重氮树脂与银纳米颗粒自组装膜的图像化

从巯基乙酸包覆的银纳米颗粒(MA-AgNP)和重氮树脂(DR)由自组装方法, 制备了感光性的超薄膜. 在掩模(photomask)覆盖下对膜进行选择性曝光和紧接着的十二烷基硫酸钠水溶液显影, 未光照部分的膜被显影液完全洗脱, 而光照部分的膜不能洗脱, 从而形成清晰的图像. 用AFM和SEM对图像进行了表征.     

聚-4-偶氮磺酸基苯乙烯与四-(三甲氨基苯基)-卟啉的自组装膜及其光电转换性能

聚-4-重氮基苯乙烯(PDS)在碱性水溶液下通过与Na₂SO₃反应,制备了聚-4-偶氮磺酸基苯乙烯(PDSS).作为负离子聚电解质PDSS能与四-(三甲氨基苯基)-卟啉(TTMAP)通过离子相互作用进行层-层自组装.光照下该组装膜中的离子键转变为共价键,结果是组装膜对极性溶剂和盐水溶液变为非常稳定,从而能直接在KCl水溶液中测定其光电流.结果表明,该组装膜具有良好的光电转换性质.     

基于感光性重氮基高分子组装膜的微图像

从重氮基高分子的自组装膜,在掩膜覆盖下进行选择性曝光,再在十二烷基硫酸钠水溶液中显影,未曝光部分在显影中被洗除,而曝光部分因形成共价交联结构不被洗除,得到清晰图像。本文简要介绍了CdS纳米颗粒、Au纳米颗粒、手性聚苯胺以及DNA-Ag膜的微图像。     

水溶性含C_(60)聚电解质的制备及其与重氮树脂自组装膜AFMFFM的初步研究

通过BPO引发的溶液聚合 ,合成了水溶性的星状C6 0 苯乙烯 苯乙烯磺酸钠的三元共聚物 [Star shapedC6 0 poly(St SS) ],运用自组装技术 ,在水溶液中 ,含C6 0 的三元共聚物与重氮树脂 (Diazoresin)通过正负离子间的吸附力在云母基片上交替一层一层有序地组装成固体膜 .自组装膜经紫外光幅照反应 ,通过重氮基的分解 ,层间连接的离子键转变成共价键 ,从而增加薄膜的稳定性和堆砌密度 .用原子力显微镜 摩擦力显微镜(AFM FFM)考察了C6 0 在膜中的承载作用及比较不同链结构、不同链长、不同层数自组装膜的表面形貌和微摩擦性能 .初步的研究结果显示了聚合物薄膜的微摩擦性能与聚合物的化学结构、链长和膜的层数有密切关系     

聚(4-偶氮磺酸苯乙烯-co-4-乙烯基吡啶)与本征态聚苯胺的氢键自组装及其光电转换性能

合成了一种新的共聚体——聚(4-偶氮磺酸苯乙烯-co-4-乙烯基吡啶), 它含有吡啶环, 能作为氢受体与本征态聚苯胺进行氢键自组装. 在紫外光照下, 组装膜通过偶氮磺酸基的光解, 形成稳定的共价交联结构, 在电解质水溶液中也不被破坏, 可用作光电转换膜, 并能在盐水溶液中直接测定它的光电流. 结果表明含有本征态聚苯胺的自组装膜是一种良好的光电转换材料.     

共价键合四磺酸基铁酞菁有序多层膜电极

以玻碳电极为基础电极,经静电自组装方法将带负电荷的四磺酸基铁酞菁与带正电荷的含重氮基团的重氮树脂在电极表面进行层-层自组装,然后经紫外光照射,使铁酞菁的磺酸基与重氮树脂的重氮基发生交联反应,使层与层之间的离子键转为共价键,从而使铁酞菁在电极表面形成稳定、有序且处于分子水平的层-层构筑.用UV-Vis和IR光谱表征了组装过程,用CV方法研究了该电极的电化学性能及其对三氯乙酸的电催化还原.同时用计时电流法测定了三氯乙酸通过该类膜的扩散系数.     

含C60的聚电解质自组装膜微摩擦性能的研究

通过自由基引发溶液聚合反应,合成星状C₆₀-苯乙烯-丙烯酸聚合物,其钠盐作为高聚物负离子,与高聚物正离子的重氮树脂在云母上自组装成膜,利用紫外光照射反应,使膜层间连接的离子键转化成共价键.用原子力显微镜(AFM)和摩擦力显微镜(FFM)研究了不同链长和不同层数自组装膜的表面形貌及微摩擦性能.     

