Sign in to use this feature.

Years

Between: -

Subjects

remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline

Journals

Article Types

Countries / Regions

Search Results (29)

Search Parameters:
Keywords = magnetic aerogels

Order results
Result details
Results per page
Select all
Export citation of selected articles as:
47 pages, 5231 KB  
Article
Optimized Microfluidic Synthesis of Magnesium Magnetic Silica-Based Aerogels for Pesticide Removal and Antimicrobial Water Treatment
by Dana-Ionela Tudorache (Trifa), Alexandra-Cătălina Bîrcă, Alexandra Cristina Burdușel, Adelina-Gabriela Niculescu, Elena-Theodora Moldoveanu, Ionela C. Voinea, Miruna S. Stan, Roxana Trușcă, Bogdan Purcăreanu, Tony Hadibarata, Marius Rădulescu, Alina Maria Holban, Dan Eduard Mihaiescu, Valentin Crăciun and Alexandru Mihai Grumezescu
Int. J. Mol. Sci. 2026, 27(3), 1456; https://doi.org/10.3390/ijms27031456 (registering DOI) - 1 Feb 2026
Abstract
Water represents the fundamental source of life for all human and animal populations; however, its consumption has become increasingly hazardous due to high levels of pollution. Modern agricultural practices rely heavily on pesticides, which significantly contribute to water contamination and imbalances in aquatic [...] Read more.
Water represents the fundamental source of life for all human and animal populations; however, its consumption has become increasingly hazardous due to high levels of pollution. Modern agricultural practices rely heavily on pesticides, which significantly contribute to water contamination and imbalances in aquatic ecosystems. Moreover, another critical category of pollutants consists of pathogenic bacteria that proliferate in aquatic environments, mainly originating from hospital and urban wastewater because of human activity. Considering these major environmental and health challenges, the present study aims to develop an optimized method for water treatment by synthesizing magnetic silica-based aerogels using a microfluidic vortex chip and systematically varying synthesis parameters to enhance material performance. The physicochemical properties of the aerogels were characterized using XRD, FTIR, SEM, EDS, and BET. The pesticide adsorption capacity of the materials was evaluated using FT-ICR HR-MS analysis, which demonstrated the high efficiency of the aerogels in removing a complex mixture of pesticides. In parallel, antimicrobial efficacy was assessed against E. faecalis, E. coli, and P. aeruginosa isolated from surface water, hospital wastewater, and the influent of a well-known wastewater treatment plant in Bucharest, as well as against ATCC reference strains. Additionally, the study investigated the biocompatibility and biological responses of magnetic aerogels using MTT assays, nitric oxide production, lactate dehydrogenase release, intracellular ROS levels, and quantification of total protein, malondialdehyde, and reduced glutathione in HaCaT and HEK293 cell lines. The results confirm the efficiency and application potential of the developed materials and emphasize the importance of optimizing synthesis to achieve high-performance aerogels for effective decontamination of polluted waters. Full article
33 pages, 3293 KB  
Review
Bridging Material Innovation and Environmental Safety: Aerogel-Based Magnetic Nanocomposites as Emerging Platforms for Water Decontamination
by Elena-Theodora Moldoveanu, Adelina-Gabriela Niculescu, Denisa Alexandra Florea, Tony Hadibarata, Alexandru-Mihai Grumezescu and Dan-Eduard Mihaiescu
Toxics 2026, 14(2), 115; https://doi.org/10.3390/toxics14020115 - 26 Jan 2026
Viewed by 184
Abstract
Currently, water pollution is one of the major global environmental sustainability and public health issues that requires efficient and viable remediation technologies, as existing decontamination methods face limitations. In this sense, this review aims to highlight the potential of multifunctional aerogel-based magnetic nanocomposites [...] Read more.
Currently, water pollution is one of the major global environmental sustainability and public health issues that requires efficient and viable remediation technologies, as existing decontamination methods face limitations. In this sense, this review aims to highlight the potential of multifunctional aerogel-based magnetic nanocomposites as a novel strategy for water decontamination by integrating magnetic nanostructures into aerogel matrices that promote high adsorption capacity, selective catalysis, and facile magnetic recovery. In this regard, providing a comprehensive analysis of their functional design, contaminant-removal mechanisms, and multifunctional performance is crucial for developing and optimizing a system capable of addressing complex pollutants through multiple mechanisms (e.g., adsorption, photocatalysis, and reductive pathways). However, ecotoxicological evaluations focus on the potential for nanoparticles to leach, induce oxidative stress, and cause aquatic toxicity, supporting the development of strategies that comply with safety principles. Additionally, this review examines the aerogels’ capabilities for regeneration, operational stability, and scalability across repeated-use cycles, as well as their potential for real-world wastewater applications. Moreover, future directions for these aerogels include the development of smart, stimuli-responsive aerogels, machine-learning-based modeling, and the use of green synthesis approaches to enable sustainable water remediation strategies. Full article
(This article belongs to the Special Issue Degradation and Remediation of Environmental Pollutants)
Show Figures

