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Evaluation of Morphological Effect on Thermal and Mechanical Performance of PS/PMMA/CdS Nanocomposite Systems 被引量:1
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作者 Vishal Mathur Kananbala Sharma 《Advances in Nanoparticles》 2013年第3期205-216,共12页
In the present paper an effort has been made to investigate effect of dispersion of CdS nanoparticles on the thermal and mechanical properties of PS/PMMA blends. Samples have been prepared through dispersion of CdS na... In the present paper an effort has been made to investigate effect of dispersion of CdS nanoparticles on the thermal and mechanical properties of PS/PMMA blends. Samples have been prepared through dispersion of CdS nanoparticles (prepared separately) during solution casting blend fabrication processing. These nanocomposites samples are structurally characterized through Wide angle X-ray Scattering (WAXS) and Small Angle X-ray Scattering (SAXS) techniques. Scanning Electron Microscopy (SEM) analyses of these samples have been carried out in lieu of surface morphological characterization. The measurements of glass transition temperature and stress-strain analyses have been performed through Dynamic Mechanical Analyzer (DMA). The thermal conductivity of nanocomposite samples has been determined using Hot Disk Thermal Constants Analyzer. The study shows that the incorporation of dispersed CdS nanoparticles in PS/PMMA blend matrix significantly alter their glass transition behaviour, thermal conductivity and tensile properties. 展开更多
关键词 THERMAL CONDUCTIVITY CDS nanocompositeS Glass Transition Temperature TENSILE Properties
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Sensing Behaviour of Some Nanocomposite Systems
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作者 Dipankar Chakravorty Bhola Nath Pal +3 位作者 Shilpi Banerjee Amrita Mandal Sreemanta Mitra Dhriti Ranjan Saha 《Soft Nanoscience Letters》 2013年第4期12-15,共4页
Silver nanoparticles of diameters 3.4 to 13.2 nm grown at the interfaces between silicate glass and some oxide crystallites exhibited about six orders of magnitude reduction in resistivity for a relative humidity chan... Silver nanoparticles of diameters 3.4 to 13.2 nm grown at the interfaces between silicate glass and some oxide crystallites exhibited about six orders of magnitude reduction in resistivity for a relative humidity change from 25% to 80%. Sn-SnO2 nano core-shell structure prepared within a gel-derived silica glass film by electrodeposition technique followed by heat treatment showed large change in resistivity as a function of humidity. The resistivity also changed due to gas flow of CO2, C2H5OH and NO2, respectively. The latter arose because of reduction/oxidation of Sn4+/Sn2+ species present at the shell layer of the nanostructures. Nickel nanosheets of thickness ~0.6 nm grown within the interlayer spaces of Na-4 mica crystallites showed a change of dielectric permittivity (5%) for an applied magnetic field of 1.2 Tesla. An inhomogeneous model was used to explain this behavior. Two dimensional CuO phase was grown within the channels of diameter ~5 nm of mesoporous SiO2 structure. A magnetodielectric (MD) parameter M.D. of 4.4% was obtained in this case. BaTiO3 nanoparticles of diameter ~25 nm having pores with diameter 10 nm showed multiferroic behavior which arose due to the presence of oxygen vacancies as a result of large surface area present. An M.D. parameter of 11% was found. Similarly mesoporous LiNbO3 of 10 nm diameter showed an M.D. parameter of ~4.5% at a magnetic field 1 Tesla. A giant magnetocapacitance effect with a value of 44% at 1.5 T was observed in nickel zinc ferrite (NZF) impregnated mesoporous silica. A magnetocapacitance of 51% at magnetic field 1.7 T was found in the case of nanocomposites comprising of iron ion containing silica based nanoglass and mesoporous silica. In the last two examples the behavior was explained on the basis of Catalan model of space-charge polarization with extracted values of magnetoresistance of the NZF and nanoglass phases being 58%. 展开更多
关键词 nanocomposites Na-4 MICA MESOPOROUS SILICA BaTiO3+LiNbO3 MAGNETO Dielectric Effect
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Dielectric spectroscopy characterization of Naþ ion-conducting polymer nanocomposite system PEO–PVP–NaIO_(4)–TiO_(2)
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作者 Georgi B.Hadjichristov Daniela G.Kovacheva +3 位作者 Yordan G.Marinov Daniela B.Karashanova Todor E.Vlakhov Nicola Scaramuzza 《Journal of Advanced Dielectrics》 2024年第1期59-73,共15页
We studied the effect of titanium dioxide(TiO_(2))nanoparticles(NPs)on dielectric behavior of Naþion-conducting salt-complexed polymer nanocomposite system formed from a binary polymer blend of poly(ethylene oxid... We studied the effect of titanium dioxide(TiO_(2))nanoparticles(NPs)on dielectric behavior of Naþion-conducting salt-complexed polymer nanocomposite system formed from a binary polymer blend of poly(ethylene oxide)(PEO)and polyvinyl pyrrolidone(PVP),with the addition of both sodium metaperiodate(NaIO_(4))at concentration 10 wt.%and TiO_(2) NPs of size10 nm,at concentrations 1,2,3,4 and 5 wt.%.Free standing nanocomposite PEO/PVP/NaIO_(4)/TiO_(2) films(150m)were characterized at room-temperature by analyzing their complex electrical impedance and dielectric spectra in the range 1 Hz–1 MHz.At the concentration of 3 wt.%of TiO_(2) NPs,both ion conductivity and dielectric permittivity of the PEO/PVP/NaIO_(4)/TiO_(2) ion-conducting dielectrics reach an enhancement by more than one order of magnitude as compared to nanoadditive-free case. 展开更多
