高容量锂离子电池核壳型硅/碳复合电极材料的制备与性能

通过自组装方式采用一步法制备了锂离子电池硅碳复合电极材料.使用X射线衍射仪(XRD)、透射电子显微镜(TEM)和扫描电子显微镜(SEM)等对样品结构进行表征.结果表明,聚乙烯吡咯烷酮(PVP)包覆的纳米硅颗粒(Si@PVP)均匀嵌入到具有三维网络纳米孔结构的导电石墨化炭黑(GCB)骨架中,形成核壳复合型(Si@PVP-GCB)纳米颗粒,既提高了该复合电极材料的导电性能,又改善了材料的机械强度.在纳米级GCB颗粒内部存在的中空石墨环结构和包覆在纳米Si颗粒外面的PVP包覆层都有效缓冲了纳米Si颗粒在充放电过程中较大的体积变化,从而使纳米Si颗粒更加稳定.电化学测试结果表明,Si@PVP-GCB电极材料在电流密度为50 m A/g时,经过100次循环后其可逆容量仍达到545 m A·h/g时,远高于商品化的石墨微球(GMs)电极材料的容量(理论容量为372 m A·h/g).     

计算机模拟研究聚合物纳米复合材料的分散与界面

针对聚合物纳米复合材料,系统综述了计算机模拟技术(分子动力学模拟)在纳米颗粒的分散与聚合物-纳米颗粒界面作用取得的成果与进展,包括不同形状纳米颗粒在聚合物基体的分散机理、相行为与微观结构、纳米颗粒对分子链构象的影响(分子链均方回转半径的变化)、分子链在纳米颗粒表面结构(取向与排列)、分子链与纳米颗粒界面作用能、界面区分子链活动性与纳米颗粒形成的网络结构.为构建聚合物纳米复合材料的组成、结构与性能之间的关系,提出了3个模拟方面的挑战,包括发展长时间跨尺度计算机模拟技术、建立准确模拟材料力学性能的方法与导电导热功能性的模拟.     

导电高分子PEDOT/PSS保护银纳米颗粒的制备与表征

利用导电高分子聚(3,4-二氧乙基噻吩)/聚(对苯乙烯磺酸)(PEDOT/PSS)作保护剂,制备了银纳米颗粒,用UV-Vis和TEM对其进行了表征.结果表明,选择合适量的PEDOT/PSS保护剂可以得到大小分布较窄银纳米颗粒.     

Ag/ZnO纳米纤维的制备及光催化性能

采用静电纺丝技术及煅烧法制备了氧化锌纳米纤维, 然后采用水热法将银纳米颗粒负载到了氧化锌纳米纤维表面. 利用X射线衍射(XRD)、 X射线光电子能谱(XPS)、 能量色散X射线光谱(EDX)、 扫描电子显微镜(SEM)及透射电子显微镜(TEM)等技术对合成的Ag/ZnO纳米纤维的结构和组成进行了表征. SEM结果表明, 直径在5~100 nm之间的银纳米颗粒附着在直径在80~330 nm之间的氧化锌纤维表面形成了异质结构. 以常见的有机污染物甲基橙、 亚甲基蓝和罗丹明B等为降解底物, 对Ag/ZnO纳米纤维的光催化性能进行了表征. 结果表明, 负载银纳米颗粒后, 复合催化剂的光催化性能明显提高.     

尺寸可控的聚苯胺复合微球的电纺制备与表征

以十二烷基苯磺酸(DBSA)掺杂的导电聚苯胺与聚乙二醇(PEG)及Fe3O4的混合氯仿溶液,采用静电纺丝(spinning technology)方法制备含Fe3O4纳米颗粒的导电聚苯胺(PANI)/PEG/Fe3O4复合微球.SEM结果表明,电纺所得的PANI/PEG/Fe3O4复合微球结构依赖于PEG聚合物浓度、静...     

