蜂窝状有序膜功能化研究进展*

水滴模板法是近年来引人瞩目的一种制备有序微结构材料的方法,所制备的蜂窝状有序膜在微容器和微反应器、图案化模板、细胞培养支架、光学材料、超疏水表面、分离膜等领域具有十分重要的应用前景。本文对蜂窝状有序膜功能化研究的最新进展进行了系统总结,详细介绍和分析了原位多层次自组装、表面接枝、生物活性分子固定、交联、模板法成膜以及表面填充等蜂窝状有序膜的功能化方法。     

针尖化学方法研究单壁碳纳米管末端羧基的解离性质

针尖化学利用化学手段对扫描探针显微镜 ( SPM)的针尖进行功能化修饰 ,将其作为化学反应的“探针”用于研究表面的局域化学反应性质、跟踪表面发生的化学反应过程等 [1] .用针尖化学技术来研究自组装膜 ( SAMs)表面酸碱基团的局域解离性质 ,称之为化学力滴定 [2～ 8] .利用表面缩合方法将单壁碳纳米管短管组装到 AFM针尖上 ,通过测定针尖上碳纳米管的末端基团与羟基自组装膜表面之间的粘滞力 ,研究碳纳米管末端羧基的解离性质 ,可得到碳纳米管结构与化学性质的信息 .1　实验部分1 .1　碳纳米管针尖和羟基末端自组装膜的制备　基底 [Si( …     

新型树枝状硫醇的自组装单层膜──图案化表面及其浸润性的调控

近年来 ,自组装膜的研究不断引起人们重视[1] .一方面 ,其兴趣可能源于纳米级器件的组装 ,如生物传感器等 [2 ] ;另一方面 ,它可作为研究摩擦学 [3]、生物膜模拟 [4 ]和微观浸润性的模型体系 [5] .树枝状分子的结构可在分子水平上精确控制 ,是很有潜力的纳米构筑基元 [6 ] .不同于常规的自组装膜构筑基元 ,树枝状分子的特殊结构使其在金属表面形成某些特殊的组装结构成为可能 .结合界面分子自组装技术和树枝状分子化学 ,国内外已有机构开展了树枝状硫醇的自组装膜的研究[7～ 9] .我们曾发现一种聚醚树枝状硫醇分子在金表面形成的自组装单层…     

电流滴定法对自组装膜表面酸碱性的研究

近年来 ,有序分子自组装体系在基础研究和应用领域均得到了较大的发展 .选择末端可以解离的自组装分子而制成的自组装膜 ,可以方便地通过调节底液的 p H值来控制膜体系的荷电状况 [1] ,这在利用静电作用吸附蛋白质 [2 ] 、多肽 [3] 、 DNA[4 ] 、聚电解质 [5] 、金属离子及其它物种 [6] 等方面具有重要作用 .精确测定表面解离常数 (即表面 p Ka)和控制自组装膜表面的荷电状况 ,无疑在理论研究和实践中均占有重要地位 .目前 ,一些方法如接触角滴定 [7] 、微分界面电容 [8] 、电流滴定法 [9,10 ] 以及 AFM的力曲线滴定 [11,12 ]被用于表面…     

层层组装构建抗凝血和内皮细胞化协同功能界面

本文采用天然细胞外基质组分、强抗凝血活性的肝素和促细胞黏附生长的胶原蛋白, 在不锈钢支架表面构建肝素/胶原多层膜, 探索利用层层组装多层膜所显示出的协同效应, 实现抗凝血和促进内皮细胞生长的协同功能, 为改善心血管支架抗凝血和抗再狭窄修饰寻求新方法.     

自组装超薄膜及其应用

自组装膜是指以价键或非价键相互作用在一定表面形成的具有某种特定结构、性能的单层或多层超薄膜。在自然界中 ,人们可以看到许多不同的组分通过自组装形成具有层状超分子结构的复杂体系 ,但直到 1 946年 ,人类才在清洁表面制备了单分子层膜[1] 。与分子束外延和化学气相沉积等制备膜的方法相比 ,以自组装方式形成的超薄膜具有有序性高、平整度好、膜的厚度分子水平可控以及不受基底形状限制等优点[2 ] 。近 1 0多年来 ,随着人们对界面化学研究的深入以及对具有特定功能的薄膜材料的需求 ,使自组装超薄膜的研究成为一个热点。本文从分类、…     

在N,N-二甲基甲酰胺/水混合溶剂中制备偶氮聚电解质自组装膜

利用静电吸附逐层自组装方法在有机溶剂N,N二甲基甲酰胺(DMF)和H2O的混合介质中制备非水溶性偶氮聚电解质自组装多层膜.研究了DMF和H2O的配比对自组装膜生长、结构与表面形态的影响.结果表明,DMFH2O的混合溶剂是非水溶性偶氮聚电解质自组装的理想介质,二者之间的配比对自组装膜的生长速度,膜的结构以及表面形态均有显著影响.随着混合溶液中DMF含量的升高,自组装膜的生长速度逐渐下降但线形生长关系越来越好,所得自组装膜中偶氮生色团的H聚集程度逐渐下降,而且自组装膜的表面越来越平整.     

