procedure was optimized, and the figures of merit such as selectivity, limit of detection (0.43 µg L−1), limit of quantification (1.29 µg L−1, corresponding to 12.9 µg kg−1 in tissue sample, considering the digestion), working range, linearity, repeatability ((RSDr 4.15%), intermediate precision (RSDR 8.07%), recovery in accuracy study (97%), were methodically evaluated. The measurement uncertainty was assessed considering the main sources of uncertainties and the calculated relative expanded uncertainty (k = 2) was 12.5%. The method was applied for the determination of AuNPs in six biological tissues (liver, small intestine, heart, lungs, brain and kidneys) and the found concentrations were generally at low levels, close or lower than LOQ. Full article
(This article belongs to the Special Issue Theranostic Nanomedicine and Nanomaterials)
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11 pages, 2376 KiB  
Article
Cation Crosslinking-Induced Stable Copper Nanoclusters Powder as Latent Fingerprints Marker
by Yi Qiu, Zhuoqi Wen, Shiliang Mei, Jinxin Wei, Yuanyuan Chen, Zhe Hu, Zhongjie Cui, Wanlu Zhang, Fengxian Xie and Ruiqian Guo
Nanomaterials 2021, 11(12), 3371; https://doi.org/10.3390/nano11123371 - 12 Dec 2021
Cited by 1 | Viewed by 2599
Abstract
Luminescent copper nanoclusters (Cu NCs) have shown great potential in light-emitting devices (LEDs), chemical sensing, catalysis and biological fields. However, their practical use has been restricted by poor stability, and study on the stability of Cu NCs solid powder along with the mechanism [...] Read more.
Luminescent copper nanoclusters (Cu NCs) have shown great potential in light-emitting devices (LEDs), chemical sensing, catalysis and biological fields. However, their practical use has been restricted by poor stability, and study on the stability of Cu NCs solid powder along with the mechanism is absent. In this study, stablized Cu NCs powder was first obtained by cation crosslinking method. Compared with the powder synthesized by solvent precipitation method, the stability of Cu NCs powder crosslinked by ionic inducer Ce3+ was enhanced around 100-fold. The storage time when the fluorescence intensity decreased to 85% (T85) was improved from 2 h to 216 h, which is the longest so far. The results of characterizations indicated that the aggregation structure was formed by the binding of Ce3+ with the capping ligands of Cu NCs, which helped in obtaining Ce-Cu NCs powder from aggregate precipitation in solution. Furthermore, this compact structure could avoid the destruction of ambient moisture resulting in long-lasting fluorescence and almost unchanged physical form. This demonstrated that phosphor, with excellent characteristics of unsophisticated synthesis, easy preservation and stable fluorescence, showed great potential in light sources, display technology and especially in latent fingerprints visualization on different substrates for forensic science. Full article
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13 pages, 3446 KiB  
Article
Facile Fabrication of Single-Walled Carbon Nanotube/Anatase Composite Thin Film on Quartz Glass Substrate for Translucent Conductive Photoelectrode
by Yutaka Suwazono, Takuro Murayoshi, Hiroki Nagai and Mitsunobu Sato
Nanomaterials 2021, 11(12), 3352; https://doi.org/10.3390/nano11123352 - 10 Dec 2021
Cited by 3 | Viewed by 2007
Abstract
A single-walled carbon nanotube/anatase (SWCNT/anatase) composite thin film with a transmittance of over 70% in the visible-light region was fabricated on a quartz glass substrate by heat treating a precursor film at 500 °C in air. The precursor film was formed by spin [...] Read more.
A single-walled carbon nanotube/anatase (SWCNT/anatase) composite thin film with a transmittance of over 70% in the visible-light region was fabricated on a quartz glass substrate by heat treating a precursor film at 500 °C in air. The precursor film was formed by spin coating a mixed solution of the titania molecular precursor and well-dispersed SWCNTs (0.075 mass%) in ethanol. The anatase crystals and Ti3+ ions in the composite thin films were determined by X-ray diffraction and X-ray photoelectron spectroscopy, respectively. The effect of the heating process on the SWCNTs was analyzed using Raman spectroscopy. The composite film showed an even surface with a scratch resistance of 4H pencil hardness, as observed using field-emission scanning electron microscopy and atomic force microscopy. The electrical resistivity and optical bandgap energy of the composite thin film with a thickness of 100 nm were 6.6 × 10−2 Ω cm and 3.4 eV, respectively, when the SWCNT content in the composite thin film was 2.9 mass%. An anodic photocurrent density of 4.2 μA cm−2 was observed under ultraviolet light irradiation (16 mW cm−2 at 365 nm) onto the composite thin film, thus showing excellent properties as a photoelectrode without conductive substrates. Full article
(This article belongs to the Special Issue Research of Carbon Nanomaterials and Nanocomposites)
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16 pages, 4430 KiB  
Article
Structural and Surfacial Modification of Carbon Nanofoam as an Interlayer for Electrochemically Stable Lithium-Sulfur Cells
by Yee-Jun Quay and Sheng-Heng Chung
Nanomaterials 2021, 11(12), 3342; https://doi.org/10.3390/nano11123342 - 09 Dec 2021
Cited by 10 | Viewed by 2614
Abstract
Electrochemical lithium-sulfur batteries engage the attention of researchers due to their high-capacity sulfur cathodes, which meet the increasing energy-density needs of next-generation energy-storage systems. We present here the design, modification, and investigation of a carbon nanofoam as the interlayer in a lithium-sulfur cell [...] Read more.
