介孔氧化硅膜在多孔陶瓷载体上的组装

采用过滤成膜方式结合溶剂挥发诱导自组装方法在多孔氧化铝中空纤维上制备了介孔氧化硅膜。XRD、TEM和N₂吸附脱附实验结果显示非担载膜具有有序的六方介孔结构。通过对中空纤维担载膜的XRD分析进一步确认介孔氧化硅膜的形成。SEM和EDS线扫描结果显示制备的担载膜表面完整、无缺陷,膜层和载体界面之间结合紧密。在此基础上对介孔膜在多孔陶瓷载体上的形成机理进行了探讨。     

骨架结构多孔TiO2薄膜增强染料敏化太阳能电池性能

以空心球状TiO₂为基体、以片状TiO₂为骨架,采用刮刀法制备了染料敏化太阳能电池的多孔TiO₂光阳极薄膜。光电转化效率测试结果表明,当作为骨架支撑材料的片状TiO₂含量为20wt%时,光阳极薄膜组装成太阳能电池的光电转化效率达到最高值4.53%,比商业P₂₅制备的无孔无骨架TiO₂薄膜电池(4.06%)及无骨架结构的多孔TiO₂薄膜电池(4.17%)的性能均有显著提高。当片状TiO₂的最佳含量为20wt%电池薄膜厚度为33μm时,太阳能电池光电转化效率进一步提升为7.06%。光电性能增强的原因是骨架结构有利于快速传输电子并增大染料吸附量。本研究通过设计制备具有骨架结构的多孔TiO₂薄膜为提高染料敏化太阳能电池性能提供了新的思路。     

纳米TiO2介孔薄膜的模板组装制备研究

以TiCl₄为无机前驱体、三嵌段高分子共聚物EO₂₀PO₇₀EO₂₀为模板剂，在非水条件下制备了有序的锐钛矿TiO₂纳米晶介孔薄膜。通过热重-差热（TG-DTA）分析、X射线衍射（XRD）分析、原子力显微观察（AFM）及N₂吸附-脱附等测试对样品进行了表征。结果表明，薄膜具有均一的大介孔孔径（～10 nm），其BET比表面积为150 m²·g^-1，薄膜较宽的无机壁厚显著提高了介孔结构的热稳定性。通过红外（IR）光谱分析考察了溶胶-凝胶过程中发生的物理化学变化。在对薄膜表面形貌进行AFM观察的基础上初步探讨了嵌段共聚物EO₂₀PO₇₀EO₂₀对薄膜孔结构形成的导向机理。     

骨架结构多孔TiO2薄膜增强染料敏化太阳能电池性能

以空心球状TiO₂为基体、以片状TiO₂为骨架,采用刮刀法制备了染料敏化太阳能电池的多孔TiO₂光阳极薄膜。光电转化效率测试结果表明,当作为骨架支撑材料的片状TiO₂含量为20wt%时,光阳极薄膜组装成太阳能电池的光电转化效率达到最高值4.53%,比商业P25制备的无孔无骨架TiO₂薄膜电池(4.06%)及无骨架结构的多孔TiO₂薄膜电池(4.17%)的性能均有显著提高。当片状TiO₂的最佳含量为20wt%电池薄膜厚度为33 μm时,太阳能电池光电转化效率进一步提升为7.06%。光电性能增强的原因是骨架结构有利于快速传输电子并增大染料吸附量。本研究通过设计制备具有骨架结构的多孔TiO₂薄膜为提高染料敏化太阳能电池性能提供了新的思路。     