浸泡法和旋涂法对偶氮聚电解质静电吸附自组装膜结构及性能的影响

利用浸泡和旋涂静电吸附自组装技术制备了含有偶氮生色团的聚电解质薄膜,比较了两种方法在自组装膜生长机理、膜结构以及膜光学性能方面的差异.利用紫外光谱和椭偏仪检测自组装膜的生长情况,利用原子力显微镜对膜表面结构进行了表征,并用偏振激光在膜表面进行了写光栅实验.结果表明,采用浸泡法和旋涂法都可以制备出表面光滑均匀的含偶氮生色团的聚电解质自组装膜.但是浸泡法自组装膜的生长速度要比旋涂法快.在自组装膜厚度较小的情况下,旋涂法得到的自组装膜可以写出明显的光栅而浸泡法不可以.随着自组装膜厚度的增加,两种方法得到的自组装膜都可以写出明显的光栅.这些结果说明浸泡法自组装膜内部聚电解质分子的层间穿插比较严重,而旋涂法自组装膜内分子穿插要弱得多.     

多金属氧酸盐-三(2,2′-联吡啶)钌层接层自组装纳米复合膜的制备及光致发光性质

层接层自组装技术作为制备均匀、超薄多层薄膜的有效方法已引起人们极大的关注 .利用这种方法可以将无机、有机组分有序地组合在薄膜中 ,在固体基底上构建功能性分子的超分子结构 ,并且可以在分子水平上调控每层膜的结构和厚度 ,从而实现薄膜的光、电、磁、非线性光学等功能化 [1～ 6 ] .多金属氧酸盐具有独特、优异的物理化学性能 ,在药物化学、电化学、催化化学及材料化学等方面具有十分广阔的应用前景 [7～ 9] ,将其组合在薄膜中 ,可赋予膜材料更优异的功能特性 .钌的联吡啶配合物在光化学、电化学及电子和能量转移等领域颇受关注 ,并已…     

TiO2/十六烷基三甲基溴化铵有序交替层状纳米复合薄膜的制备与结构表征

近年来有序交替的层状纳米结构薄膜的制备吸引了研究者们的极大关注. 目前, 这类薄膜的制备方法研究得最多的是LB技术[1～3]、基于化学吸附的自组装成膜技术[4,5]和交替沉积组装技术[6～8]. 但这几种方法都有明显的缺陷[9,10], 其中,通过LB技术制备有序交替层状纳米复合薄膜需要昂贵的仪器, 而且由于层间是分子相互作用, 膜的稳定性较差; 基于化学吸附的自组装成膜技术由于需要高反应活性的分子和特殊的基底表面, 并且由于化学反应的产率很难达到100%, 因此通过这种方法制备结构有序的多层膜并不容易; 利用交替沉积的方法制备出具有实用厚度的纳米多层膜需要耗费大量的时间. 最近, 出现了一种称为蒸发诱导的超分子自组装方法, 由这种方法制备的纳米多层膜具有成膜速度快和膜有序度高等优点, 此外还可以通过改变成膜物质浓度和拉膜速度来控制薄膜的厚度, 但与LB膜相比其厚度无法在分子水平上控制. 利用这种方法制备多层膜目前的文献报道仅限于线形SiO2与有机物的组装[10～13]. 本文利用这种方法制备了TiO2/十六烷基三甲基溴化铵纳米复合薄膜并对其结构进行了表征, 结果表明所制备的薄膜具有TiO2/十六烷基三甲基溴化铵有序交替的层状结构.     