关键词 Dielectric properties sodium-ion-polymer electrolyte systems titanium dioxide(TiO_(2))nanoparticles nanocompositeS KWW model
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Application of nanotechnology to dentistry:Impact of graphene nanocomposites on clinical air quality
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作者 Ruth Rodríguez Montaño Mario A Alarcón-Sánchez +2 位作者 Melissa Martínez Nieto Juan J Varela Hernández Sarah M LomelíMartínez 《World Journal of Clinical Cases》 SCIE 2025年第8期1-7,共7页
Concerns about air quality in dental clinics where aerosol generation during procedures poses significant health risks,have prompted investigations on advanced disinfection technologies.This editorial describes the st... Concerns about air quality in dental clinics where aerosol generation during procedures poses significant health risks,have prompted investigations on advanced disinfection technologies.This editorial describes the strengths and limitations of ventilation and aerosol control measures in dental offices,especially with respect to the use of graphene nanocomposites.The potential of graphene nanocomposites as an innovative solution to aerosol-associated health risks is examined in this review due to the unique properties of graphene(e.g.,high con-ductivity,mechanical strength,and antimicrobial activity).These properties have produced promising results in various fields,but the application of graphene in dentistry remains unexplored.The recent study by Ju et al which was published in World Journal of Clinical Cases evaluated the effectiveness of graphene-based air disinfection systems in dental clinics.The study demonstrated that graphene-based disinfection techniques produced significant reductions in suspended particulate matter and bacterial colony counts,when co-mpared with traditional methods.Despite these positive results,challenges such as material saturation,frequency of filter replacement,and associated costs must be addressed before widespread adoption of graphene-based disinfection techniques in clinical practice.Therefore,there is need for further research on material structure optimization,long-term safety evaluations,and broader clinical applications,in order to maximize their positive impact on public health. 展开更多
关键词 GRAPHENE nanocompositeS Antibacterial activity Biomedical applications Air disinfection
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Use of graphene nanocomposites for air disinfection in dental clinics:A game-changer in infection control
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作者 Chun-Han Cheng Wen-Rui Hao Tzu-Hurng Cheng 《World Journal of Clinical Cases》 SCIE 2025年第8期57-62,共6页
This manuscript features the promising findings of a study conducted by Ju et al,who used graphene nanocomposites for air disinfection in dental clinics.Their study demonstrated that,compared with conventional filters... This manuscript features the promising findings of a study conducted by Ju et al,who used graphene nanocomposites for air disinfection in dental clinics.Their study demonstrated that,compared with conventional filters,graphene nanocom-posites substantially improved air quality and reduced microbial contamination.This manuscript highlights the innovative application of graphene materials,emphasizing their potential to enhance dental clinic environments by minimizing secondary pollution.On the basis of the unique antimicrobial properties of gra-phene and the original study’s rigorous methodology,we recommend using gra-phene nanocomposites in clinical settings to control airborne infections. 展开更多
关键词 Graphene nanocomposites Air disinfection Dental clinics Antimicrobial properties Secondary pollution
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Innovative dispersion techniques of graphene nanoplatelets(GNPs)through mechanical stirring and ultrasonication:Impact on morphological,mechanical,and thermal properties of epoxy nanocomposites
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作者 Vasi Uddin Siddiqui S.M.Sapuan Mohd Roshdi Hassan 《Defence Technology(防务技术)》 2025年第1期13-25,共13页
Graphene nanoplatelets(GNPs)have attracted tremendous interest due to their unique properties and bonding capabilities.This study focuses on the effect of GNP dispersion on the mechanical,thermal,and morphological beh... Graphene nanoplatelets(GNPs)have attracted tremendous interest due to their unique properties and bonding capabilities.This study focuses on the effect of GNP dispersion on the mechanical,thermal,and morphological behavior of GNP/epoxy nanocomposites.This study aims to understand how the dispersion of GNPs affects the properties of epoxy nanocomposite and to identify the best dispersion approach for improving mechanical performance.A solvent mixing technique that includes mechanical stirring and ultrasonication was used for producing the nanocomposites.Fourier transform infrared spectroscopy was used to investigate the