Li＋-CaxPb1－xTiO3湿敏纳米薄膜的激光拉曼光谱、晶格畸变和激光显微组织——应用“软模理论”解谱

测定了标题物Li^＋-Ca_xPb_1－xTiO₃ (缩写为Li-CPT, 其中x＝0.35, Li/Ti＝1.0%, mol/mol, 850 ℃/h)的激光拉曼光谱(LRS)和激光显微组织, 并与湿敏性能极差的纯钛酸铅PbTiO₃ (缩写为PT)以及不同钙掺杂量的钛酸铅Ca_xPb_1－xTiO₃ (缩写为CPT, x＝0.08, 0.16, 0.24, 0.32, 0.40)的LRS进行比较, Li-CPT以及CPT的LRS与PT的LRS相比有很大差别,仅在75, 125, 190, 273和585 cm^－1出现五个谱峰. 应用“软模理论”将其分别归属于PT四方晶相的五个特征单模E(1TO), A₁(1TO), E(2TO), B₁＋E和A₁(3TO)的红移及宽化, PT的其它五个特征单模在Li-CPT及CPT的谱图中完全消失或被淹没. 对于这种拉曼活性的降低, 可以根据“软模理论”与晶格畸变作用的关联加以解释. Pauling离子半径较小的Ca^2＋的掺杂, 等价取代了半径较大的Pb^2＋的晶格位置, 降低了四方晶相畸变度δ＝c/a和不对称性导致的各向异性, 不单消除了薄膜冷却时位移型相变可能引起的破裂, 而且改变了晶格中氧八面体“TiO₆”及十二面体“PbO₁₂”的几何结构和电荷分布, 改变了晶格c轴上M-O (M＝Ti, Pb)键的化学环境, 直接阻尼了M—O键的伸缩振动软模, 减小了电偶矩及其自发极化, 使Li-CPT的振动模的拉曼活性大大降低, 因此LRS提供了一种表征晶格畸变的有效方法, 反过来也佐证了“软模理论”可以用来解释拉曼光谱.     

氢键给体和受体对纤维素醚复合薄膜后处理的影响研究

纤维素醚是一类水溶性大分子,它可以作为氢键受体和聚丙烯酸(PAA)形成氢键复合物。利用层层组装的方法制备出羟乙基纤维素(HEC)与PAA的界面复合薄膜,选取氢键给体单宁酸(TA)和氢键受体甲基纤维素(MC)、羟丙基纤维素(HPC)、聚乙烯吡咯烷酮(PVPON)溶液分别对薄膜进行浸泡后处理。研究表明浸泡后处理是一个动态的过程,会改变薄膜的厚度和组成,对于薄膜的实际应用具有指导意义,为多组分复合薄膜的制备提供了新思路。     

Electrocatalytic Oxidation of Dopamine by Ferrocene in Lipid Film Cast on a Glassy Carbon Electrode

ＩｎｔｒｏｄｕｃｔｉｏｎＤＡｉｓｏｎｅｏｆｅｓｓｅｎｔｉａｌｐａｒｔｉｃｉｐａｎｔｓｉｎｔｈｅｎｅｕｒｏ ｔｒａｎｓｍｉｓｓｉｏｎｐｒｏｃｅｓｓｉｎｍａｍｍａｌｉａｎｃｅｎｔｒａｌｎｅｒｖｏｕｓｓｙｓ ｔｅｍ .ＡｌｏｓｓｏｆＤＡ ｃｏｎｔａｉｎｉｎｇｎｅｕｒｏｎｓｍａｙｒｅｓｕｌｔｉｎｓｏｍｅｓｅｒｉｏｕｓｄｉｓｅａｓｅｓｕｃｈａｓＰａｒｋｉｎｓｏｎｉｓｍ .1Ｓｉｎｃｅｉｔｓｄｉｓｃｏｖ ｅｒｙｉｎｔｈｅ 195 0ｓ ,ＤＡｈａｓｂｅｅｎｏｆｉｎｔｅｒｅｓｔｔｏｎｅｕｒｏｓｃｉｅｎ ｔｉｓｔｓａｎｄｃｈｅｍ…     