基于单晶TiO_2纳米颗粒光阳极的高效染料敏化太阳能电池

以阳极氧化法制备的TiO_2纳米管阵列为原料,在含氟化铵的密闭环境中通过热处理直接将TiO_2纳米管阵列转化为单晶TiO_2纳米颗粒膜.不同热处理时间样品的扫描电子显微镜(SEM)图表明,单晶TiO_2纳米颗粒是由TiO_2纳米管坍塌后重新生长成的.X射线衍射(XRD)及高倍率透射电子显微镜(HR-TEM)图显示出TiO_2纳米颗粒为锐钛矿单晶.将这种单晶TiO_2纳米颗粒膜转移到导电玻璃上制备染料敏化太阳能电池光阳极,获得良好的光电性能.对单晶TiO_2纳米颗粒膜厚度进行优化后,染料敏化太阳能电池最高光电转换效率达到8.66%,单色光光电转换效率最高值为86.70%.该方法是一种非水热制备法,克服了水热法对产量的限制,从而为大量制备高质量单晶TiO_2纳米颗粒提供了一种简单可行的方法.     

Au/ZnO/TiO_2复合薄膜的制备及光电转换性质

以含有Au和ZnO纳米颗粒的氢氧化钛溶胶作为成膜液,通过浸渍-提拉及灼烧处理在导电玻璃表面制备Au/ZnO/TiO2复合薄膜.利用X射线衍射仪(XRD)、扫描电子显微镜(SEM)等方法对所得产物进行表征.结果表明,Au和ZnO纳米颗粒均匀地分布在多孔TiO2薄膜上,通过TiO2、ZnO和Au三组分的协同效应促进了光吸收和电荷分离,使Au/ZnO/TiO2复合薄膜具有较好的光电转换性质,可用作太阳能电池材料.     

Ag/ZnO纳米纤维的制备及光催化性能（英文）

采用静电纺丝技术及煅烧法制备了氧化锌纳米纤维,然后采用水热法将银纳米颗粒负载到了氧化锌纳米纤维表面.利用X射线衍射(XRD)、X射线光电子能谱(XPS)、能量色散X射线光谱(EDX)、扫描电子显微镜(SEM)及透射电子显微镜(TEM)等技术对合成的Ag/ZnO纳米纤维的结构和组成进行了表征.SEM结果表明,直径在5~100 nm之间的银纳米颗粒附着在直径在80~330 nm之间的氧化锌纤维表面形成了异质结构.以常见的有机污染物甲基橙、亚甲基蓝和罗丹明B等为降解底物,对Ag/ZnO纳米纤维的光催化性能进行了表征.结果表明,负载银纳米颗粒后,复合催化剂的光催化性能明显提高.     

多聚赖氨酸淀粉纳米颗粒基因载体的研制及应用

以可溶性淀粉为原料, 利用反向微乳液法, 加入交联剂三氯氧磷, 制备了直径为50 nm左右带负电荷的交联淀粉纳米颗粒. 以该纳米颗粒为内核, 经多聚赖氨酸修饰, 得到了多聚赖氨酸淀粉纳米颗粒(PLL-StNP). 对PLL-StNP进行了颗粒粒度、稳定性和电性的表征, 并通过颗粒的体外细胞毒性检测、颗粒与DNA结合能力及细胞转染等方面的分析, 发现多聚赖氨酸淀粉纳米颗粒(PLL-StNP)有可能作为基因载体, 在此基础上发展了多聚赖氨酸淀粉纳米颗粒基因载体的构建与基因转染技术. 作为非病毒基因载体, 赖氨酸淀粉纳米颗粒具有基因装载量大、转染率高、细胞毒性低以及可生物降解等优点.     

静电纺丝法制备聚丙烯腈/聚苯胺复合纳米纤维及其表征

利用静电纺丝技术,以聚丙烯腈(PAN)和苯胺(ANI)为前驱物,用过硫酸胺(APS)溶液在低温下缓慢氧化聚合,制备了PAN/PANI复合纳米纤维,直径约500 nm.通过扫描电子显微镜(SEM)、红外光谱(FTIR)、X射线衍射(XRD)和激光拉曼(RAMAN)光谱仪等测试手段对材料的形貌和结构进行了表征.探讨了材料制备过程中影响纤维形貌、尺寸、均匀度的因素和PANI含量对复合纤维导电性能的影响,结果表明,PAN浓度、ANI的加入量和电压是影响纤维特性的主要因素;PANI在PAN基体中呈纳米尺寸分布,复合纳米纤维具有良好的导电性能,导电率可达10-2S/cm.     