interaction between GNPs and the epoxy matrix.The measurements of density and moisture content were used to confirm that GNPs were successfully incorporated into the nanocomposite.The findings showed that GNPs are successfully dispersed in the epoxy matrix by combining mechanical stirring and ultrasonication in a single step,producing well-dispersed nanocomposites with improved mechanical properties.Particularly,the nanocomposites at a low GNP loading of 0.1 wt%,demonstrate superior mechanical strength,as shown by increased tensile properties,including improved Young's modulus(1.86 GPa),strength(57.31 MPa),and elongation at break(4.98).The nanocomposite with 0.25 wt%GNP loading performs better,according to the viscoelastic analysis and flexural properties(113.18 MPa).Except for the nanocomposite with a 0.5 wt%GNP loading,which has a higher thermal breakdown temperature,the thermal characteristics do not significantly alter.The effective dispersion of GNPs in the epoxy matrix and low agglomeration is confirmed by the morphological characterization.The findings help with filler selection and identifying the best dispersion approach,which improves mechanical performance.The effective integration of GNPs and their interaction with the epoxy matrix provides the doorway for additional investigation and the development of sophisticated nanocomposites.In fields like aerospace,automotive,and electronics where higher mechanical performance and functionality are required,GNPs'improved mechanical properties and successful dispersion present exciting potential. 展开更多
关键词 Graphene nanoplatelets Epoxy nanocomposites Mechanical properties Thermal properties Mechanical stirrer Sonication
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Synthesis,characterization and evaluation of polyacrylamide graft starch/clay nanocomposite hydrogel system for enhanced oil recovery 被引量:9
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作者 Rituraj Singh Vikas Mahto 《Petroleum Science》 SCIE CAS CSCD 2017年第4期765-779,共15页
In this paper the suitability of a graft polymer nanocomposite hydrogel system for enhanced oil recovery was examined using polyacrylamide graft starch/clay nanocomposite(a laboratory synthesized product) and chromium... In this paper the suitability of a graft polymer nanocomposite hydrogel system for enhanced oil recovery was examined using polyacrylamide graft starch/clay nanocomposite(a laboratory synthesized product) and chromium(III) acetate(crosslinker). X-ray diffraction analysis,Fourier transform infrared spectrometry analysis, field-emission scanning electron microscopy and transmission electron microscopy were carried out to reveal the laboratory synthesized product as a nanocomposite. The effects of various parameters like salt concentration, p H, temperature, polymer concentration and crosslinker concentration on the properties of the developed gel system were systematically evaluated.The thermal stability of the nanocomposite gel and the conventional gel system were also determined by thermogravimetric analysis. The graft polymer nanocomposite gel system exhibited acceptable gel strength, gelation time and gel stability compared with the conventional gel system. The nanocomposite gels prepared using a low crosslinker concentration showed higher gel strength and required longer gelation time than the conventional gel which is more desirable properties for the effective placement of gel during enhanced oil recovery operations. In addition, sand pack flooding experiments show that the graft polymer nanocomposite gels had better plugging capacity than the conventional gel systems under reservoir conditions. Hence, this gel system may be suitable in the water shutoff treatments required for enhanced oil recovery from oilfields. 展开更多
关键词 nanocomposite Graft polymer NANOCLAY HYDROGEL Water shutoff
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Site-selective oral delivery of therapeutic antibodies to the inflamed colon via a folic acid-grafted organic/inorganic hy brid nanocomposite system 被引量:2
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作者 Sang Hoon Lee Jae Geun Song Hyo-Kyung Han 《Acta Pharmaceutica Sinica B》 SCIE CAS CSCD 2022年第11期4249-4261,共13页
This study aimed to develop a pH-responsive folic acid-grafted organic/inorganic hybrid nanocomposite system for site-selective oral delivery of therapeutic antibodies. A folic acid-grafted aminoclay(FA-AC) was prepar... This study aimed to develop a pH-responsive folic acid-grafted organic/inorganic hybrid nanocomposite system for site-selective oral delivery of therapeutic antibodies. A folic acid-grafted aminoclay(FA-AC) was prepared via an in situ sol-gel method. Then, a drug-loaded nanocomplex was prepared via the electrostatic interaction of FA-AC with infliximab(IFX), a model antibody, and coated with Eudragit? S100(EFA-AC-IFX). FA-AC exhibited favorable profiles as a drug carrier including low cytotoxicity, good target selectivity, and capability to form a nanocomplex with negatively charged macromolecules. A pH-responsive FA-AC-based nanocomplex containing IFX(EFA-AC-IFX) was also obtained in a narrow size distribution with high entrapment efficiency(>87%). The conformational stability of IFX entrapped in EFA-AC-IFX was well maintained in the presence of proteolytic enzymes. EFA-ACIFX exhibited pH-dependent drug release, minimizing premature drug release in gastric conditions and the upper intestine. Accordingly, oral administration of EFA-AC-IFX to colitis-induced mice was effective in alleviating the progression of ulcerative colitis, while oral IFX solution had no efficacy. These results suggest that a pH-responsive FA-AC-based nanocomposite system can be a new platform for the site-selective oral delivery of therapeutic antibodies. 展开更多
