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Preparation of Supermacroporous Composite Cryogel Embedded with SiO_2 Nanoparticles 被引量:4
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作者 许潘萍 姚雨辰 +2 位作者 沈绍传 贠军贤 姚克俭 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2010年第4期667-671,共5页
Supermacroporous composite cryogels embedded with SiO2 nanoparticles were prepared by radical cryogenic copolymerization of the reactive monomer mixture of acrylamide(AAm) and N,N-methylene-bis-acrylamide(MBAAm) c... Supermacroporous composite cryogels embedded with SiO2 nanoparticles were prepared by radical cryogenic copolymerization of the reactive monomer mixture of acrylamide(AAm) and N,N-methylene-bis-acrylamide(MBAAm) containing SiO2 nanoparticles(mass ratios of nanoparticles to the monomer AAm from 0.01 to 0.08) under the freezing-temperature variation condition in glass columns.The properties of these composite cryogels were measured.The height equivalent to theoretical plate(HETP) of the cryogel beds at different liquid flow rates was determined by residence time distribution(RTD) using tracer pulse-response method.The composite cryogel matrix embedded with the mass fraction of SiO2 nanoparticles of 0.02 presented the best properties and was employed in the following graft polymerization.Chromatographic process of lysozyme in the composite cryogel grafted with 2-acrylamido-2-methyl-1-propanesulfonic acid(AMPSA) was carried out to evaluate the protein breakthrough and elution characteristics.The chromatography can be carried out at relatively high superficial velocity,i.e.,15 cm·min-1,indicating the satisfactory mechanical strength due to the embedded nanoparticles. 展开更多
关键词 composite cryogel SiO2 nanoparticle protein chromatography
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Biosensor Based on TTF@SiO_2 Nanoparticles as Electron Transfer Mediator for the Determination of Glucose 被引量:1
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作者 LI Xiao-hua XIAN Yue-zhong MIN Hong LI Chen-xin XIE Zong-hong ZHANG Fen-fen JIN Li-tong 《Chemical Research in Chinese Universities》 SCIE CAS CSCD 2006年第4期474-478,共5页
Tetrathiafulvalene(TTF) was doped in an SiO2 network and the resulting nanocompesite was used as a mediator for the selective detection of glucose. The uniform TTF-doped silica(TIT@SiO2 ) nanoparticles were prepar... Tetrathiafulvalene(TTF) was doped in an SiO2 network and the resulting nanocompesite was used as a mediator for the selective detection of glucose. The uniform TTF-doped silica(TIT@SiO2 ) nanoparticles were prepared by the water-in-oil(W/O) microemulsion method, and were characterized by transmission electron microscopy(TEM). The core-shell structure TTF@ SiO2 could prevent TIT from leaching out into an aqueous solution. Combined with chitosan (CHIT), which serves as a scaffold for glucose oxidase and nanocomposite immobilization, the GCE/TTF@ SiO2- CHIT-GOx biosensor was developed. Under optimal conditions, the biosensors exhibit a linear range of 1.0 × 10^-5 5 × 10^-3 mol/L with a detection limit down to 5.0 μmol/L(S/N = 3 ). The excellent selectivity, sensitivity, and stability of the glucose biosensor show its potential for practical applications. 展开更多
关键词 TTF@ SiO2 nanoparticle CHITOSAN GLUCOSE BIOSENSOR
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Porous silica nano-flowers stabilized Pt-Pd bimetallic nanoparticles as heterogeneous catalyst for efficiently synthesizing guaiacol from 2-methoxycyclohexanol
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作者 Junbo Feng Junyan Wu +1 位作者 Dongdong Yan Yadong Zhang 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2024年第6期222-233,共12页
Porous silica nano-flowers(KCC-1)immobilized Pt-Pd alloy NPs(Pt-Pd/KCC-1)with different mass ratios of Pd and Pt were successfully prepared by a facile in situ one-step reduction,using hydrazinium hydroxide as a reduc... Porous silica nano-flowers(KCC-1)immobilized Pt-Pd alloy NPs(Pt-Pd/KCC-1)with different mass ratios of Pd and Pt were successfully prepared by a facile in situ one-step reduction,using hydrazinium hydroxide as a reducing agent.The as-synthesized silica nanospheres possess radial fibers with a distance of 15 nm,exhibiting a high specific surface area(443.56 m^(2)·g^(-1)).Meanwhile,the obtained Pt-Pd alloy NPs are uniformly dispersed on the silica surface with a metallic particle size of 4-6 nm,which exist as metallic Pd and Pt on the surface of monodisperse KCC-1,showing the transfer of electrons from Pd to Pt.The as-synthesized 2.5%Pt-2.5%Pd/KCC-1 exhibited excellent catalytic activity and stability for the continuous dehydrogenation of 2-methoxycyclohexanol to prepare guaiacol.Compared with Pt or Pd single metal supported