Next Issue
Previous Issue

Table of Contents

Nanomaterials, Volume 7, Issue 12 (December 2017)

  • Issues are regarded as officially published after their release is announced to the table of contents alert mailing list.
  • You may sign up for e-mail alerts to receive table of contents of newly released issues.
  • PDF is the official format for papers published in both, html and pdf forms. To view the papers in pdf format, click on the "PDF Full-text" link, and use the free Adobe Readerexternal link to open them.
Cover Story (view full-size image) Rh is an intriguing metal due to its good UV plasmonic and photocatalytic properties. The most [...] Read more.
View options order results:
result details:
Displaying articles 1-55
Export citation of selected articles as:
Open AccessArticle Computer Simulations of Lipid Nanoparticles
Nanomaterials 2017, 7(12), 461; https://doi.org/10.3390/nano7120461
Received: 4 November 2017 / Revised: 5 December 2017 / Accepted: 14 December 2017 / Published: 20 December 2017
Cited by 1 | PDF Full-text (6558 KB) | HTML Full-text | XML Full-text
Abstract
Lipid nanoparticles (LNP) are promising soft matter nanomaterials for drug delivery applications. In spite of their interest, little is known about the supramolecular organization of the components of these self-assembled nanoparticles. Here, we present a molecular dynamics simulation study, employing the Martini coarse-grain
[...] Read more.
Lipid nanoparticles (LNP) are promising soft matter nanomaterials for drug delivery applications. In spite of their interest, little is known about the supramolecular organization of the components of these self-assembled nanoparticles. Here, we present a molecular dynamics simulation study, employing the Martini coarse-grain forcefield, of self-assembled LNPs made by tripalmitin lipid in water. We also study the adsorption of Tween 20 surfactant as a protective layer on top of the LNP. We show that, at 310 K (the temperature of interest in biological applications), the structure of the lipid nanoparticles is similar to that of a liquid droplet, in which the lipids show no nanostructuration and have high mobility. We show that, for large enough nanoparticles, the hydrophilic headgroups develop an interior surface in the NP core that stores liquid water. The surfactant is shown to organize in an inhomogeneous way at the LNP surface, with patches with high surfactant concentrations and surface patches not covered by surfactant. Full article
(This article belongs to the Special Issue Experimental Nanosciences, Computational Chemistry, and Data Analysis)
Figures

Figure 1

Open AccessArticle Structure and Optical Properties of Titania-PDMS Hybrid Nanocomposites Prepared by In Situ Non-Aqueous Synthesis
Nanomaterials 2017, 7(12), 460; https://doi.org/10.3390/nano7120460
Received: 23 November 2017 / Revised: 15 December 2017 / Accepted: 18 December 2017 / Published: 20 December 2017
Cited by 1 | PDF Full-text (5096 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
Organic-inorganic hybrid materials are attractive due to the combination of properties from the two distinct types of materials. In this work, transparent titania-polydimethylsiloxane hybrid materials with up to 15.5 vol. % TiO2 content were prepared by an in situ non-aqueous method using
[...] Read more.
Organic-inorganic hybrid materials are attractive due to the combination of properties from the two distinct types of materials. In this work, transparent titania-polydimethylsiloxane hybrid materials with up to 15.5 vol. % TiO2 content were prepared by an in situ non-aqueous method using titanium (IV) isopropoxide and hydroxy-terminated polydimethylsiloxane as precursors. Spectroscopy (Fourier transform infrared, Raman, Ultraviolet-visible, ellipsometry) and small-angle X-ray scattering analysis allowed to describe in detail the structure and the optical properties of the nanocomposites. Titanium alkoxide was successfully used as a cross-linker and titania-like nanodomains with an average size of approximately 4 nm were shown to form during the process. The resulting hybrid nanocomposites exhibit high transparency and tunable refractive index from 1.42 up to 1.56, depending on the titania content. Full article
(This article belongs to the Special Issue Hybrid Nanomaterials for Future Technologies)
Figures

Figure 1

Open AccessArticle Acidic Mesoporous Zeolite ZSM-5 Supported Cu Catalyst with Good Catalytic Performance in the Hydroxysulfurization of Styrenes with Disulfides
Nanomaterials 2017, 7(12), 459; https://doi.org/10.3390/nano7120459
Received: 20 November 2017 / Revised: 10 December 2017 / Accepted: 13 December 2017 / Published: 19 December 2017
PDF Full-text (4077 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
Development of highly active heterogeneous catalysts is an effective strategy for modern organic synthesis chemistry. In this work, acidic mesoporous zeolite ZSM-5 (HZSM-5-M), acidic-free mesoporous zeolite TS-1 (TS-1-M), and basic ETS-10 zeolite supported metal Cu catalysts were prepared to investigate their catalytic performances
[...] Read more.
Development of highly active heterogeneous catalysts is an effective strategy for modern organic synthesis chemistry. In this work, acidic mesoporous zeolite ZSM-5 (HZSM-5-M), acidic-free mesoporous zeolite TS-1 (TS-1-M), and basic ETS-10 zeolite supported metal Cu catalysts were prepared to investigate their catalytic performances in the hydroxysulfurization of styrenes with diaryl disulfides. The effect of pore size and acidities of the supports, as well as the Cu species electronic properties of the catalysts on reaction activity were investigated. The results show that Cu+ and Cu2+ binded on HZSM-5-M show the highest activity and product selectivity for the desired β-hydroxysulfides compounds. Full article
(This article belongs to the Special Issue Nanosized Zeolites and their Applications)
Figures

Graphical abstract

Open AccessArticle Preparation and Characterization of Nanoparticles Made from Co-Incubation of SOD and Glucose
Nanomaterials 2017, 7(12), 458; https://doi.org/10.3390/nano7120458
Received: 11 October 2017 / Revised: 6 November 2017 / Accepted: 20 November 2017 / Published: 19 December 2017
Cited by 2 | PDF Full-text (1651 KB) | HTML Full-text | XML Full-text
Abstract
The attractive potential of natural superoxide dismutase (SOD) in the fields of medicine and functional food is limited by its short half-life in circulation and poor permeability across the cell membrane. The nanoparticle form of SOD might overcome these limitations. However, most preparative
[...] Read more.
The attractive potential of natural superoxide dismutase (SOD) in the fields of medicine and functional food is limited by its short half-life in circulation and poor permeability across the cell membrane. The nanoparticle form of SOD might overcome these limitations. However, most preparative methods have disadvantages, such as complicated operation, a variety of reagents—some of them even highly toxic—and low encapsulation efficiency or low release rate. The aim of this study is to present a simple and green approach for the preparation of SOD nanoparticles (NPs) by means of co-incubation of Cu/Zn SOD with glucose. This method was designed to prepare nanoscale aggregates based on the possible inhibitory effect of Maillard reaction on heating-induced aggregation during the co-incubation. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) results indicated that the Maillard reaction occurred during the co-incubation process. It was found that enzymatically active NPs of Cu/Zn SOD were simultaneously generated during the reaction, with an average particle size of 175.86 ± 0.71 nm, and a Zeta potential of −17.27 ± 0.59 mV, as established by the measurement of enzymatic activity, observations using field emission scanning electron microscope, and analysis of dynamic light scattering, respectively. The preparative conditions for the SOD NPs were optimized by response surface design to increase SOD activity 20.43 fold. These SOD NPs showed storage stability for 25 days and better cell uptake efficacy than natural SOD. Therefore, these NPs of SOD are expected to be a potential drug candidate or functional food factor. To our knowledge, this is the first report on the preparation of nanoparticles possessing the bioactivity of the graft component protein, using the simple and green approach of co-incubation with glucose, which occurs frequently in the food industry during thermal processing. Full article
(This article belongs to the Special Issue Nanomaterials in Food Safety)
Figures