红外光谱法研究重氮树脂自组装膜的光化学反应

将具有导电功能的聚(4-羧酸钠苯基)乙炔阴离子(PCPA)与具有生物活性的DNA聚阴离子交替与重氮树脂聚阳离子(DR)进行自组装,可以得到层重复单元为DR／DNA／DR／PCPA的三夹层聚电解质自组装膜。重氮树脂聚阳离子在紫外光照射下可与聚阴离子发生光化学反应,使层与层之间的离子键连接转化为共价键连接,从而制备稳定的纳米级超薄膜。本文用红外光谱法对此类聚电解质自组装膜的光化学反应过程进行了研究。     

Self-assembly of homopolymer and copolymers of N-4-hydroxyphenyl-acrylamide with diazoresin via H-bonding attraction

A kind of photoactive multilayer utrathin films has been fabricated via H-bonding attraction from hydroxyphenyl containing polymers as H-donor and diazoresin (DR) as H-acceptor by means of a self-assembly technique. The layer-by-layer deposition of two components is monitored spectrometrically and shows that the UV-VIS absorbance of the film increases linearly both at 250 nm (absorption of benzene nucleus) and at 383 nm (absorption of diazonium group), which indicates that the fabrication proceeds regularly. The nature of H-bonding between layers was verified by the determination of IR spectra of the film fabricated directly on a CaF₂ wafer. The stability of the films toward polar solvents increases dramatically after UV irradiation of the films. It was confirmed provisionally that the bond nature between the layers of the film changes from H-bonding to covalent bonding under UV irradiation. The photodecomposition of the -N₂⁺ groups of the film under UV light follows first order reaction kinetics and a mechanism of the photoreaction has been tentatively proposed.     

聚(对乙烯基苯酚)的合成及其与重氮树脂的氢键自组装研究

带相反电荷的聚电解质,交替沉积在基片,形成超薄有序膜,通常称为静电自组装,自1991年由Decher首次阐明以来,静电自组装技术引起了广泛重视,利用氢键相互作用的氢键自组装1997年才有报道,沈家骢、张希等从聚丙烯酸和聚乙烯基吡啶通过氢键组装了有序超薄膜。和乙烯基吡啶通过氢键组装超薄膜的制备。由于静电力和氢键均很弱,此类膜对极性溶剂不稳定,如在DMF中会离解而遭破坏,我们曾报道重氮树脂（DR）与酚醛树脂间通过氢键的自组装,本文报道聚（对乙烯基苯酚）（PVPh）的制备及春与重氮树脂（DR）间的氢键相经作用,并结合光照,制备了对极性溶剂稳定的超薄膜。     

Fabrication of photosensitive multilayer films based on polyoxometalate and diazoresin

A novel photosensitive organic-inorganic composite film incorporating polyoxometalate, K7[SiW11O39Co(H3P2O7)] (SiW11CoPP), and diazoresin (DR) has been prepared via layer-by-layer (LBL) self-assembly. Under UV irradiation, followed the decomposition of diazonium in DR, the ionic bonds between the adjacent interfaces of the multilayer film convert to covalent bonds. The LBL multilayers were characterized by UV-vis spectroscopy, X-ray photoelectron spectra (XPS), atomic force microscopy (AFM), FTIR spectrum, cyclic voltammograms (CV), and electron spin resonance (ESR) measurements. UV spectroscopy shows that the deposition process is regular and highly reproducible from layer to layer. XPS spectra confirm the incorporation of DR and SiW(11)CoPP into the films. Atomic force microscopy image indicates that the film surface is uniform and smooth. Solvent etching experiment proves that the film has significant stability towards polar solvent. Electrochemical behavior of the multilayers is investigated.     

重氮树脂接枝罗丹明B聚合物对酸、碱的响应性

利用重氮树脂(DR)中N2+的光解特性,通过罗丹明(B(RhB))对重氮树脂的接枝反应,得到了染料功能化的接枝聚合物DR-g-RhB,并由傅里叶红外光谱、1H-NMR、紫外-可见吸收光谱和荧光光谱等分析方法确认了产物结构。结果表明DR-g-RhB具有良好的热稳定性,失重5%所对应的温度超过360°C。通过溶液涂敷法形成的薄膜在不同酸碱度溶液中的UV-Vis吸收光谱会随浸入时间产生规律性变化:在pH=7.0的水中,吸光值基本不随时间变化;而在pH=12.0的肼水溶液中,吸光值随时间先下降、再增加;但在酸中则持续增加,而且对盐酸(pH=2.0)的响应比对醋酸(pH=2.3)更灵敏。     

Self-assembled film of poly(4-carboxyphenyl)acetylene and diazoresin and its photoelectric conversion property

A novel multilayer film was assembled from water-soluble poly(4-carboxyphenyl)acetylene sodium salt (PCPA) and diazoresin (DR) in aqueous solution via electrostatic attraction. Under UV irradiation, following the decomposition of the diazonium group between the adjacent interfaces of the multilayers, the ionic bonds of the self-assembled film convert to covalent bonds and the film becomes very stable toward electrolyte aqueous solutions. Thus, the photoelectric conversion property of PCPA-containing film can be measured in a conventional three-electrode photoelectrochemical cell, and 0.5 mol/l KCl solution can be used as the supporting electrolyte. The photocurrent spectroscopy response coincides with the absorption spectrum of the irradiated self-assembled film, which indicates that the irradiated DR/PCPA film is responsible for the photocurrent generation.     