Electrochemical lithium-sulfur batteries engage the attention of researchers due to their high-capacity sulfur cathodes, which meet the increasing energy-density needs of next-generation energy-storage systems. We present here the design, modification, and investigation of a carbon nanofoam as the interlayer in a lithium-sulfur cell to enable its high-loading sulfur cathode to attain high electrochemical utilization, efficiency, and stability. The carbon-nanofoam interlayer features a porous and tortuous carbon network that accelerates the charge transfer while decelerating the polysulfide diffusion. The improved cell demonstrates a high electrochemical utilization of over 80% and an enhanced stability of 200 cycles. With such a high-performance cell configuration, we investigate how the battery chemistry is affected by an additional polysulfide-trapping MoS2 layer and an additional electron-transferring graphene layer on the interlayer. Our results confirm that the cell-configuration modification brings major benefits to the development of a high-loading sulfur cathode for excellent electrochemical performances. We further demonstrate a high-loading cathode with the carbon-nanofoam interlayer, which attains a high sulfur loading of 8 mg cm−2, an excellent areal capacity of 8.7 mAh cm−2, and a superior energy density of 18.7 mWh cm−2 at a low electrolyte-to-sulfur ratio of 10 µL mg−1. Full article
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14 pages, 5344 KiB  
Article
Direct Plasmonic Solar Cell Efficiency Dependence on Spiro-OMeTAD Li-TFSI Content
by Xinjian Geng, Mohamed Abdellah, Robert Bericat Vadell, Matilda Folkenant, Tomas Edvinsson and Jacinto Sá
Nanomaterials 2021, 11(12), 3329; https://doi.org/10.3390/nano11123329 - 08 Dec 2021
Cited by 4 | Viewed by 3115
Abstract
The proliferation of the internet of things (IoT) and other low-power devices demands the development of energy harvesting solutions to alleviate IoT hardware dependence on single-use batteries, making their deployment more sustainable. The propagation of energy harvesting solutions is strongly associated with technical [...] Read more.
The proliferation of the internet of things (IoT) and other low-power devices demands the development of energy harvesting solutions to alleviate IoT hardware dependence on single-use batteries, making their deployment more sustainable. The propagation of energy harvesting solutions is strongly associated with technical performance, cost and aesthetics, with the latter often being the driver of adoption. The general abundance of light in the vicinity of IoT devices under their main operation window enables the use of indoor and outdoor photovoltaics as energy harvesters. From those, highly transparent solar cells allow an increased possibility to place a sustainable power source close to the sensors without significant visual appearance. Herein, we report the effect of hole transport layer Li-TFSI dopant content on semi-transparent, direct plasmonic solar cells (DPSC) with a transparency of more than 80% in the 450–800 nm region. The findings revealed that the amount of oxidized spiro-OMeTAD (spiro+TFSI) significantly modulates the transparency, effective conductance and conditions of device performance, with an optimal performance reached at around 33% relative concentration of Li-TFSI concerning spiro-OMeTAD. The Li-TFSI content did not affect the immediate charge extraction, as revealed by an analysis of electron–phonon lifetime. Hot electrons and holes were injected into the respective layers within 150 fs, suggesting simultaneous injection, as supported by the absence of hysteresis in the I–V curves. The spiro-OMeTAD layer reduces the Au nanoparticles’ reflection/backscattering, which improves the overall cell transparency. The results show that the system can be made highly transparent by precise tuning of the doping level of the spiro-OMeTAD layer with retained plasmonics, large optical cross-sections and the ultrathin nature of the devices. Full article
(This article belongs to the Special Issue Nanostructured Materials for Photonics and Plasmonics)
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12 pages, 5082 KiB  
Article
Aptamer Conjugated Indium Phosphide Quantum Dots with a Zinc Sulphide Shell as Photoluminescent Labels for Acinetobacter baumannii
by Zeineb Ayed, Shiana Malhotra, Garima Dobhal and Renee V. Goreham
Nanomaterials 2021, 11(12), 3317; https://doi.org/10.3390/nano11123317 - 07 Dec 2021
Cited by 9 | Viewed by 3193
Abstract
Acinetobacter baumannii is a remarkable microorganism known for its diversity of habitat and its multi-drug resistance, resulting in hard-to-treat infections. Thus, a sensitive method for the identification and detection of Acinetobacter baumannii is vital. However, current methods used for the detection of pathogens [...] Read more.