Analysis of anatoxin-a using polyaniline as a sorbent in solid-phase microextraction coupled to gas chromatography-mass spectrometry

A simple and sensitive method for determining anatoxin-a in aqueous samples was developed using solid-phase microextraction (SPME) and gas chromatography with mass spectrometry (GC-MS) detection. Three forms of polyaniline (PANI) films and a single form of polypyrrole (PPY) film were prepared and applied for SPME. The extraction properties of these films to anatoxin-a were examined and it was shown that leucoemeraldine form of PANI displayed a better selectivity to this compound. SPME conditions were optimized by selecting the appropriate extraction parameters, including type of coating (leucoemeraldine form of PANI at 32 microm thicknesses), salt concentration (10%, w/v), time of extraction (30 min) and stirring rate (1000 rpm). The calibration curve was linear in the range from 50 to 10,000 ng/ml, with the detection limit (S/N = 3) of 11.2 ng/ml. This method was successfully applied for the analysis of anatoxin-a in the cultured media of two species of cyanobacteria.     

Nanocomposite and nanoporous polyaniline conducting polymers exhibit enhanced catalysis of nitrite reduction

Nanostructured polyaniline (PANI) conducting polymer films were prepared on electrochemically pretreated glassy carbon electrodes, which were previously modified with multilayers of polystyrene (PS) nanoparticles with a diameter of 100 nm. PANI was electropolymerised and grown through the interstitial spaces between the PS nanoparticles, which formed a nanocomposite film of PANI and PS nanoparticles on the electrode surface. Furthermore, a nanoporous PANI film was fabricated through the removal of the PS nanoparticles by dissolution in toluene. As a result of their nanostructure, both of the PANI films (before and after removal of the PS nanoparticles) exhibited enhanced electrocatalytic behaviour towards the reduction of nitrite relative to bulk-PANI films; however, partial collapse or shrinkage may have occurred with the removal of the nanoparticles and could have resulted in a less enhanced response. Under optimised conditions, the nanocomposite-film-modified electrode exhibited a fast response time of 5 s and a linear range from 5.0 x 10(-7) to 1.4 x 10(-3) M for the detection of nitrite; the detection limit was 2.4 x 10(-7) M at a signal-to-noise ratio of 3.     

Electrochemical Study of a Polypyrrole Film/Decanethiol Self-Assembled Monolayer on a Gold Electrode

Cyclic voltammetry and chronoamperometry were used to study the deposition of polypyrrole on a decanethiol self-assembled monolayer modified gold electrode (PPY/SAM/Au). The voltammetric behavior of the PPY/SAM film was investigated in the presence of several different electrolytes. It is found that the SAM shows great influence on the nucleation and growth of the PPY film. The reaction of the SAM and the anions causes the different voltammetric behavior of the polymerization of pyrrole on the modified electrode. Chronoamperometry shows the nucleation and growth of the PPY is initially inhibited but followed by a rapid increase. The SAM also influences electrochemical behavior of PPY film. Experiments show that the SAM can greatly depress the diffusion of anions in the PPY film, and minimize the background capacitance current.     

Thin films of Ag nanoparticles prepared from the reduction of AgI nanoparticles in self-assembled films

A novel method for the preparation of thin films of Ag nanoparticles is reported. Using mercaptoacetic acid as the stabilizing agent, AgI nanoparticles were prepared in aqueous solution. And based on electrostatic interactions, the thiol-passivated AgI nanoparticles were assembled in a self-assembled film by alternative deposition with a cationic polyelectrolyte. Then the AgI nanoparticles in the composite film were reduced by NaBH(4), which resulted in the formation of a thin film of Ag nanoparticles. UV-visible spectra and X-ray photoelectron spectroscopy data confirmed the transformation from AgI to Ag. Atomic force microscopy (AFM) showed that the formed Ag nanoparticles distributed on the film homogeneously. Surface-enhanced Raman spectroscopy (SERS) measurement indicated that the prepared thin films could be used as effective SERS substrates. The reduction process was also carried out by UV light at selective surface regions, which resulted in the formation of patterned nanoparticle arrays.     

