Steady TiO2 water-sol was prepared by peptization and the effects of pH value, temperature, concentration of colloid and peptizator on sol were investigated. Laser grain analyzer was used to verify nano-particles in t...Steady TiO2 water-sol was prepared by peptization and the effects of pH value, temperature, concentration of colloid and peptizator on sol were investigated. Laser grain analyzer was used to verify nano-particles in the sol. The photocatalytic degradation ratio and antibacterial property of nano-Ag/TiO2 thin-film on ceramics were used as the main index in addition to XRD analysis. The effect of film layers, embedding Ag+, annealing temperature and time on the degradation ratio and antibacterial property was studied. The temperature 30-80 ℃, pH 1.2-2.0, concentrations of 0.05-0.3 mol/L sol and 5% HNO3 would be the optimal parameters for the TiO2 water-sol preparation. The nano-Ag/TiO2 film of three layers with 3% AgNO3 embedded and treated at 350 ℃ for 2 h exhibits good performance. The elementary research on the kinetics of degradation shows that the reactions are on the first order kinetics equation.展开更多
光催化灭活是公认的控制病原微生物最具前景手段之一。本文以尿素和硫代巴比妥酸为起始原料,通过热聚合反应制备S掺杂g-C_(3)N_(4)(SCN),随后采用光还原法将Ag纳米粒负载于SCN表面获得新颖的可见光响应型Ag/SCN抗菌材料。对所制备纳米...光催化灭活是公认的控制病原微生物最具前景手段之一。本文以尿素和硫代巴比妥酸为起始原料,通过热聚合反应制备S掺杂g-C_(3)N_(4)(SCN),随后采用光还原法将Ag纳米粒负载于SCN表面获得新颖的可见光响应型Ag/SCN抗菌材料。对所制备纳米材料进行XRD、SEM、TEM、XPS及UV-Vis DRS表征,并深入探讨其在可见光下灭活大肠杆菌(E.coli)的性能和机制。结果表明,Ag纳米粒均匀且牢固地负载在SCN表面,纳米材料表现出显著增强的可见光响应能力。当负载量为6%时,Ag/SCN-6呈现出最佳的光催化灭菌活性,60 min内能够将6.2 lg CFU·mL^(-1)的E.coli全部灭活。自由基捕获实验结果表明,超氧自由基(·O-2)是灭活过程中最主要活性物种,它协同光生空穴(h+)和羟基自由基(·OH)主导了光催化抗菌的进程。展开更多
Graphene oxide (GO) is a graphene derivatives that has oxygen-containing functional groups on the graphene basal plane, such as hydroxyl, carbonyl, epoxy and carboxyl groups. GO is considered as a promising material f...Graphene oxide (GO) is a graphene derivatives that has oxygen-containing functional groups on the graphene basal plane, such as hydroxyl, carbonyl, epoxy and carboxyl groups. GO is considered as a promising material for biological applications owing to its excellent surface functionalizability, high specific suface area and good biocompatibility. In this study, GO/chitosan hybrid scaffolds were prepared for tissue engineering. Nano silver was loaded into the scaffold to improve its antibacterial ability and biomimetic Ca-P coatings were deposited on the scaffold surface to enhance its osteoconductivity. First, GO was prepared by the chemical oxidization of graphite. Secondly, nano-Ag loaded GO was prepared by chemical reducing Ag ions in GO solutions. Then, nano-Ag loaded GO solution was mixed with CS solution to form GO-CS gel. Chitosan (CS) and GO were crosslinked by electrostatic interactions between oxygen-containing functional groups of GO and NH2 groups of CS. The gel were freeze dried to produce nano-Ag loaded GO/CS hybrid porous scaffolds. Finally, the as-prepared scaffolds were immersed the into a supersaturated calcium phosphate solution (SCPS) for 7 days to deposite CaP coatings on the surface of the micropores. SEM images showed that nano-Ag uniformly distributed in the scaffold and the CaP covered most of the scaffold surfaces. In vitro cell culture and antimicrobial test indicated the biomimetic mineralized Ag-CS-GO scaffolds have good osteoconductivity and bactericidal ability.展开更多
The recent rapid growth in electronics has reached the point where there is a need for solid-state devices with excellent physical flexibility, which will be a significant advantage in modern electronic devices. In ...The recent rapid growth in electronics has reached the point where there is a need for solid-state devices with excellent physical flexibility, which will be a significant advantage in modern electronic devices. In particular, metal nanowires and nano-particles are chosen for electrodes because of their low resistance and high mechanical stability. Among the various alternatives, Ag nanomaterials have recently garnered increasing attention due to the high intrinsic conductivity, a transparency with a low sheet resistance and relatively low cost. We herein summarize recent developments toward flexible electronics on the basis of Ag nanomaterials , which show promising performance and outperform the commonly used. The typical fabrication techniques along with the promising applications for flexible devices, are thoroughly discussed.展开更多
The thermal performance of nano fluid containing Ag NPs with different stabilizers was studied in detail. The wall temperature distributions of the heat pipe containing pure water and a small amount of PAN/Ag, PVP/Ag,...The thermal performance of nano fluid containing Ag NPs with different stabilizers was studied in detail. The wall temperature distributions of the heat pipe containing pure water and a small amount of PAN/Ag, PVP/Ag, L-cys/Ag, and OA/Ag were determined, respectively. With the addition of a small amount ofAg NPs in the pure water, the heat pipe wall temperature became lower than that of pipes filled with pure water. The efficiency under the same conditions was ranked as PVP/Ag 〉 L-cys/Ag 〉 PAN/Ag 〉 OA/ Ag. After adding a small amount of CNT in the mixture, the effect was enhanced further. As more CNT became dispersed in the working fluid, the opposite effect was observed. Therefore, the optimal amount is 4 mg/L CNT in nano-fluid. Ag nano fluid could form the multi-scaled surface with higher wettability and spreadability. The wettability of nano-fluid was improved with the addition of a small amount of CNT in the mixture. However, the spreadability of the mixture would decrease significantly in the presence of more CNT.展开更多
基金Projects(04GK2007,2007CK3075 ) supported by Industrial Key Project of Science and Technology of Hunan Province, China
文摘Steady TiO2 water-sol was prepared by peptization and the effects of pH value, temperature, concentration of colloid and peptizator on sol were investigated. Laser grain analyzer was used to verify nano-particles in the sol. The photocatalytic degradation ratio and antibacterial property of nano-Ag/TiO2 thin-film on ceramics were used as the main index in addition to XRD analysis. The effect of film layers, embedding Ag+, annealing temperature and time on the degradation ratio and antibacterial property was studied. The temperature 30-80 ℃, pH 1.2-2.0, concentrations of 0.05-0.3 mol/L sol and 5% HNO3 would be the optimal parameters for the TiO2 water-sol preparation. The nano-Ag/TiO2 film of three layers with 3% AgNO3 embedded and treated at 350 ℃ for 2 h exhibits good performance. The elementary research on the kinetics of degradation shows that the reactions are on the first order kinetics equation.