Graphical abstract

18 pages, 8206 KB  
Article
Structural–Material Coupling Enabling Broadband Absorption for a Graphene Aerogel All-Medium Metamaterial Absorber
by Kemeng Yan, Yuhui Ren, Jiaxuan Zhang, Man Song, Xuhui Du, Meijiao Lu, Dingfan Wu, Yiqing Li and Jiangni Yun
Nanomaterials 2026, 16(1), 18; https://doi.org/10.3390/nano16010018 - 22 Dec 2025
Cited by 1 | Viewed by 554
Abstract
All-medium metamaterial absorbers (MMAs) have attracted considerable attention for ultra-broadband electromagnetic wave (EMW) absorption. Herein, a lightweight graphene aerogel (GA) was synthesized through a low-temperature, atmospheric-pressure reduction route. Benefiting from its 3D porous network, enriched oxygen-containing functional groups, and improved graphitization, the GA [...] Read more.
All-medium metamaterial absorbers (MMAs) have attracted considerable attention for ultra-broadband electromagnetic wave (EMW) absorption. Herein, a lightweight graphene aerogel (GA) was synthesized through a low-temperature, atmospheric-pressure reduction route. Benefiting from its 3D porous network, enriched oxygen-containing functional groups, and improved graphitization, the GA offers diverse intrinsic attenuation pathways and a limited effective absorption bandwidth (EAB) of only 6.46 GHz (11.54–18.00 GHz at 1.95 mm). To clarify its attenuation mechanism, nonlinear least-squares fitting was used to quantitatively separate electrical loss contributions. Compared with graphene, the GA shows markedly superior attenuation capability, making it a more suitable medium for MMA design. Guided by equivalent circuit modeling, a stacked frustum-configured GA-based MMA (GA-MMA) was developed, where structure-induced resonances compensate for the intrinsic absence of magnetic components in the GA, thereby substantially broadening its absorption range. The GA-MMA achieves an EAB of 40.7 GHz (9.1–49.8 GHz, reflection loss < −10 dB) and maintains stable absorption under incident angles up to ± 70°. Radar cross-section simulations further indicate its potential in electromagnetic interference mitigation, human health protection, and defense information security. This work provides a feasible route for constructing ultralight and broadband MMAs by coupling electrical loss with structural effects. Full article
(This article belongs to the Special Issue Harvesting Electromagnetic Fields with Nanomaterials)
Show Figures

