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Giant electrorheological effects of aluminum-doped TiO_2 nanoparticles

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Particuology 2010年第5期8卷 442-446页

作者： Hongzhe Tang junhui he Jacques Persello Beihang Sino-French EngineerSchool Beihang University Beijing 100191 China Functional Nanomaterials Laboratory Technical Institute of Physics and Chemistry Chinese Academy of Sciences Beijing 100190 China LCMI - University ofFranche-Comte 16 route de Gray La Bouloie 25030 Besancon cedex France

Titania nanoparticles doped with cations have been synthesized via a modified hydrolysis method. The X-ray diffraction analyses, scanning electron microscopy and other characteristics measurements, were used to study the structure of the nanoparticles. The results showed interesting electrorheological （ER） effect with titania nanoparticles modified by aluminum ions, and different cations on ER effect were determined by ionic potential and resistance of the particle aggregates in the electric field. The doping ratio of aluminum ions was dominated by the appropriate sites of the particle surface and the ER effect strongly depends on the doping ratio.

关键词： Electrorheological fluidIonic potentialSurface structureAluminum ions

Preparation of birnessite-supported Pt nanoparticles and their application in catalytic oxidation of formaldehyde

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Journal of Environmental Sciences 2012年第6期24卷 1117-1124页

作者： Linlin Liu Hua Tian junhui he Donghui Wang Qiaowen Yang Functional Nanomaterials Laboratory and Key Laboratory of Photochemical Conversion and Optoelectronic Materials Technical Institute of Physics and Chemistry(TIPC)Chinese Academy of SciencesBeijing 100190China School of Chemical&Environmental Engineering China University of Mining&TechnologyBeijing 100083China Research Institute of Chemical Defense Beijing 100083China

Flaky and nanospherical birnessite and birnessite-supported Pt catalysts were successfully prepared and characterized by means of Xray diffraction （XRD）,transmission electron microscopy （TEM）,energy dispersive spectroscopy （EDS） and N2 *** of the birnessite morphology and Pt reduction method on the catalytic activity for the complete oxidation of formaldehyde （HCHO） were *** was found that flaky birnessite exhibited higher catalytic activity than nanospherical *** promoting effect of Pt on the birnessite catalyst indicated that the reduction method of the Pt precursor greatly influenced the catalytic *** birnessite-supported Pt nanoparticles reduced by KBH 4 showed the highest catalytic activity and could completely oxidize HCHO into CO2 and H2O at 50℃,whereas the sample reduced using H2-plasma showed lower activity for HCHO *** differences in catalytic activity of these materials were jointly attributed to the effects of pore structure,surface active sites exposed to HCHO and the dispersion of Pt nanoparticles.

关键词： birnessite manganese oxide noble metals formaldehyde oxidation

Rapid assessment of DNA damage induced by polystyrene nanosphere suspension using a photoelectrochemical DNA sensor

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Science China Chemistry 2011年第8期54卷 1260-1265页

作者： ZHANG BinTian DU Xin JIA SuPing he junhui GUO LiangHong State Key Laboratory of Environmental Chemistry and Ecotoxicology Research Center for Eco-Environmental Sciences Chinese Academy of Sciences Beijing 100085 China Functional Nanomaterials Laboratory and Key Laboratory of Organic Optoelectronic Functional Materials and Molecular Engineering Technical Institute of Physics and Chemistry Chinese Academy of Sciences Beifing 100080 China

Nanomaterials have been used increasingly in a wide variety of applications, and some of them have shown toxic effects on experimental animals and cells. In this study, a previously established photoelectrochemical DNA sensor was employed to rapidly detect DNA damage induced by polystyrene nanosphere （PSNS） suspensions. In the sensor, a double-stranded DNA film was assembled on a semiconductor electrode, and a DNA intercalator, Ru（bpy）2（dppz）2＋（bpy = 2,2＇-bipyridine, dppz = dipyrido[3,2-a：2＇,3＇-c]phenazine） was used as the photoelectrochemical signal indicator. After the DNA-modified electrode was exposed to 2.0 mg/mL PSNS suspension, photocurrent of DNA-bound Ru（bpy）2（dppz）2＋ decreased by about 20%. The decrease is attributed to the chemical damage of DNA and consequently less binding of Ru（bpy）2（dppz）2＋ molecules to the electrode. Gel electrophoresis of DNA samples incubated with PSNS suspension confirmed DNA damage after the chemical exposure. However, in both photoelectrochemical and gel electrophoresis experiments, extensively washed PSNS did not induce any DNA damage, and the supernatant of PSNS suspension exhibited comparable DNA damage as the unwashed PSNS suspension. Furthermore, UV-visible absorption spectrum of the supematant displayed a pattern very similar to that of styrene oxide （SO）, a compound which has been shown to induce DNA damage by forming covalent DNA adducts. It is therefore suggested that styrene oxide and other residual chemicals in the PSNS may be responsible for the observed DNA damage. The results highlight the importance of full characterization of nanomaterials before their toxicity study, and demonstrate the utility of photoelectrochemical DNA sensors in the rapid assessment of DNA damage induced by chemicals and nanomaterials.