文摘光催化灭活是公认的控制病原微生物最具前景手段之一。本文以尿素和硫代巴比妥酸为起始原料,通过热聚合反应制备S掺杂g-C_(3)N_(4)(SCN),随后采用光还原法将Ag纳米粒负载于SCN表面获得新颖的可见光响应型Ag/SCN抗菌材料。对所制备纳米材料进行XRD、SEM、TEM、XPS及UV-Vis DRS表征,并深入探讨其在可见光下灭活大肠杆菌(E.coli)的性能和机制。结果表明,Ag纳米粒均匀且牢固地负载在SCN表面,纳米材料表现出显著增强的可见光响应能力。当负载量为6%时,Ag/SCN-6呈现出最佳的光催化灭菌活性,60 min内能够将6.2 lg CFU·mL^(-1)的E.coli全部灭活。自由基捕获实验结果表明,超氧自由基(·O-2)是灭活过程中最主要活性物种,它协同光生空穴(h+)和羟基自由基(·OH)主导了光催化抗菌的进程。
文摘Graphene oxide (GO) is a graphene derivatives that has oxygen-containing functional groups on the graphene basal plane, such as hydroxyl, carbonyl, epoxy and carboxyl groups. GO is considered as a promising material for biological applications owing to its excellent surface functionalizability, high specific suface area and good biocompatibility. In this study, GO/chitosan hybrid scaffolds were prepared for tissue engineering. Nano silver was loaded into the scaffold to improve its antibacterial ability and biomimetic Ca-P coatings were deposited on the scaffold surface to enhance its osteoconductivity. First, GO was prepared by the chemical oxidization of graphite. Secondly, nano-Ag loaded GO was prepared by chemical reducing Ag ions in GO solutions. Then, nano-Ag loaded GO solution was mixed with CS solution to form GO-CS gel. Chitosan (CS) and GO were crosslinked by electrostatic interactions between oxygen-containing functional groups of GO and NH2 groups of CS. The gel were freeze dried to produce nano-Ag loaded GO/CS hybrid porous scaffolds. Finally, the as-prepared scaffolds were immersed the into a supersaturated calcium phosphate solution (SCPS) for 7 days to deposite CaP coatings on the surface of the micropores. SEM images showed that nano-Ag uniformly distributed in the scaffold and the CaP covered most of the scaffold surfaces. In vitro cell culture and antimicrobial test indicated the biomimetic mineralized Ag-CS-GO scaffolds have good osteoconductivity and bactericidal ability.
基金Program for the Top Young Academic Leaders of Higher Learning Institutions of Shanxi,100 Persons Program of Shanxithe Project Supported by Science Foundation of North University of China(No.110248-28140)The Project Supported by Science and Technology on Electronic Test & Measurement Laboratory(No.110103112113)
文摘The recent rapid growth in electronics has reached the point where there is a need for solid-state devices with excellent physical flexibility, which will be a significant advantage in modern electronic devices. In particular, metal nanowires and nano-particles are chosen for electrodes because of their low resistance and high mechanical stability. Among the various alternatives, Ag nanomaterials have recently garnered increasing attention due to the high intrinsic conductivity, a transparency with a low sheet resistance and relatively low cost. We herein summarize recent developments toward flexible electronics on the basis of Ag nanomaterials , which show promising performance and outperform the commonly used. The typical fabrication techniques along with the promising applications for flexible devices, are thoroughly discussed.
基金Funded by the Program of Introducing Talents of Discipline to Universities(No.B13009)
文摘The thermal performance of nano fluid containing Ag NPs with different stabilizers was studied in detail. The wall temperature distributions of the heat pipe containing pure water and a small amount of PAN/Ag, PVP/Ag, L-cys/Ag, and OA/Ag were determined, respectively. With the addition of a small amount ofAg NPs in the pure water, the heat pipe wall temperature became lower than that of pipes filled with pure water. The efficiency under the same conditions was ranked as PVP/Ag 〉 L-cys/Ag 〉 PAN/Ag 〉 OA/ Ag. After adding a small amount of CNT in the mixture, the effect was enhanced further. As more CNT became dispersed in the working fluid, the opposite effect was observed. Therefore, the optimal amount is 4 mg/L CNT in nano-fluid. Ag nano fluid could form the multi-scaled surface with higher wettability and spreadability. The wettability of nano-fluid was improved with the addition of a small amount of CNT in the mixture. However, the spreadability of the mixture would decrease significantly in the presence of more CNT.