Acinetobacter baumannii is a remarkable microorganism known for its diversity of habitat and its multi-drug resistance, resulting in hard-to-treat infections. Thus, a sensitive method for the identification and detection of Acinetobacter baumannii is vital. However, current methods used for the detection of pathogens have not improved in the past decades and suffer from long process times and low detection limits. A cheap, quick, and easy detection mechanism is needed. In this work, we successfully prepared indium phosphide quantum dots with a zinc sulphide shell, conjugated to a targeting aptamer ligand, to specifically label Acinetobacter baumannii. The system retained both the photophysical properties of the quantum dots and the folded structure and molecular recognition function of the aptamer, therefore successfully targeting Acinetobacter baumannii. Confocal microscopy and transmission electron microscopy showed the fluorescent quantum dots surrounding the Acinetobacter baumannii cells confirming the specificity of the aptamer conjugated to indium phosphide quantum dots with a zinc sulphide shell. Controls were undertaken with a different bacteria species, showing no binding of the aptamer conjugated quantum dots. Our strategy offers a novel method to detect bacteria and engineer a scalable platform for fluorescence detection, therefore improving current methods and allowing for better treatment. Full article
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8 pages, 1795 KiB  
Article
Band Structure and Energy Level Alignment of Chiral Graphene Nanoribbons on Silver Surfaces
by Martina Corso, Rodrigo E. Menchón, Ignacio Piquero-Zulaica, Manuel Vilas-Varela, J. Enrique Ortega, Diego Peña, Aran Garcia-Lekue and Dimas G. de Oteyza
Nanomaterials 2021, 11(12), 3303; https://doi.org/10.3390/nano11123303 - 06 Dec 2021
Cited by 5 | Viewed by 3041
Abstract
Chiral graphene nanoribbons are extremely interesting structures due to their narrow band gaps and potential development of spin-polarized edge states. Here, we study their band structure on low work function silver surfaces. The use of a curved Ag single crystal provides, within the [...] Read more.
Chiral graphene nanoribbons are extremely interesting structures due to their narrow band gaps and potential development of spin-polarized edge states. Here, we study their band structure on low work function silver surfaces. The use of a curved Ag single crystal provides, within the same sample, regions of disparate step structure and step density. Whereas the former leads to distinct azimuthal growth orientations of the graphene nanoribbons atop, the latter modulates the substrate’s work function and thereby the interface energy level alignment. In turn, we disclose the associated charge transfer from the substrate to the ribbon and assess its effect on the nanoribbon’s properties and the edge state magnetization. Full article
(This article belongs to the Special Issue On-Surface Synthesis of Low-Dimensional Organic Nanostructures)
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29 pages, 5883 KiB  
Article
Quantitative Assessment of Chirality of Protein Secondary Structures and Phenylalanine Peptide Nanotubes
by Alla Sidorova, Vladimir Bystrov, Aleksey Lutsenko, Denis Shpigun, Ekaterina Belova and Ilya Likhachev
Nanomaterials 2021, 11(12), 3299; https://doi.org/10.3390/nano11123299 - 05 Dec 2021
Cited by 12 | Viewed by 1948
Abstract
In this study we consider the features of spatial-structure formation in proteins and their application in bioengineering. Methods for the quantitative assessment of the chirality of regular helical and irregular structures of proteins are presented. The features of self-assembly of phenylalanine (F) into [...] Read more.
In this study we consider the features of spatial-structure formation in proteins and their application in bioengineering. Methods for the quantitative assessment of the chirality of regular helical and irregular structures of proteins are presented. The features of self-assembly of phenylalanine (F) into peptide nanotubes (PNT), which form helices of different chirality, are also analyzed. A method is proposed for calculating the magnitude and sign of the chirality of helix-like peptide nanotubes using a sequence of vectors for the dipole moments of individual peptides. Full article
(This article belongs to the Special Issue Simulation and Modeling of Nanomaterials)
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15 pages, 2793 KiB  
Article
Comparison of Different Commercial Nanopolystyrenes: Behavior in Exposure Media, Effects on Immune Function and Early Larval Development in the Model Bivalve Mytilus galloprovincialis
by Manon Auguste, Teresa Balbi, Angelica Miglioli, Stefano Alberti, Sonja Prandi, Riccardo Narizzano, Annalisa Salis, Gianluca Damonte and Laura Canesi
Nanomaterials 2021, 11(12), 3291; https://doi.org/10.3390/nano11123291 - 04 Dec 2021
Cited by 8 | Viewed by 1882
Abstract
In the absence of standard methods for the detection/quantification of nanoplastics (NPs) in environmental samples, commercial nanopolymers are utilized as proxies for toxicity testing and environmental risk assessment. In marine species, a considerable amount of data are now available on the effects of [...] Read more.
In the absence of standard methods for the detection/quantification of nanoplastics (NPs) in environmental samples, commercial nanopolymers are utilized as proxies for toxicity testing and environmental risk assessment. In marine species, a considerable amount of data are now available on the effects of nanopolystyrene (PS-NPs) of different size/surface characteristics. In this work, amino modified PS-NPs (PS-NH2) (50 and 100 nm), purchased from two different companies, were compared in terms of behavior in exposure media and of biological responses, from molecular to organism level, in the model marine bivalve Mytilus. Different PS-NH2 showed distinct agglomeration and surface charge in artificial sea water (ASW) and hemolymph serum (HS). Differences in behavior were largely reflected by the effects on immune function in vitro and in vivo and on early larval development. Stronger effects were generally observed with PS-NH2 of smaller size, showing less agglomeration and higher positive charge in exposure media. Specific molecular interactions with HS components were investigated by the isolation and characterization of the NP-corona proteins. Data obtained in larvae demonstrate interference with the molecular mechanisms of shell biogenesis. Overall, different PS-NH2 can affect the key physiological functions of mussels at environmental concentrations (10 µg/L). However, detailed information on the commercial NPs utilized is required to compare their biological effects among laboratory experiments. Full article
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9 pages, 2579 KiB  
Article
The Applications of Ultra-Thin Nanofilm for Aerospace Advanced Manufacturing Technology
by Guibai Xie, Hongwu Bai, Guanghui Miao, Guobao Feng, Jing Yang, Yun He, Xiaojun Li and Yun Li
Nanomaterials 2021, 11(12), 3282; https://doi.org/10.3390/nano11123282 - 03 Dec 2021
Cited by 11 | Viewed by 2126
Abstract
With the development of industrial civilization, advanced manufacturing technology has attracted widespread concern, including in the aerospace industry. In this paper, we report the applications of ultra-thin atomic layer deposition nanofilm in the advanced aerospace manufacturing industry, including aluminum anti-oxidation and secondary electron [...] Read more.