Graphical abstract

22 pages, 8987 KB  
Article
Microfluidic Synthesis of Magnetic Silica Aerogels for Efficient Pesticide Removal from Water
by Dana-Ionela Tudorache (Trifa), Adelina-Gabriela Niculescu, Alexandra-Cătălina Bîrcă, Denisa Alexandra Florea, Marius Rădulescu, Bogdan-Ștefan Vasile, Roxana Trușcă, Dan-Eduard Mihaiescu, Tony Hadibarata and Alexandru-Mihai Grumezescu
Gels 2025, 11(6), 463; https://doi.org/10.3390/gels11060463 - 17 Jun 2025
Cited by 3 | Viewed by 1830
Abstract
Aerogels have gained much interest in the last decades due to their specific properties, such as high porosity, high surface area, and low density, which have caused them to be used in multiple and varied fields. As the applicability of aerogels is tightly [...] Read more.
Aerogels have gained much interest in the last decades due to their specific properties, such as high porosity, high surface area, and low density, which have caused them to be used in multiple and varied fields. As the applicability of aerogels is tightly correlated to their morpho-structural features, special consideration must be allocated to the fabrication method. An emerging technique for producing nanostructured materials with tailored morphology and dimensions is represented by continuous-flow microfluidics. In this context, this work explores the synergic combination of aerogel-based materials with microfluidic synthesis platforms to generate advanced nanocomposite adsorbents for water decontamination. Specifically, this study presents the novel synthesis of a magnetic silica-based aerogel using a custom-designed 3D microfluidic platform, offering enhanced control over nanoparticle incorporation and gelation compared to conventional sol–gel techniques. The resulting gel was further dried via supercritical CO2 extraction to preserve its unique nanostructure. The multi-faceted physicochemical investigations (XRD, DLS, FT-IR, RAMAN, SEM, and TEM) confirmed the material’s uniform morphology, high porosity, and surface functionalization. The HR-MS FT-ICR analysis has also demonstrated the advanced material’s adsorption capacity for various pesticides, suggesting its adequacy for further environmental applications. An exceptional 93.7% extraction efficiency was registered for triazophos, underscoring the potential of microfluidic synthesis approaches in engineering advanced, eco-friendly adsorbent materials for water decontamination of relevant organic pollutants. Full article
(This article belongs to the Special Issue Silica Aerogel: Synthesis, Properties and Characterization)
Show Figures

Figure 1

20 pages, 13042 KB  
Article
Biomass Cellulose-Derived Carbon Aerogel Supported Magnetite-Copper Bimetallic Heterogeneous Fenton-like Catalyst Towards the Boosting Redox Cycle of ≡Fe(III)/≡Fe(II)
by Qiang Zhao, Jiawei Yang, Jiayi Xia, Gaotian Zhao, Yida Yang, Zongwei Zhang, Jing Li, Fang Wei and Weiguo Song
Nanomaterials 2025, 15(8), 614; https://doi.org/10.3390/nano15080614 - 16 Apr 2025
Cited by 4 | Viewed by 1343
Abstract
To degrade high-concentration and toxic organic effluents, we developed Fe-Cu active sites loaded on biomass-source carbon aerogel (CA) to produce a low-cost and high-efficiency magnetic Fenton-like catalyst for the catalytic oxidative decomposition of organic pollutants. It exhibits excellent performance in catalytic Fenton-like reactions [...] Read more.
To degrade high-concentration and toxic organic effluents, we developed Fe-Cu active sites loaded on biomass-source carbon aerogel (CA) to produce a low-cost and high-efficiency magnetic Fenton-like catalyst for the catalytic oxidative decomposition of organic pollutants. It exhibits excellent performance in catalytic Fenton-like reactions for RhB removal at an ultrahigh initial concentration of up to 1000 ppm. To be specific, Fe3O4 and Cu nanoparticles are generated in situ on a mesoporous CA support, denoted as an Fe3O4-Cu/CA catalyst. Experimentally, factors including initial dye concentration, catalyst dosage, H2O2 dosage, pH, and temperature, which significantly influence the oxidative degradation rate of RhB, are carefully studied. The RhB (1000 ppm) degradation ratio reaches 93.7% within 60 min under low catalyst and H2O2 dosage. The catalyst also shows slight metal leaching (almost 1.4% of total Fe and 4.0% of total Cu leached after a complete degradation of 25 μmol RhB under conditions of 15 mg catalyst dosage, 20 mL RhB solution (600 ppm), and 200 μL 30 wt% H2O2 dosage, at pH of 2.5, at 40 °C), good catalytic activity for degrading organic pollutants, excellent reusability, and good catalytic stability (the degradation ratio is nearly 82.95% in the 8th cycle reaction). The synergistic effect between Fe and Cu species plays a vital role in promoting the redox cycle of Fe(III)/Fe(II) and enhancing the generation of ·OH. It is suitable for ultrahigh-concentration organic pollutant degradation in practical wastewater treatment applications. Full article
(This article belongs to the Special Issue Nanostructured Materials for Electrocatalysis)
Show Figures

