聚苯胺在聚酰亚胺膜基体表面的原位沉积成膜机理

采用分散聚合方法,在聚酰亚胺(PI)膜基体表面原位成膜,制备聚苯胺-聚酰亚胺-聚苯胺(PANI-PI-PANI)导电复合膜.通过反应历程跟踪、扫描电镜(SEM)及静滴接触角-界面张力测量仪研究了PANI在PI基体表面原位成膜的过程及其驱动力.结果表明,PANI在PI基体表面的成膜过程有3个阶段:含苯胺的结构单元(包括An盐酸盐、An阳离子自由基及低聚物)在PI表面吸附成核阶段、膜快速增长阶段和增长完成阶段;PANI膜由PANI小颗粒逐渐堆积而成,直至覆盖整个PI膜表面;PANI成膜的主要驱动力来自亲水-疏水相互作用.     

层层自组装原位聚合聚苯胺复合膜成膜机理研究

从苯胺单体出发, 通过原位聚合、现场掺杂以及基于静电力的层层自组装制备了聚苯胺复合膜. 通过苯胺活性溶液的温度及颜色变化跟踪聚合反应进程, 同时考察不同聚合反应阶段所得聚苯胺复合膜的紫外-可见吸收, 并进一步探讨聚苯胺复合膜的成膜机理. 研究表明, 成膜机制是由聚合反应初始阶段的苯胺阳离子或苯胺阳离子自由基通过静电作用快速吸附到负电性的基片表面, 形成均匀的聚合中心, 链增长生成聚苯胺; 该聚苯胺在酸性条件下经现场掺杂显电正性, 可吸附电负性的聚苯乙烯磺酸钠(PSS), 以此循环层层组装得到多层聚苯胺复合膜.     

气体分离膜成膜技术及成膜机理的研究进展

介绍了气体分离膜的发展历史，从７０年代初期反渗透膜干燥技术获得气体分离膜，８０年代出现的“阻力型”“复合型”到９０年代发明的致密皮层非对称气体分离膜，着重介绍了成膜液相转化过程中发生微相分离的成膜机理，最后，提出现行成膜技术的不足及成膜机理的研究方向。     

纳米纤维聚苯胺膜在不锈钢电极表面的生长过程

研究了脉冲电流法(PGM)聚合苯胺时, 纳米纤维聚苯胺(PANI)膜在不锈钢(SS)电极表面的生长过程. 用计时电位法和扫描电子显微镜(SEM)表征了聚苯胺生长过程的电化学特征和微观形貌; 并通过循环伏安(CV)法研究了苯胺的聚合速率. 结果表明, 聚苯胺的生长经历了两个阶段, 首先是在裸不锈钢电极表面上形成颗粒状聚苯胺, 此时聚合电位约为1.10 V, 经历了30 s后, 电极表面被一层颗粒状聚苯胺膜所覆盖; 在此基础上, 聚苯胺以纳米纤维状结构继续生长, 当颗粒状聚苯胺被纳米纤维状聚苯胺膜完全覆盖时, 聚合电位降至0.75 V左右并保持稳定.     

聚苯乙烯胶乳颗粒的成膜过程及尺寸效应

聚合物乳液成膜过程可分为介质蒸发、颗粒形变和相邻颗粒间高分子的扩散融合三个阶段.一般认为,环境温度达到或高于高分子的玻璃化转变温度(T_g)时颗粒才可能发生形变.Goudy等研究了粒径为0.24～1.05μm的聚苯乙烯(PS)胶乳的成膜过程,发现PS颗粒在368K(T_g约373K)热处理很长时间也不发生形变,而在378K热处理后,粒径较小的颗粒融合速度快于较大颗粒.     