液相沉积法制备光催化活性TiO2薄膜和纳米粉体

采用液相沉积法，在35℃通过向六氟钛酸铵水溶液中添加硼酸和结晶诱导剂锐 铁矿型TiO2纳米晶，沉积出具有光催化活性的Ti02薄膜和纳米粉体．用XRD，AFM， 阶梯仪,UV-vis，BET法对Ti02薄膜和粉体的沉积条件、结构、厚度和性能进行了测 定和表征，并用亚甲兰的降解，评价了TiO2薄膜和纳米粉体的光催化活性．结果表 明，当反应物六氟钛酸铵与硼酸的摩尔比为1：2—1：4时，沉积的粉体和薄膜含有 锐钛矿相Ti02；经300℃热处理的Ti02薄膜和纳米粉体具有最高的光催化活性，它 的光催化活性是未经热处理前的5倍．本文还解释了经300℃热处理的薄膜和纳米粉 体具有最高光催化活性的原因．     

Interlayer Energy Transfer from Naphthalene to Anthracene Chromophores Organized in Langmuir—Blodgett Films

Interlayer energy transfer between 2,3-naphthol-10-hexadecylaza-15-crown-5(NC16) and N-[1-(9-methoxyanthryl)] decylaza-15-crown-5(A10C) within multilayer Langmuir-Blodgett films has been studied by steady-state fluorescence spectra. The donor and acceptor could be separated precisely by inserting stearic acid (SA) spacers. The efficiency of the energy transfer increases with the decrease in the donor-acceptor distance by a quadratic manner, suggesting the donor excitations are delocalized in the layer.     

A Transparent Thin Film with Hexagonal Mesostructure Containing Rhodamine 6G

A transparent this film was prepared by depositing the sol-gel mixture for the synthesis of MCM-41 mesoporous molecular sieve doped with rhodamine 6G(R6G) dye on glass substrates. The film of silica-surfactant-R6G materials, which was identified to possess hexagonally ordered mesostructure,was composed of nanocrystallites about 35 nm in diameter and 1-10μm in thickness. Cleanness of the substrates, concentration of the sol-gel mixture and rate of evaporation of the solvent were the key factors affecting transparency and homogeneity of the film. Moreover,optical change and lack in dye aggregation were observed to the R6G-functionalized MCM-41 thin film in contrast with that in ethanol solution.     

光降解性聚乙烯薄膜降解过程的表征

用全反射傅里叶红外光谱、Ｘ射线光电子能谱和示差扫描量热仪研究了含光敏剂的低密度聚乙烯薄膜在光降解过程中降解速率的变化规律，结果表明，光降解性聚乙烯薄膜在降解过程初期，降解速率很小，光敏剂显示抗氧化剂性能；降解２４ｈ后，降解速率迅速增加，直至薄膜破坏，光敏剂显示光引发剂性能。作为对比，同时研究了光敏剂和其它两种添加剂对聚乙薄膜光解速率的协同效应和两种添加剂体系显示的性能。     

STRUCTURE OF CRYSTALLINE DOMAINS IN SEMICRYSTALLINE BLOCK COPOLYMER THIN FILMS

Thin film morphology of a symmetric semicrystalline oxyethylene/oxybutylene diblock copolymer （E76B38） on silicon was investigated by tapping mode atomic force microscopy （AFM）. It is found that the nascent thin film is composed of multiple polymer layers having mixed thicknesses of L ≈ L0 and L ≈ L0/2 （L0 is the long period of the block copolymer in bulk） besides the first layer near the substrate. This shows that the crystalline domain in the block copolymer consists of double poly（oxyethylene） layers. Annealing leads to disappearance of the polymer layers with thickness L ≈L0/2, indicating that such polymer layers are metastable.     

表面活性剂模板在空气-水界面ZrO2薄膜中的稳定性

采用模板——十二烷基苯磺酸(DBS-H)在空气-水界面组装ZrO₂薄膜，研究了DBS-H在ZrO₂自组装薄膜中的水溶性、化学稳定性、热稳定性和光化学稳定性。模板的各类稳定性将直接控制ZrO₂薄膜结构，主要表现在层间距变化上。从模板与Na₂SiO₃反应的研究中获得了一种制备ZrO₂ / SiO₂复合氧化物薄膜的新方法，并推测出该复合薄膜的结构。     

高分辨率磁旋转编码器磁鼓材料的研制

采用磁浆涂布工艺制作了磁鼓涂层材料.研究了不同组分的配方对磁鼓涂层材料性能的影响,制备出性能良好的磁鼓.对Φ32～40mm的磁鼓进行了充磁测试,写入了128和256对极.采用金属薄膜磁电阻传感探头检测磁鼓表面分布磁场,信号通过电路放大、整形后接入示波器和计数器,结果显示输出信号波形良好,计数完整.