Graphical abstract

Open AccessArticle The Room-Temperature Chemiresistive Properties of Potassium Titanate Whiskers versus Organic Vapors
Nanomaterials 2017, 7(12), 455; https://doi.org/10.3390/nano7120455
Received: 13 November 2017 / Revised: 2 December 2017 / Accepted: 11 December 2017 / Published: 19 December 2017
PDF Full-text (2508 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
The development of portable gas-sensing units implies a special care of their power efficiency, which is often approached by operation at room temperature. This issue primarily appeals to a choice of suitable materials whose functional properties are sensitive toward gas vapors at these
[...] Read more.
The development of portable gas-sensing units implies a special care of their power efficiency, which is often approached by operation at room temperature. This issue primarily appeals to a choice of suitable materials whose functional properties are sensitive toward gas vapors at these conditions. While the gas sensitivity is nowadays advanced by employing the materials at nano-dimensional domain, the room temperature operation might be targeted via the application of layered solid-state electrolytes, like titanates. Here, we report gas-sensitive properties of potassium titanate whiskers, which are placed over a multielectrode chip by drop casting from suspension to yield a matrix mono-layer of varied density. The material synthesis conditions are straightforward both to get stable single-crystalline quasi-one-dimensional whiskers with a great extent of potassium replacement and to favor the increase of specific surface area of the structures. The whisker layer is found to be sensitive towards volatile organic compounds (ethanol, isopropanol, acetone) in the mixture with air at room temperature. The vapor identification is obtained via processing the vector signal generated by sensor array of the multielectrode chip with the help of pattern recognition algorithms. Full article
(This article belongs to the Special Issue Oxide Nanomaterials for Chemical Sensors)
Figures

Graphical abstract

Open AccessArticle High-Performance and Self-Powered Deep UV Photodetectors Based on High Quality 2D Boron Nitride Nanosheets
Nanomaterials 2017, 7(12), 454; https://doi.org/10.3390/nano7120454
Received: 6 November 2017 / Revised: 10 December 2017 / Accepted: 15 December 2017 / Published: 19 December 2017
Cited by 1 | PDF Full-text (4982 KB) | HTML Full-text | XML Full-text
Abstract
High-quality two-dimensional (2D) crystalline boron nitride nanosheets (BNNSs) were grown on silicon wafers by using pulsed plasma beam deposition techniques. Self-powered deep ultraviolet (DUV) photodetectors (PDs) based on BNNSs with Schottky contact structures are designed and fabricated. By connecting the fabricated DUV photodetector
[...] Read more.
High-quality two-dimensional (2D) crystalline boron nitride nanosheets (BNNSs) were grown on silicon wafers by using pulsed plasma beam deposition techniques. Self-powered deep ultraviolet (DUV) photodetectors (PDs) based on BNNSs with Schottky contact structures are designed and fabricated. By connecting the fabricated DUV photodetector to an ammeter, the response strength, response time and recovery time to different DUV wavelengths at different intensities have been characterized using the output short circuit photocurrent without a power supply. Furthermore, effects of temperature and plasma treatment on the induced photocurrent response of detectors have also been investigated. The experimental data clearly indicate that plasma treatment would significantly improve both induced photocurrent and response time. The BNNS-based DUV photodetector is demonstrated to possess excellent performance at a temperature up to 400 °C, including high sensitivity, high signal-to-noise ratio, high spectral selectivity, high speed, and high stability, which is better than almost all reported semiconducting nanomaterial-based self-powered photodetectors. Full article
Figures

Graphical abstract

Open AccessArticle Fabrication of GO/Cement Composites by Incorporation of Few-Layered GO Nanosheets and Characterization of Their Crystal/Chemical Structure and Properties
Nanomaterials 2017, 7(12), 457; https://doi.org/10.3390/nano7120457
Received: 16 November 2017 / Revised: 8 December 2017 / Accepted: 14 December 2017 / Published: 18 December 2017
Cited by 1 | PDF Full-text (22420 KB) | HTML Full-text | XML Full-text
Abstract
Original graphene oxide (GO) nanosheets were prepared using the Hummers method and found to easily aggregate in aqueous and cement composites. Using carboxymethyl chitosan (CCS) as a dispersant, few-layered GO nanosheets (1–2 layers) were obtained by forming CCS/GO intercalation composites. The testing results
[...] Read more.
Original graphene oxide (GO) nanosheets were prepared using the Hummers method and found to easily aggregate in aqueous and cement composites. Using carboxymethyl chitosan (CCS) as a dispersant, few-layered GO nanosheets (1–2 layers) were obtained by forming CCS/GO intercalation composites. The testing results indicated that the few-layered GO nanosheets could uniformly spread, both in aqueous and cement composites. The cement composites were prepared with GO dosages of 0.03%, 0.05% and 0.07% and we found that they had a compact microstructure in the whole volume. A special feature was determined, namely that the microstructures consisted of regular-shaped crystals created by self-crosslinking. The X-ray diffraction (XRD) results indicated that there was a higher number of cement hydration crystals in GO/cement composites. Meanwhile, we also found that partially-amorphous Calcium-Silicate-Hydrate (C-S-H) gel turned into monoclinic crystals. At 28 days, the GO/cement composites reached the maximum compressive and flexural strengths at a 0.05% dosage. These strengths were 176.64 and 31.67 MPa and, compared with control samples, their increased ratios were 64.87% and 149.73%, respectively. Durability parameters, such as penetration, freeze-thaw, carbonation, drying-shrinkage value and pore structure, showed marked improvement. The results indicated that it is possible to obtain cement composites with a compact microstructure and with high performances by introducing CCS/GO intercalation composites. Full article
(This article belongs to the Special Issue Layered Nano-Sheets: Synthesis and Applications)
Figures