Self-assembled film based on carboxymethyl-beta-cyclodextrin and diazoresin and its binding properties for methylene blue

Polyelectrolyte-layered films containing beta-cyclodextrin (beta-CD) were fabricated by a layer-by-layer deposition of carboxymethyl-beta-cyclodextrin (CM-beta-CD) as a polyanion and cationic photosensitive diazoresin (DR) on a solid surface. Under UV irradiation, following the decomposition of diazonium group between the adjacent interfaces of the multilayers, the ionic bonds of the self-assembly film convert to covalent bonds and the film become stable toward many common organic solvent. When a high-ionic-strength buffer is employed as a bathing solution, the film is thicker than that deposited from water solution. And the deposition increases with the increase of the carboxymethylated degree of CM-beta-CD. The CM-beta-CD/DR film can bind methylene blue (MB), and the durability of MB-adsorbing films to reductive glucose indicates that MB molecules not only diffuse into the film, but also load to the cavity of beta-CD through a host-guest complexation assisted by electrostatic interactions. The binding quantity of MB increases linearly with increasing the number of bilayers, and is influenced obviously by the pH value of MB aqueous solution. MB molecules can desorb from the 12-bilayer MB-absorbing CM-beta-CD/DR films when being immersed in water/ethanol mixture, and the released quantity of MB increases a little with increasing the concentration of water when it is below 30%, while decreases evidently over 30%.     

6AZO-CONTAINING SELF-ASSEMBLY ULTRA-THIN FILMS AND THEIR PHOTOVOLTAIC PROPERTIES

A kind of azo-containing resin (Azo-R) was synthesized by a simple way through the coupling reaction of 2-nitro-N-methyldiphenylamine-4-diazoresin (NDR) with phenol, and a new covalentely attached multilayer film from Azo-R as H-donor and photosensitive diazoresin, diphenylamine-4-diazoresin (DR) as H-acceptor via H-bonding attraction by selfassembly technique has been fabricated. Following the decomposition of diazonium group of DR under exposure to UV light, the H-bonds between the layers of the film convert to covalent bonds and the film becomes very stable toward polar solvents or electrolyte aqueous solutions. Thus the UV-irradiated azo-containing films can be used to measure photocurrent in a conventional three-electrode photoelectrochemical cell using KCl as supporting electrolyte. It was confirmed that the azo-containing multilayer film is responsible for the photocurrent generation.     

Covalently attached self‐assembly of ultrathin films from hydroxy‐containing porphyrin and diazoresin

Ultrathin films from 5,10,15,20‐tetrakis(4‐hydroxyphenyl) porphyrin (HPP) and diazoresin (DR) via a H bonding interaction were fabricated with the self‐assembly technique. Under UV irradiation, the H bonds between the layers will convert to covalent bonds following the decomposition of the diazonium group of DR. The stability of the film against the polar solvent and electrolyte aqueous solution increases a lot because of the formation of the covalent crosslinking structure. Thus, the photoelectric conversion property of DR/HPP film can be measured directly with a normal photoelectric chemical cell with potassium chloride as the electrolyte. The maximum of the anodic photocurrent was measured as 1.7 μ Å for an eight bilayer DR/HPP film deposited on an indium–tin oxide glass electrode. The action spectrum of the photocurrent generation indicated that the HPP contained in the film is responsible for the generation of the observed photocurrent. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 3103–3108, 2003     

重氮树脂—聚磷酸复合物

带有相反电荷 (通常在侧链 )的聚电解质 ,通过静电相互作用形成的复合物 ,称聚电解质复合物 (ＰＥＣ) .ＰＥＣ已有很多研究[1～ 3] ,也有一些应用的报道[4,5] .重氮树脂 (ＤＲ) ,一种由二苯胺 4 重氮盐与多聚甲醛在浓硫酸中缩合得到的缩聚物[6] ,因侧链带重氮基 ,所以是正离子聚电解质 .它能与各种负离子聚电解质生成感光性的ＰＥＣ ,并可用作光成像体系的感光剂[7,8] .ＤＲ与聚磷酸 (ＰＰＡ)生成重氮基为正离子 ,磷酸基为负离子的复合物 ,这种复合物文献上未有过报道 .本文初步研究了这种复合物的制备与性质 .1　重氮树脂 聚磷酸复合物 (…