catalysts,the obtained 2.5%Pt-2.5%Pd/KCC-1 shows 97.2%conversion rate of 2-methoxycyclohexanol and 76.8%selectivity for guaiacol,which attributed to the significant synergistic effect of bimetallic Pt-Pd alloy NPs.Furthermore,turn over frequency value of the obtained 2.5%Pt-2.5%Pd/KCC-1 NPs achieved 4.36 s^(-1),showing higher catalytic efficiency than other two monometallic catalysts.Reaction pathways of dehydro-aromatization of 2-methoxycyclohexanol over the obtained catalyst are proposed.Consequently,the obtained 2.5%Pt-2.5%Pd/KCC-1 NPs prove their potential in the dehydrogenation of 2-methoxycyclohexanol,while the kinetics and mechanistic study of the dehydrogenation reaction over the catalyst in a continuous fixed-bed reactor may provide valuable information for the development of green,outstanding and powerful synthetic pathway of guaiacol. 展开更多
关键词 Supported catalyst nanoparticles Dehydrogenation 2-Methoxycyclohexanol GUAIACOL
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Selective CO_(2)Electroreduction to Multi-Carbon Products on Organic-Functionalized CuO Nanoparticles by Local Micro-Environment Modulation
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作者 Shan Ren Xi Cao +5 位作者 Qikui Fan Zhimao Yang Fei Wang Xin Wang Licheng Bai Jian Yang 《Nano-Micro Letters》 SCIE EI CAS CSCD 2024年第12期120-132,共13页
Surface functionalization of Cu-based catalysts has demonstrated promising potential for enhancing the electrochemical CO_(2)reduction reaction(CO_(2)RR)toward multi-carbon(C2+)products,primarily by suppressing the pa... Surface functionalization of Cu-based catalysts has demonstrated promising potential for enhancing the electrochemical CO_(2)reduction reaction(CO_(2)RR)toward multi-carbon(C2+)products,primarily by suppressing the parasitic hydrogen evolution reaction and facilitating a localized CO_(2)/CO concentration at the electrode.Building upon this approach,we developed surface-functionalized catalysts with exceptional activity and selectivity for electrocatalytic CO_(2)RR to C_(2+)in a neutral electrolyte.Employing CuO nanoparticles coated with hexaethynylbenzene organic molecules(HEB-CuO NPs),a remarkable C_(2+)Faradaic efficiency of nearly 90%was achieved at an unprecedented current density of 300 mA cm^(-2),and a high FE(>80%)was maintained at a wide range of current densities(100-600 mA cm^(-2))in neutral environments using a flow cell.Furthermore,in a membrane electrode assembly(MEA)electrolyzer,86.14%FEC2+was achieved at a partial current density of 387.6 mA cm^(-2)while maintaining continuous operation for over 50 h at a current density of 200 mA cm^(-2).In-situ spectroscopy studies and molecular dynamics simulations reveal that reducing the coverage of coordinated K⋅H2O water increased the probability of intermediate reactants(CO)interacting with the surface,thereby promoting efficient C-C coupling and enhancing the yield of C_(2+)products.This advancement offers significant potential for optimizing local micro-environments for sustainable and highly efficient C_(2+)production. 展开更多
关键词 CO_(2)electroreduction to C_(2+) Neutral electrolyte Organic-functionalized CuO nanoparticles Local micro-environment
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Improvement of the piezoelectricity of PVDF-HFP by CoFe_(2)O_(4)nanoparticles
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作者 Dan Lei Ning Hu +5 位作者 Liangke Wu Alamusi Huiming Ning Yang Wang Zhaonan Jin Yaolu Liu 《Nano Materials Science》 EI CAS CSCD 2024年第2期201-210,共10页
High piezoelectric composite films composed of poly(vinylidene fluoride-co-hexafluoropropylene)(PVDF-HFP)and ferromagnetic cobalt ferrite(CoFe_(2)O_(4))(0.00 wt%to 0.2 wt%)are prepared by a solution casting method acc... High piezoelectric composite films composed of poly(vinylidene fluoride-co-hexafluoropropylene)(PVDF-HFP)and ferromagnetic cobalt ferrite(CoFe_(2)O_(4))(0.00 wt%to 0.2 wt%)are prepared by a solution casting method accompanied by uniaxial stretching and high electric field poling.The decisive effect of the poling electric field on the power generating capability was confirmed by the experiments.For pure PVDF-HFP films,when the maximum electric field Emax is 120 MV/m,the calibrated open circuit voltage reaches 2.93 V,which is much higher than those poled at lower electric fields(70 MV/m:1.41 V;90 MV/m:2.11 V).Furthermore,the addition of CoFe_(2)O_(4)also influences the piezoelectricity dramatically.In the samples containing 0.15 wt%CoFe_(2)O_(4),the calibrated open circuit voltage increases to the maximum value of 3.57 V.Meanwhile,the relative fraction of theβ-phase and the crystallinity degree are 99%and 48%,respectively.The effects of CoFe_(2)O_(4)nanoparticles on initial crystallization,uniaxial stretching and high electric field poling are investigated by XRD,FTIR and DSC. 展开更多