Graphical abstract

Open AccessArticle Pure and Highly Nb-Doped Titanium Dioxide Nanotubular Arrays: Characterization of Local Surface Properties
Nanomaterials 2017, 7(12), 456; https://doi.org/10.3390/nano7120456
Received: 16 October 2017 / Revised: 11 December 2017 / Accepted: 15 December 2017 / Published: 18 December 2017
Cited by 1 | PDF Full-text (4553 KB) | HTML Full-text | XML Full-text
Abstract
This paper presents the results of studies of the local surface properties of pure and highly Nb-doped (12 wt %) TiO2 nanotubes (TNT) using the X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM) methods, respectively. XPS analysis showed that the pure
[...] Read more.
This paper presents the results of studies of the local surface properties of pure and highly Nb-doped (12 wt %) TiO2 nanotubes (TNT) using the X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM) methods, respectively. XPS analysis showed that the pure TNT exhibit an evident over-stoichiometry combined with high level of undesired C contaminations, which was confirmed by the relative concentration of specific elements O, Ti and C (with respect to all the surface atoms) equal to 0.46, 018 and 0.36, respectively. In turn, for the highly Nb-doped (12 wt %) TNT, a slightly different surface chemistry was observed because the relative concentration of specific elements O and Ti and, with respect to all the surface atoms, is slightly lower, that is, 0.42 and 0.12, respectively; this is directly related to the fact that Nb atoms appeared having the relative concentration at the level of 0.09, whereas the undesired C contaminations reached the same level (0.36), as is the case of pure TNT. In addition, SEM analysis confirms that there are evident free spaces between the specific slops containing several TNT, what was additionally confirmed by the contribution of specific surface bonding coming from the SiO2/Si substrate. The obtained information allowed us a new insight on the potential origin of aging effect at the surface of TNT in atmosphere being the undesired limitation for their potential application as the chemical resistive type sensors or in any other fields of their application related to their surface activity. Full article
Figures

Figure 1

Open AccessArticle Influence of Sterilization and Preservation Procedures on the Integrity of Serum Protein-Coated Magnetic Nanoparticles
Nanomaterials 2017, 7(12), 453; https://doi.org/10.3390/nano7120453
Received: 30 October 2017 / Revised: 8 December 2017 / Accepted: 12 December 2017 / Published: 15 December 2017
PDF Full-text (2919 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
Protein-coated magnetic nanoparticles are promising candidates for various medical applications. Prior to their application into a biological system, one has to guarantee that the particle dispersions are free from pathogens or any other microbiologic contamination. Furthermore, to find entrance into clinical routine, the
[...] Read more.
Protein-coated magnetic nanoparticles are promising candidates for various medical applications. Prior to their application into a biological system, one has to guarantee that the particle dispersions are free from pathogens or any other microbiologic contamination. Furthermore, to find entrance into clinical routine, the nanoparticle dispersions have to be storable for several months. In this study, we tested several procedures for sterilization and preservation of nanoparticle containing liquids on their influence on the integrity of the protein coating on the surface of these particles. For this, samples were treated by freezing, autoclaving, lyophilization, and ultraviolet (UV) irradiation, and characterized by means of dynamic light scattering, determination of surface potential, and gel electrophoresis afterwards. We found that the UV sterilization followed by lyophilization under the addition of polyethylene glycol are the most promising procedures for the preparation of sterilized long-term durable protein-coated magnetic nanoparticles. Ongoing work is focused on the optimization of used protocols for UV sterilization and lyophilization for further improvement of the storage time. Full article
(This article belongs to the Special Issue Magnetic Nanoparticles in Biological Applications)
Figures

Figure 1

Open AccessArticle Comparative Evaluation of U.S. Brand and Generic Intravenous Sodium Ferric Gluconate Complex in Sucrose Injection: In Vitro Cellular Uptake
Nanomaterials 2017, 7(12), 451; https://doi.org/10.3390/nano7120451
Received: 8 November 2017 / Revised: 6 December 2017 / Accepted: 11 December 2017 / Published: 15 December 2017
Cited by 2 | PDF Full-text (7499 KB) | HTML Full-text | XML Full-text
Abstract
Iron deficiency anemia is a common clinical consequence for people who suffer from chronic kidney disease, especially those requiring dialysis. Intravenous (IV) iron therapy is a widely accepted safe and efficacious treatment for iron deficiency anemia. Numerous IV iron drugs have been approved
[...] Read more.
Iron deficiency anemia is a common clinical consequence for people who suffer from chronic kidney disease, especially those requiring dialysis. Intravenous (IV) iron therapy is a widely accepted safe and efficacious treatment for iron deficiency anemia. Numerous IV iron drugs have been approved by U.S. Food and Drug Administration (FDA), including a single generic product, sodium ferric gluconate complex in sucrose. In this study, we compared the cellular iron uptake profiles of the brand (Ferrlecit®) and generic sodium ferric gluconate (SFG) products. We used a colorimetric assay to examine the amount of iron uptake by three human macrophage cell lines. This is the first published study to provide a parallel evaluation of the cellular uptake of a brand and a generic IV iron drug in a mononuclear phagocyte system. The results showed no difference in iron uptake across all cell lines, tested doses, and time points. The matching iron uptake profiles of Ferrlecit® and its generic product support the FDA’s present position detailed in the draft guidance on development of SFG complex products that bioequivalence can be based on qualitative (Q1) and quantitative (Q2) formulation sameness, similar physiochemical characterization, and pharmacokinetic bioequivalence studies. Full article
(This article belongs to the Special Issue Pharmaceutical Nanotechnology)
Figures

Figure 1

Open AccessArticle Constructing Sheet-On-Sheet Structured Graphitic Carbon Nitride/Reduced Graphene Oxide/Layered MnO2 Ternary Nanocomposite with Outstanding Catalytic Properties on Thermal Decomposition of Ammonium Perchlorate
Nanomaterials 2017, 7(12), 450; https://doi.org/10.3390/nano7120450
Received: 27 October 2017 / Revised: 3 December 2017 / Accepted: 9 December 2017 / Published: 15 December 2017
Cited by 7 | PDF Full-text (5519 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
We unprecedentedly report that layered MnO2 nanosheets were in situ formed onto the surface of covalently bonded graphitic carbon nitride/reduced graphene oxide nanocomposite (g-C3N4/rGO), forming sheet-on-sheet structured two dimension (2D) graphitic carbon nitride/reduced graphene oxide/layered MnO2 ternary
[...] Read more.
We unprecedentedly report that layered MnO2 nanosheets were in situ formed onto the surface of covalently bonded graphitic carbon nitride/reduced graphene oxide nanocomposite (g-C3N4/rGO), forming sheet-on-sheet structured two dimension (2D) graphitic carbon nitride/reduced graphene oxide/layered MnO2 ternary nanocomposite (g-C3N4/rGO/MnO2) with outstanding catalytic properties on thermal decomposition of ammonium perchlorate (AP). The covalently bonded g-C3N4/rGO was firstly prepared by the calcination of graphene oxide-guanidine hydrochloride precursor (GO-GndCl), following by its dispersion into the KMnO4 aqueous solution to construct the g-C3N4/rGO/MnO2 ternary nanocomposite. FT-IR, XRD, Raman as well as the XPS results clearly demonstrated the chemical interaction between g-C3N4, rGO and MnO2. TEM and element mapping indicated that layered g-C3N4/rGO was covered with thin MnO2 nanosheets. Furthermore, the obtained g-C3N4/rGO/MnO2 nanocomposite exhibited promising catalytic capacity on thermal decomposition of AP. Upon addition of 2 wt % g-C3N4/rGO/MnO2 ternary nanocomposite as catalyst, the thermal decomposition temperature of AP was largely decreased up by 142.5 °C, which was higher than that of pure g-C3N4, g-C3N4/rGO and MnO2, respectively, demonstrating the synergistic catalysis of the as-prepared nanocomposite. Full article
(This article belongs to the Special Issue Graphitic Carbon Nitride Nanostructures: Catalysis and Beyond)
Figures