Graphical abstract

13 pages, 6302 KB  
Article
Fabrication and Advanced Imaging Characterization of Magnetic Aerogel-Based Thin Films for Water Decontamination
by Adelina-Gabriela Niculescu, Bogdan Mihaiescu, Alexandra Cătălina Bîrcă, Alina Moroșan, Oana Maria Munteanu (Mihaiescu), Bogdan Ștefan Vasile, Tony Hadibarata, Daniela Istrati, Dan Eduard Mihaiescu and Alexandru Mihai Grumezescu
Gels 2024, 10(6), 394; https://doi.org/10.3390/gels10060394 - 11 Jun 2024
Cited by 6 | Viewed by 2336
Abstract
Aerogels have emerged as appealing materials for various applications due to their unique features, such as low density, high porosity, high surface area, and low thermal conductivity. Aiming to bring the advantages of these materials to the environmental field, this study focuses on [...] Read more.
Aerogels have emerged as appealing materials for various applications due to their unique features, such as low density, high porosity, high surface area, and low thermal conductivity. Aiming to bring the advantages of these materials to the environmental field, this study focuses on synthesizing magnetic silica aerogel-based films suitable for water decontamination. In this respect, a novel microfluidic platform was created to obtain core-shell iron oxide nanoparticles that were further incorporated into gel-forming precursor solutions. Afterward, dip-coating deposition was utilized to create thin layers of silica-based gels, which were further processed by 15-hour gelation time, solvent transfer, and further CO2 desiccation. A series of physicochemical analyses (XRD, HR-MS FT-ICR, FT-IR, TEM, SEM, and EDS) were performed to characterize the final films and intermediate products. The proposed advanced imaging experimental model for film homogeneity and adsorption characteristics confirmed uniform aerogel film deposition, nanostructured surface, and ability to remove pesticides from contaminated water samples. Based on thorough investigations, it was concluded that the fabricated magnetic aerogel-based thin films are promising candidates for water decontamination and novel solid-phase extraction sample preparation. Full article
Show Figures

Figure 1

15 pages, 4317 KB  
Article
Magnetic Aerogels for Room-Temperature Catalytic Production of Bis(indolyl)methane Derivatives
by Nicola Melis, Danilo Loche, Swapneel V. Thakkar, Maria Giorgia Cutrufello, Maria Franca Sini, Gianmarco Sedda, Luca Pilia, Angelo Frongia and Maria Francesca Casula
Molecules 2024, 29(10), 2223; https://doi.org/10.3390/molecules29102223 - 9 May 2024
Cited by 3 | Viewed by 1564
Abstract
The potential of aerogels as catalysts for the synthesis of a relevant class of bis-heterocyclic compounds such as bis(indolyl)methanes was investigated. In particular, the studied catalyst was a nanocomposite aerogel based on nanocrystalline nickel ferrite (NiFe2O4) dispersed on amorphous [...] Read more.
The potential of aerogels as catalysts for the synthesis of a relevant class of bis-heterocyclic compounds such as bis(indolyl)methanes was investigated. In particular, the studied catalyst was a nanocomposite aerogel based on nanocrystalline nickel ferrite (NiFe2O4) dispersed on amorphous porous silica aerogel obtained by two-step sol–gel synthesis followed by gel drying under supercritical conditions and calcination treatments. It was found that the NiFe2O4/SiO2 aerogel is an active catalyst for the selected reaction, enabling high conversions at room temperature, and it proved to be active for three repeated runs. The catalytic activity can be ascribed to both the textural and acidic features of the silica matrix and of the nanocrystalline ferrite. In addition, ferrite nanocrystals provide functionality for magnetic recovery of the catalyst from the crude mixture, enabling time-effective separation from the reaction environment. Evidence of the retention of species involved in the reaction into the catalyst is also pointed out, likely due to the porosity of the aerogel together with the affinity of some species towards the silica matrix. Our work contributes to the study of aerogels as catalysts for organic reactions by demonstrating their potential as well as limitations for the room-temperature synthesis of bis(indolyl)methanes. Full article
Show Figures

