功能性层层组装厚膜

层层组装是一种基于物质交替沉积而制备复合膜的方法,可以实现膜的结构和组成的精确调控。层层组装通常被认为是超薄膜的构筑方法。与超薄膜相比,微米或亚微米的厚膜更容易实现高的负载、微纳复合结构的调控、多功能集成以及赋予膜更高的稳定性。以作者的研究结果为基础,阐明TN用大尺度的构筑基元,包括聚合物复合物、大尺度的无机粒子以及聚集的粒子,可以方便地实现微米厚度的层层组装膜的快速构筑。以快速构筑的厚膜为功能载体,实现了层层组装膜的自修复、高负载、细胞可控粘附及多功能集成。进一步,将层层组装厚膜从基底上剥离制备了自支持膜,拓展了层层组装膜的功能。     

聚电解质层层组装在甲氨蝶呤负载与缓释方面的应用研究

基于层层组装技术,制备了能够长效释放抗癌药物甲氨蝶呤(MTX)的层层组装膜。分别通过聚天冬氨酸(PASP)和聚烯丙基胺盐酸盐-甲氨蝶呤(PAH-MTX)复合物基于静电作用的层层组装负载,以及先制备空白膜再后扩散负载这两种方法完成了MTX的膜内负载。层层组装负载中,聚电解质浓度增大则MTX负载量增多,当复合物pH=7.5时MTX的负载量较高且可持续释放36h。后扩散负载中,PASP-PAH/PAH空白膜与PASP/PAH及PASP/PAH-PASP空白膜相比,更有利于MTX的后扩散负载。后扩散负载与层层组装负载相比,药物负载量增多,但缓释时间降低。该研究为药物负载及缓释材料的制备提供了参考。     

纳滤膜制备方法的研究

作为一种新型分离膜,纳滤膜与反渗透膜和超滤膜相比具有特殊性能和优点,已经在很多领域得到了广泛的应用。目前国内外纳滤膜制备方法主要分为相转化法、复合法;着重介绍了目前应用最广泛也是最高效的复合法制备纳滤膜,其中复合法主要包括化学交联法、界面聚合法、层层组装法和膜表面接枝法,并指出了纳滤膜的发展方向。     

微球堆积有机无机复合膜及渗透汽化性能初探

采用分散聚合法制备了聚甲基丙烯酸缩水甘油酯(PGMA)微球,考察了温度对微球合成的影响;采用聚乙烯亚胺(PEI)对微球进行氨基化改性,通过层层自组装技术制备了微球堆积有机无机复合膜并对其成膜机理进行了研究;初步尝试了通过动态LbL法在陶瓷支撑体上组装微球堆积有机无机复合膜,复合膜显示了一定的醇水渗透汽化分离性能,在复合层数为7层的情况下,复合膜对95%的叔丁醇/水体系的分离因子α为74,通量J为359 g/(m2·h)(75℃).     

壳聚糖的分维模拟及自组装复合膜的制备与表征

用原子力显微术及计算机模拟计算研究了壳聚糖的分形维数,壳聚糖与肝素形成的自组装复合膜。对壳聚糖的分形维数的模拟计算表明,壳聚糖胶粒堆积程度越高,其分形维数越小．利用两种方法即层层自组装法和混合成膜法制备了壳聚糖／肝素的复合膜,与后一方法所制备的膜相反,前一方法制备的膜的表面颗粒虽然较小但平均粗糙度较大。原子力显微术是生物大分子分形表征、生物膜表征的有力工具。     

聚电解质层层自组装制备PV、NF膜研究进展

层层自组装作为一种新的膜制备技术已被人们应用于渗透汽化膜、纳滤膜等分离膜的研制中,主要介绍了基膜、聚电解质电荷密度、聚合物浓度、分子量、组装层数等因素对膜性能的影响以及近年来人们为提高组装效率所做的一些研究工作.     

硼钨铜杂多酸/聚酰胺-胺多层膜的制备及其电催化性能

通过层层自组装技术在氧化锢锡(ITO)电极上制备Keggin型硼钨铜杂多酸/聚酰胺-胺有机-无机复合多层膜.利用X射线光电子能谱(XPS),UV-Vis光谱和原子力显微镜(AFM)等手段对多层膜的组成和表面形貌进行了表征.结果表明,杂多酸阴离子和聚酰胺-胺树形分子通过静电相互作用形成了多层膜且膜的增长均匀.杂多酸阴离子...     