关键词 INFLIXIMAB Aminoclay Colonic delivery:TNF-x Infammation Folate rceptor Anibody nanocomposite
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A Systematic Molecular Dynamics Investigation on the Graphene Polymer Nanocomposites for Bulletproofing 被引量:1
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作者 Hamidreza Noori Zi Goangseup +5 位作者 Bohayra Mortazavi Alessandro Di Pierro Emad Jomehzadeh Xiaoying Zhuang Kim Sang-Hyun Timon Rabczuk 《Computers, Materials & Continua》 SCIE EI 2020年第12期2009-2032,共24页
In modern physics and fabrication technology,simulation of projectile and target collision is vital to improve design in some critical applications,like;bulletproofing and medical applications.Graphene,the most promin... In modern physics and fabrication technology,simulation of projectile and target collision is vital to improve design in some critical applications,like;bulletproofing and medical applications.Graphene,the most prominent member of two dimensional materials presents ultrahigh tensile strength and stiffness.Moreover,polydimethylsiloxane(PDMS)is one of the most important elastomeric materials with a high extensive application area,ranging from medical,fabric,and interface material.In this work we considered graphene/PDMS structures to explore the bullet resistance of resulting nanocomposites.To this aim,extensive molecular dynamic simulations were carried out to identify the penetration of bullet through the graphene and PDMS composite structures.In this paper,we simulate the impact of a diamond bullet with different velocities on the composites made of single-or bi-layer graphene placed in different positions of PDMS polymers.The underlying mechanism concerning how the PDMS improves the resistance of graphene against impact loading is discussed.We discuss that with the same content of graphene,placing the graphene in between the PDMS result in enhanced bullet resistance.This work comparatively examines the enhancement in design of polymer nanocomposites to improve their bulletproofing response and the obtained results may serve as valuable guide for future experimental and theoretical studies. 展开更多
关键词 GRAPHENE nanocompositeS bulletproofing IMPACT PDMS
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Layered Potassium Titanium Niobate/Reduced Graphene Oxide Nanocomposite as a Potassium‑Ion Battery Anode 被引量:5
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作者 Charlie A.F.Nason Ajay Piriya Vijaya Kumar Saroja +3 位作者 Yi Lu Runzhe Wei Yupei Han Yang Xu 《Nano-Micro Letters》 SCIE EI CAS CSCD 2024年第1期1-16,共16页
With graphite currently leading as the most viable anode for potassium-ion batteries(KIBs),other materials have been left relatively underexamined.Transition metal oxides are among these,with many positive attributes ... With graphite currently leading as the most viable anode for potassium-ion batteries(KIBs),other materials have been left relatively underexamined.Transition metal oxides are among these,with many positive attributes such as synthetic maturity,longterm cycling stability and fast redox kinetics.Therefore,to address this research deficiency we report herein a layered potassium titanium niobate KTiNbO5(KTNO)and its rGO nanocomposite(KTNO/rGO)synthesised via solvothermal methods as a high-performance anode for KIBs.Through effective distribution across the electrically conductive rGO,the electrochemical performance of the KTNO nanoparticles was enhanced.The potassium storage performance of the KTNO/rGO was demonstrated by its first charge capacity of 128.1 mAh g^(−1) and reversible capacity of 97.5 mAh g^(−1) after 500 cycles at 20 mA g^(−1),retaining 76.1%of the initial capacity,with an exceptional rate performance of 54.2 mAh g^(−1)at 1 A g^(−1).Furthermore,to investigate the attributes of KTNO in-situ XRD was performed,indicating a low-strain material.Ex-situ X-ray photoelectron spectra further investigated the mechanism of charge storage,with the titanium showing greater redox reversibility than the niobium.This work suggests this lowstrain nature is a highly advantageous property and well worth regarding KTNO as a promising anode for future high-performance KIBs. 展开更多
关键词 Potassium-ion batteries INTERCALATION Transition metal oxides Anodes nanocomposite
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Lightweight Dual‑Functional Segregated Nanocomposite Foams for Integrated Infrared Stealth and Absorption‑Dominant Electromagnetic Interference Shielding 被引量:2
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作者 Zhonglei Ma Ruochu Jiang +8 位作者 Jiayao Jing Songlei Kang Li Ma Kefan Zhang Junxian Li Yu Zhang Jianbin Qin Shuhuan Yun Guangcheng Zhang 《Nano-Micro Letters》 SCIE EI CAS CSCD 2024年第11期38-55,共18页