Graphical abstract

41 pages, 3217 KB  
Review
An Updated Overview of Magnetic Composites for Water Decontamination
by Adelina-Gabriela Niculescu, Bogdan Mihaiescu, Dan Eduard Mihaiescu, Tony Hadibarata and Alexandru Mihai Grumezescu
Polymers 2024, 16(5), 709; https://doi.org/10.3390/polym16050709 - 5 Mar 2024
Cited by 17 | Viewed by 7215
Abstract
Water contamination by harmful organic and inorganic compounds seriously burdens human health and aquatic life. A series of conventional water purification methods can be employed, yet they come with certain disadvantages, including resulting sludge or solid waste, incomplete treatment process, and high costs. [...] Read more.
Water contamination by harmful organic and inorganic compounds seriously burdens human health and aquatic life. A series of conventional water purification methods can be employed, yet they come with certain disadvantages, including resulting sludge or solid waste, incomplete treatment process, and high costs. To overcome these limitations, attention has been drawn to nanotechnology for fabricating better-performing adsorbents for contaminant removal. In particular, magnetic nanostructures hold promise for water decontamination applications, benefiting from easy removal from aqueous solutions. In this respect, numerous researchers worldwide have reported incorporating magnetic particles into many composite materials. Therefore, this review aims to present the newest advancements in the field of magnetic composites for water decontamination, describing the appealing properties of a series of base materials and including the results of the most recent studies. In more detail, carbon-, polymer-, hydrogel-, aerogel-, silica-, clay-, biochar-, metal–organic framework-, and covalent organic framework-based magnetic composites are overviewed, which have displayed promising adsorption capacity for industrial pollutants. Full article
(This article belongs to the Collection Polymer Applications in Environmental Science)
Show Figures

Figure 1

23 pages, 3993 KB  
Article
Cellulose Nanofiber–Alginate Biotemplated Cobalt Composite Multifunctional Aerogels for Energy Storage Electrodes
by Felita W. Zhang, Paul D. Trackey, Vani Verma, Galen T. Mandes, Rosemary L. Calabro, Anthony W. Presot, Claire K. Tsay, Timothy J. Lawton, Alexa S. Zammit, Edward M. Tang, Andrew Q. Nguyen, Kennedy V. Munz, Enoch A. Nagelli, Stephen F. Bartolucci, Joshua A. Maurer and F. John Burpo
Gels 2023, 9(11), 893; https://doi.org/10.3390/gels9110893 - 11 Nov 2023
Cited by 9 | Viewed by 5436
Abstract
Tunable porous composite materials to control metal and metal oxide functionalization, conductivity, pore structure, electrolyte mass transport, mechanical strength, specific surface area, and magneto-responsiveness are critical for a broad range of energy storage, catalysis, and sensing applications. Biotemplated transition metal composite aerogels present [...] Read more.
Tunable porous composite materials to control metal and metal oxide functionalization, conductivity, pore structure, electrolyte mass transport, mechanical strength, specific surface area, and magneto-responsiveness are critical for a broad range of energy storage, catalysis, and sensing applications. Biotemplated transition metal composite aerogels present a materials approach to address this need. To demonstrate a solution-based synthesis method to develop cobalt and cobalt oxide aerogels for high surface area multifunctional energy storage electrodes, carboxymethyl cellulose nanofibers (CNF) and alginate biopolymers were mixed to form hydrogels to serve as biotemplates for cobalt nanoparticle formation via the chemical reduction of cobalt salt solutions. The CNF–alginate mixture forms a physically entangled, interpenetrating hydrogel, combining the properties of both biopolymers for monolith shape and pore size control and abundant carboxyl groups that bind metal ions to facilitate biotemplating. The CNF–alginate hydrogels were equilibrated in CaCl2 and CoCl2 salt solutions for hydrogel ionic crosslinking and the prepositioning of transition metal ions, respectively. The salt equilibrated hydrogels were chemically reduced with NaBH4, rinsed, solvent exchanged in ethanol, and supercritically dried with CO2 to form aerogels with a specific surface area of 228 m2/g. The resulting aerogels were pyrolyzed in N2 gas and thermally annealed in air to form Co and Co3O4 porous composite electrodes, respectively. The multifunctional composite aerogel’s mechanical, magnetic, and electrochemical functionality was characterized. The coercivity and specific magnetic saturation of the pyrolyzed aerogels were 312 Oe and 114 emu/gCo, respectively. The elastic moduli of the supercritically dried, pyrolyzed, and thermally oxidized aerogels were 0.58, 1.1, and 14.3 MPa, respectively. The electrochemical testing of the pyrolyzed and thermally oxidized aerogels in 1 M KOH resulted in specific capacitances of 650 F/g and 349 F/g, respectively. The rapidly synthesized, low-cost, hydrogel-based synthesis for tunable transition metal multifunctional composite aerogels is envisioned for a wide range of porous metal electrodes to address energy storage, catalysis, and sensing applications. Full article
(This article belongs to the Special Issue International Perspectives on Aerogels)
Show Figures