With the development of industrial civilization, advanced manufacturing technology has attracted widespread concern, including in the aerospace industry. In this paper, we report the applications of ultra-thin atomic layer deposition nanofilm in the advanced aerospace manufacturing industry, including aluminum anti-oxidation and secondary electron suppression, which are critical in high-power and miniaturization development. The compact and uniform aluminum oxide film, which is formed by thermal atomic layer deposition (ALD), can prevent the deep surface oxidation of aluminum during storage, avoiding the waste of material and energy in repetitive production. The total secondary electron yield of the C/TiN component nanofilm, deposited through plasma-enhanced atomic layer deposition, decreases 25% compared with an uncoated surface. The suppression of secondary electron emission is of great importance in solving the multipactor for high-power microwave components in space. Moreover, the controllable, ultra-thin uniform composite nanofilm can be deposited directly on the complex surface of devices without any transfer process, which is critical for many different applications. The ALD nanofilm shows potential for promoting system performance and resource consumption in the advanced aerospace manufacturing industry. Full article
(This article belongs to the Special Issue Nanomaterials for Membranes, Membrane Reactors and Catalyst Systems)
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20 pages, 5332 KiB  
Article
Extra-Low Dosage Graphene Oxide Cementitious Nanocomposites: A Nano- to Macroscale Approach
by Mehdi Chougan, Francesca Romana Lamastra, Eleonora Bolli, Daniela Caschera, Saulius Kaciulis, Claudia Mazzuca, Giampiero Montesperelli, Seyed Hamidreza Ghaffar, Mazen J. Al-Kheetan and Alessandra Bianco
Nanomaterials 2021, 11(12), 3278; https://doi.org/10.3390/nano11123278 - 02 Dec 2021
Cited by 11 | Viewed by 2171
Abstract
The impact of extra-low dosage (0.01% by weight of cement) Graphene Oxide (GO) on the properties of fresh and hardened nanocomposites was assessed. The use of a minimum amount of 2-D nanofiller would minimize costs and sustainability issues, therefore encouraging the market uptake [...] Read more.
The impact of extra-low dosage (0.01% by weight of cement) Graphene Oxide (GO) on the properties of fresh and hardened nanocomposites was assessed. The use of a minimum amount of 2-D nanofiller would minimize costs and sustainability issues, therefore encouraging the market uptake of nanoengineered cement-based materials. GO was characterized by X-ray Photoelectron Spectroscopy (XPS), Fourier-transform infrared spectroscopy (FTIR), Atomic Force Microscopy (AFM), X-ray Diffraction (XRD), and Raman spectroscopy. GO consisted of stacked sheets up to 600 nm × 800 nm wide and 2 nm thick, oxygen content 31 at%. The impact of GO on the fresh admixtures was evaluated by rheology, flowability, and workability measurements. GO-modified samples were characterized by density measurements, Scanning Electron Microscopy (SEM) analysis, and compression and bending tests. Permeability was investigated using the boiling-water saturation technique, salt ponding test, and Initial Surface Absorption Test (ISAT). At 28 days, GO-nanocomposite exhibited increased density (+14%), improved compressive and flexural strength (+29% and +13%, respectively), and decreased permeability compared to the control sample. The strengthening effect dominated over the adverse effects associated with the worsening of the fresh properties; reduced permeability was mainly attributed to the refining of the pore network induced by the presence of GO. Full article
(This article belongs to the Special Issue Smart Cementitious Materials for Sustainable Building Engineering)
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9 pages, 1300 KiB  
Article
The High Coercivity Field in Chemically Bonded WSe2/MoSe2 Powder
by Shiu-Ming Huang, Pin-Cyuan Chen and Pin-Cing Wang
Nanomaterials 2021, 11(12), 3263; https://doi.org/10.3390/nano11123263 - 01 Dec 2021
Cited by 1 | Viewed by 1780
Abstract
We studied the magnetic properties of WSe2/MoSe2 powder. The coercivity field reaches 2600 Oe at 5 K, 4233 Oe at 100 K and 1300 Oe at 300 K. These are the highest values reported for two-dimensional transition metal dichalcogenides. This [...] Read more.