石墨烯分散液及其组装膜的性能

通过对比表面活性剂十二烷基硫酸钠(SDS)和聚乙烯醇(PVA)对石墨烯的分散能力,发现SDS可有效避免石墨烯片层之间的团聚,使得石墨烯在水溶液中分散得更加均匀.将浓度分别为0.39和0.30 mg/m L的石墨烯(G)和石墨烯片(GF)的SDS分散液旋涂在ITO电极表面制备出G膜和GF膜.透射电子显微镜和原子力显微镜观测结果表明,两类石墨烯膜均呈现出纱状透明的片状结构,同时具有石墨烯特有的褶皱.在石墨烯膜上继续进行钌配合物分子膜的自组装实验,得到G/Ru复合膜和GF/Ru复合膜.采用循环伏安法及紫外-可见吸收光谱法对石墨烯复合膜进行光电化学分析,结果表明石墨烯膜与钌配合物分子膜的复合可有效加强薄膜对太阳光的吸收.     

以OTS自组装单分子膜为探针研究TiO2液相空穴氧化机理

通过引入十八烷基三氯硅烷(OTS)自组装单分子膜作为氧化反应的探针, 在排除反应物的吸附和扩散的条件下研究溶胶-凝胶制备的TiO2薄膜表面光催化空穴氧化初始过程. 研究结果表明, 在紫外光照下, 水溶液中OTS部分覆盖的TiO2表面能够很快从憎水变成亲水. 存在空穴捕获剂后, TiO2表面OTS自组装单分子膜碳链的脱除受到明显抑制, 水接触角随光照时间变化非常小; 而水中羟基自由基捕获剂或者F-的存在则对TiO2表面OTS自组装单分子膜碳链的脱除几乎无影响. 这表明, 空穴氧化在TiO2表面OTS自组装单分子膜碳链的脱除中占主要地位.     

银电极上植酸钠/2-氨基-5-巯基-1,3,4-噻二唑混合自组装层的表面增强拉曼光谱和电化学研究

应用表面增强拉曼散射光谱(SERS)和电化学方法, 对银电极上2-氨基-5-巯基-1,3,4-噻二唑(AMT)和植酸钠混合自组装单层结构和缓蚀性能关系进行了研究. SERS光谱表明, 银电极表面形成AMT膜后, 再组装植酸钠分子能够弥合AMT膜的缺陷. 交流阻抗和极化曲线实验表明, 形成的混合自组装层比单一AMT自组装层表现出更好的缓蚀性能. AMT膜层的等效电路为R(Q(R(Q(RW)))); 混合膜层电路图为LR(Q(R(Q(R)))).     

Au nanoparticle micropatterns prepared from self-assembled films

A kind of hybrid multilayer film based on mercaptobenzoic acid-capped Au nanoparticles (MBA-Au-NPs) and photoreactive nitrodiazoresin (NDR) has been fabricated via electrostatic self-assembly. Upon exposure to UV light, the initial ionic bonds between the layers of the film convert into covalent bonds and the film stability toward polar solvents, salt, or surfactant solutions increases significantly. The micropatterned NDR/MBA-Au-NP film with the covalently linked architecture was formed by selecting exposure of the film through a photomask and later developed in sodium dodecyl sulfate (SDS) aqueous solution. The metallic Au-NP micropatterns, furthermore, are produced by sintering the micropatterned NDR/MBA-Au-NP film at 550 degrees C, at which the organic components are removed completely. The well-defined micropatterns were characterized with atomic force microscopy (AFM), field emission scanning electron microscopy (FE-SEM), microscope with a charge-coupled device (CCD) camera, and X-ray photoelectron spectroscopy (XPS).     

NIR-light-induced deformation of cross-linked liquid-crystal polymers using upconversion nanophosphors

When upconversion nanophosphors were incorporated into an azotolane-containing cross-linked liquid-crystal polymer film, the resulting composite film generated fast bending upon exposure to continuous-wave near-IR light at 980 nm. This occurs because the upconversion luminescence of the nanophosphors leads to trans-cis photoisomerization of the azotolane units and an alignment change of the mesogens. The bent film completely reverted to the initial flat state after the light source was removed.     

Voltammaetric characterization of small platinum-iridium-based mercury film electrodes

A 25-μm diameter microelectrode is constructed from 80% platinum-20% iridium alloy. Mercury films and hemispheres are readily deposited by cathodic reduction of mercury(I) onto the electrode surface and are completely removed by anodic oxidation. The platinum-iridium surface, in contrast with a platinum surface, is not scarred by interaction with mercury. Steady-state reduction currents and sharp oxidation peaks are obtained for the determination of cadmium at the PtIr-based mercury film electrode. The voltammetric signals depend on the age of the film, and hence routine analytical applications will require further development.     

Enhanced removal of bilirubin on molecularly imprinted titania film

Titania film imprinted by bilirubin molecule at the surface of quartz crystal was prepared using molecular imprinting and surface sol-gel process. The molecularly imprinted titania film was characterized by FTIR spectra, and the interaction between bilirubin and imprinted film was investigated using quartz crystal microbalance (QCM) technique. Compared with pure titania film, the molecularly imprinted titania film exhibits a much higher adsorption capacity for the target molecule, and the adsorption kinetic parameter estimated from the in situ frequency measurement is about 1.6×10(8) M(-1), which is ten times higher than that obtained on pure titania film. The photocatalytic measurements indicate that the bilirubin adsorbed on molecularly imprinted titania film can be completely removed under UV illumination. Moreover, our study indicates that the molecularly imprinted titania film possesses a better stability and reusability.     