Figure 1

14 pages, 2446 KB  
Article
Analysis of Polycyclic Aromatic Hydrocarbons Using Magnetic Three-Dimensional Graphene Solid-Phase Extraction Coupled with Gas Chromatography–Mass Spectrometry
by Hassan Sereshti, Mahsa Karimi, Sajad Karami, Shokouh Mahpishanian, Mehdi Esmaeili Bidhendi, Shahabaldin Rezania, Amin Mojiri, Hesam Kamyab and Hamid Rashidi Nodeh
Separations 2023, 10(11), 564; https://doi.org/10.3390/separations10110564 - 10 Nov 2023
Cited by 10 | Viewed by 3590
Abstract
In this study, a composite material consisting of three-dimensional graphene aerogel and iron oxide nanoparticles (3DG/Fe3O4) was created and utilized for the purpose of magnetic solid-phase extraction (MSPE) of thirteen polycyclic aromatic hydrocarbon (PAH) compounds via gas chromatography–mass spectrometry/selected [...] Read more.
In this study, a composite material consisting of three-dimensional graphene aerogel and iron oxide nanoparticles (3DG/Fe3O4) was created and utilized for the purpose of magnetic solid-phase extraction (MSPE) of thirteen polycyclic aromatic hydrocarbon (PAH) compounds via gas chromatography–mass spectrometry/selected ion monitoring (GC-MS/SIM) analysis. The synthesized adsorbent underwent a range of characterization techniques, including scanning electron microscopy, vibrating sample magnetometry, Raman spectroscopy, X-ray diffraction, Brunauer–Emmett–Teller, Fourier transform-infrared spectroscopy, and Barrett–Joyner–Halenda techniques, to examine its properties and morphology. The synthesized adsorbent integrates the benefits of superior adsorption capacity from modified graphene oxide (GO) with the magnetic separability of magnetite microparticles, resulting in a high adsorption capacity with easy separation from sample solutions. The efficiency of the proposed method was optimized and modeled using a central composite design (CCD), which considered the primary factors influencing it. The optimal conditions were obtained as the adsorbent dosage of 10 mg, the extraction time of 4 min, and the salt concentration of 3% w/v. The limit of detection for the target PAHs was established to range from 0.016 to 0.2 ng mL−1 in optimal conditions, exhibiting a signal-to-noise ratio of 3. The linear dynamic range spanned from 5 to 100 ng mL−1, with determination coefficients (R2) ranging from 0.9913 to 0.9997. The intra- and inter-day precisions were calculated as relative standard deviations (RSDs) equal to 3.9% and 4.7%, respectively. The proposed method was successfully applied to the determination of PAHs in water samples (tap, river, and rainwater), and recoveries in the range of 71–110% (RSDs < 5.2%, n = 3) were obtained. Full article
(This article belongs to the Section Environmental Separations)
Show Figures