单分散聚苯乙烯乳液高温成膜过程的形态观察

单分散乳液指微粒具有相同化学组成、粒径及界面性质等特征的分散体系 ,因其颗粒均一 ,结构可调 ,赋予了其很多独特性质 ,广泛应用于计量、电子、生物、分析、医学、化工和信息等领域 .同时 ,单分散微粒体系作为研究原子或分子结晶过程的模型物 [1] ,在凝聚态物理中具有重要作用 .单分散乳液在一些条件下能排列成最大密堆积规整结构 ,从而赋予乳胶膜更优异的性能 [2 ] .因此 ,研究单分散乳液的成膜过程 ,在基础理论和实际应用中具有重要意义 .软的乳胶微粒玻璃化温度在室温附近 ,它们在常温下就可形变融合成膜 ,此时水蒸发速度较慢 ,乳液中…     

改性聚丙烯表面成膜性

通过添加功能改性剂与聚丙烯（PP）共混,改善其润湿性能。结果表明：润湿改性后,改性PP单板成膜率显著提高,由19.9%提高到94.4%,而纯PP则变化不大,润湿改性PP的浸湿功为正值,液膜可稳定存在,此时单板液膜流动也较为稳定。     

PI/PANI复合材料的制备与表征

以纳米聚苯胺为电磁波的吸收剂,高强度、耐高温的聚酰亚胺为基体设计与制备了高强度、耐热、质轻、薄和吸收宽的新型纳米复合吸波材料.利用微乳液法,以十二烷基苯磺酸(DBSA)为乳化剂和掺杂剂,以过硫酸铵(APS)为氧化剂合成了纳米级聚苯胺(PANI).在此基础上,以PANI的NMP溶液为均苯四甲酸二酐(PMDA)与4,4′-二氨基二苯醚(ODA)的聚合场所,室温下,原位聚合出PANI/聚酰胺酸(PAA)复合材料,再经过亚胺化制备出了PANI/PI复合材料.利用XRD表征了聚合物的结晶形态.红外光谱表征了中间体和聚合物.利用场发射扫描电镜发现PANI/PI复合材料呈现海岛结构,PANI像岛屿一样分散在PI的连续相中,两种材料复合并没有破坏各自的结晶形态.利用数字电桥和自制电极表征了不同含量复合材料的损耗性能,当聚苯胺加到3.4%以上时,复合材料的损耗因数提高了,并且随着频率的增大损耗因数直线增大.     

中性介质中铜缓蚀剂的成膜过程

使用光电化学与电化学石英晶体微天平联用（PECQCM）技术对中性介质铜缓蚀剂成膜过程进行了现场研究．结果表明，在中性Na2SO4溶液中钝化型缓蚀剂Na2OrO4对Cu成膜生长有抛物线规律，而由于Cl-的影响，在中性NaCl溶液中，该缓蚀剂膜生长曲线为折线型．沉淀型缓蚀剂Na2SiO3在Na2SO4溶液中的铜晶振电极上不成膜，而在NaCl溶液中可成膜．     

非对称结构的CO2分离膜成膜过程的研究

采用干/湿相转化法制备了一系列非对称结构的气体分离膜。动态监测成膜过程的不同阶段,用傅立叶变换红外光谱仪来研究干相转化的蒸发过程,采用数码相机连续照相的方法,用光学显微镜来研究湿相转化的凝胶过程,并探讨成膜动力学过程对膜的最终结构及性能的影响。结果表明,对流蒸发和凝胶过程溶剂/非溶剂的交换速率对形成非对称结构的高渗透性能气体分离膜有着重要的影响。     