Lightweight infrared stealth and absorption-dominant electromagnetic interference(EMI)shielding materials are highly desirable in areas of aerospace,weapons,military and wearable electronics.Herein,lightweight and hig... Lightweight infrared stealth and absorption-dominant electromagnetic interference(EMI)shielding materials are highly desirable in areas of aerospace,weapons,military and wearable electronics.Herein,lightweight and high-efficiency dual-functional segregated nanocomposite foams with microcellular structures are developed for integrated infrared stealth and absorption-dominant EMI shielding via the efficient and scalable supercritical CO_(2)(SC-CO_(2))foaming combined with hydrogen bonding assembly and compression molding strategy.The obtained lightweight segregated nanocomposite foams exhibit superior infrared stealth performances benefitting from the synergistic effect of highly effective thermal insulation and low infrared emissivity,and outstanding absorption-dominant EMI shielding performances attributed to the synchronous construction of microcellular structures and segregated structures.Particularly,the segregated nanocomposite foams present a large radiation temperature reduction of 70.2℃ at the object temperature of 100℃,and a significantly improved EM wave absorptivity/reflectivity(A/R)ratio of 2.15 at an ultralow Ti_(3)C_(2)T_(x) content of 1.7 vol%.Moreover,the segregated nanocomposite foams exhibit outstanding working reliability and stability upon dynamic compression cycles.The results demonstrate that the lightweight and high-efficiency dual-functional segregated nanocomposite foams have excellent potentials for infrared stealth and absorption-dominant EMI shielding applications in aerospace,weapons,military and wearable electronics. 展开更多
关键词 Segregated nanocomposite foams Microcellular structures Infrared stealth EMI shielding Low infrared emissivity
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A Generic Strategy to Create Mechanically Interlocked Nanocomposite/Hydrogel Hybrid Electrodes for Epidermal Electronics 被引量:2
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作者 Qian Wang Yanyan Li +7 位作者 Yong Lin Yuping Sun Chong Bai Haorun Guo Ting Fang Gaohua Hu Yanqing Lu Desheng Kong 《Nano-Micro Letters》 SCIE EI CAS CSCD 2024年第5期120-133,共14页
Stretchable electronics are crucial enablers for next-generation wearables intimately integrated into the human body.As the primary compliant conductors used in these devices,metallic nanostructure/elastomer composite... Stretchable electronics are crucial enablers for next-generation wearables intimately integrated into the human body.As the primary compliant conductors used in these devices,metallic nanostructure/elastomer composites often struggle to form conformal contact with the textured skin.Hybrid electrodes have been consequently developed based on conductive nanocomposite and soft hydrogels to establish seamless skin-device interfaces.However,chemical modifications are typically needed for reliable bonding,which can alter their original properties.To overcome this limitation,this study presents a facile fabrication approach for mechanically interlocked nanocomposite/hydrogel hybrid electrodes.In this physical process,soft microfoams are thermally laminated on silver nanowire nanocomposites as a porous interface,which forms an interpenetrating network with the hydrogel.The microfoam-enabled bonding strategy is generally compatible with various polymers.The resulting interlocked hybrids have a 28-fold improved interfacial toughness compared to directly stacked hybrids.These electrodes achieve firm attachment to the skin and low contact impedance using tissue-adhesive hydrogels.They have been successfully integrated into an epidermal sleeve to distinguish hand gestures by sensing mus-cle contractions.Interlocked nanocomposite/hydrogel hybrids reported here offer a promising platform to combine the benefits of both materials for epidermal devices and systems. 展开更多
关键词 Stretchable electronics Epidermal electronics Silver nanowire Conductive nanocomposites HYDROGEL
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Efficacy of graphene nanocomposites for air disinfection in dental clinics: A randomized controlled study 被引量:2
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作者 Ya-Qiong Ju Xiang-Hua Yu +3 位作者 Jing Wu Ying-Hui Hu Xiang-Yong Han Dan Fang 《World Journal of Clinical Cases》 SCIE 2024年第28期6173-6179,共7页
BACKGROUND Aerosols containing disease-causing microorganisms are produced during oral diagnosis and treatment can cause secondary contamination.AIM To investigate the use of graphene material for air disinfection in ... BACKGROUND Aerosols containing disease-causing microorganisms are produced during oral diagnosis and treatment can cause secondary contamination.AIM To investigate the use of graphene material for air disinfection in dental clinics by leveraging its adsorption and antibacterial properties.METHODS Patients who received ultrasonic cleaning at our hospital from April 2023 to April 2024.They were randomly assigned to three groups(n=20 each):Graphene nanocomposite material suction group(Group A),ordinary filter suction group(Group B),and no air suction device group(Group C).The air quality and air colony count in the clinic rooms were assessed before,during,and after the procedure.Additionally,bacterial colony counts were obtained from the air outlets of the suction devices and the filter screens in Groups A and B.RESULTS Before ultrasonic cleaning,no significant differences in air quality PM2.5 and colony counts were observed among the three groups.However,significant differences in air quality PM2.5 and colony counts were noted among the three groups during ultrasonic cleaning and after ultrasonic treatment.Additionally,the number of colonies on the exhaust port of the suction device and the surface of the filter were significantly lower in Group A than in Group B(P=0.000 and P=0.000,respectively).CONCLUSION Graphene nanocomposites can effectively sterilize the air in dental clinics by exerting their antimicrobial effects and may be used to reduce secondary pollution. 展开更多