Figure 1

16 pages, 3042 KB  
Article
Magnetic Polypyrrole-Gelatin-Barium Ferrite Cryogel as an Adsorbent for Chromium (VI) Removal
by Konstantin A. Milakin, Oumayma Taboubi, Jiřina Hromádková and Patrycja Bober
Gels 2023, 9(10), 840; https://doi.org/10.3390/gels9100840 - 23 Oct 2023
Cited by 7 | Viewed by 2174
Abstract
Polypyrrole-gelatin aerogels, containing magnetic barium ferrite (BaFe) particles, (PPy-G-BaFe) were synthesized by oxidative cryopolymerization and used as adsorbents for the removal of Cr(VI) from aqueous media. The removal was performed at pH 4, which was shown to be the optimal value, due to [...] Read more.
Polypyrrole-gelatin aerogels, containing magnetic barium ferrite (BaFe) particles, (PPy-G-BaFe) were synthesized by oxidative cryopolymerization and used as adsorbents for the removal of Cr(VI) from aqueous media. The removal was performed at pH 4, which was shown to be the optimal value, due to HCrO4 being the dominant species in these conditions and its more favorable adsorption and reduction compared to CrO42−, present at pH > 4. It was found that the presence of magnetic BaFe particles had no effect on the adsorption performance of PPy aerogels in terms of capacity and kinetics, which was attributed to its relatively low content in the composite. After the adsorption, the presence of chromium in the composites was confirmed by EDX and its electrostatic interaction with the adsorbent was pointed at by vibrational spectroscopy, corresponding to the accepted adsorption mechanism. The adsorption kinetics followed the pseudo-second-order model pointing at chemisorption being the rate-limiting step. The adsorption isotherm data was best fitting with the Temkin model. The maximum adsorption capacity, calculated using the Langmuir model, was 255.8 mg g−1 (the maximum experimental value was 161.6 mg g−1). Additionally, the possibility of Cr(VI) adsorption in the presence of Cl, Br, NO3 and SO42− as interfering ions was shown. Full article
(This article belongs to the Special Issue Gels in Separation Science)
Show Figures

Figure 1

5 pages, 204 KB  
Editorial
Application of Graphene-Based Materials
by Marcelo Antunes
Nanomaterials 2023, 13(20), 2748; https://doi.org/10.3390/nano13202748 - 12 Oct 2023
Cited by 9 | Viewed by 2479
Abstract
This Topic on the “Application of Graphene-Based Materials”, which consists of a total of twenty-six articles, including two review articles, written by research groups of experts in the field, considers the most recent research and trends on the synthesis and characterization of graphene-based [...] Read more.
This Topic on the “Application of Graphene-Based Materials”, which consists of a total of twenty-six articles, including two review articles, written by research groups of experts in the field, considers the most recent research and trends on the synthesis and characterization of graphene-based materials, including nanohybrids, intended for a vast array of high-demanding technological applications, namely batteries/fuel cells, aerogels, laser technology, sensors, electronic/magnetic devices, catalysts, etc [...] Full article
(This article belongs to the Topic Application of Graphene-Based Materials)
16 pages, 8600 KB  
Article
Superhydrophobic, Magnetic Aerogels Based on Nanocellulose Fibers Derived from Harakeke for Oily Wastewater Remediation
by Yitong Zhai and Xiaowen Yuan
Polymers 2023, 15(19), 3941; https://doi.org/10.3390/polym15193941 - 29 Sep 2023
Cited by 9 | Viewed by 2960
Abstract
Cellulose-based aerogels have been seen as a promising sorbent for oil and organic pollutant cleaning; however, their intrinsic hydrophilicity and difficulty of recycling has hindered their practical application. In this work, a superhydrophobic, magnetic cellulose-based aerogel was fabricated as a highly efficient sorbent [...] Read more.
Cellulose-based aerogels have been seen as a promising sorbent for oil and organic pollutant cleaning; however, their intrinsic hydrophilicity and difficulty of recycling has hindered their practical application. In this work, a superhydrophobic, magnetic cellulose-based aerogel was fabricated as a highly efficient sorbent for the adsorption of oils and organic solvents. The aerogel was prepared via a simple freeze-drying method, followed by chemical vapor deposition (CVD). The incorporation of Fe3O4 nanoparticles into the aerogel not only makes it responsive to external magnetic field, but also contributes to the better hydrophobicity of the aerogel, in which the water contact angle (WCA) was about 20° higher than the aerogel without loading with Fe3O4 nanoparticles. The adsorption test showed that the resultant aerogel can selectively adsorb a wide range of oils and organic solvents from oil/water mixtures with a high adsorption capacity (up to 113.49 g/g for silicone oil). It can retain about 50% of its adsorption capacity even after 10 adsorption–squeezing cycles, which indicates its outstanding reusability. Moreover, the aerogels can be easily controlled by an external magnet, which is preferred for the adsorption of oily contaminants in harsh environments and enhanced the recyclability of the aerogel. We believe that this study provides a green and convenient approach for the practical fabrication of cellulose-based oil sorbents. Full article
(This article belongs to the Special Issue Advanced Preparation and Application of Cellulose)
Show Figures