溶胶-凝胶伴随相分离制备SiO2多孔块体

以正硅酸甲酯(TMOS)为前驱体, 0.01 mol·L^-1盐酸(HCl)为催化剂, 环氧丙烷(PO)为凝胶促进剂, 粘均分子量(M_v)为10000的聚氧化乙烯(PEO)为相分离诱导剂, 采用溶胶-凝胶伴随相分离制备SiO₂多孔块体材料,利用差热分析(DTA)、傅里叶变换红外(FT-IR)光谱、扫描电镜(SEM)、X射线衍射(XRD)、汞压、N₂吸附/脱附等测试技术对所制得的SiO₂多孔块体进行了表征, 探讨了环氧化物调控溶胶-凝胶以及PEO诱导相分离机理. 结果表明, 加入PEO能诱导SiO₂凝胶发生相分离, 当PEO/TMOS摩尔比为0.0018时, 可以获得共连续多孔结构的SiO₂块体材料, 其大孔孔径分布在1-3 μm之间, 比表面积达719 m²·g^-1, 孔体积为0.48 m³·g^-1. 环氧丙烷因其环氧原子的强亲核性和不可逆的开环反应, 促进溶胶-凝胶转换, 同时借助吸附在SiO₂低聚物上的PEO诱导SiO₂凝胶相分离, 从而制备共连续大孔及骨架结构的多孔块体.     

二氧化硅溶胶的形成与硅胶膜性能

采取溶胶-凝胶成膜技术,以正硅酸乙酯(TEOS)为原料,分别以水为溶剂NH3催化、乙醇为溶剂HCl催化和冰醋酸为溶剂各自制备出粒状结构、簇状结构和网状结构的二氧化硅溶胶,丙三醇作为添加剂与TEOS水解中间体以氢键结合控制二氧化硅溶胶形态,聚乙烯醇(PVA)与二氧化硅溶胶形成有机/无机互穿网络结构,易于成膜。热处理能使二氧化硅凝胶薄膜中的添加剂逸出并形成疏松结构,塑性形变使硅胶薄膜形成多孔、疏松、致密结构二氧化硅薄膜。实验表明,催化剂和溶剂效应直接影响着二氧化硅溶胶微观结构,从而影响着所形成的硅胶薄膜的微结构。多孔硅胶膜的平衡吸湿量是致密硅胶薄膜的3倍;而疏松结构的硅胶薄膜的吸湿量高于多孔硅胶薄膜的吸湿量,且其吸附速率明显大于多孔硅胶薄膜的吸附速率。     

Ag3PO4/Ni薄膜的制备及其光催化降解罗丹明B的性能和机理

用电化学方法制备Ag₃PO₄/Ni薄膜,以扫描电子显微镜(SEM)、X射线衍射(XRD)和紫外-可见漫反射光谱(UV-Vis DRS)对薄膜的表面形貌、晶相结构、光谱特性及能带结构进行了表征,以罗丹明B为模拟污染物对薄膜的光催化活性和稳定性进行了测定,采用向溶液中加入活性物种捕获剂的方法对薄膜光催化降解机理进行了探索.结果表明:最佳工艺下制备的Ag₃PO₄/Ni薄膜具有致密的层状表面结构,是由多晶纳米颗粒构成的薄膜.薄膜具有较高的光催化活性和突出的光催化稳定性,可见光下催化作用60 min,薄膜光催化罗丹明B的降解率是多孔P25 TiO₂/ITO纳米薄膜(自制)的2.3倍;在保持薄膜光催化活性基本不变的前提下可循环使用6次.给出了可见光下薄膜光催化降解罗丹明B的反应机理.     