关键词 GRAPHENE nanocompositeS Oral clinic Air disinfection Secondary contamination
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Synthesis of Catalytic Systems Based on Nanocomposites Containing Palladium and Hydroxycarbonates of Rare-Earth Elements
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作者 GALANTSEVA M. V. BUSLAEVA T. M. +2 位作者 PAKKANEN T. FOMICHEV V. V. MISCHIHINA E. A. 《贵金属》 CAS CSCD 北大核心 2012年第A01期76-78,共3页
The purpose of this work is to synthesize the catalytic systems containing palladium nanoparticles and using hydroxycarbonates of yttrium and cerium as supports,and to test the catalytic activity of the obtained catal... The purpose of this work is to synthesize the catalytic systems containing palladium nanoparticles and using hydroxycarbonates of yttrium and cerium as supports,and to test the catalytic activity of the obtained catalysts in the Suzuki cross-couping reaction.Nanocomposites Pd/Y(OH)CO 3 and Pd/Ce(OH)CO 3 were synthesized according to two methods:the first one-simultaneous production of nanoscale substrate and immobilization of palladium nanoparticles on its surface(nanocomposites 1),the second one-the prior synthesis of polyvinylpyrrolidone stabilized palladium nanoparticles followed by their immobilization on the nano sized substrate surface(nanocomposites 2).The reaction between phenylboronic acid and iodobenzene is chosen as a model one.The dependence of the catalytic activity of catalysts on the method of their synthesis was established.It was established that nanocomposites 2 exhibit higher catalytic activity in the selected reaction compared to the nanocomposites 1.The TOF values for the nanocomposites 1 are 6663~14617 h 1 when using the substrate Ce(OH)CO 3 and 13774~27084 h 1 when using the substrate Y(OH)CO 3,while the nanocomposites 2 reveal TOF = 87287 h 1 for the substrate Ce(OH)CO 3 and TOF = 97746 h 1 for the substrate Y(OH)CO 3 under other equal conditions.In addition,nanocomposites 2 "work" at room temperature giving a high yield of the desired product.It is noted that the support nanoparticles Y(OH)CO 3 and Ce(OH)CO 3 also exhibit catalytic activity.The yield of the final product of the reaction using them as catalysts is 55%(TOF = 11 and 8 h 1,respectively).Thus,the use of yttrium and cerium hydroxycarbonates as supports allows to decrease the palladium content in the nanocomposites to 0.01%~1% and,consequently,reduce the cost of the catalyst while maintaining its high catalytic activity. 展开更多
关键词 palladium nanoparticles support Y(OH)CO3 Ce(OH)CO3 nanocompositeS Suzuki reaction catalytic activity
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Solar Water Splitting by Semiconductor Nanocomposites and Hydrogen Storage with Quinoid Systems
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作者 Thorsten Wilke Daniela Schricker +1 位作者 Josefin Rolf Karl Kleinermanns 《Open Journal of Physical Chemistry》 2012年第4期195-203,共9页
Photocatalytic splitting of water was carried out in a two-phase system. The efficiencies of different types of nanocrystalline semiconductors were investigated and compared with commercialised TiO2 nanopowder. Genera... Photocatalytic splitting of water was carried out in a two-phase system. The efficiencies of different types of nanocrystalline semiconductors were investigated and compared with commercialised TiO2 nanopowder. Generated hydrogen was chemically stored by use of a quinoid system, which seems to be useable for fuel cells. Solar light sensitive nanocomposites of CdSe/TiO2 and CdSxSey/TiO2 type were prepared and their good photocatalytic performance was demonstrated. In the visible range of 400 - 600 nm CdSxSey/TiO2 composites show comparable good results as in the UV range, which is very promising for their use as solar light water splitters. The concept of sensitising TiO2 with different kind of semiconductor nanoparticles, which is already known from quantum dot sensitised solar cells (QDSC), was demonstrated here for water splitting as well. Furthermore the kinetics of the storage reaction was investigated by UV-Vis spectroscopy and found to proceed via a consecutive reaction with an 1:1 charge transfer complex of quinone and hydroquinone as intermediate. The electron transfer process via a Fe2+/Fe3+ redox couple was investigated by UV-Vis spectroscopy as well as by a dye reaction on the TiO2 surface. A light microscopic view of the surface of larger aggregates of TiO2 nanoparticles indicated different areas of photocatalytic activity with photocatalysis preferentially at catalyst edges. The global electron transfer process could be traced by following the dye colour in real time. 展开更多