Graphical abstract

Open AccessEditorial Nanoengineered Interfaces, Coatings, and Structures by Plasma Techniques
Nanomaterials 2017, 7(12), 449; https://doi.org/10.3390/nano7120449
Received: 7 October 2017 / Revised: 12 December 2017 / Accepted: 12 December 2017 / Published: 15 December 2017
PDF Full-text (148 KB) | HTML Full-text | XML Full-text
Abstract
Nanoparticles, nanotubes, nanobelts, nanoneedles, nanosheets, nanowires, nanopillars: the variety of nanostructured interfaces that can be created and modified using plasma processes is virtually endless.[...] Full article
Open AccessArticle Sequential Growth of Uniform β-NaYF4@β-NaLnF4 (Ln = Y, Lu, Yb) Microcrystals with Luminescent Properties of Multicolor Tuning and Dual-Mode Emission
Nanomaterials 2017, 7(12), 448; https://doi.org/10.3390/nano7120448
Received: 13 November 2017 / Revised: 8 December 2017 / Accepted: 11 December 2017 / Published: 14 December 2017
Cited by 2 | PDF Full-text (4092 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
We synthesized the uniform core-shell microstructured compounds with hexagonal phase NaYF4:Er/Yb microrods as the core and hexagonal phase NaLnF4 (NaYbF4, NaLuF4:Yb/Tm, NaYF4:Yb/Er, NaYF4:Eu) as the shell based on the hydrothermal reaction. These
[...] Read more.
We synthesized the uniform core-shell microstructured compounds with hexagonal phase NaYF4:Er/Yb microrods as the core and hexagonal phase NaLnF4 (NaYbF4, NaLuF4:Yb/Tm, NaYF4:Yb/Er, NaYF4:Eu) as the shell based on the hydrothermal reaction. These microscale core-shell structures provided a platform for the spatially confining optical process while possessing high luminescence efficiency. The thickness of the shell could be controlled by adjusting the amounts of shell precursor, which significantly affected the intensity of the shell dopant ions emission and the emission color of core-shell upconversion luminescence (UCL). The uniform NaYF4@NaLnF4 (Ln = Y, Lu, Yb) microrods, with a series of rare-earth ions doped into the core and shell layer at various doping concentrations, achieved color-tuning of the upconversion (UC) emission and dual-mode emission at the single-microcrystal level, thus allowing the efficient utilization of core-shell microcrystals in the photonics and security labeling. This study suggests a new class of luminescent materials in the microscopic field. Full article
Figures

Figure 1

Open AccessCommunication Enhanced Reduction of Few-Layer Graphene Oxide via Supercritical Water Gasification of Glycerol
Nanomaterials 2017, 7(12), 447; https://doi.org/10.3390/nano7120447
Received: 31 October 2017 / Revised: 5 December 2017 / Accepted: 6 December 2017 / Published: 14 December 2017
PDF Full-text (1508 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
A sustainable and effective method for de-oxygenation of few-layer graphene oxide (FLGO) by glycerol gasification in supercritical water (SCW) is described. In this manner, reduction of FLGO and valorization of glycerol, in turn catalyzed by FLGO, are achieved simultaneously. The addition of glycerol
[...] Read more.
A sustainable and effective method for de-oxygenation of few-layer graphene oxide (FLGO) by glycerol gasification in supercritical water (SCW) is described. In this manner, reduction of FLGO and valorization of glycerol, in turn catalyzed by FLGO, are achieved simultaneously. The addition of glycerol enhanced FLGO oxygen removal by up to 59% due to the in situ hydrogen generation as compared to the use of SCW only. Physicochemical characterization of the reduced FLGO (rFLGO) showed a high restoration of the sp2-conjugated carbon network. FLGO sheets with a starting C/O ratio of 2.5 are reduced by SCW gasification of glycerol to rFLGO with a C/O ratio of 28.2, above those reported for hydrazine-based methods. Additionally, simultaneous glycerol gasification resulted in the concurrent production of H2, CO, CH4 and valuable hydrocarbons such as alkylated and non-alkylated long chain hydrocarbon (C12–C31), polycyclic aromatic hydrocarbons (PAH), and phthalate, phenol, cresol and furan based compounds. Full article
Figures

Graphical abstract

Open AccessArticle Impedance Spectroscopy Analysis and Equivalent Circuit Modeling of Graphene Oxide Solutions
Nanomaterials 2017, 7(12), 446; https://doi.org/10.3390/nano7120446
Received: 11 October 2017 / Revised: 2 December 2017 / Accepted: 9 December 2017 / Published: 14 December 2017
PDF Full-text (3130 KB) | HTML Full-text | XML Full-text
Abstract
The optical and electrical characteristics of a graphene oxide solution (GS) with different graphene oxide (GO) concentrations in de-ionized water are investigated via the electrochemical impedance spectroscopy (EIS) method. The measurement results produced by the EIS for the GS are represented with both
[...] Read more.
The optical and electrical characteristics of a graphene oxide solution (GS) with different graphene oxide (GO) concentrations in de-ionized water are investigated via the electrochemical impedance spectroscopy (EIS) method. The measurement results produced by the EIS for the GS are represented with both Bode and Nyquist plots in a frequency range from 1 kHz to 10 MHz. Using these results, we develop an equivalent circuit model as a function of the GO concentration, representing the GS as a mixed circuit of two-dimensional (2D) GO dispersed in parallel in de-ionized (DI) water. The underlying physics of the current-flowing behavior in the GS are explained and interpreted using empirical circuit models; the circuit model also shows that highly resistive GO becomes conductive in GS form in the DI water. The findings in this work should draw new attention toward GSes and related applications, including functional composite materials, catalysts, and filter membranes. Full article
Figures

Graphical abstract

Open AccessReview From Ion Current to Electroosmotic Flow Rectification in Asymmetric Nanopore Membranes
Nanomaterials 2017, 7(12), 445; https://doi.org/10.3390/nano7120445
Received: 13 November 2017 / Revised: 6 December 2017 / Accepted: 11 December 2017 / Published: 14 December 2017
Cited by 3 | PDF Full-text (4321 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
Asymmetrically shaped nanopores have been shown to rectify the ionic current flowing through pores in a fashion similar to a p-n junction in a solid-state diode. Such asymmetric nanopores include conical pores in polymeric membranes and pyramidal pores in mica membranes. We review
[...] Read more.
Asymmetrically shaped nanopores have been shown to rectify the ionic current flowing through pores in a fashion similar to a p-n junction in a solid-state diode. Such asymmetric nanopores include conical pores in polymeric membranes and pyramidal pores in mica membranes. We review here both theoretical and experimental aspects of this ion current rectification phenomenon. A simple intuitive model for rectification, stemming from previously published more quantitative models, is discussed. We also review experimental results on controlling the extent and sign of rectification. It was shown that ion current rectification produces a related rectification of electroosmotic flow (EOF) through asymmetric pore membranes. We review results that show how to measure and modulate this EOF rectification phenomenon. Finally, EOF rectification led to the development of an electroosmotic pump that works under alternating current (AC), as opposed to the currently available direct current EOF pumps. Experimental results on AC EOF rectification are reviewed, and advantages of using AC to drive EOF are discussed. Full article
Figures