纳米多孔结构镍基复合膜电极的电化学法制备及其电容特性

通过对电沉积法得到的Ni-Cu合金镀层进行电化学去合金化处理, 制备了纳米多孔结构金属镍膜. 采用循环伏安法对多孔金属镍膜在1 mol·L^-1 KOH溶液中进行阳极氧化处理, 获得了纳米多孔结构的镍基复合膜电极. 应用扫描电子显微镜(SEM)、X射线衍射(XRD)、X射线光电子能谱(XPS)和电化学技术对所制备的膜电极的物理性质及赝电容特性进行了表征. SEM、XRD和XPS的测试结果表明, 所制备的纳米多孔结构镍基复合膜由Ni、Ni(OH)₂和NiOOH组成. 电化学实验结果显示, 该复合膜在20 A·g^-1的充放电电流密度下, 给出了578 F·g^-1的初始比电容; 在1000次充放电循环后, 它的比电容值为544 F·g^-1, 电容保持率为94%. 纳米多孔结构有利于KOH电解液的渗透, 从而促进反应物种在电极内部的传输; 纳米多孔的金属镍基体可以提高Ni(OH)₂膜的电子导电性; 纳米大小的Ni(OH)₂颗粒能够缩短质子的固相扩散路径. 上述因素是所制备的纳米多孔结构镍基复合膜电极具有优异赝电容特性的主要原因.     

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。     

电沉积三维多孔Pt/SnO2薄膜及其对甲醇的电催化氧化

在高电流密度下以阴极析出的氢气泡为“模板”电沉积三维多孔Sn薄膜, 经在200 ℃ 2 h和400 ℃ 2 h热处理氧化后电沉积金属Pt, 制得三维多孔的Pt/SnO₂ (3D-Pt/SnO₂)薄膜. 通过扫描电镜(SEM)和X射线衍射(XRD)分析了薄膜的形貌和结构. 结果显示Pt主要沉积在SnO₂枝晶上, 形成Pt_shell/SnO_2core结构的枝晶. 在0.5 mol•dm^－3 H₂SO₄＋1.0 mol•dm^－3 CH₃OH溶液中的循环伏安结果表明, 3D-Pt/SnO₂薄膜电极在酸性溶液中电催化氧化甲醇的性能优于电沉积的纯铂电极, 而且具有较高的稳定性.     

Porous structures of polymer films prepared by spin coating with mixed solvents under humid condition

We investigate the effects of interfacial energy between water and solvent as well as polymer concentration on the formation of porous structures of polymer films prepared by spin coating of cellulose acetate butyrate (CAB) in mixed solvent of tetrahydrofuran (THF) and chloroform under humid condition. The interfacial energy between water and the solvent was gradually changed by the addition of chloroform to the solvent. At a high polymer concentration (0.15 g/cm3 in THF), porous structures were limited only at the top surfaces of CAB films, regardless of interfacial energies, due to the high viscosity of the solution. At a medium concentration (approximately 0.08 g/cm3 in THF), CAB film had relatively uniform pores at the top surface and very small pores inside the film because of the mixing of the water droplets with THF solution. When chloroform was added to THF, pores at the inner CAB film had a comparable size with those at the top surface because of the reduced degree of the mixing between the water droplets and the mixed solvent. A further decrease in polymer concentration (0.05 g/cm3 in THF) caused the final films to have a two-layer porous structure, and the size of pores at each layer was almost the same.     

聚乳酸蜂窝状多孔膜的形成与控制

以单一组分聚L-乳酸(PLLA)为成膜材料,利用水辅助法制备了聚乳酸(PLLA)蜂窝状多孔膜.利用扫描电镜(SEM)和原子力显微镜(AFM)观察多孔膜形貌.研究溶剂、溶液浓度、环境温度和湿度等因素对所成多孔膜结构的影响.实验结果表明,高湿度环境和具有一定浓度的聚合物溶液是制备蜂窝状多孔膜的必要条件.溶剂的挥发性是形成规整蜂窝状孔结构的关键因素.环境相对湿度由43%增加到91%,PLLA多孔膜的孔径由(1.75±0.24)μm增加到(11.50±1.43)μm,且孔呈现六边形的蜂窝状结构.扫描电镜断面和AFM表明:膜表面形成了深度约为1.8μm的单层孔结构.通过控制溶液浓度、环境温度和湿度等因素来控制膜的表面形貌及其所成蜂窝状孔的大小.最佳的成膜条件为溶剂CH2Cl2,湿度75%RH,温度34℃,浓度3 wt%.讨论了蜂窝状多孔膜的形成机理.     