Figure 1

21 pages, 11312 KB  
Review
A Review of Nitrogen-Doped Graphene Aerogel in Electromagnetic Wave Absorption
by Ze Wu, Xinke Yao and Youqiang Xing
Micromachines 2023, 14(9), 1762; https://doi.org/10.3390/mi14091762 - 12 Sep 2023
Cited by 15 | Viewed by 3695
Abstract
Graphene aerogels (GAs) possess a remarkable capability to absorb electromagnetic waves (EMWs) due to their favorable dielectric characteristics and unique porous structure. Nevertheless, the introduction of nitrogen atoms into graphene aerogels can result in improved impedance matching. In recent years, nitrogen-doped graphene aerogels [...] Read more.
Graphene aerogels (GAs) possess a remarkable capability to absorb electromagnetic waves (EMWs) due to their favorable dielectric characteristics and unique porous structure. Nevertheless, the introduction of nitrogen atoms into graphene aerogels can result in improved impedance matching. In recent years, nitrogen-doped graphene aerogels (NGAs) have emerged as promising materials, particularly when combined with magnetic metals, magnetic oxides, carbon nanotubes, and polymers, forming innovative composite systems with excellent multi-functional and broadband absorption properties. This paper provides a comprehensive summary of the synthesis methods and the EMW absorption mechanism of NGAs, along with an overview of the absorption properties of nitrogen-doped graphene-based aerogels. Furthermore, this study sheds light on the potential challenges that NGAs may encounter. By highlighting the substantial contribution of NGAs in the field of EMW absorption, this study aims to facilitate the innovative development of NGAs toward achieving broadband absorption, lightweight characteristics, and multifunctionality. Full article
Show Figures

Figure 1

17 pages, 3629 KB  
Article
Exploring the Conformational Equilibrium of Mefenamic Acid Released from Silica Aerogels via NMR Analysis
by Ilya Khodov, Valentina Sobornova, Valeriya Mulloyarova, Konstantin Belov, Alexey Dyshin, Luís Batista de Carvalho, Peter Tolstoy and Michael Kiselev
Int. J. Mol. Sci. 2023, 24(8), 6882; https://doi.org/10.3390/ijms24086882 - 7 Apr 2023
Cited by 17 | Viewed by 18300
Abstract
This study examines the influence of mefenamic acid on the physical and chemical properties of silica aerogels, as well as its effect on the sorption characteristics of the composite material. Solid state magic angle spinning nuclear magnetic resonance (MAS NMR) and high-pressure 13 [...] Read more.
This study examines the influence of mefenamic acid on the physical and chemical properties of silica aerogels, as well as its effect on the sorption characteristics of the composite material. Solid state magic angle spinning nuclear magnetic resonance (MAS NMR) and high-pressure 13C NMR kinetic studies were conducted to identify the presence of mefenamic acid and measure the kinetic rates of CO2 sorption. Additionally, a high-pressure T1–T2 relaxation-relaxation correlation spectroscopy (RRCOSY) study was conducted to estimate the relative amount of mefenamic acid in the aerogel’s pores, and a high-pressure nuclear Overhauser effect spectoscopy (NOESY) study was conducted to investigate the conformational preference of mefenamic acid released from the aerogel. The results indicate that mefenamic acid is affected by the chemical environment of the aerogel, altering the ratio of mefenamic acid conformers from 75% to 25% in its absence to 22% to 78% in the presence of aerogel. Full article
(This article belongs to the Special Issue Advances in NMR Spectroscopy for Bioactive Small Molecules)
Show Figures

Figure 1

Back to TopTop