关键词： nanomaterial toxicity DNA damage sensor

An Advance in Complete Oxidation of Formaldehyde at Low Temperatures

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Science Foundation in China 2009年第2期17卷 36-38页

作者： Hua Tian junhui he Functional Nanomaterials Laboratory Technical Institute of Physics and Chemistry Chinese Academy of Sciences Beijing 100190 China

Editor＇s comments Formaldehyde （HCHO） emitted from chemical manufacturing plants including methanol-gasoline/diesel fuel vehicles and the construction and decoration materials is one of the major air pollutions, which induces photochemical pollution and hazards human health. Great efforts have been made for the reduction or control of the emission of HCHO to satisfy the stringent environmental regulations. Now, a new study supported by the National Natural Science Foundation of China reports mesoporous manganese oxide with novel nanostructures for the decomposition of HCHO. The obtained manganese oxide nanomaterials showed high catalytic activities for oxidative decomposition of HCHO at low temperatures. Complete conversion of HCHO to CO2 and H2O were achieved, and no harmful by- products were detected in effluent gases. The catalytic activities of these nanomaterials are significantly higher than those of previously reported manganese oxide octahedral molecular sieve （OMS-2） nanorods , MnO x powders, and alumnina-supported mangnaese-palladium oxide catalysts. These results provide a new route for the removal of HCHO and other air pollutions.

关键词： Manganese oxide honeycomb nanosphere hollow nanosphere formaldehyde oxidation

Fabrication and Its Transient Optical Properties of Graphene Thin Films

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Fabrication and Its Transient Optical Properties of Graphene...

Robust Nonlinear Servo Control of Permanent Magnet Synchronous Motor Based on Finite-time Extended State Observer

中国材料大会2012

作者： Jiayi Zhu junhui he Functional Nanomaterials Laboratory and Key Laboratory of Photochemical Conversion and Optoelectronic Materials Technical Institute of Physics and Chemistry Chinese Academy of Sciences University of Chinese Academy of Sciences

ISBN: (纸本)9783037856062

Graphene thin films were fabricated via layer-by-layer （LbL） assembly of oppositely charged reduced graphene oxides （RGOs） and benign post-treatment. RGOs dispersions and thin films were characterized by means of transmission electron microscopy, UV-visible absorption spectrophotometer, Raman spectroscopy, and four-point probe. It was found that graphene thin films exhibited a significant increase in electrical conductivity after post-treatment. In addition, post-treatment and film thickness showed an effect on transient optical properties of graphene thin films. The transmittance （800 nm, pulse） of （RGO-PDDA + /RGO-O - ） 30 film decreased after post-treatment, and the transmittance （800 nm, pulse） of post-treated films decreased with increasing the number of LbL assembled bilayers.

关键词： Oppositely charged reduced graphene oxides Layer-by-layer assembly Benign post-treatment Transient optical properties

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Robust Nonlinear Servo Control of Permanent Magnet Synchrono...

沸石及水泥基材料二次负载TiO2的光催化性能

第43届中国控制会议

作者： Mingyang he junhui he Guoyang Cheng College of Electrical Engineering and Automation Fuzhou University Group R&D Center Shenzhen INVT Electric Co.LTD The Fuzhou University-INVT Industrial Control Joint Laboratory

In this paper,a nonlinear servo control method based on finite-time observer is developed for position control of permanent magnet synchronous motor(PMSM).The nonlinear servo control law consists of two parts,where the linear part is responsible for the fast dynamic response and the nonlinear part is responsible for reducing the overshoot when the system approaches the steady *** tackle the time-varying uncertainty occurring in the system,a finite-time extended state observer is proposed to estimate the lumped disturbance for feed-forward compensation in the control *** and experimental results verify that the proposed control scheme can track the target position quickly and accurately,and is robust against disturbance and uncertainty.

关键词： nonlinear control finite time permanent magnet synchronous motor feedforward compensation

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建筑材料学报 2020年第1期23卷 35-39页

作者：何军辉姚武同济大学先进土木工程材料教育部重点实验室

以天然沸石为原料,通过6 h碱处理及400℃热处理对沸石进行改性,以改性沸石为载体来分散负载光催化剂纳米TiO2,制备出了改性沸石负载光催化剂.通过内掺法、喷涂法和露骨料法将改性沸石负载光催化剂二次负载于水泥基材料,研究负载纳米TiO... 详细信息

以天然沸石为原料,通过6 h碱处理及400℃热处理对沸石进行改性,以改性沸石为载体来分散负载光催化剂纳米TiO2,制备出了改性沸石负载光催化剂.通过内掺法、喷涂法和露骨料法将改性沸石负载光催化剂二次负载于水泥基材料,研究负载纳米TiO2水泥基材料的光催化性能.结果表明:碱热处理增加了改性沸石对纳米TiO2的负载量,光催化剂的吸附水平与降解水平均明显提升;改性沸石与纳米TiO2形成了新的Ti—O—Si化学键,结合牢固;喷涂法二次负载制备的光催化水泥基材料具有较高的降解率.

关键词：纳米TiO2 碱热处理改性沸石光催化水泥基材料