聚苯乙烯-嵌段-聚丁二烯有序多孔膜在可收缩膜上的形变研究和光学性质

利用溶剂散逸自组装法在潮湿的条件下,制备了聚苯乙烯-聚丁二烯嵌段聚合物（PS-b-PB）有序多孔膜。 利用聚乙烯可收缩膜将PS-b-PB多孔膜进行两次收缩,形成小孔径的有序多孔膜。 通过收缩,膜上的孔由圆形变为长方形或者梭形,孔的尺寸从微米级收缩至亚微米级。 利用扫描电子显微镜对膜收缩过程中2种形状产生的机理进行了研究。 结果表明,PS-b-PB结合了聚苯乙烯（PS）和聚丁二烯（PB）两个均聚物的优点,收缩后仍然保持膜结构的平整性,从而将不可见的热场变化转变为可见的光学变化。     

界面上蜂窝状多孔薄膜的构建、性质和应用

综述了以Breath Figure(呼吸图案)法制备聚合物及纳米颗粒蜂窝状多孔结构的研究现状.当潮湿的气流吹到聚合物或纳米颗粒的有机溶液表面时,溶剂蒸发导致水微滴在液体表面冷凝重排成六角阵列结构.溶剂和水微滴蒸发完毕后,聚合物或纳米颗粒在基底上形成具有六角阵列的蜂窝状多孔结构.该技术是自组装领域的一大进展,在生物技术、组织工程、微图像技术、高端分离技术、光催化及医药等领域有望获得重要应用.本文系统阐述了规整蜂窝状孔结构材料的构建方法、构建材料、形成机理以及影响因素(包括湿度、浓度、气流方向和速度、溶剂、基底曲率等),评述了蜂窝状多孔薄膜的性质和应用,并对其在化学和材料科学领域的应用前景作了展望.     

Tunable morphology of 2D honeycomb-patterned films and the hydrophobicity of a ferrocenyl-based oligomer

Honeycomb-patterned polymer films with tunable pore size and regularity of ordered two- or three-dimensional hexagonal arrays have met with widespread interest in recent years in different areas, for instance as separation and superhydrophobic materials. Herein, 2D honeycomb-patterned films of amphiphilic ferrocenyl-based oligomer with cholesterol as side chains were prepared by the breath-figure method on solid surfaces and their surface-wetting behavior were tested. These films can be simply prepared by spreading a mixture of polymer and organic solvents on a solid surface under moist airflow and at an air/water interface without any extra moist airflow. An ordered 2D hexagonal array of pores with monodisperse size distribution can be obtained over a large area by changing various influencing factors, including humidity, wet volume, concentration, selective solvent, and spreading method, which provides a facile route to regulate the morphology of patterned porous films. The surface-wetting behavior indicates that a higher hydrophobicity of the ferrocenyl-based oligomer honeycomb films can be obtained by modulating the pore size and regularity. It is expected that this could promote the potential application of ordered porous polymer films in hydrophobic materials and biochemistry.     

Porous thin films based on photo-cross-linked star-shaped poly(D,L-lactide)s

Self-assembly processes and subsequent photo-cross-linking were used to generate cross-linked, ordered microporous structures on the surfaces of well defined four-arm star-shaped poly(D,L-lactide) (PDLLA) thin films. The four-arm star-shaped PDLLAs were synthesized using an ethoxylated pentaerythritol initiator. Solutions of the PDLLAs were cast in a humid environment, and upon solvent evaporation, ordered honeycomb structures (or breath figures) were obtained. Correlations between molar mass, polymer solution viscosity, and pore dimensions were established. The average pore dimension decreased with increasing polymer solution concentration, and a linear relationship was observed between relative humidity and average pore dimensions. Highly ordered microporous structures were also developed on four-arm star-shaped methacrylate-modified PDLLA (PDLLA-UM) thin films. Subsequent photo-cross-linking resulted in more stable PDLLA porous films. The photo-cross-linked films were insoluble, and the honeycomb structures were retained despite solvent exposure. Free-standing, structured PDLLA-UM thin films were obtained upon drying for 24 h. Ordered microporous films based on biocompatible and biodegradable polymers, such as PDLLA, offer potential applications in biosensing and biomedical applications.     

