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Controlled surface modification of poly(methyl methacrylate) film by fluoroalkyl end-capped vinyltrimethoxysilane oligomeric silica/hexagonal boron nitride nanocomposites
摘要： Fluoroalkyl end-capped vinyltrimethoxysilane oligomer [RF-(CH2CHSi(OMe)3)n-RF; n = 2, 3; RF = CF(CF3)OC3F7] undergoes sol–gel reactions in the presence of hexagonal boron nitride (h-BN) nanoparticles under alkaline or acidic conditions at room temperature to afford the corresponding fluorinated oligomeric silica/h-BN nanocomposites in good isolated yields (≥ 80%), respectively. The fluorinated oligomeric silica/h-BN nanocomposites thus obtained were found to exhibit a good dispersibility toward the traditional organic media including water. These two kinds of fluorinated nanocomposites were applied to the surface modification of poly(methyl methacrylate) (PMMA). The fluorinated nanocomposites prepared under alkaline conditions can give not only a good oleophobic characteristic imparted by longer fluoroalkyl groups in the composites but also the higher fluorescent emission related to the presence of h-BN on the only surface side of the modified PMMA film. In contrast, the fluorinated nanocomposites prepared under acidic conditions can provide a good oleophobic characteristic and a higher fluorescent emission on both the surface and even on the reverse side of the PMMA film. Such unique controlled surface modification ability will be discussed by 29Si solid-state NMR spectra of these two types of the nanocomposites.
关键词： Surface arrangement ability,Fluorescent ability,Oleophobicity,Hexagonal boron nitride,Surface modification,Fluorinated oligomeric nanocomposite,PMMA
更新于2025-09-16 10:30:52
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Enhanced Visible Light Photodegradation of Microplastic Fragments with Plasmonic Platinum/Zinc Oxide Nanorod Photocatalysts
摘要： Microplastics are persistent anthropogenic pollutants which have become a global concern owing to their widespread existence and unfamiliar threats to the environment and living organisms. This study demonstrates the degradation of fragmented microplastics particularly low-density polyethylene (LDPE) film in water, through visible light-induced plasmonic photocatalysts comprising of platinum nanoparticles deposited on zinc oxide (ZnO) nanorods (ZnO-Pt). The ZnO-Pt nanocomposite photocatalysts were observed to have better degradation kinetics for a model organic dye (methylene blue) compared to bare ZnO nanorods, attributed to the plasmonic effects leading to better interfacial exciton separation and improved hydroxyl radical activity along with a 78% increase in visible light absorption. These demonstrations of the plasmonically enhanced photocatalyst enabled it to effectively degrade microplastic fragments as confirmed following the changes in carbonyl and vinyl indices in infrared absorption. In addition, visual proof of physical surface damage of the LDPE film establishes the efficacy of using plasmonically enhanced nanocomposite photocatalytic materials to tackle the microplastic menace using just sunlight for a clean and green approach towards mitigation of microplastics in the ecosystem.
关键词： microplastics,platinum nanoparticle,ZnO nanorod,LDPE film,visible light photodegradation,nanocomposite
更新于2025-09-16 10:30:52
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Synthesis of N-doped TiO <sub/>2</sub> /SiO <sub/>2</sub> /Fe <sub/>3</sub> O <sub/>4</sub> magnetic nanocomposites as a novel purple LED illumination-driven photocatalyst for photocatalytic and photoelectrocatalytic degradation of naproxen: optimization and different scavenger agents study
摘要： N-doped TiO2/SiO2/Fe3O4 as a new magnetic photocatalyst that is active in visible light has been prepared by simple sol–gel method. The prepared samples were characterized by XRD, FESEM, EDX, TEM, BET, BJH, VSM, XPS, FT-IR, and DRS–UV/Vis analysis. The photocatalytic effect of synthesized samples on naproxen degradation was studied. The operational parameters were optimized through central composite design to achieve maximum efficiency. The optimum values for maximum efficiency were obtained at pH of 4.29, catalyst mass of 0.06 g, naproxen concentration of 9.33 mg L(cid:1)1, and irradiation time of 217.06 min. At these optimum conditions, the maximum photocatalytic degradation percentages of naproxen were found to be 96.32% at desirability function value of 1.0. Coupling the electrical current with the photocatalytic process proved that the electrical current was considerably efficient in decreasing the degradation time of removing the naproxen from aqueous solutions. The photocatalytic activity of the nanoparticles was also studied under sunlight. Considering the results provided by UV–Vis spectrophotometry and total organic carbon, it was found that the prepared samples are extraordinarily efficient to degrade naproxen under both purple LED and solar lights. Furthermore, the effect of different scavenger agents on naproxen degradation has been studied.