Graphical abstract

Open AccessArticle Increased Efficiency of Solar Cells Protected by Hydrophobic and Hydrophilic Anti-Reflecting Nanostructured Glasses
Nanomaterials 2017, 7(12), 437; https://doi.org/10.3390/nano7120437
Received: 4 October 2017 / Revised: 31 October 2017 / Accepted: 6 December 2017 / Published: 14 December 2017
Cited by 2 | PDF Full-text (3996 KB) | HTML Full-text | XML Full-text
Abstract
We investigated the fabrication of large-area (cm2) nanostructured glasses for solar cell modules with hydrophobic and hydrophilic properties using soft lithography and colloidal lithography. Both of these techniques entail low-cost and ease of nanofabrication. We explored the use of simple 1D
[...] Read more.
We investigated the fabrication of large-area (cm2) nanostructured glasses for solar cell modules with hydrophobic and hydrophilic properties using soft lithography and colloidal lithography. Both of these techniques entail low-cost and ease of nanofabrication. We explored the use of simple 1D and 2D nanopatterns (nanowires and nanocones) and the effect of introducing disorder in the nanostructures. We observed an increase in the transmitted light for ordered nanostructures with a maximum value of 99% for wavelengths >600 nm when ordered nanocones are fabricated on the two sides of the solar glass. They produced an increment in the efficiency of the packaged solar cell with respect to the glass without nanostructures. On the one hand, the wettability properties showed that the ordering of the nanostructures improved the hydrophobicity of the solar glasses and increased their self-cleaning capacity. On the other hand, the disordered nanostructures improved the hydrophilic properties of solar glasses, increasing their anti-fogging capacity. The results show that by selecting the appropriate nanopattern, the wettability properties (hydrophobic or hydrophilic) can be easily improved without decreasing the efficiency of the solar cell underneath. Full article
Figures

Graphical abstract

Open AccessArticle Morphological and Optical Characteristics of Chitosan(1−x):Cuox (4 ≤ x ≤ 12) Based Polymer Nano-Composites: Optical Dielectric Loss as an Alternative Method for Tauc’s Model
Nanomaterials 2017, 7(12), 444; https://doi.org/10.3390/nano7120444
Received: 26 October 2017 / Revised: 26 November 2017 / Accepted: 8 December 2017 / Published: 13 December 2017
Cited by 3 | PDF Full-text (8367 KB) | HTML Full-text | XML Full-text
Abstract
In this work, copper (Cu) nanoparticles with observable surface plasmonic resonance (SPR) peaks were synthesized by an in-situ method. Chitosan host polymer was used as a reduction medium and a capping agent for the Cu nanoparticles. The surface morphology of the samples was
[...] Read more.
In this work, copper (Cu) nanoparticles with observable surface plasmonic resonance (SPR) peaks were synthesized by an in-situ method. Chitosan host polymer was used as a reduction medium and a capping agent for the Cu nanoparticles. The surface morphology of the samples was investigated through the use of scanning electron micrograph (SEM) technique. Copper nanoparticles appeared as chains and white specks in the SEM images. The strong peaks due to the Cu element observed in the spectrum of energy dispersive analysis of X-rays. For the nanocomposite samples, obvious peaks due to the SPR phenomena were obtained in the Ultraviolet-visible (UV-vis) spectra. The effect of Cu nanoparticles on the host band gap was understood from absorption edges shifting of absorption edges to lower photon energy. The optical dielectric loss parameter obtained from the measurable quantities was used as an alternative method to study the band structure of the samples. Quantum mechanical models drawbacks, in the study of band gap, were explained based on the optical dielectric loss. A clear dispersion region was able to be observed in refractive indices spectra of the composite samples. A linear relationship with a regression value of 0.99 was achieved between the refractive index and volume fractions of CuI content. Cu nanoparticles with various sizes and homogenous dispersions were also determined from transmission electron microscope (TEM) images. Full article
(This article belongs to the Special Issue Polymer Nanocomposites)
Figures

Graphical abstract

Open AccessArticle Novel Hydrogel-Advanced Modified Clay Nanocomposites as Possible Vehicles for Drug Delivery and Controlled Release
Nanomaterials 2017, 7(12), 443; https://doi.org/10.3390/nano7120443
Received: 31 October 2017 / Revised: 24 November 2017 / Accepted: 8 December 2017 / Published: 13 December 2017
PDF Full-text (6304 KB) | HTML Full-text | XML Full-text
Abstract
Present study refers to the synthesis of new advanced materials based on poly(methacrylic acid) (PMAA) with previously reported own advanced modified clays by edge covalent bonding. This will create the premises to obtain nanocomposite hydrogels with combined hydrophilic-hydrophobic behavior absolutely necessary for co-delivery
[...] Read more.
Present study refers to the synthesis of new advanced materials based on poly(methacrylic acid) (PMAA) with previously reported own advanced modified clays by edge covalent bonding. This will create the premises to obtain nanocomposite hydrogels with combined hydrophilic-hydrophobic behavior absolutely necessary for co-delivery of polar/nonpolar substances. For the synthesis, N,N’-methylenebisacrylamide was used as cross-linker and ammonium persulphate as initiator. As a consequence of the inclusion of clay into the polymer matrix and the intercalation of PMAA between the layers as well as the presence of hydrophobic interactions occurred between partners, the final hydrogel nanocomposites possessed greater swelling degrees, slower de-swelling process and enhanced mechanical properties depending on the clay type in comparison with pure hydrogel. In vitro MTS ([3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium, inner salt]) colorimetric assay showed that direct exposure with PMMA-clay-based constructs did not affect cell viability and proliferation in time (24 and 48 h) on either normal or adenocarcinoma cell lines. Full article
Figures

Graphical abstract

Open AccessArticle Exploring the Optical and Morphological Properties of Ag and Ag/TiO2 Nanocomposites Grown by Supersonic Cluster Beam Deposition
Nanomaterials 2017, 7(12), 442; https://doi.org/10.3390/nano7120442
Received: 27 October 2017 / Revised: 4 December 2017 / Accepted: 6 December 2017 / Published: 13 December 2017
Cited by 2 | PDF Full-text (6832 KB) | HTML Full-text | XML Full-text
Abstract
Nanocomposite systems and nanoparticle (NP) films are crucial for many applications and research fields. The structure-properties correlation raises complex questions due to the collective structure of these systems, often granular and porous, a crucial factor impacting their effectiveness and performance. In this framework,
[...] Read more.
Nanocomposite systems and nanoparticle (NP) films are crucial for many applications and research fields. The structure-properties correlation raises complex questions due to the collective structure of these systems, often granular and porous, a crucial factor impacting their effectiveness and performance. In this framework, we investigate the optical and morphological properties of Ag nanoparticles (NPs) films and of Ag NPs/TiO2 porous matrix films, one-step grown by supersonic cluster beam deposition. Morphology and structure of the Ag NPs film and of the Ag/TiO2 (Ag/Ti 50-50) nanocomposite are related to the optical properties of the film employing spectroscopic ellipsometry (SE). We employ a simple Bruggeman effective medium approximation model, corrected by finite size effects of the nano-objects in the film structure to gather information on the structure and morphology of the nanocomposites, in particular porosity and average NPs size for the Ag/TiO2 NP film. Our results suggest that SE is a simple, quick and effective method to measure porosity of nanoscale films and systems, where standard methods for measuring pore sizes might not be applicable. Full article
Figures