关键词 PVDF-HFP CoFe_(2)O_(4)nanoparticles PIEZOELECTRICITY NANOCOMPOSITE
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The Capture and Catalytic Conversion of CO_(2) by Dendritic Mesoporous Silica-Based Nanoparticles
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作者 Yabin Wang Liangzhu Huang +2 位作者 Songwei Li Chuntai Liu Hua He 《Energy & Environmental Materials》 SCIE EI CAS CSCD 2024年第2期126-151,共26页
Dendritic mesoporous silica nanoparticles own three-dimensional center-radial channels and hierarchical pores,which endows themselves with super-high specific surface area,extremely large pore volumes,especially acces... Dendritic mesoporous silica nanoparticles own three-dimensional center-radial channels and hierarchical pores,which endows themselves with super-high specific surface area,extremely large pore volumes,especially accessible internal spaces,and so forth.Dissimilar guest species(such as organic groups or metal nanoparticles)could be readily decorated onto the interfaces of the channels and pores,realizing the functionalization of dendritic mesoporous silica nanoparticles for targeted applications.As adsorbents and catalysts,dendritic mesoporous silica nanoparticles-based materials have experienced nonignorable development in CO_(2)capture and catalytic conversion.This comprehensive review provides a critical survey on this pregnant subject,summarizing the designed construction of novel dendritic mesoporous silica nanoparticles-based materials,the involved chemical reactions(such as CO_(2)methanation,dry reforming of CH_(4)),the value-added chemicals from CO_(2)(such as cyclic carbonates,2-oxazolidinones,quinazoline-2,4(1H,3H)-diones),and so on.The adsorptive and catalytic performances have been compared with traditional silica mesoporous materials(such as SBA-15 or MCM-41),and the corresponding reaction mechanisms have been thoroughly revealed.It is sincerely expected that the in-depth discussion could give materials scientists certain inspiration to design brand-new dendritic mesoporous silica nanoparticles-based materials with superior capabilities towards CO_(2)capture,utilization,and storage. 展开更多
关键词 catalytic conversion CO_(2)adsorption CO_(2)capture dendritic mesoporous silica nanoparticles
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Functionalized selenium nanoparticles ameliorated acetaminophen-induced hepatotoxicity through synergistically triggering PKCδ/Nrf2 signaling pathway and inhibiting CYP 2E1
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作者 Si Zou Yetao Gong +4 位作者 Xiujie Li Yanbin Wu Jinzhong Wu Jianguo Wu Ka-Hing Wong 《Food Science and Human Wellness》 SCIE CSCD 2024年第2期932-945,共14页
Selenium nanoparticles(SeNPs)have been demonstrated potential for use in diseases associated with oxidative stress.Functionalized SeNPs with lower toxicity and higher biocompatibility could bring better therapeutic ac... Selenium nanoparticles(SeNPs)have been demonstrated potential for use in diseases associated with oxidative stress.Functionalized SeNPs with lower toxicity and higher biocompatibility could bring better therapeutic activity and clinical application value.Herein,this work was conducted to investigate the protective effect of Pleurotus tuber-regium polysaccharide-protein complex funtionnalized SeNPs(PTR-SeNPs)against acetaminophen(APAP)-induced oxidative injure in HepG2 cells and C57BL/6J mouse liver.Further elucidation of the underlying molecular mechanism,in particular their modulation of Nrf2 signaling pathway was also performed.The results showed that PTR-SeNPs could significantly ameliorate APAP-induced oxidative injury as evidenced by a range of biochemical analysis,histopathological examination and immunoblotting study.PTR-SeNPs could hosphorylate and activate PKCδ,depress Keap1,and increase nuclear accumulation of Nrf2,resulting in upregulation of GCLC,GCLM,HO-1 and NQO-1 expression.Besides,PTR-SeNPs suppressed the biotransformation of APAP to generate intracellular ROS through CYP 2E1 inhibition,restoring the mitochondrial morphology.Furthermore,the protective effect of PTR-SeNPs against APAP induced hepatotoxicity was weakened as Nrf2 was depleted in vivo,indicating the pivotal role of Nrf2 signaling pathway in PTR-SeNPs mediated hepatoprotective efficacy.Being a potential hepatic protectant,PTR-SeNPs could serve as a new source of selenium supplement for health-promoting and biomedical applications. 展开更多
关键词 PTR-SeNPs(polysaccharide-proteincomplex functionalized selenium nanoparticles) Acetaminophen-induced hepatotoxicity Nuclear factor erythroid 2-related factor 2 Cytochrome P450 enzyme 2E1 Mitochondria