The use of Photoshop software to estimate the adhesion and rust‐resistant properties of coating film

A new method for evaluating the adhesion and rust‐resistant properties of coating film is proposed and validated by Photoshop software. A color scanner and Photoshop processing software are used to scan coatings film and analyze images by this method. The percentage of film area removed calculated by pixels is used to classify adhesion of the cross‐cut test ASTM D3359. The area removed is measured by using the functions of area selection and histogram in Photoshop software. The adhesion of 14 samples about standard classification pictures of crosscut adhesion test of ASTM D3359‐02 and self‐made samples, are classified. The percent area removed given by ASTM standard and the percent pixels removed measured by Photoshop is correlated, with the correlation coefficient being 0.997. On the other hand, the rusty areas of regular and irregular graphics are quantitatively determined using $A' = {X'\over X}\times A$ to estimate the rust resistant properties. The determining error of rusty areas compared with the vernier caliper is under 3.0%. Quantitative evaluation for extent of corrosion of the coating is realized. The method is more scientific and specific than the present method of that evaluated by the human mind. Copyright © 2010 John Wiley & Sons, Ltd.     

微电极结构Ag/ZnO/NiO三层复合膜的制备及光催化性能的研究

通过溶胶-凝胶结合光还原沉积法在普通玻璃片上制备了Ag-ZnO-NiO系复合薄膜。使用SEM,PL,XRD,UV-Vis等手段对薄膜的表面形貌,物相组成及光学性质作了考察和研究。XRD和UV-Vis分析表明复合薄膜中包含NiO和ZnO的双层异质结构;FESEM结果表明Ag和ZnO分别在其各自的衬底上生长但没有形成完全覆盖,PL光谱表明三层膜的发光强度小于双层膜和单层膜。使用甲基橙为模型底物测试了薄膜在紫外线下的光催化氧化能力,结果表明,三层复合薄膜Ag/ZnO/NiO的活性相比氧化锌单层薄膜和双层薄膜有不同程度的提高。这是由于上层薄膜不能完全包裹下层膜,导致在表面形成了许多微电极结构,这些微电极结构能够使光生电子空穴对得到有效分离。     

Structures of 17,19-hexatriacontadiyne monolayers on Au(111) studied by infrared reflection absorption spectroscopy and scanning tunneling microscopy

The aggregation and reaction of 17,19-hexatriacontadiyne molecules are studied on a Au(111) surface. The molecular orientation and arrangement are elucidated by infrared reflection absorption spectroscopy (IRAS) and scanning tunneling microscopy (STM). A vapor-deposited monolayer and a multilayered film formed by adsorption from the solution provide IRA spectra with bands due to the antisymmetric and symmetric stretching of methylenes in the gauche conformation. After the adsorbed film is rinsed with the solvent, however, the spectrum loses the gauche bands and is characterized by the enhanced C-H(distal) and C-H(proximal) stretching bands, which means that all-trans molecules are laid flat. Only STM images for the rinsed film display columnar structures on the herringbones of the reconstructed Au(111) surface; the alkyl chain direction is found to be parallel to the Au atom row. The results indicate that an ordered monolayer is formed first at the liquid-solid interface, and then, disordered overlayers with the gauche conformation are grown but removed by a rinse. Upon exposure to UV light, thus obtained monomer columns are converted into oligomers with flexible backbones and an increased gauche population in the alkyl chains, which resemble red phase polydiacetylenes in LB films.     

Biodegradation of a medium-chain-length polyhydroxyalkanoate in tropical river water

The medium-chain-length polyhydroxyalkanoate (PHA_MCL) produced by Pseudomonas putida PGA1 using saponified palm kernel oil as the carbon source could degrade readily in water taken from Kayu Ara River in Selangor, Malaysia. A weight loss of 71.3% of the PHA film occurred in 86 d. The pH of the river water medium fell from 7.5 (at d 0) to 4.7 (at d 86), and there was a net release of CO₂. In sterilized river water, the PHA film also lost weight and the pH of the water fell, but to lesser extents. The C8 monomer of the PHA was completely removed after 6 d of immersion in the river water, while the proportions of the other monomers (C10, C12, and C14) were reversed from that of the undegraded PHA. By contrast, the monomer composition of the PHA immersed in sterilized river water did not change significantly from that of the undegraded PHA. Scanning electron microscopy showed physical signs of degradation on the PHA film immersed in the river water, but the film immersed in sterilized river water was relatively unblemished. The results thus indicate that the PHA_MCL was degraded in tropical river water by biologic as well as nonbiologic means. A significant finding is that shorter-chain monomers were selectively removed throughout the entire PHA molecule, and this suggests enzymatic action.