Superhydrophobic and lipophobic properties of self-organized honeycomb and pincushion structures

This report describes the simple preparation of superhydrophobic and lipophobic surfaces by self-organization. Microporous polymer films of a fluorinated polymer with hexagonally arranged pores were prepared by casting from solution under humid conditions. Hexagonally packed water microdroplets were formed by evaporative cooling on the surface of the casting solution. After solvent evaporation, a honeycomb-patterned polymer film was formed with the water droplet array acting as a template; the water droplets themselves evaporated soon after the solvent. Two porous polymer layers were stacked vertically, separated by pillars at the hexagon vertexes. After peeling off the top layer using adhesive tape, a pincushion-like structure was obtained. Here, we show that superhydrophobic behavior was achieved, with the maximum contact angle, 170 degrees, observed using these pincushion structures. Theoretical calculations fit the experimental results well. The lipophobic properties of the films are also discussed.     

Stabilization of self‐assembled microdroplets using short chain alcohols

The condensation of water vapor on a volatile polymeric solution leads to a porous surface after evaporation of both solvent and water. However, the stabilization of the water microdroplet is of great importance, which can be achieved using specific polymer or adding a third substance to the polymer solution. Short chain alcohols (methanol, ethanol, and n‐propanol) are utilized to fabricate a self‐assembled porous honeycomb film of linear, low molecular weight polystyrene using the breath figure technique. A combination of breath figure processing and the effect of alcohol on a water droplet can stabilize the pattern and make pores on the surface of the polymer film. The quality of the porous honeycomb film is strongly dependent on the type of alcohols and the concentration of polymer. In a specific range of polymer and alcohol concentration, pores cover all the surface of the polymer film. This method offers the possibility of producing a honeycomb structure with no trace of additive residual after the fabrication process and avoiding polymer modification. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2015 , 53, 709–718     

聚丁二烯有序多孔膜在热缩型聚乙烯膜上的收缩

采用溶剂散逸自组装制备了聚丁二烯(PB)有序多孔膜。水珠能在冷的高分子溶液表面凝结形成有序的阵列,溶剂蒸发后,高分子材料按照水珠排列的形貌形成了有序多孔膜。两性共聚物的加入能够起到稳定水滴的作用,从而确保多孔膜成为有序的结构。利用聚乙烯可收缩膜将聚丁二烯多孔膜收缩2次,得到长方形、梭形、条形和哑铃形的孔。孔的尺寸从微米级收缩至亚微米级,并对产生各种形状的机理进行了研究。     

Preparation of porous crosslinked polymers with different surface morphologies via chemically induced phase separation

A novel and simple method for producing crosslinked polymers with controlled surface morphology is demonstrated in this study. The porous crosslinked polymers were made via stepwise polymerization of a mixture of epoxy resin, D.E.R. 331, and diethylene triamine in diisobutyl ketone (DIBK). Both the surface and bulk morphology of the cured polymers are dependent on the solvent fraction of the reactive solution. When the concentration of DIBK was more than about 30 vol %, chemically induced phase separation (CIPS) occurred during cure at 30 °C, and closed spherical pores, about 4 μm in diameter, appeared in the bulk of the crosslinked polymers, whose diameter increased to about 4.5 and 9 μm when the solvent was increased to 40% and 50%, respectively. The surface morphology of the epoxy networks is different from that of the bulk. Smaller pore size or dense skin was formed via the CIPS process, which can be tailored by covering the reactive solution with different contacting films during cure. The competition between the solvent‐rich and polymer‐rich phase absorbed onto the surface of contacting film could change the surface morphology. Therefore, the porous crosslinked polymers having similar bulk morphology could be prepared with a variety of surface structures. © 2011 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2011