气-液界面非担载SiO2无机膜的仿生制备

利用有机大分子CTAB的自组装体为模板来调制正硅酸乙酯（TEOS）的水解缩聚，于气－液界面上制备出非担载SiO2无机膜，对了膜时间进行了选择，考察了仿生制备SiO2膜过程中物料配比对成膜质量的影响，对其进行了优化，由CTAB极性头基排列而成的六边形区域聚集于溶液表面，TEOS在其内部的水解缩聚及随后的层层复制过程形成了仿生合成膜的空间网络结构。     

层层自组装法制备氧化石墨烯复合单价选择性离子交换膜

将氧化石墨烯(GO)添加到聚丙烯酸(PAA)溶液中,并与聚乙烯亚胺(PEI)在阳离子交换膜表面通过层层自组装(LBL)法制备了单价选择性离子交换膜。结果表明,PEI为表层的复合膜,具有更高的单价离子选择性,随着层层自组装的进行,GO连续地沉积到膜的表面。复合膜的面电阻随组装层数的增加而增大,相比于未添加GO的多层膜,GO的加入有利于膜电阻的降低。同时,随着自组装层数的增加,复合膜的单价离子分离效率提高;GO浓度升高,复合膜的单价离子选择性先升高后降低,当GO浓度升高至0.5 g/L时,复合膜的分离效率最高。     

氧化石墨烯改性聚乙烯亚胺/木质素磺酸钠纳滤膜的制备及性能研究

在聚乙烯亚胺(PEI)/木质素磺酸钠(SL)纳滤膜的基础上,利用层层自组装技术,制备了氧化石墨烯(GO)改性的PEI/SL纳滤膜,通过ATR-FTIR、XPS、SEM等表征手段研究添加GO对复合膜结构的影响.结果表明,GO加入PEI或SL不影响自组装过程,并可嵌入改性膜的分离层内,且GO在PEI中的分散性优于其在SL中的分散性.在1.0 MPa操作压力下,GO改性膜分离2 g/L MgSO_4溶液的纳滤性能测试结果显示,GO在PEI溶液中添加质量浓度为0.025和0.035 g/L时性能较优,在SL溶液中添加质量浓度为0.015和0.025 g/L时性能较优,其中最优膜截留率可达90%,较未改性的PEI/SL膜提高了19%.通过层层自组装法制备的GO改性的新型纳滤膜,为改善纳滤膜性能提供了参考.     

层层自组装技术的研究进展及应用情况

层层自组装技术(Layer-by-layer self-assembly,LbL)是正处于发展阶段的新技术。与传统成膜技术相比,该技术能组装的材料多种多样(如聚电解质、纳米颗粒、有机小分子等),可以通过模板精确控制薄膜的表面结构和尺寸。薄膜的通透性能和力学性能可以通过控制组装材料、沉积层数、组装条件等来改善。对层层自组装技术的研究进展及应用情况进行了综述,较为详细地介绍了层与层之间作用力的研究进展,阐述了LbL技术在电化学电容器、光敏微胶囊、分离膜、生物化学及药物释放中的应用,并对LbL技术的发展前景进行了展望     

强化自组装技术在多层复合分离膜领域的应用

强化自组装技术是近年来被发展的一种制备聚电解质复合物多层膜的新方法,该法巧妙地利用外加力与聚合物间作用力的协同效应,强化组装过程,简化成膜程序,提高膜分离性能.总结了近年来课题组在这一领域的研究进展.     

基于LBL技术组装的渗透汽化聚电解质复合膜

综述了近年来采用层层静电吸附(LBL)技术组装的聚离子复合物渗透汽化膜的研究进展.对支撑体荷电处理方法进行了分类,讨论了聚离子派对、选择原则及自组装条件,并就LBL技术组装聚电解质复合物的一些发展动向提出了建议.     

Fabrication of Au/SiO2 Nanocomposite Films by Self-Assembly Multilayer Method

Gold colloid was prepared by chemical reduction of hydrogen tetrachloroaurate, polyelectrolyte/gold nanoparticle/silica nanoparticie composite films were fabricated via an electrostatic self-assembly multilayer method, and composite films of gold nanoparticle dispersed in silica matrix were formed by heat-treating the polyelectrolyte/gold nanoparticle/silica nanoparticle composite films to eliminate the polyelectrolyte. The obtained composite films were investigated with UV-vis, TEM, AFM and XRD. The results show that the self-assembly multilayer method is a promising process to produce composite films of gold nanoparticle-dispersed in organic and/or inorganic matrixes.     