We studied the magnetic properties of WSe2/MoSe2 powder. The coercivity field reaches 2600 Oe at 5 K, 4233 Oe at 100 K and 1300 Oe at 300 K. These are the highest values reported for two-dimensional transition metal dichalcogenides. This study is different from the widely reported vacancy and zigzag structure-induced ferromagnetism studies. Importantly, a Raman peak red shift was observed, and that supports the chemical bonding at the interface between WSe2 and MoSe2. The large coercivity field originates from the chemical bonding-induced structural distortion at the interface between WSe2 and MoSe2. Full article
(This article belongs to the Topic Advances and Applications of 2D Materials)
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10 pages, 1169 KiB  
Article
Gold Nanostars Embedded in PDMS Films: A Photothermal Material for Antibacterial Applications
by Gemma Toci, Francesca Olgiati, Piersandro Pallavicini, Yuri Antonio Diaz Fernandez, Lorenzo De Vita, Giacomo Dacarro, Pietro Grisoli and Angelo Taglietti
Nanomaterials 2021, 11(12), 3252; https://doi.org/10.3390/nano11123252 - 30 Nov 2021
Cited by 12 | Viewed by 2465
Abstract
Bacteria infections and related biofilms growth on surfaces of medical devices are a serious threat to human health. Controlled hyperthermia caused by photothermal effects can be used to kill bacteria and counteract biofilms formation. Embedding of plasmonic nano-objects like gold nanostars (GNS), able [...] Read more.
Bacteria infections and related biofilms growth on surfaces of medical devices are a serious threat to human health. Controlled hyperthermia caused by photothermal effects can be used to kill bacteria and counteract biofilms formation. Embedding of plasmonic nano-objects like gold nanostars (GNS), able to give an intense photothermal effect when irradiated in the NIR, can be a smart way to functionalize a transparent and biocompatible material like polydimethylsiloxane (PDMS). This process enables bacteria destruction on surfaces of PDMS-made medical surfaces, an action which, in principle, can also be exploited in subcutaneous devices. We prepared stable and reproducible thin PDMS films containing controllable quantities of GNS, enabling a temperature increase that can reach more than 40 degrees. The hyperthermia exerted by this hybrid material generates an effective thermal microbicidal effect, killing bacteria with a near infrared (NIR) laser source with irradiance values that are safe for skin. Full article
(This article belongs to the Special Issue Advanced Noble Metal Nanoparticles)
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13 pages, 4084 KiB  
Article
Nanocone-Shaped Carbon Nanotubes Field-Emitter Array Fabricated by Laser Ablation
by Jiuzhou Zhao, Zhenjun Li, Matthew Thomas Cole, Aiwei Wang, Xiangdong Guo, Xinchuan Liu, Wei Lyu, Hanchao Teng, Yunpeng Qv, Guanjiang Liu, Ke Chen, Shenghan Zhou, Jianfeng Xiao, Yi Li, Chi Li and Qing Dai
Nanomaterials 2021, 11(12), 3244; https://doi.org/10.3390/nano11123244 - 29 Nov 2021
Cited by 5 | Viewed by 2043
Abstract
The nanocone-shaped carbon nanotubes field-emitter array (NCNA) is a near-ideal field-emitter array that combines the advantages of geometry and material. In contrast to previous methods of field-emitter array, laser ablation is a low-cost and clean method that does not require any photolithography or [...] Read more.
The nanocone-shaped carbon nanotubes field-emitter array (NCNA) is a near-ideal field-emitter array that combines the advantages of geometry and material. In contrast to previous methods of field-emitter array, laser ablation is a low-cost and clean method that does not require any photolithography or wet chemistry. However, nanocone shapes are hard to achieve through laser ablation due to the micrometer-scale focusing spot. Here, we develop an ultraviolet (UV) laser beam patterning technique that is capable of reliably realizing NCNA with a cone-tip radius of ≈300 nm, utilizing optimized beam focusing and unique carbon nanotube–light interaction properties. The patterned array provided smaller turn-on fields (reduced from 2.6 to 1.6 V/μm) in emitters and supported a higher (increased from 10 to 140 mA/cm2) and more stable emission than their unpatterned counterparts. The present technique may be widely applied in the fabrication of high-performance CNTs field-emitter arrays. Full article
(This article belongs to the Special Issue The Research Related to Nanomaterial Cold Cathode)
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16 pages, 9804 KiB  
Article
Amorphous MoSxOy/h-BNxOy Nanohybrids: Synthesis and Dye Photodegradation
by Andrei T. Matveev, Anton S. Konopatsky, Denis V. Leybo, Ilia N. Volkov, Andrey M. Kovalskii, Liubov A. Varlamova, Pavel B. Sorokin, Xiaosheng Fang, Sergei A. Kulinich and Dmitry V. Shtansky
Nanomaterials 2021, 11(12), 3232; https://doi.org/10.3390/nano11123232 - 28 Nov 2021
Cited by 6 | Viewed by 2224
Abstract
Molybdenum sulfide is a very promising catalyst for the photodegradation of organic pollutants in water. Its photocatalytic activity arises from unsaturated sulfur bonds, and it increases with the introduction of structural defects and/or oxygen substitutions. Amorphous molybdenum sulfide (a-MoSxO [...] Read more.