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Experimental investigation of the effects of oil asphaltene content on CO_(2) foam stability in the presence of nanoparticles and sodium dodecyl sulfate
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作者 SADEGHI Hossein KHAZ'ALI Ali Reza MOHAMMADI Mohsen 《Petroleum Exploration and Development》 SCIE 2024年第1期239-250,共12页
Foam stability tests were performed using sodium dodecyl sulfate(SDS)surfactant and SiO2 nanoparticles as foaming system at different asphaltene concentrations,and the half-life of CO_(2) foam was measured.The mechani... Foam stability tests were performed using sodium dodecyl sulfate(SDS)surfactant and SiO2 nanoparticles as foaming system at different asphaltene concentrations,and the half-life of CO_(2) foam was measured.The mechanism of foam stability reduction in the presence of asphaltene was analyzed by scanning electron microscope(SEM),UV adsorption spectrophotometric concentration measurement and Zeta potential measurement.When the mass ratio of synthetic oil to foam-formation suspension was 1:9 and the asphaltene mass fraction increased from 0 to 15%,the half-life of SDS-stabilized foams decreased from 751 s to 239 s,and the half-life of SDS/silica-stabilized foams decreased from 912 s to 298 s.When the mass ratio of synthetic oil to foam-formation suspension was 2:8 and the asphaltene mass fraction increased from 0 to 15%,the half-life of SDS-stabilized foams decreased from 526 s to 171 s,and the half-life of SDS/silica-stabilized foams decreased from 660 s to 205 s.In addition,due to asphaltene-SDS/silica interaction in the aqueous phase,the absolute value of Zeta potential decreases,and the surface charges of particles reduce,leading to the reduction of repulsive forces between two interfaces of thin liquid film,which in turn,damages the foam stability. 展开更多
关键词 CO_(2)foam foam stability ASPHALTENE silica nanoparticle sodium dodecyl sulfate(SDS) repulsive forces surface charges Zeta potential
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基于瞬态平面热源法测定SiO_2气凝胶导热系数的试验
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作者 戴健彪 桂晓丽 《科技视界》 2024年第3期63-65,共3页
阐述基于瞬态平面热源法的Hot Disk热常数分析仪的测试原理,利用测试标准304不锈钢对仪器准确性及重复性进行了验证,同时研究了不同孔隙率SiO_2气凝胶的导热系数随温度和压力变化的特点。结果表明:Hot Disk热常数分析仪在测试SiO_2气凝... 阐述基于瞬态平面热源法的Hot Disk热常数分析仪的测试原理,利用测试标准304不锈钢对仪器准确性及重复性进行了验证,同时研究了不同孔隙率SiO_2气凝胶的导热系数随温度和压力变化的特点。结果表明:Hot Disk热常数分析仪在测试SiO_2气凝胶导热系数方面具有优异的准确性和重复性;在相同的温度和压力下,SiO_2气凝胶的导热系数随着孔隙率增大而变小;当环境压力小于5×10~3 Pa时,导热系数随环境压力改变而变化不明显,当环境压力大于5×10~3 Pa,导热系数随环境压力升高而变化较大;当环境温度在100~500℃范围内,SiO_2气凝胶的导热系数随环境温度升高而略微变大,当环境温度继续升高时,导热系数随环境温度升高而迅速增大。 展开更多
关键词 瞬态平面热源法 孔隙率 SiO_2气凝胶 导热系数
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Synthesis of Ultraviolet Absorber Benzotriazole by Nanoparticles Ag/SiO_2 Catalytic Hydrogenation 被引量:1
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作者 祁刚 张文国 戴勇 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2012年第12期1810-1814,共5页
The Ag/SiO2 nanoparticles had been successfully synthesized. The Ag/SiO2 nano- particles can be an excellent catalyst for the synthesis of ultraviolet absorber benzotriazole by catalytic hydrogenation. The synthesis r... The Ag/SiO2 nanoparticles had been successfully synthesized. The Ag/SiO2 nano- particles can be an excellent catalyst for the synthesis of ultraviolet absorber benzotriazole by catalytic hydrogenation. The synthesis route is very efficient with less pollution and excellent yields. It is also easy to industrialized production. 展开更多
关键词 Ag/SiO2 nanoparticles CATALYST BENZOTRIAZOLE
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PREPARATION OF POLYSTYRENE/SiO_2 COMPOSITE NANOPARTICLES BEARING SULFONIC GROUPS ON THE SURFACE VIA EMULSION COPOLYMERIZATION USING A POLYMERIZABLE EMULSIFIER
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作者 于建 《Chinese Journal of Polymer Science》 SCIE CAS CSCD 2009年第5期629-637,共9页
Functionalized PS/SiO_2 composite nanoparticles bearing sulfonic groups on the surface were successfully synthesized via emulsion copolymerization using a polymerizable emulsifierαolefin solfonate(AOS).As demonstrate... Functionalized PS/SiO_2 composite nanoparticles bearing sulfonic groups on the surface were successfully synthesized via emulsion copolymerization using a polymerizable emulsifierαolefin solfonate(AOS).As demonstrated by transmission electron microscopy and atomic force microscopy,well-defined core-shell PS/SiO_2 composite nanoparticles with a diameter of 50 nm were obtained.Sulfonic groups introduced onto the surface of the composite nanoparticles were quantified by FTIR,and can be controlled to some exten... 展开更多
关键词 PS/SiO_2 composite nanoparticles Polymerizable emulsifier Core-shell structure Sulfonic functionalization.