关键词： pharmaceutical compound,experimental design,Photodegradation,core–shell nanocomposite,titanium dioxide
更新于2025-09-16 10:30:52
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A new nanocomposite optical sensor based on polyurethane foam and gold nanorods for solid-phase spectroscopic determination of catecholamines
摘要： A new nanocomposite material based on gold nanorods and polyurethane foam was obtained, and a method for the determination of catecholamines with the use of this nanocomposite modified with silver nitrate was developed. The determination is based on the measuring hypsochromic shift of a short-wave surface plasmon resonance band in a diffuse reflection spectrum of the nanocomposite. This shift is caused by reduction of silver from silver ions on the surface of gold nanorods under the influence of catecholamines. Effects of time, pH, volume of the reaction mixture, concentration of silver ions, and catecholamines on the interaction were examined. The proposed method allows to determine dobutamine, epinephrine, norepinephrine and dopamine with the detection limits of 0.1, 0.07, 0.07, and 0.05 μg mL?1, respectively. The developed method can be applied to analysis of medicines.
关键词： Nanocomposite,Au nanorods,Surface plasmon resonance,Polyurethane foam,Catecholamines,Solid-phase spectroscopy
更新于2025-09-12 10:27:22
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A review of fundamental principles and applications of polymer nanocomposites filled with both nanoclay and nano-sized carbon allotropes – Graphene and carbon nanotubes
摘要： Advancements in polymer/nanoclay nanocomposites have supported the development of distinctive preparation strategies and characteristic features. High-performance polymer/nanoclay nanocomposites have applications in aerospace, automotive, construction, environmental, and biomedicine. To further improve polymer/nanoclay nanocomposite performance, nanoclay nanobifillers have been considered. In this regard, nano-sized carbon allotropes are potential contenders to form nanoclay nano-bifillers. This article presents a detailed and state-of-the-art review on polymer/nanoclay nanobifiller nanocomposites. The primary focus of this pioneering effort is to deliver an up-to-date overview on polymer/nanoclay nanobifiller nanocomposites along with their categorization, fabrication, properties, and uses. Nanoclay nanobifiller designs using carbon nanotube, graphene, and fullerene are considered. Consequently, ensuing nanocomposite categories are discussed including polymer/nanoclay-carbon nanotube, polymer/nanoclay-graphene, and polymer/nanoclay-fullerene nanocomposites. The dispersion properties and alignment of nanoclay nanobifiller in polymeric nanocomposites have been investigated. Enhancing the interfacial bonding strength between matrix and nanoclay nanobifiller enhances the resulting nanocomposite physical properties. Application areas for polymer/nanoclay nanobifiller nanocomposites include supercapacitors, non-flammable materials, and self-healing materials. The discussion also highlights potential future directions for this emerging research field. Forthcoming advancements in polymer/nanoclay nanobifiller nanocomposites must focus the intensive design control, nanobifiller functionality, new processing techniques, superior dispersion, and enhanced features to further broaden the application prospects of these materials.
关键词： nanoclay,nanocomposite,nanobifiller,Polymer,non-flammable
更新于2025-09-12 10:27:22
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AIP Conference Proceedings [AIP Publishing PROCEEDINGS OF THE INTERNATIONAL CONFERENCE ON ADVANCED MATERIALS: ICAM 2019 - Kerala, India (12–14 June 2019)] PROCEEDINGS OF THE INTERNATIONAL CONFERENCE ON ADVANCED MATERIALS: ICAM 2019 - Study of plasmonic effect in Cu2ZnSnS4-Ag nanocomposite thin film fabricated by vacuum thermal co-evaporation
摘要： CZTS-Ag nanocomposite thin films were fabricated by co-evaporating CZTS in the form of pellet and Ag powder as source materials simultaneously using vacuum thermal co-evaporator. The weight percentage of Ag to CZTS is increased from 2 to 4%. The as-prepared nanocomposite films were post annealed at 500 °C for 1 hour in a vacuum tubular furnace. The crystal structure of the as-prepared and annealed samples is analyzed by x-ray diffraction. Chemical structure of the prepared films is studied using confocal Raman spectroscopy with an excitation wavelength of 785 nm which depicts the mixed phase formation of SnS and CZTS. The observed blue shift in absorption edge in CZTS as well as broadened absorption in the entire visible region in Ag based CZTS nanocomposite could be due to the effect from Ag nanoparticles, verifying the strong existence of surface plasmon resonance in the visible region.
关键词： surface plasmon resonance,Raman spectroscopy,optical absorption,vacuum thermal co-evaporation,CZTS-Ag nanocomposite
更新于2025-09-12 10:27:22
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Polyoxometalate‐derived multi‐component X/W2C@X, N‐C (X=Co, Si, Ge, B and P) nanoelectrocatalysts for efficient triiodide reduction in dye‐sensitized solar cells
摘要： A series of multi-component X/W2C@X,N-C hybrid catalysts have been prepared to systematically investigate the electro-catalytic activity of triiodide reduction in DSSCs. Different components in catalyst promote photovoltaic performance by synergistic effect. The electronegativity of dopants can directly influence the catalytic activity of catalysts.