Molybdenum sulfide is a very promising catalyst for the photodegradation of organic pollutants in water. Its photocatalytic activity arises from unsaturated sulfur bonds, and it increases with the introduction of structural defects and/or oxygen substitutions. Amorphous molybdenum sulfide (a-MoSxOy) with oxygen substitutions has many active sites, which create favorable conditions for enhanced catalytic activity. Here we present a new approach to the synthesis of a-MoSxOy and demonstrate its high activity in the photodegradation of the dye methylene blue (MB). The MoSxOy was deposited on hexagonal boron oxynitride (h-BNO) nanoflakes by reacting h-BNO, MoCl5, and H2S in dimethylformamide (DMF) at 250 °C. Both X-ray diffraction analysis and high-resolution TEM show the absence of crystalline order in a-MoSxOy. Based on the results of Raman and X-ray photoelectron spectroscopy, as well as analysis by the density functional theory (DFT) method, a chain structure of a-MoSxOy was proposed, consisting of MoS3 clusters with partial substitution of sulfur by oxygen. When a third of the sulfur atoms are replaced with oxygen, the band gap of a-MoSxOy is approximately 1.36 eV, and the valence and conduction bands are 0.74 eV and −0.62 eV, respectively (relative to a standard hydrogen electrode), which satisfies the conditions of photoinduced splitting of water. When illuminated with a mercury lamp, a-MoSxOy/h-BNxOy nanohybrids have a specific mass activity in MB photodegradation of approximately 5.51 mmol g−1 h−1, which is at least four times higher than so far reported values for nonmetal catalysts. The photocatalyst has been shown to be very stable and can be reused. Full article
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19 pages, 3238 KiB  
Article
In Vitro Toxicity of Industrially Relevant Engineered Nanoparticles in Human Alveolar Epithelial Cells: Air–Liquid Interface versus Submerged Cultures
by Maria João Bessa, Fátima Brandão, Paul H. B. Fokkens, Daan L. A. C. Leseman, A. John F. Boere, Flemming R. Cassee, Apostolos Salmatonidis, Mar Viana, Adriana Vulpoi, Simion Simon, Eliseo Monfort, João Paulo Teixeira and Sónia Fraga
Nanomaterials 2021, 11(12), 3225; https://doi.org/10.3390/nano11123225 - 27 Nov 2021
Cited by 9 | Viewed by 2496
Abstract
Diverse industries have already incorporated within their production processes engineered nanoparticles (ENP), increasing the potential risk of worker inhalation exposure. In vitro models have been widely used to investigate ENP toxicity. Air–liquid interface (ALI) cell cultures have been emerging as a valuable alternative [...] Read more.
Diverse industries have already incorporated within their production processes engineered nanoparticles (ENP), increasing the potential risk of worker inhalation exposure. In vitro models have been widely used to investigate ENP toxicity. Air–liquid interface (ALI) cell cultures have been emerging as a valuable alternative to submerged cultures as they are more representative of the inhalation exposure to airborne nano-sized particles. We compared the in vitro toxicity of four ENP used as raw materials in the advanced ceramics sector in human alveolar epithelial-like cells cultured under submerged or ALI conditions. Submerged cultures were exposed to ENP liquid suspensions or to aerosolised ENP at ALI. Toxicity was assessed by determining LDH release, WST-1 metabolisation and DNA damage. Overall, cells were more sensitive to ENP cytotoxic effects when cultured and exposed under ALI. No significant cytotoxicity was observed after 24 h exposure to ENP liquid suspensions, although aerosolised ENP clearly affected cell viability and LDH release. In general, all ENP increased primary DNA damage regardless of the exposure mode, where an increase in DNA strand-breaks was only detected under submerged conditions. Our data show that at relevant occupational concentrations, the selected ENP exert mild toxicity to alveolar epithelial cells and exposure at ALI might be the most suitable choice when assessing ENP toxicity in respiratory models under realistic exposure conditions. Full article
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8 pages, 2220 KiB  
Article
One-Step Solution Deposition of Antimony Selenoiodide Films via Precursor Engineering for Lead-Free Solar Cell Applications
by Yong Chan Choi and Kang-Won Jung
Nanomaterials 2021, 11(12), 3206; https://doi.org/10.3390/nano11123206 - 26 Nov 2021
Cited by 11 | Viewed by 2137
Abstract
Ternary chalcohalides are promising lead-free photovoltaic materials with excellent optoelectronic properties. We propose a simple one-step solution-phase precursor-engineering method for antimony selenoiodide (SbSeI) film fabrication. SbSeI films were fabricated by spin-coating the precursor solution, and heating. Various precursor solutions were synthesized by adjusting [...] Read more.
Ternary chalcohalides are promising lead-free photovoltaic materials with excellent optoelectronic properties. We propose a simple one-step solution-phase precursor-engineering method for antimony selenoiodide (SbSeI) film fabrication. SbSeI films were fabricated by spin-coating the precursor solution, and heating. Various precursor solutions were synthesized by adjusting the molar ratio of two solutions based on SbCl3-selenourea and SbI3. The results suggest that both the molar ratio and the heating temperature play key roles in film phase and morphology. Nanostructured SbSeI films with a high crystallinity were obtained at a molar ratio of 1:1.5 and a temperature of 150 °C. The proposed method could be also used to fabricate (Bi,Sb)SeI. Full article
(This article belongs to the Special Issue Advances in Nanomaterials for Photovoltaic Applications)
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15 pages, 4159 KiB  
Article
Examining the Transmission of Visible Light through Electrospun Nanofibrous PCL Scaffolds for Corneal Tissue Engineering
by Marcus Himmler, Dirk W. Schubert and Thomas A. Fuchsluger
Nanomaterials 2021, 11(12), 3191; https://doi.org/10.3390/nano11123191 - 25 Nov 2021
Cited by 9 | Viewed by 2075
Abstract
The transparency of nanofibrous scaffolds is of highest interest for potential applications like corneal wound dressings in corneal tissue engineering. In this study, we provide a detailed analysis of light transmission through electrospun polycaprolactone (PCL) scaffolds. PCL scaffolds were produced via electrospinning, with [...] Read more.