Development of a Controlled Release System for Risperidone Using Polypyrrole: Mechanistic Studies

Polypyrrole (PPY) film has been selected as a platform material for drug delivery due to its inherent conductivity, ease of preparation and apparent biocompatibility. PPY films were prepared containing the antipsychotic drug risperidone as a model compound. Drug release profiles could be altered by applying different electrical stimulation to these films. Atomic force microscopy was used to investigate changes in PPY film thickness when different stimuli were applied. The highest levels of drug release were observed when PPY was reduced; this was accompanied by expansion of the film. Technology such as this could be utilized for implantable drug delivery devices, where the dose could be adjusted by external signaling.     

SnO2-TiO2薄膜载体对Au-Pt纳米颗粒电化学性能的影响

采用真空镀膜法在玻碳(GC)电极表面修饰SnO2-TiO2薄膜, 在SnO2-TiO2/GC复合电极表面组装Au-Pt双金属纳米颗粒, 制得Au-Pt/SnO2-TiO2/GC复合电极. 通过循环伏安法(CV)研究了SnO2-TiO2薄膜载体对Au-Pt双金属纳米颗粒电化学性能的影响; 采用扫描电镜(SEM)及X射线光电子能谱(XPS)对Au-Pt在SnO2-TiO2薄膜沉积的形貌及结构进行了表征. 研究结果表明, 10 nm的Au-Pt双金属纳米颗粒均匀地组装于SnO2-TiO2薄膜表面; SnO2-TiO2薄膜载体改善了复合电极抗CO中毒能力; Au-Pt双金属合金的形成提高了Pt 对甲醇氧化的电催化能力, SnO2-TiO2薄膜载体又使Pt纳米粒子d空轨道增多, 提高了Au-Pt双金属纳米颗粒的稳定性和催化性能.     

Study of congo red adsorption on the polyaniline and polypyrrole

Polyaniline (PANI) and polypyrrole (PPY) were synthesized via in situ chemical oxidative polymerization and are used as adsorbents for removal of Congo Red (CR) dye from aqueous solution. The effects of various experimental parameters including pH of the solution, contact time, initial concentration, adsorbent dosage, and temperature on adsorption of CR by PANI and PPY were systematically investigated. The experimental results showed that the adsorption efficiency was increased with contact time and adsorbent dosage. The maximum removal efficiency was found after 45 minutes of solid/liquid contact with adsorbent doses of 0.4 and 1.73?g/L for PANI and PPY, respectively. The kinetic data were best fitted by the pseudo-second-order model. The adsorption equilibrium results were well fitted by the Langmuir isotherm model. These results suggest that the PANI and PPY can be used as alternative adsorbents for the treatment of wastewaters containing dyes.     

自掺杂基团对聚苯胺自组装膜电化学性能的影响

基于离子相互作用,实现了以聚苯胺(PANI)为聚阳离子,以聚(邻氨基苯甲酸)(PCAN)、聚(邻氨基苯磺酸)(PSAN)为聚阴离子的层-层自组装,形成层厚均匀的全共轭超薄功能膜.由于磺酸基—SO3-的电负性高于—COO-,使得PANI-PSAN自组装膜沉积量小于PANI-PCAN;电化学实验结果显示,由于PCAN和PSAN的导电性均弱于PANI,所以两种自组装膜的电化学性能取决于PANI,但同时受到羧酸、磺酸基团的较大影响,使得PANI-PCAN自组装膜的电化学性能要优于PANI-PSAN.     

PbS纳米粒子与全共轭高分子的自组装膜原位复合及其光电转换性质

无机纳米粒子因其在催化、磁学、光子学等方面的特殊性质而越来越受到关注,纳米粒子粒径及分布可以人为控制,由此能够改变与有机聚合物所形成的纳米复合材料性能,在各种无机纳米粒子／有机聚合物复合材料制备方法中,纳米反应器(Nanoreactor)技术正日益受到关注,与常规的作为化学反应特定场所的化学反应器不同,纳米反应器不是一般的具体的机械设备,     

聚吡咯(PPY)/聚己内酰胺(Nylon 6)——导电复合材料的研究

本文用电化学氧化聚合的方法制备出了既具有优良的导电性能又具有良好机械性能的聚吡咯(PPY)/聚己内酰胺(Nylon 6)的复合材料,该复合材料的导电率可达119s/cm,并对聚吡咯/聚己内酰胺导电复合材料进行了扫描电子显微镜、电导率及机械性能的测试及表征。