关键词 Water SPLITTING nanocompositeS CADMIUM Selenosulphide Titanium dioxide Hydrogen Storage
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Cu-doped nanocomposite Pr_(2)Fe_(14)B/α-Fe ribbons with high(BH)max
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作者 Mehran Khan Alam Shahzab Raza +2 位作者 Chengyong Gao Guangbing Han Shishou Kang 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第12期422-429,共8页
The melt-spun ribbons of nominal composition Pr_(9)Fe_(84.2-x)B_(6.2)P_(0.3)Zr_(0.3)Cu_(x)(x=0,0.5,1,2)were prepared at wheel speeds of 21 m·s^(-1),27 m·s^(-1),30 m·s^(-1),and 33 m·s^(-1).The XRD p... The melt-spun ribbons of nominal composition Pr_(9)Fe_(84.2-x)B_(6.2)P_(0.3)Zr_(0.3)Cu_(x)(x=0,0.5,1,2)were prepared at wheel speeds of 21 m·s^(-1),27 m·s^(-1),30 m·s^(-1),and 33 m·s^(-1).The XRD patterns show that as the wheel speed increases,the crystallinity of the 2:14:1 hard phase decreases,while that of theα-Fe soft phase increases.The(BH)_(max),remanence,and coercivity are improved from 63 kJ·m^(-3),0.85 T,and 515 kA·m^(-1)for the Cu-free ribbons to 171 kJ·m^(-3),1.08 T,and684 kA·m^(-1)with x=0.5.The high squareness ratio of J_(r)/J_(s)~0.82 at 0.5 at.%Cu(27 m·s^(-1))indicates strong exchange coupling due to small grain sizes of 15 nm and 30 nm for soft and hard magnetic phases,respectively.The SEM images revealed smooth morphology and uniform element distribution at 0.5 at.%Cu(27 m·s^(-1)),contributing to the high magnetic properties.The low recoil permeability(μrec)value of 5.466×10^(-4)T/kA·m^(-1)to 1.970×10^(-4)T/kA·m^(-1)confirms the strong exchange coupling with x=0.5(27m·s^(-1)).The initial magnetization curves show that the coercivity mechanism of the Cu-free alloy evolves from the nucleation of the reverse domain to the domain wall pinning as the wheel speed increases,resulting in a high coercivity value of 818 kA·m^(-1)(33 m·s^(-1)).Conversely,for the Cu-added alloy,the coercivity mechanism changes from pinning to the nucleation of the reverse domain from low to high wheel speed. 展开更多
关键词 Cu addition nanocomposite magnetic properties energy product REMANENCE
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Using Electrodeposition of Carboxylated Chitosan for Green Preparation of Copper Nanoclusters and Nanocomposite Films
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作者 ZHANG Xiaoli LI Tingxue +4 位作者 WANG Qinghua YANG Yan ZHANG Chenyu LIU Yaning WANG Yifeng 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS CSCD 2024年第6期1348-1357,共10页
On the basis of coordinated electrodeposition of carboxylated chitosan(CCS),we presented a green method to prepare Cu NCs and Cu NCs/CCS nanocomposite films.The method shows a range of benefits,such as the convenient ... On the basis of coordinated electrodeposition of carboxylated chitosan(CCS),we presented a green method to prepare Cu NCs and Cu NCs/CCS nanocomposite films.The method shows a range of benefits,such as the convenient and eco-friendly process,mild conditions,and simple post-treatment.The experimental results reveal that a homogeneous deposited film(Cu NCs/CCS nanocomposite film)is generated on the Cu plate(the anode)after electrodeposition,which exhibits an obvious red florescence.The results from TEM observation suggest there are nanoparticles(with the average particle size of 2.3 nm)in the deposited film.Spectral analysis results both demonstrate the existence of Cu NCs in the deposited film.Moreover,the Cu NCs/CCS film modified electrode is directly created through electrodeposition of CCS,which enables promising application in the electrochemical sensing.By means of fluorescence properties of Cu NCs,the Cu NCs/CCS film also owns the potential in fluorescence detection.Therefore,this work builds a novel method for the green synthesis of Cu NCs,meanwhile it offers a convenient and new electrodeposition strategy to prepare polysaccharide-based Cu NCs nanocomposites for uses in functional nanocomposites and bioelectronic devices. 展开更多
关键词 nanocomposite films copper nanoclusters ELECTRODEPOSITION carboxylated chitosan POLYSACCHARIDES
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Mechanochemical synthesis of Ag/TiO_(2)@PANI nanocomposites for enhanced toluene photocatalytic degradation under near-ultraviolet light
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作者 Qiulian Zhu Binghao Wang +3 位作者 Ying Mo Shengfan Liao Yinfei Chen Hanfeng Lu 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2024年第11期222-229,共8页