Graphical abstract

Open AccessFeature PaperArticle Silver Nanoparticles in the Lung: Toxic Effects and Focal Accumulation of Silver in Remote Organs
Nanomaterials 2017, 7(12), 441; https://doi.org/10.3390/nano7120441
Received: 30 October 2017 / Revised: 1 December 2017 / Accepted: 5 December 2017 / Published: 12 December 2017
Cited by 4 | PDF Full-text (11960 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
The distribution of silver (Ag) into remote organs secondary to the application of Ag nanoparticles (Ag-NP) to the lung is still incompletely understood and was investigated in the rat with imaging methods. Dose-finding experiments were carried out with 50 nm- or 200 nm-sized
[...] Read more.
The distribution of silver (Ag) into remote organs secondary to the application of Ag nanoparticles (Ag-NP) to the lung is still incompletely understood and was investigated in the rat with imaging methods. Dose-finding experiments were carried out with 50 nm- or 200 nm-sized polyvinyl pyrrolidine (PVP)-coated Ag-NP using alveolar macrophages in vitro and female rats, which received Ag-NP via intratracheal instillation. In the main study, we administered 37.5–300 µg per rat lung of the more toxic Ag50-PVP and assessed the broncho-alveolar lavage fluid (BALF) for inflammatory cells, total protein and fibronectin after three and 21 days. In parallel, lung tissue was analysed for DNA double-strand breaks and altered cell proliferation. While 75–150 µg Ag50-PVP per rat lung caused a reversible inflammation, 300 µg led to DNA damage, accelerated cell proliferation and progressively increasing numbers of neutrophilic granulocytes. Ag accumulation was significant in homogenates of liver and other peripheral organs upon lung dose of ≥75 µg. Quantitative laser-ablation inductively-coupled plasma mass spectrometry (LA-ICP-MS) combined with enhanced dark field microscopy and autometallography revealed focal accumulations of Ag and/or Ag-NP in sections of peripheral organs: mediastinal lymph nodes contained Ag-NP especially in peripheral macrophages and Ag in argyrophilic fibres. In the kidney, Ag had accumulated within proximal tubuli, while renal filter structures contained no Ag. Discrete localizations were also observed in immune cells of liver and spleen. Overall, the study shows that concentrations of Ag-NP, which elicit a transient inflammation in the rat lung, lead to focal accumulations of Ag in peripheral organs, and this might pose a risk to particular cell populations in remote sites. Full article
Figures

Graphical abstract

Open AccessArticle Synthesis of Formate Esters and Formamides Using an Au/TiO2-Catalyzed Aerobic Oxidative Coupling of Paraformaldehyde
Nanomaterials 2017, 7(12), 440; https://doi.org/10.3390/nano7120440
Received: 18 September 2017 / Revised: 20 November 2017 / Accepted: 6 December 2017 / Published: 12 December 2017
Cited by 1 | PDF Full-text (2043 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
A simple method for the synthesis of formate esters and formamides is presented based on the Au/TiO2-catalyzed aerobic oxidative coupling between alcohols or amines and formaldehyde. The suitable form of formaldehyde is paraformaldehyde, as cyclic trimeric 1,3,5-trioxane is inactive. The reaction
[...] Read more.
A simple method for the synthesis of formate esters and formamides is presented based on the Au/TiO2-catalyzed aerobic oxidative coupling between alcohols or amines and formaldehyde. The suitable form of formaldehyde is paraformaldehyde, as cyclic trimeric 1,3,5-trioxane is inactive. The reaction proceeds via the formation of an intermediate hemiacetal or hemiaminal, respectively, followed by the Au nanoparticle-catalyzed aerobic oxidation of the intermediate. Typically, the oxidative coupling between formaldehyde (2 equiv) and amines occurs quantitatively at room temperature within 4 h, and there is no need to add a base as in analogous coupling reactions. The oxidative coupling between formaldehyde (typically 3 equiv) and alcohols is unprecedented and occurs more slowly, yet in good to excellent yields and selectivity. Minor side-products (2–12%) from the acetalization of formaldehyde by the alcohol are also formed. The catalyst is recyclable and can be reused after a simple filtration in five consecutive runs with a small loss of activity. Full article
(This article belongs to the Special Issue Noble Metal Nanoparticles in Catalysis)
Figures

Graphical abstract

Open AccessArticle The Effect of Different Coupling Agents on Nano-ZnO Materials Obtained via the Sol–Gel Process
Nanomaterials 2017, 7(12), 439; https://doi.org/10.3390/nano7120439
Received: 10 October 2017 / Revised: 27 November 2017 / Accepted: 8 December 2017 / Published: 12 December 2017
Cited by 3 | PDF Full-text (4003 KB) | HTML Full-text | XML Full-text
Abstract
Hybrid nanomaterials based on zinc oxide were synthesized via the sol–gel method, using different silane coupling agents: (3-glycidyloxypropyl)trimethoxysilane (GPTMS), phenyltriethoxysilane (PhTES), octyltriethoxysilane (OTES), and octadecyltriethoxysilane (ODTES). Morphological properties and the silane precursor type effect on the particle size were investigated using dynamic light
[...] Read more.
Hybrid nanomaterials based on zinc oxide were synthesized via the sol–gel method, using different silane coupling agents: (3-glycidyloxypropyl)trimethoxysilane (GPTMS), phenyltriethoxysilane (PhTES), octyltriethoxysilane (OTES), and octadecyltriethoxysilane (ODTES). Morphological properties and the silane precursor type effect on the particle size were investigated using dynamic light scattering (DLS), environmental scanning electron microscopy (ESEM), transmission electron microscopy (TEM), thermogravimetric analysis (TGA), and X-ray diffraction (XRD). The bonding characteristics of modified ZnO materials were investigated using Fourier transform infrared spectroscopy (FTIR). The final solutions were deposited on metallic substrate (aluminum) in order to realize coatings with various wettability and roughness. The morphological studies, obtained by ESEM and TEM analysis, showed that the sizes of the ZnO nanoparticles are changed as function of silane precursor used in synthesis. The thermal stability of modified ZnO materials showed that the degradation of the alkyl groups takes place in the 300–500 °C range. Water wettability study revealed a contact angle of 142 ± 5° for the surface covered with ZnO material modified with ODTES and showed that the water contact angle increases as the alkyl chain from the silica precursor increases. These modified ZnO materials, therefore, can be easily incorporated in coatings for various applications such as anti-corrosion and anti-icing. Full article
(This article belongs to the Special Issue Sol-Gel Preparation of Nanomaterials)
Figures