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Rationally designed hollow carbon nanospheres decorated with S,P co-doped NiSe_(2) nanoparticles for high-performance potassium-ion and lithium-ion batteries 被引量:3
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作者 Jiajia Ye Zizhong Chen +4 位作者 Zhiqiang Zheng Zhanghua Fu Guanghao Gong Guang Xia Cheng Hu 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2023年第3期401-411,I0011,共12页
Hollow nanostructures with external shells and inner voids have been proved to greatly shorten the transport distance of ions/electrons and buffer volume change,especially for the large-sized potassium-ions in seconda... Hollow nanostructures with external shells and inner voids have been proved to greatly shorten the transport distance of ions/electrons and buffer volume change,especially for the large-sized potassium-ions in secondary batteries.In this work,hollow carbon(HC) nanospheres embedded with S,P co-doped NiSe_(2)nanoparticles are fabricated by "drop and dry" and "dissolving and precipitation" processes to form Ni(OH)2nanocrystals followed by annealing with S and P dopants to form nanoparticles.The resultant S,P-NiSe_(2)/HC composite exhibits excellent cyclic performance with 131.6 mA h g^(-1)at1000 mA g^(-1)after 3000 cycles for K^(+)storage and a capacity of 417.1 mA h g^(-1)at 1000 mA g^(-1)after1000 cycles for Li^(+)storage.K-ion full cells are assembled and deliver superior cycling stability with a ca pacity of 72.5 mA h g^(-1)at 200 mA g^(-1)after 500 cycles.The hollow carbon shell with excellent electrical conductivity effectively promotes the transporta tion and tolerates large volume variation for both K^(+)and Li^(+).Density functional theory calculations confirm that the S and P co-doping NiSe_(2) enables stronger adsorption of K^(+)ions and higher electrical conductivity that contributes to the improved electrochemical performance. 展开更多
关键词 S P co-doping NiSe_(2)nanoparticles Hollow carbon nanospheres Potassium-ion batteries Lithium-ion batteries
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Double spatial confinement on ruthenium nanoparticles inside carbon frameworks as durable catalysts for a quasi-solid-state Li–O_(2) battery 被引量:2
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作者 Meiling Wang Ying Yao +5 位作者 Feiyang Yang Zhenwu Tang Jingjie Ren Cunzhong Zhang Feng Wu Xiangke Wang 《Carbon Energy》 SCIE CSCD 2023年第8期114-125,共12页
The rational design of large-area exposure,nonagglomeration,and longrange dispersion of metal nanoparticles(NPs)in the catalysts is critical for the development of energy storage and conversion systems.Little attentio... The rational design of large-area exposure,nonagglomeration,and longrange dispersion of metal nanoparticles(NPs)in the catalysts is critical for the development of energy storage and conversion systems.Little attention has been focused on modulating and developing catalyst interface contact engineering between a carbon substrate and dispersed metal.Here,a highly dispersed ultrafine ruthenium(Ru)NP strategy by double spatial confinement is proposed,that is,incorporating directed growth of metal–organic framework crystals into a bacterial cellulose templating substrate to integrate their respective merits as an excellent electrocatalytic cathode catalyst for a quasi-solid-state Li–O_(2) battery.The porous carbon matrix with highly dispersed ultrafine Ru NPs is well designed and used as cathode catalysts in a Li–O_(2) battery,demonstrating a high discharge areal capacity of 6.82 mAh cm^(–2) at 0.02 mA cm^(–2),a high-rate capability of 4.93 mAh cm^(–2) at 0.2 mA cm^(–2),and stable discharge/charge cycling for up to 500 cycles(2000 h)with low overpotentials of~1.4 V.This fundamental understanding of the structure–performance relationship demonstrates a new and promising approach to optimize highly efficient cathode catalysts for solid-state Li–O_(2) batteries. 展开更多
关键词 bacterial cellulose cathode materials metal-organic frameworks Ru nanoparticles solid-state Li-O_(2)batteries
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Multiple effects of polydopamine nanoparticles on Cu^(2+)-mediated Alzheimer's β-amyloid aggregation 被引量:1
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作者 Xueqing Chen Weiqun Gao +1 位作者 Yan Sun Xiaoyan Dong 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2023年第2期144-152,共9页