玻璃表面原位聚合沉积pani薄膜机理的探讨

分散聚合;原位沉积;聚苯胺薄膜;纳米sio2;生长机理     

Au/PATP/PANI膜电极和Au/PATP/PANI/TiO2膜电极的光电化学

聚苯胺（PANI）是一种结构、 性质不同于聚乙炔和聚吡咯的新型导电高聚物,有着十分广泛的应用[1,2].近年来利用光电化学研究聚苯胺的电子结构、 掺杂情况引起人们的重视[3～5].在酸性溶液中电聚合制备聚苯胺的循环伏安曲线上出现两对氧化还原峰,其峰值电位分别为E11/2=0.13 V和E21/2=0.7 V(对饱和甘汞电极).通过改变电极电位,可获得部分氧化态、还原态、氧化态等3种状态的聚苯胺.部分氧化态具有金属导电性,还原态和氧化态均为绝缘体.本文测量3种状态聚苯胺膜电极的光电响应,首次得到其光电流谱,发现聚苯胺一些新的光电化学实验结果.提出了覆盖绝缘体的金属内发射的光电化学模型.同时,在聚苯胺膜上电沉积纳米TiO2微粒膜,得到广谱区的复合光电材料.     

Analysis of Optical Parameter of the Glass Surface Layers and Its Influence on the Film Measurement

We propose a new and simple method for analyzing the optical profiles of glass surface layers based on the theory of optical admittance and data fitting.     

二氧化钛表面包覆氧化硅纳米膜的热力学研究

热力学计算结果表明,氧化硅的临界成核半径为2.8nm.由起伏引起的核胚如果小于2.8nm则不会形成晶核而继续生长.上述热力学分析虽然是半理想化的,但是非常有效.可以找到这样一个体系,其溶液条件不发生均匀成核,而是异相表面成核.这在理论上为氧化硅包覆在二氧化钛表面形成均匀膜而不生成单独的氧化硅相提供了可能.     

Formation Mechanism of a Silane‐PVA/PVAc Complex Film on a Glass Fiber Surface

Mechanical properties of glass fiber reinforced composite materials are affected by fiber sizing. A complex film formation, based on a silane film and PVA/PVAc (polyvinyl alcohol/polyvinyl acetate) microspheres on a glass fiber surface is determined at 1) the nanoscale by using atomic force microscopy (AFM), and 2) the macroscale by using the zeta potential. Silane groups strongly bind through the Si? O? Si bond to the glass surface, which provides the attachment mechanism as a coupling agent. The silane groups form islands, a homogeneous film, as well as empty sites. The average roughness of the silanized surface is 6.5 nm, whereas it is only 0.6 nm for the non‐silanized surface. The silane film vertically penetrates in a honeycomb fashion from the glass surface through the deposited PVA/PVAc microspheres to form a hexagonal close pack structure. The silane film not only penetrates, but also deforms the PVA/PVAc microspheres from the spherical shape in a dispersion to a ellipsoidal shape on the surface with average dimensions of 300/600 nm. The surface area value S_a represents an area of PVA/PVAc microspheres that are not affected by the silane penetration. The areas are found to be 0.2, 0.08, and 0.03 μm² if the ellipsoid sizes are 320/570, 300/610, and 270/620 nm for silane concentrations of 0, 3.8, and 7.2 μg mL^?1, respectively. The silane film also moves PVA/PVAc microspheres in the process of complex film formation, from the low silane concentration areas to the complex film area providing enough silane groups to stabilize the structure. The values for the residual silane honeycomb structure heights (H_a) are 6.5, 7, and 12 nm for silane concentrations of 3.8, 7.2, and 14.3 μg mL^?1, respectively. The pH‐dependent zeta‐potential results suggest a specific role of the silane groups with effects on the glass fiber surface and also on the PVA/PVAc microspheres. The non‐silanized glass fiber surface and the silane film have similar zeta potentials ranging from ?64 to ?12 mV at pH’s of 10.5 and 3, respectively. The zeta potentials for the PVA/PVAc microspheres on the glass fiber surface and within the silane film significantly decrease and range from ?25 to ?5 mV. The shapes of the pH‐dependent zeta potentials are different in the cases of silane groups over a pH range from 7 to 4. A triple‐layer model is used to fit the non‐silanized glass surface and the silane film. The value of the surface‐site density for Γ_Xglass and Γ_Xsilane, in which X denotes the Al? O? Si group, differs by a factor of 10^?4, which suggests an effective coupling of the silane film. A soft‐layer model is used to fit the silane‐PVA/PVAc complex film, which is approximated as four layers. Such a simplification and compensation of the microsphere shape gives an approximation of the relevant widths of the layers as the follows: 1) the layer of the silane groups makes up 10 % of the total length (27 nm), 2) the layer of the first PVA shell contributes 30 % to the total length (81 nm), 3) the layer of the PVAc core contributes 30 % to the total length (81 nm), and finally 4) the layer of the second PVA shell provides 30 % of the total length (81 nm). The coverage simulation resulted in a value of 0.4, which corresponds with the assumption of low‐order coverage, and is supported by the AFM scans. Correlating the results of the AFM scans, and the zeta potentials sheds some light on the formation mechanism of the silane‐PVA/PVAc complex film.     