Figure 1

Open AccessArticle New Three-Dimensional Porous Electrode Concept: Vertically-Aligned Carbon Nanotubes Directly Grown on Embroidered Copper Structures
Nanomaterials 2017, 7(12), 438; https://doi.org/10.3390/nano7120438
Received: 9 November 2017 / Revised: 30 November 2017 / Accepted: 5 December 2017 / Published: 11 December 2017
Cited by 2 | PDF Full-text (3100 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
New three-dimensional (3D) porous electrode concepts are required to overcome limitations in Li-ion batteries in terms of morphology (e.g., shapes, dimensions), mechanical stability (e.g., flexibility, high electroactive mass loadings), and electrochemical performance (e.g., low volumetric energy densities and rate capabilities). Here a new
[...] Read more.
New three-dimensional (3D) porous electrode concepts are required to overcome limitations in Li-ion batteries in terms of morphology (e.g., shapes, dimensions), mechanical stability (e.g., flexibility, high electroactive mass loadings), and electrochemical performance (e.g., low volumetric energy densities and rate capabilities). Here a new electrode concept is introduced based on the direct growth of vertically-aligned carbon nanotubes (VA-CNTs) on embroidered Cu current collectors. The direct growth of VA-CNTs was achieved by plasma-enhanced chemical vapor deposition (PECVD), and there was no application of any post-treatment or cleaning procedure. The electrochemical behavior of the as-grown VA-CNTs was analyzed by charge/discharge cycles at different specific currents and with electrochemical impedance spectroscopy (EIS) measurements. The results were compared with values found in the literature. The as-grown VA-CNTs exhibit higher specific capacities than graphite and pristine VA-CNTs found in the literature. This together with the possibilities that the Cu embroidered structures offer in terms of specific surface area, total surface area, and designs provide a breakthrough in new 3D electrode concepts. Full article
(This article belongs to the Special Issue Carbon nanostructure for energy storage and conversion)
Figures

Graphical abstract

Open AccessArticle Evaluation of Fibrin-Based Interpenetrating Polymer Networks as Potential Biomaterials for Tissue Engineering
Nanomaterials 2017, 7(12), 436; https://doi.org/10.3390/nano7120436
Received: 31 October 2017 / Revised: 30 November 2017 / Accepted: 5 December 2017 / Published: 10 December 2017
Cited by 2 | PDF Full-text (4012 KB) | HTML Full-text | XML Full-text
Abstract
Interpenetrating polymer networks (IPNs) have gained great attention for a number of biomedical applications due to their improved properties compared to individual components alone. In this study, we investigated the capacity of newly-developed naturally-derived IPNs as potential biomaterials for tissue engineering. These IPNs
[...] Read more.
Interpenetrating polymer networks (IPNs) have gained great attention for a number of biomedical applications due to their improved properties compared to individual components alone. In this study, we investigated the capacity of newly-developed naturally-derived IPNs as potential biomaterials for tissue engineering. These IPNs combine the biologic properties of a fibrous fibrin network polymerized at the nanoscale and the mechanical stability of polyethylene oxide (PEO). First, we assessed their cytotoxicity in vitro on L929 fibroblasts. We further evaluated their biocompatibility ex vivo with a chick embryo organotypic culture model. Subcutaneous implantations of the matrices were subsequently conducted on nude mice to investigate their biocompatibility in vivo. Our preliminary data highlighted that our biomaterials were non-cytotoxic (viability above 90%). The organotypic culture showed that the IPN matrices induced higher cell adhesion (across all the explanted organ tissues) and migration (skin, intestine) than the control groups, suggesting the advantages of using a biomimetic, yet mechanically-reinforced IPN-based matrix. We observed no major inflammatory response up to 12 weeks post implantation. All together, these data suggest that these fibrin-based IPNs are promising biomaterials for tissue engineering. Full article
(This article belongs to the Special Issue Nanofibrous Scaffolds for Biomedical Application)
Figures

Figure 1

Open AccessArticle Zinc-Modified Nanotransporter of Doxorubicin for Targeted Prostate Cancer Delivery
Nanomaterials 2017, 7(12), 435; https://doi.org/10.3390/nano7120435
Received: 26 October 2017 / Revised: 23 November 2017 / Accepted: 30 November 2017 / Published: 8 December 2017
Cited by 2 | PDF Full-text (2431 KB) | HTML Full-text | XML Full-text
Abstract
This work investigated the preparation of chitosan nanoparticles used as carriers for doxorubicin for targeted cancer delivery. Prepared nanocarriers were stabilized and functionalized via zinc ions incorporated into the chitosan nanoparticle backbone. We took the advantage of high expression of sarcosine in the
[...] Read more.
This work investigated the preparation of chitosan nanoparticles used as carriers for doxorubicin for targeted cancer delivery. Prepared nanocarriers were stabilized and functionalized via zinc ions incorporated into the chitosan nanoparticle backbone. We took the advantage of high expression of sarcosine in the prostate cancer cells. The prostate cancer targeting was mediated by the AntiSar antibodies decorated surface of the nanocage. Formation of the chitosan nanoparticles was determined using a ninhydrin assay and differential pulse voltammetry. Obtained results showed the strong effect of tripolyphosphine on the nanoparticle formation. The zinc ions affected strong chitosan backbone coiling both in inner and outer chitosan nanoparticle structure. Zinc electrochemical signal depended on the level of the complex formation and the potential shift from −960 to −950 mV. Formed complex is suitable for doxorubicin delivery. It was observed the 20% entrapment efficiency of doxorubicin and strong dependence of drug release after 120 min in the blood environment. The functionality of the designed nanotransporter was proven. The purposed determination showed linear dependence in the concentration range of Anti-sarcosine IgG labeled gold nanoparticles from 0 to 1000 µg/mL and the regression equation was found to be y = 3.8x − 66.7 and R2 = 0.99. Performed ELISA confirmed the ability of Anti-sarcosine IgG labeled chitosan nanoparticles with loaded doxorubicin to bind to the sarcosine molecule. Observed hemolytic activity of the nanotransporter was 40%. Inhibition activity of our proposed nanotransporter was evaluated to be 0% on the experimental model of S. cerevisiae. Anti-sarcosine IgG labeled chitosan nanoparticles, with loaded doxorubicin stabilized by Zn ions, are a perspective type of nanocarrier for targeted drug therapy managed by specific interaction with sarcosine and metallothionein for prostate cancer. Full article
(This article belongs to the Special Issue Pharmaceutical Nanotechnology)
Figures