Photocatalytic oxidation technology is a promising green technology for degrading volatile organic compounds(VOCs)due to its non-toxic,environmentally friendly,energy-saving and affordable characteristics.In this pape... Photocatalytic oxidation technology is a promising green technology for degrading volatile organic compounds(VOCs)due to its non-toxic,environmentally friendly,energy-saving and affordable characteristics.In this paper,Ag/TiO_(2)@PANI-MC with high stability and activity was synthesized by the mechanochemical method.The designed Ag/TiO_(2)@PANI-MC were of high specific surface area,light absorption capacity and low recombination rate of electronehole pairs,which was demonstrated by various characterizations.When applied in photocatalytic toluene oxidation,the conversion is 17%at 20℃under 100 W high-pressure mercury lamp.This photocatalytic performance is with less temperature sensitivity and significantly improved compared with Ag/TiO_(2)or TiO_(2)catalysts.Furthermore,the reaction routine was also confirmed by gas chromatography-mass spectrometry and toluene was mineralized to CO_(2).More importantly,the Ag/TiO_(2)@PANI-MC indicated good reusability after three cycles,which was verified by the Fourier transform-infrared spectroscopy comparison with fresh and used catalysts.Our work proves a potential way of constructing nanocomposites based on mechanochemical synthesis for enhanced toluene photocatalytic degradation. 展开更多
关键词 TOLUENE Photocatalytic degradation Mechanochemical synthesis nanocomposite
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Predicting the Mechanical Behavior of a Bioinspired Nanocomposite through Machine Learning
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作者 Xingzi Yang Wei Gao +1 位作者 Xiaodu Wang Xiaowei Zeng 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第8期1299-1313,共15页
The bioinspired nacre or bone structure represents a remarkable example of tough,strong,lightweight,and multifunctional structures in biological materials that can be an inspiration to design bioinspired high-performa... The bioinspired nacre or bone structure represents a remarkable example of tough,strong,lightweight,and multifunctional structures in biological materials that can be an inspiration to design bioinspired high-performance materials.The bioinspired structure consists of hard grains and soft material interfaces.While the material interface has a very low volume percentage,its property has the ability to determine the bulk material response.Machine learning technology nowadays is widely used in material science.A machine learning model was utilized to predict the material response based on the material interface properties in a bioinspired nanocomposite.This model was trained on a comprehensive dataset of material response and interface properties,allowing it to make accurate predictions.The results of this study demonstrate the efficiency and high accuracy of the machine learning model.The successful application of machine learning into the material property prediction process has the potential to greatly enhance both the efficiency and accuracy of the material design process. 展开更多
关键词 Bioinspired nanocomposite computational model machine learning finite element material interface
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Enhancing Defect-Induced Dipole Polarization Strategy of SiC@MoO_(3)Nanocomposite Towards Electromagnetic Wave Absorption
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作者 Ting Wang Wenxin Zhao +8 位作者 Yukun Miao Anguo Cui Chuanhui Gao Chang Wang Liying Yuan Zhongning Tian Alan Meng Zhenjiang Li Meng Zhang 《Nano-Micro Letters》 SCIE EI CAS CSCD 2024年第12期406-426,共21页
Defect engineering in transition metal oxides semiconductors(TMOs)is attracting considerable interest due to its potential to enhance conductivity by intentionally introducing defects that modulate the electronic stru... Defect engineering in transition metal oxides semiconductors(TMOs)is attracting considerable interest due to its potential to enhance conductivity by intentionally introducing defects that modulate the electronic structures of the materials.However,achieving a comprehensive understanding of the relationship between micro-structures and electromagnetic wave absorption capabilities remains elusive,posing a substantial challenge to the advancement of TMOs absorbers.The current research describes a process for the deposition of a MoO_(3)layer onto SiC nanowires,achieved via electro-deposition followed by high-temperature calcination.Subsequently,intentional creation of oxygen vacancies within the MoO_(3)layer was carried out,facilitating the precise adjustment of electromagnetic properties to enhance the microwave absorption performance of the material.Remarkably,the SiC@MO-t4 sample exhibited an excellent minimum reflection loss of-50.49 dB at a matching thickness of 1.27 mm.Furthermore,the SiC@MO-t6 sample exhibited an effective absorption bandwidth of 8.72 GHz with a thickness of 2.81 mm,comprehensively covering the entire Ku band.These results not only highlight the pivotal role of defect engineering in the nuanced adjustment of electromagnetic properties but also provide valuable insight for the application of defect engineering methods in broadening the spectrum of electromagnetic wave absor ption effectiveness.SiC@MO-t samples with varying concentrations of oxygen vacancies were prepared through in-situ etching of the SiC@MoO_(3)nanocomposite.The presence of oxygen vacancies plays a crucial role in adjusting the band gap and local electron distribution,which in turn enhances conductivity loss and induced polarization loss capacity.This finding reveals a novel strategy for improving the absorption properties of electromagnetic waves through defect engineering. 展开更多
关键词 Defect engineering Oxygen vacancies SiC@MoO_(3)nanocomposite Electromagnetic wave absorption Induced dipole polarization
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