Deposition of β-amyloid protein(Aβ) is the main hallmark of Alzheimer's disease(AD), and it has been well recognized that Cu^(2+)-mediated Aβ aggregation plays a crucial role in AD pathological processes.Cu^(2+... Deposition of β-amyloid protein(Aβ) is the main hallmark of Alzheimer's disease(AD), and it has been well recognized that Cu^(2+)-mediated Aβ aggregation plays a crucial role in AD pathological processes.Cu^(2+)binding to Aβ can promote the production of reactive oxygen species(ROS) through Fenton-like reactions and produce more toxic Aβ-Cu^(2+)species under Cu^(2+)stimulation. Thus, the development of nanomaterials that can inhibit Cu^(2+)-mediated Aβ aggregation and degrade Aβ-Cu^(2+)complexes is considered an effective strategy for the prevention and treatment of AD. In this study, polydopamine nanoparticles(PDA NPs) were prepared and the results reveal that PDA NPs potently inhibit Cu^(2+)-mediated Aβaggregation and effectively reduce the formation of Aβ-Cu^(2+)complexes. In vitro experiments show that PDA NPs efficiently eliminate ROS generation catalyzed by Cu^(2+)or Aβ-Cu^(2+)complexes, thus rescuing cultured cells by reducing intracellular ROS levels. More importantly, PDA NPs can depolymerize Aβ-Cu^(2+)complexes, and the degradation of Aβ-Cu^(2+)complexes is promoted by near-infrared light irradiation due to their high photothermal conversion ability. In vivo studies reveal that PDA NPs significantly reduce the deposition of Aβ plaques in the presence of Cu^(2+)and extend the lifespan of AD nematodes from 11 to 14 d. Thus, the PDA NPs developed herein are multifunctional against Cu^(2+)-mediated Aβ aggregation for the potential prevention and treatment of AD. 展开更多
关键词 Protein AGGREGATION nanoparticles Photothermal therapy Reactive oxygen species Cu^(2+)chelator
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Calculation of photon attenuation coefficient and dose rate in concrete with the addition of SiO_2 and MnFe_2O_4 nanoparticles using MCNPX code and comparison with experimental results
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作者 M.Hassanzadeh S.M.Sadat Kiai 《Nuclear Science and Techniques》 SCIE CAS CSCD 2018年第11期152-158,共7页
One of the most important safety features of nuclear facilities is the shielding material used to protect the operating personnel from radiation exposure. The most common materials used in radiation shielding are conc... One of the most important safety features of nuclear facilities is the shielding material used to protect the operating personnel from radiation exposure. The most common materials used in radiation shielding are concretes. In this study, a Monte Carlo N-Particle eXtended code is used to calculate the gamma-ray attenuation coefficients and dose rates for a new concrete material composed of MnFe_2O_4 nanoparticles, which is then compared with the theoretical and experimental results obtained for a SiO_2 nanoparticle concrete material. According to the results, the average relative differences between the simulations and the theoretical and experimental results for the linear attenuation coefficient(l) in the SiO_2 nanoparticle materials are 6.4% and 5.5%, respectively. By increasing the SiO_2 content up to 1.5% and the temperature of MnFe_2O_4 up to 673 K, l is increased for all energies. In addition, the photon dose rate decreases up to 9.2% and3.7% for MnFe_2O_4 and SiO_2 for gamma-ray energies of0.511 and 1.274 MeV, respectively. Therefore, it was concluded that the addition of SiO_2 and MnFe_2O_4 nanoparticles to concrete improves its nuclear properties and could lead to it being more useful in radiation shielding. 展开更多
关键词 SHIELDING Radiation CONCRETE Attenuation COEFFICIENT Photon DOSE MCNPX code SiO2 and MnFe2O4 nanoparticles
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Fluorometric enzyme immunosensing system based on natural product resveratrol for horseradish peroxidase and Ag/SiO_2 nanoparticles
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作者 GONG FuChun, CAO Zhong, TAN ShuZhen, TAN YaFei & HE XiaoChun College of Chemistry and Environmental Engineering, Changsha University of Science and Technology, Changsha 410076, China 《Science China Chemistry》 SCIE EI CAS 2008年第3期233-240,共8页