Figure 1

Open AccessArticle Development of Octyl Methoxy Cinnamates (OMC)/Silicon Dioxide (SiO2) Nanoparticles by Sol-Gel Emulsion Method
Nanomaterials 2017, 7(12), 434; https://doi.org/10.3390/nano7120434
Received: 13 November 2017 / Revised: 26 November 2017 / Accepted: 27 November 2017 / Published: 7 December 2017
PDF Full-text (2189 KB) | HTML Full-text | XML Full-text
Abstract
Although octyl methoxy cinnamates (OMC) is the most used Ultraviolet B (UVB) filter in sunscreen, it has poor light stability in emulsion system. In this study, OMC/SiO2 nanoparticles were prepared via sol-gel emulsion method. Tetraethoxy silane (TEOS) was used as the silica
[...] Read more.
Although octyl methoxy cinnamates (OMC) is the most used Ultraviolet B (UVB) filter in sunscreen, it has poor light stability in emulsion system. In this study, OMC/SiO2 nanoparticles were prepared via sol-gel emulsion method. Tetraethoxy silane (TEOS) was used as the silica source to encapsulate OMC. Modification of experimental parameters such as stirring speed of condensation reaction and emulsion condition, pH value of acid-catalyzed, surfactant and different percentage of TEOS and OMC, adding of OMC and surfactant to different phase may affect the particle size, and yield and entrapment efficiency in preparation process of OMC/SiO2 nanoparticles. Concluding all the parameter, we found that when condensation reaction and emulsion conditions are at 1000 rpm, pH 1.5, Span 80/Tween 20, TEOS/OMC ratios 1:1, OMC and surfactants added in oil phase, resulting in smaller particle sizes 476.5 nm, higher yield 95.8%, and higher entrapment efficiency 61.09%. Fourier transform infrared (FTIR) analysis demonstrated that OMC/SiO2 nanoparticles were successfully prepared. In vitro release profile supposed that OMC/SiO2 nanoparticles can delay OMC releasing and had 60.83% decreasing of cumulative amount. Therefore, the OMC/SiO2 nanoparticles have the potential to develop as new sunscreen materials in the use for cosmetics field in the future. Full article
Figures

Graphical abstract

Open AccessArticle Piezoelectric Potential in Single-Crystalline ZnO Nanohelices Based on Finite Element Analysis
Nanomaterials 2017, 7(12), 430; https://doi.org/10.3390/nano7120430
Received: 7 October 2017 / Revised: 8 November 2017 / Accepted: 1 December 2017 / Published: 7 December 2017
Cited by 4 | PDF Full-text (1155 KB) | HTML Full-text | XML Full-text
Abstract
Electric potential produced in deformed piezoelectric nanostructures is of significance for both fundamental study and practical applications. To reveal the piezoelectric property of ZnO nanohelices, the piezoelectric potential in single-crystal nanohelices was simulated by finite element method calculations. For a nanohelix with a
[...] Read more.
Electric potential produced in deformed piezoelectric nanostructures is of significance for both fundamental study and practical applications. To reveal the piezoelectric property of ZnO nanohelices, the piezoelectric potential in single-crystal nanohelices was simulated by finite element method calculations. For a nanohelix with a length of 1200 nm, a mean coil radius of 150 nm, five active coils, and a hexagonal coiled wire with a side length 100 nm, a compressing force of 100 nN results in a potential of 1.85 V. This potential is significantly higher than the potential produced in a straight nanowire with the same length and applied force. Maintaining the length and increasing the number of coils or mean coil radius leads to higher piezoelectric potential in the nanohelix. Appling a force along the axial direction produces higher piezoelectric potential than in other directions. Adding lateral forces to an existing axial force can change the piezoelectric potential distribution in the nanohelix, while the maximum piezoelectric potential remains largely unchanged in some cases. This research demonstrates the promising potential of ZnO nanohelices for applications in sensors, micro-electromechanical systems (MEMS) devices, nanorobotics, and energy sciences. Full article
(This article belongs to the Special Issue ZnO and TiO2 Based Nanostructures) Printed Edition available
Figures

Figure 1

Open AccessFeature PaperArticle Self-Supported Ni(P, O)x·MoOx Nanowire Array on Nickel Foam as an Efficient and Durable Electrocatalyst for Alkaline Hydrogen Evolution
Nanomaterials 2017, 7(12), 433; https://doi.org/10.3390/nano7120433
Received: 31 October 2017 / Revised: 24 November 2017 / Accepted: 28 November 2017 / Published: 6 December 2017
Cited by 1 | PDF Full-text (9784 KB) | HTML Full-text | XML Full-text
Abstract
Earth-abundant and low-cost catalysts with excellent electrocatalytic hydrogen evolution reaction (HER) activity in alkaline solution play an important role in the sustainable production of hydrogen energy. In this work, a catalyst of Ni(P, O)x·MoOx nanowire array on nickel foam has
[...] Read more.
Earth-abundant and low-cost catalysts with excellent electrocatalytic hydrogen evolution reaction (HER) activity in alkaline solution play an important role in the sustainable production of hydrogen energy. In this work, a catalyst of Ni(P, O)x·MoOx nanowire array on nickel foam has been prepared via a facile route for efficient alkaline HER. Benefiting from the collaborative advantages of Ni(P, O)x and amorphous MoOx, as well as three-dimensional porous conductive nickel scaffold, the hybrid electrocatalyst shows high catalytic activity in 1 M KOH aqueous solution, including a small overpotential of 59 mV at 10 mA cm−2, a low Tafel slope of 54 mV dec-1, and excellent cycling stability. Full article
(This article belongs to the Special Issue Nanomaterials Based Fuel Cells and Supercapacitors)
Figures

Figure 1

Open AccessArticle Evaluation of the Corrosion Resistance Properties of Electroplated Chitosan-Zn1−xCuxO Composite Thin Films
Nanomaterials 2017, 7(12), 432; https://doi.org/10.3390/nano7120432
Received: 4 November 2017 / Revised: 27 November 2017 / Accepted: 1 December 2017 / Published: 6 December 2017
Cited by 1 | PDF Full-text (3489 KB) | HTML Full-text | XML Full-text
Abstract
Novel chitosan–zinc copper oxide (Zn1−xCuxO) composites were electrochemically synthesized through galvanostatic deposition. The prepared chitosan-based composite thin films were elaborately investigated to determine their structural, morphological, compositional, impedance, and corrosion properties. X-ray diffraction analysis was performed to reveal their
[...] Read more.
Novel chitosan–zinc copper oxide (Zn1−xCuxO) composites were electrochemically synthesized through galvanostatic deposition. The prepared chitosan-based composite thin films were elaborately investigated to determine their structural, morphological, compositional, impedance, and corrosion properties. X-ray diffraction analysis was performed to reveal their structural orientation of composite thin films. Energy dispersive analysis by X-ray evidently confirmed the existence of Zn, Cu, and O in the composite thin films. Nyquist plots revealed that the chitosan-Zn1−xCuxO thin films had obvious semi-circular boundaries, and higher resistance was observed for chitosan-ZnO due to the grain boundary effect. Corrosion properties were evaluated using both an electrochemical method and the ASTM weight gain method, which revealed good corrosion rates of 34 and 35 × 10−3 mm/y, respectively, for chitosan-ZnO thin film. Full article
Figures

Figure 1

Back to Top