关键词： nanocomposite,dye-sensitized solar cells,counter electrode,tungsten carbide,polyoxometalate
更新于2025-09-12 10:27:22
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Enhanced photoelectrochemical performance of NaNbO3 nanofibers photoanode coupled with visible-light active g-C3N4 nanosheets for water splitting
摘要： Sodium niobate nanofibers (NaNbO3-NF) have been synthesized by hydrothermal technique and further coupled with visible light responsive graphitic carbon nitride (g-C3N4) nanosheets in the different concentration ratio of 2:1 (2-CN), 4:1 (4-CN) and 8:1 (8-CN). A significant improvement in the photoelectrochemical (PEC) performance of g-C3N4/NaNbO3-NF (4-CN) nanostructured photoanode as compared to bare NaNbO3 photoanode is observed. A current density of 12.55 mA cm?2 at 1 V with respect to Ag/AgCl reference electrode is achieved for g-C3N4/NaNbO3-NF (4-CN) photoanode which is ~3 times higher than the NaNbO3-NF photoanode. Also, as compared to NaNbO3-NF, g-C3N4/NaNbO3-NF (4-CN) nanocomposite photoanode showed ~3 times improvement in the incident photon-to-current conversion efficiency. The improvement in the PEC performance of visible light active g-C3N4/NaNbO3-NF (4-CN) nanocomposite is attributed to the improved photoresponse of NaNbO3-NF due to the coupling of g-C3N4 and formation of type-II heterojunction between them leading to the enhanced separation of the photogenerated charge carriers. A possible reaction mechanism for the improved photoelectrochemical water splitting performance has been proposed for g-C3N4/NaNbO3-NF (4-CN) photoanode.
关键词： Photoelectrode,Nanocomposite,Heterojunction,g-C3N4/NaNbO3-NF,PEC Water Splitting
更新于2025-09-12 10:27:22
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Influence of polymer molecular weight on the properties of in situ synthesized silver–methylcellulose nanocomposite films with a CO2 laser
摘要： We investigate the in?uence of polymer molecular weight on the properties of silver–methylcellulose (Ag–MC) nanocomposite ?lms synthesized by the irradiation of a CO2 laser. Although the reduction power of MC with a smaller molecular weight turns out to be stronger than that with a larger molecular weight in the solution phase, we do not see such a clear difference when MC is in the matrix phase. For the 30 s irradiation at the laser power of 0.8 W, the size of Ag nanoparticles (NPs) in the two types of MC matrix is similar, and it is about 30 nm. However, for the longer irradiation time at the same laser power, aggregation of Ag NPs set in, and it is more serious for the Ag–MC ?lm with MC of larger molecular weight. We also carry out the antibacterial test with the Ag–MC ?lms, and ?nd that the Ag–MC ?lm synthesized at the lower laser power and shorter irradiation time generally exhibits a stronger antibacterial effect.
关键词： antibacterial effect,polymer molecular weight,CO2 laser,silver–methylcellulose nanocomposite
更新于2025-09-12 10:27:22
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Surface Plasmon Resonance Sensor Based on D-Shaped Optical Fiber Using Fiberbench Rotating Wave Plate for Sensing Pb Ions
摘要： In this paper, a D-shaped optical fiber is presented in terms of sensor application using FiberBench rotating wave plate. The designed sensor was adopted to detect plumbum ions in aqueous medium using surface plasmon resonance (SPR). The fiber-based SPR sensor was designed using a bilayer sensor chip. The polished area of the D-shaped optical fiber was coated by reduced graphene-based maghemite nanocomposite+1-ethyl-3-(3-dimethylaminopropyl)-carbodiimidehydrochloride/N-hydroxysuccinimide as a sensing layer. The transmission response curves were investigated according to the wavelength and intensity shifts at different concentrations. By incorporating the sensing layer, Pb2+ can be easily detected by wavelength and intensity interrogation methods. The sensor exhibited a recognizable intensity shift at 0.3 ppb Pb ion concentration. The limit of detection due to wavelength shift was 1 ppm. The sensitivity of the Pb ion concentration was 0.116 nm/ppm, and the accuracy was 19.1×10?4. FiberBench rotating wave plate was used to control the depth and the width of the transmission curve using SPR. The outcome of the developed sensor revealed a high accuracy, high sensitivity, and real-time sensor in a static water environment.
关键词： Plumbum ion,nanocomposite,reduced graphene,FiberBench,SPR,polarization controller,D-shaped optical fiber
更新于2025-09-12 10:27:22