Low-Frequency Glow Discharge Deposition of a Silicon Dioxide Film onto the Surface of Glass Microspheres

Laser fusion research demands microsized hollow shells with a large diameter and a thick wall. Because these geometric parameters are difficult to provide by fabrication, the wall thickness was increased by deposition of a silicon dioxide film on the outer surface of glass microspheres. The film was obtained by decomposition of tetraethoxysilane vapor in a low-frequency discharge plasma in mixtures with argon and oxygen. The thickness of coating was shown to be a linear function of the deposition time and the consumption of the precursor organoelement compound. The composition of plasma-deposited layers was studied and their density and refractive index were determined. Elemental analysis data showed that the coating comprised silicon dioxide with carbon and hydrogen impurities.     

掺杂铈对玻璃表面TiO2薄膜上油酸光催化降解的影响

采用旋转涂膜工艺,以溶胶－凝胶法在玻璃表面制备了掺杂铈的ＴｉＯ２薄膜,利用高压液相色谱、紫外－可见光分光光度计、扫描电镜和能谱仪等手段对掺杂铈的ＴｉＯ２薄膜者了表征,考察了掺杂铈对油酸光催化妥效率及ＴｉＯ２薄膜表面晶粒分布的影响,并对薄膜的化学成分进行了定性和定量分析,结果表明,掺杂３％Ｃｅ的ＴｉＯ２薄膜对油酸有最高的光催化降解效率,４００℃为掺杂铈ＴｉＯ２薄膜的最佳热处理温度。     

掺杂铈对玻璃表面TiO_2薄膜上油酸光催化降解的影响

采用旋转涂膜工艺 ,以溶胶 凝胶法在玻璃表面制备了掺杂铈的TiO2 薄膜 .利用高压液相色谱、紫外 可见光分光光度计、扫描电镜和能谱仪等手段对掺杂铈的TiO2 薄膜进行了表征 ,考察了掺杂铈对油酸光催化降解效率及TiO2 薄膜表面晶粒分布的影响 ,并对薄膜的化学成分进行了定性和定量分析 .结果表明 ,掺杂 3%Ce的TiO2 薄膜对油酸有最高的光催化降解效率 ,40 0℃为掺杂铈TiO2 薄膜的最佳热处理温度     

铂粒子修饰单壁碳纳米管/聚苯胺复合膜对甲醛的电催化氧化

在溶有单壁碳纳米管(SWNTs)的苯胺溶液中, 通过电化学共聚合法成功制备了单壁碳纳米管(SWNT)/聚苯胺(PANI)复合膜. 用电沉积法将铂沉积到SWNT/PANI复合膜上. 样品的成分和形貌分别用XRD和SEM表征. 四探针和电化学交流阻抗的研究表明被PANI包裹的SWNTs整齐地排列在复合膜中, 从而提高了复合膜的电导率, 促进了电荷转移. 循环伏安(CV)说明Pt修饰的SWNT/PANI复合膜对于甲醛氧化具有良好的电催化活性及稳定性. 研究结果表明SWNT/PANI复合膜是一种非常好的催化剂载体, 有着广泛的应用前景.