Electric field directed layer-by-layer assembly of highly fluorescent CdTe nanoparticles

An electric field directed layer-by-layer assembly technique has been developed by combining electrophoretic deposition and the layer-by-layer self-assembly method. This technique is employed to realize spatially selective deposition of CdTe nanoparticles on electrodes of indium-tin oxide (ITO). The fluorescence measurements prove that the selectivity of the film deposition increases against applied voltage and reaches 99% when the voltage is 1.4 V. Upon further increase of the voltage, the selectivity slightly decreases. This decrease occurs because high voltage leads to a degradation of CdTe particles and thus reduces fluorescence intensity of the resultant CdTe film. However, fluorescence investigation indicates that a spacer layer of polyelectrolyte complex between the ITO electrode and the CdTe film is useful to protect the CdTe from being destroyed under high voltages.     

静电自组装制备含苝衍生物的纳米层状复合膜

采用静电自组装方法制备了稳定的含苝衍生物纳米层状复合膜．用石英晶体微天平(QCM)对静电自组装过程进行了原位监控，发现组装次数与QCM频率变化呈线性关系，通过静电吸附得到的多层累积薄膜具有层状结构，X射线光电子能谱图上出现苝衍生物的特征峰表明组装的薄膜中含有苝衍生物．原子力显微镜表征结果表明，复合膜在一定程度上规整并且均匀的覆盖在电极表面，但存在分子团聚现象，将苝衍生物小分子溶解在聚电解质溶液中作混合浸渍液，提高了组装薄膜的稳定性．     

大分子自组装体系及自组装功能膜结构的研究

本文主要介绍了３种大分子自组装体系，含硫化合物的在重金属表面的自组装功能膜、聚合物在溶液状态下的自组装体系和聚合物基材上的自组装功能膜。文中还介绍了表征自组分析方法，着重介绍了用于自组装功能膜表面、界面结构分析的两种，红外光谱法和原子力显微镜。     

聚电解质微胶囊的制备及其包埋释放行为

以高压静电法制备的壳聚糖微球为模板,与海藻酸钠层层自组装制备多层聚电解质膜,再以乙酸溶出壳聚糖微球制备出微胶囊.调节乙酸的浓度及溶出时间以控制核内壳聚糖的残留量,从而诱导负电性荧光素钠的沉积.微胶囊内部荧光素钠的浓度随着包埋时间的增加而呈线性地提高,当荧光素钠溶液的浓度为2 mg/l时其最终包埋的浓度达到10.2 mg/l.这种聚电解质微囊对于小分子负电荷荧光素钠的释放行为主要受其囊壁和内部模板结构的影响,盐离子浓度对荧光素钠释放行为的影响较小.     

Layer-by-layer self-assembly of multilayer films based on humic acid

Multilayer films consisting of negatively charged humic acid and positively charged polyelectrolyte have been fabricated on various substrates using the layer-by-layer self-assembly technique. The thickness (linearly increasing with the square root of NaCl concentration) and refractive index of the films determined by ellipsometry can be regulated by ionic strength through adjusting the coiling of the polyelectrolyte chains for assembly. The cone-shaped features on surface obtained by atomic force microscope are derived from the negatively charged colloidal humic acid binding with polyelectrolyte cation. The smooth features are corresponding to the dissociated humic acid with carboxylate ion (―COO⁻) electrostatically attracted on polyelectrolyte cation. These results are verified by Fourier transform infrared spectra. The linear dependence of the peak current on the square root of the scan rate revealed by the cyclic voltammetry indicates that the redox process at the electrode surface is diffusion-limited and the charge transport does not involve the film itself.     

Layer-by-layer self-assembled polyelectrolyte membranes for solvent dehydration by pervaporation

Polyelectrolyte composite membranes were prepared by the electrostatic layer-by-layer self-assembly of oppositely charged polyelectrolytes, and the membranes were used for dehydration of isopropanol by pervaporation. The effects of membrane preparation conditions on the separation performance of the resulting membranes were investigated. It was found that a high charge density of the polyelectrolyte was favorable to the formation of permselective membranes and that the polyelectrolyte molecules should be sufficiently larger than the pore size of the microporous substrate in order to reduce the number of polyelectrolyte depositions required to form a defect-free membrane. It has been demonstrated that using the appropriate substrate and under suitable conditions for polyelectrolyte deposition, a permselective membrane can be formed with as few as two polyelectrolyte bilayers, which is much less than those commonly used in the literature (e.g., 60–90 bilayers). At 70 °C, the polyelectrolyte composite membrane with two bilayers exhibited a flux of 1.8 kg/(m² h) and a permeate water concentration of over 98 wt.% for the dehydration of isopropanol containing 9 wt.% water, which corresponds to a separation factor of greater than 495.