The transparency of nanofibrous scaffolds is of highest interest for potential applications like corneal wound dressings in corneal tissue engineering. In this study, we provide a detailed analysis of light transmission through electrospun polycaprolactone (PCL) scaffolds. PCL scaffolds were produced via electrospinning, with fiber diameters in the range from (35 ± 13) nm to (167 ± 35) nm. Light transmission measurements were conducted using UV–vis spectroscopy in the range of visible light and analyzed with respect to the influence of scaffold thickness, fiber diameter, and surrounding medium. Contour plots were compiled for a straightforward access to light transmission values for arbitrary scaffold thicknesses. Depending on the fiber diameter, transmission values between 15% and 75% were observed for scaffold thicknesses of 10 µm. With a decreasing fiber diameter, light transmission could be improved, as well as with matching refractive indices of fiber material and medium. For corneal tissue engineering, scaffolds should be designed as thin as possible and fabricated from polymers with a matching refractive index to that of the human cornea. Concerning fiber diameter, smaller fiber diameters should be favored for maximizing graft transparency. Finally, a novel, semi-empirical formulation of light transmission through nanofibrous scaffolds is presented. Full article
(This article belongs to the Special Issue Advanced Nanomaterials for Tissue Engineering Applications)
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9 pages, 2614 KiB  
Article
Bright Silicon Carbide Single-Photon Emitting Diodes at Low Temperatures: Toward Quantum Photonics Applications
by Igor A. Khramtsov and Dmitry Yu. Fedyanin
Nanomaterials 2021, 11(12), 3177; https://doi.org/10.3390/nano11123177 - 24 Nov 2021
Viewed by 1756
Abstract
Color centers in silicon carbide have recently emerged as one of the most promising emitters for bright single-photon emitting diodes (SPEDs). It has been shown that, at room temperature, they can emit more than 109 photons per second under electrical excitation. However, [...] Read more.
Color centers in silicon carbide have recently emerged as one of the most promising emitters for bright single-photon emitting diodes (SPEDs). It has been shown that, at room temperature, they can emit more than 109 photons per second under electrical excitation. However, the spectral emission properties of color centers in SiC at room temperature are far from ideal. The spectral properties could be significantly improved by decreasing the operating temperature. However, the densities of free charge carriers in SiC rapidly decrease as temperature decreases, which reduces the efficiency of electrical excitation of color centers by many orders of magnitude. Here, we study for the first time the temperature characteristics of SPEDs based on color centers in 4H-SiC. Using a rigorous numerical approach, we demonstrate that although the single-photon electroluminescence rate does rapidly decrease as temperature decreases, it is possible to increase the SPED brightness to 107 photons/s at 100 K using the recently predicted effect of hole superinjection in homojunction p-i-n diodes. This gives the possibility to achieve high brightness and good spectral properties at the same time, which paves the way toward novel quantum photonics applications of electrically driven color centers in silicon carbide. Full article
(This article belongs to the Special Issue Advances in Silicon Carbide Nanomaterials)
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12 pages, 3965 KiB  
Article
Morphological Studies of Composite Spin Crossover@SiO2 Nanoparticles
by Yue Zan, Lionel Salmon and Azzedine Bousseksou
Nanomaterials 2021, 11(12), 3169; https://doi.org/10.3390/nano11123169 - 23 Nov 2021
Cited by 5 | Viewed by 1704
Abstract
Spin crossover (SCO) iron (II) 1,2,4-triazole-based coordination compounds in the form of composite SCO@SiO2 nanoparticles were prepared using a reverse microemulsion technique. The thickness of the silica shell and the morphology of the as obtained core@shell nanoparticles were studied by modifying the [...] Read more.
Spin crossover (SCO) iron (II) 1,2,4-triazole-based coordination compounds in the form of composite SCO@SiO2 nanoparticles were prepared using a reverse microemulsion technique. The thickness of the silica shell and the morphology of the as obtained core@shell nanoparticles were studied by modifying the polar phase/surfactant ratio (ω), as well as the quantity and the insertion phase (organic, aqueous and micellar phases) of the tetraethylorthosilicate (TEOS) precursor, the quantity of ammonia and the reaction temperature. The morphology of the nanoparticles was monitored by transmission electron microscopy (TEM/HRTEM) while their composition probed by combined elemental analyses, thermogravimetry and EDX analyses. We report that not only the particle size can be controlled but also the size of the silica shell, allowing for interesting perspectives in post-synthetic modification of the shell. The evolution of the spin crossover properties associated with the change in morphology was investigated by variable temperature optical and magnetic measurements. Full article
(This article belongs to the Special Issue Micro/Nano Emulsions: Fabrication and Applications)
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14 pages, 4003 KiB  
Article
Novel Pastes Containing Polymeric Nanoparticles for Dentin Hypersensitivity Treatment: An In Vitro Study
by Manuel Toledano-Osorio, Raquel Osorio, Estrella Osorio, Antonio L. Medina-Castillo and Manuel Toledano
Nanomaterials 2021, 11(11), 3150; https://doi.org/10.3390/nano11113150 - 22 Nov 2021
Cited by 4 | Viewed by 2248
Abstract
Tubule occlusion and remineralization are considered the two main goals of dentin hypersensitivity treatment. The objective is to assess the ability of dentifrices containing zinc-doped polymeric nanoparticles (NPs) to enduringly occlude the dentinal tubules, reinforcing dentin’s mechanical properties. Fifteen dentin surfaces were acid-treated [...] Read more.