The properties of resveratrol (3′, 4′, 5-trihydroxystlbene, RST) were for the first time evaluated as a potential substrate for horseradish peroxidase (HRP)-catalyzed fluorogenic reaction. The properties of RST for ... The properties of resveratrol (3′, 4′, 5-trihydroxystlbene, RST) were for the first time evaluated as a potential substrate for horseradish peroxidase (HRP)-catalyzed fluorogenic reaction. The properties of RST for use as fluorogenic substrates for HRP and its application in immunoassays were compared with commercially available substrates such as p-hydroxyphenylpropionic acid (pHPPA), chavicol and Amplex red by a fluoroimmunosensing method in the use of Schistosomia japonicum antibody (SjAb) as a model analyte. The fluoroimmunosensing device was constructed by dispersing Schistosomia japonicum antigen (SjAg), nano-Ag/SiO2 particles and sol-gel at low temperature. In pH 5.8 Britton-Robinson buffer (B-R), HRP-SjAb conjugates can catalyze the polymerization reaction of RST by H2O2 forming fluorescent dimmers. The increase of the fluorescence intensity of the dimmers product at emission of 462 nm (excitation: 315 nm) is proportional to the concentration of HRP-SjAb binding to the SjAg entrapped in the nano-Ag/SiO2 particles-sol-gel matrix. A competitive binding assay has been used to determine SjAb in rabbit serum with the aid of SjAb labeled with HRP. Substrate RST showed comparable ability for HRP detection and its enzyme-linked immunosensing reaction system, in a linear detection ranging of 1.5×10-6-7.3×10-4 g/L and with a detection limit of 1.5×10-6 g/L. The immobilized biocomposites surface could be regenerated by simply polishing with an alumina paper, with an excellent reproducibility (RSD = 4.7%). The proposed method has been successfully used for analysis of the rabbit serum sample with satisfactory results. 展开更多
关键词 RESVERATROL HRP FLUOROGENIC substrate Ag/SiO2 nanoparticles enzyme-linked IMMUNOSENSING Schistosomia JAPONICUM
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Silicon dioxide nanoparticles inhibit the effects of cold exposure on metabolism and inflammatory responses in brown adipocytes
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作者 Yongqiang Zhang Li Zhang +4 位作者 Shuai Wu Guanyu Zhang Xiaodie Wei Xi Li Danfeng Yang 《Frigid Zone Medicine》 2023年第2期97-104,共8页
Objective:Nanoparticles(NPs)in haze are potentially hazardous to health,which is more severe in the winter.Brown adipose tissue(BAT)plays important roles in obesity,insulin resistance,and diabetes.Though the toxicolog... Objective:Nanoparticles(NPs)in haze are potentially hazardous to health,which is more severe in the winter.Brown adipose tissue(BAT)plays important roles in obesity,insulin resistance,and diabetes.Though the toxicology of NPs has been intensively studied,few studies have been reported on the antagonistic effects between Silicon dioxide(SiO_(2))NPs and cold exposure in brown adipocytes.Materials and methods:We evaluated changes by quantitative real-time reverse-transcriptase polymerase chain reaction(qRT-PCR)on metabolism genes,plasticity genes and the inflammatory responses genes in brown adipocytes in vitro.Results:The expression of adipogenic genes PRDM16,Dio2,PGC-1αand UCP1 was upregulated upon cold exposure(P<0.05),but downregulated by SiO_(2) NPs(P<0.05).The results demonstrated that there was antagonistic effect between SiO_(2) NPs and cold exposure on the plasticity genes and metabolism genes in brown adipocytes,where the main effects of SiO_(2) NPs or cold exposure on the plasticity genes and metabolism genes were significant(P<0.05).Moreover,the levels of interleukin(IL)-1β,IL-6 and tumor necrosis factor(TNF)-αwere upregulated by SiO_(2) NPs or cold exposure(P<0.05).The factorial analysis indicated that there was also antagonistic effect between SiO_(2) NPs and cold exposure on the toxic effects in brown adipocytes,in which the main effects of cold exposure and/or SiO_(2) NPs on the toxic effects were significant(P<0.05).Conclusion:SiO_(2) NPs inhibit the effect of cold exposure on metabolic genes and inflammatory responses genes in brown adipocytes. 展开更多
关键词 SiO_(2)nanoparticles cold exposure METABOLIC inflammatory response brown adipocytes
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Effects of highly dispersed Ni nanoparticles on the hydrogen storage performance of MgH_(2)
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作者 Nuo Xu Zirui Yuan +4 位作者 Zhihong Ma Xinli Guo Yunfeng Zhu Yongjin Zou Yao Zhang 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2023年第1期54-62,共9页