Tubule occlusion and remineralization are considered the two main goals of dentin hypersensitivity treatment. The objective is to assess the ability of dentifrices containing zinc-doped polymeric nanoparticles (NPs) to enduringly occlude the dentinal tubules, reinforcing dentin’s mechanical properties. Fifteen dentin surfaces were acid-treated for dentinal tubule exposure and brushed with (1) distilled water, or with experimental pastes containing (2) 1% of zinc-doped NPs, (3) 5% of zinc-doped NPs, (4) 10% of zinc-doped NPs or (5) Sensodyne®. Topographical and nanomechanical analyses were performed on treated dentin surfaces and after a citric acid challenge. ANOVA and Student–Newman–Keuls tests were used (p < 0.05). The main results indicate that all pastes produced tubule occlusion (100%) and reinforced mechanical properties of intertubular dentin (complex modulus was above 75 GPa). After the citric acid challenge, only those pastes containing zinc-doped NPs were able to maintain tubular occlusion, as specimens treated with Sensodyne® have around 30% of tubules opened. Mechanical properties were maintained for dentin treated with Zn-doped NPs, but in the case of specimens treated with Sensodyne®, complex modulus values were reduced below 50 GPa. It may be concluded that zinc-doped NPs at the lowest tested concentration produced acid-resistant tubular occlusion and increased the mechanical properties of dentin. Full article
(This article belongs to the Special Issue Nanomaterials in Dentistry)
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10 pages, 2769 KiB  
Article
Plasmonic Gold Nanoisland Film for Bacterial Theranostics
by Shih-Hua Tan, Sibidou Yougbaré, Hsuan-Ya Tao, Che-Chang Chang and Tsung-Rong Kuo
Nanomaterials 2021, 11(11), 3139; https://doi.org/10.3390/nano11113139 - 21 Nov 2021
Cited by 12 | Viewed by 1717
Abstract
Plasmonic nanomaterials have been intensively explored for applications in biomedical detection and therapy for human sustainability. Herein, plasmonic gold nanoisland (NI) film (AuNIF) was fabricated onto a glass substrate by a facile seed-mediated growth approach. The structure of the tortuous gold NIs of [...] Read more.
Plasmonic nanomaterials have been intensively explored for applications in biomedical detection and therapy for human sustainability. Herein, plasmonic gold nanoisland (NI) film (AuNIF) was fabricated onto a glass substrate by a facile seed-mediated growth approach. The structure of the tortuous gold NIs of the AuNIF was demonstrated by scanning electron microscopy and energy-dispersive X-ray spectroscopy. Based on the ultraviolet-visible spectrum, the AuNIF revealed plasmonic absorption with maximum intensity at 624 nm. With the change to the surface topography created by the NIs, the capture efficiency of Escherichia coli (E. coli) by the AuNIF was significantly increased compared to that of the glass substrate. The AuNIF was applied as a surface-enhanced Raman scattering (SERS) substrate to enhance the Raman signal of E. coli. Moreover, the plasmonic AuNIF exhibited a superior photothermal effect under irradiation with simulated AM1.5 sunlight. For photothermal therapy, the AuNIF also displayed outstanding efficiency in the photothermal killing of E. coli. Using a combination of SERS detection and photothermal therapy, the AuNIF could be a promising platform for bacterial theranostics. Full article
(This article belongs to the Special Issue Antibacterial Applications of Nanomaterials)
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13 pages, 3117 KiB  
Article
Geometrical Nonlinearity for a Timoshenko Beam with Flexoelectricity
by Miroslav Repka, Jan Sladek and Vladimir Sladek
Nanomaterials 2021, 11(11), 3123; https://doi.org/10.3390/nano11113123 - 19 Nov 2021
Cited by 4 | Viewed by 1789
Abstract
The Timoshenko beam model is applied to the analysis of the flexoelectric effect for a cantilever beam under large deformations. The geometric nonlinearity with von Kármán strains is considered. The nonlinear system of ordinary differential equations (ODE) for beam deflection and rotation are [...] Read more.
The Timoshenko beam model is applied to the analysis of the flexoelectric effect for a cantilever beam under large deformations. The geometric nonlinearity with von Kármán strains is considered. The nonlinear system of ordinary differential equations (ODE) for beam deflection and rotation are derived. Moreover, this nonlinear system is linearized for each load increment, where it is solved iteratively. For the vanishing flexoelectric coefficient, the governing equations lead to the classical Timoshenko beam model. Furthermore, the influence of the flexoelectricity coefficient and the microstructural length-scale parameter on the beam deflection and the induced electric intensity is investigated. Full article
(This article belongs to the Section Theory and Simulation of Nanostructures)
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