MgH_(2)with a large hydrogen capacity is regarded as a promising hydrogen storage material.However,it still suffers from high thermal stability and sluggish kinetics.In this paper,highly dispersed nano-Ni has been suc... MgH_(2)with a large hydrogen capacity is regarded as a promising hydrogen storage material.However,it still suffers from high thermal stability and sluggish kinetics.In this paper,highly dispersed nano-Ni has been successfully prepared by using the polyol reduction method with an average size of 2.14 nm,which significantly improves the de/rehydrogenation properties of MgH_(2).The MgH_(2)–10wt%nano-Ni sample starts releasing H_(2)at 497 K,and roughly 6.2wt%H_(2)has been liberated at 583 K.The rehydrogenation kinetics of the sample are also greatly improved,and the adsorption capacity reaches 5.3wt%H_(2)in 1000 s at 482 K and under 3 MPa hydrogen pressure.Moreover,the activation energies of de/rehydrogenation of the MgH_(2)–10wt%nano-Ni sample are reduced to(88±2)and(87±1)kJ·mol−1,respectively.In addition,the thermal stability of the MgH_(2)–10wt%nano-Ni system is reduced by 5.5 kJ per mol H_(2)from that of pristine MgH_(2).This finding indicates that nano-Ni significantly improves both the thermodynamic and kinetic performances of the de/rehydrogenation of MgH_(2),serving as a bi-functional additive of both reagent and catalyst. 展开更多
关键词 Ni nanoparticle KINETICS THERMODYNAMICS MgH2 hydrogen storage performance
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Performance of Rhodamine-Sensitized Solar Cells Fabricated with Silver Nanoparticles
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作者 Bandana Ranamagar Isaac Abiye +2 位作者 Himsheela Karki Yucheng Lan Fasil Abebe 《Advances in Nanoparticles》 CAS 2023年第2期68-79,共12页
A plasmonic effect of silver nanoparticles (AgNPs) in dye-sensitized solar cells (DSSCs) is studied. In this investigation, the efficiency of dye-sensitized solar cells has been remarkably increased by infusion of syn... A plasmonic effect of silver nanoparticles (AgNPs) in dye-sensitized solar cells (DSSCs) is studied. In this investigation, the efficiency of dye-sensitized solar cells has been remarkably increased by infusion of synthesized silver nanoparticles into the TiO<sub>2</sub> photoanode. Rhodaminederivative RdS1 was synthesized by microwave-assisted condensation of hydrazide and 3-for-mylchromone. The synthesized silver nanoparticles were characterized with UV/Vis absorption spectroscopy and transmission electron microscopy. The interfacial charge transport phenomena of the dye-sensitized solar cell (DSSCs) are determined by electrochemical impedance spectroscopy and the corresponding efficiencies are calculated using current-voltage (I-V) curve. The solar cell photoanode with silver nanoparticles infused with RdS1 in titanium dioxide had the highest solar-to-electric power efficiency at 0.17%. 展开更多
关键词 TiO2 Silver nanoparticles RHODAMINE Optical Dye-Sensitized Solar Cell
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Green Synthesis of Titanium Oxide Nanoparticles Using Natural Extracts
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作者 Maribel Santiago Daniela Rivera Agustín Torres 《Journal of Materials Science and Chemical Engineering》 CAS 2023年第2期29-40,共12页
Green synthesis is an alternative method for obtaining nanoparticles for environmentally friendly purposes. The present work describes the synthesis and characterization of titanium oxide nanoparticles, starting from ... Green synthesis is an alternative method for obtaining nanoparticles for environmentally friendly purposes. The present work describes the synthesis and characterization of titanium oxide nanoparticles, starting from three natural sources: orange peel, hibiscus rosa sinensis and Aloe vera. Titanium (IV) tetrabutoxide in ethanol solution was used as precursor. The methodology used was based on the sol-gel technique, through which TiO<sub>2</sub> nanoparticles were obtained in the anatase phase. The characterization of the nanoparticles was carried out by means of x-ray diffraction (XRD), scanning electron microscopy (SEM) and infrared spectrophotometry (FTIR), which allowed the identification of a good degree of purity and crystallinity of the samples obtained. 展开更多
关键词 TiO2 nanoparticles Green Synthesis Sol-Gel Methodology Natural Sources
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