羧基负离子型聚电解质与重氮树脂的自组装及自组装膜的光和热反应

带相反电荷的聚电解质的自组装,由于方法简单,对环境无污染,近年来备受重视［１～８］。以重氮树脂为聚正离子的聚电解质复合物,由于光照时重氮基分解,致使复合物的离子键转为共价键,溶解性发生重大改变,从而以重氮树脂为聚正离子的聚电解质复合物是一种新的光成像体系［９,１０］。张希等用重氮树脂与聚苯乙烯磺酸钠成功地制备了对极性溶剂稳定的自组装超薄膜［１１］。本文用羧基负离子聚电解质与重氮树脂进行自组装,并研究该自组装膜的光,热反应。羧基负离子聚电解质与重氮树脂的自组装超薄膜,文献上报道较少。１　聚丙烯酸钠…     

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。     

聚N-对羟苯基丙烯酰胺与重氮树脂的氢键自组装

1991年 Decher[1] 首先从带相反电荷的聚电解质 ,通过静电相互作用在基片上交替沉积形成超薄膜 ,这种通过静电作用形成超薄膜的方法称为静电自组装 .与 L- B膜技术相比 ,静电自组装不需要专用设备 ,一般在水体系进行 ,无污染 .此外 ,静电力比形成 L- B膜的范德华力强 ,从而使其自组装膜比 L- B膜要稳定 .由于这些优点 ,静电自组装技术近年来得到迅速发展 [2～ 8] .通过氢键作用形成超薄膜的方法 (氢键自组装 )是最近才发展起来的技术 . 1 997年 ,沈家骢等 [9,10 ] 通过静电吸引和氢键组装了有序超薄膜 .几乎同时 ,Rubner等 [11] 报道从…     

一种新型的氢键自组装液晶光控取向膜

报道了一种新型的以氢键为驱动力的液晶自组装光控取向膜, 研究了薄膜的制备方法与光敏特性. 通过聚(4-乙烯基吡啶)中的吡啶基团与光敏聚丙烯酰氧基肉桂酸间的氢键作用制备了LBL(layer-by-layer)型的自组装多层膜, 制备过程的紫外-可见光谱表明, 该组装过程为逐层、均匀沉积过程. 傅里叶变换红外光谱表明, 多层膜的成膜驱动力为氢键. 用线性偏振紫外光辐照该薄膜, 多层膜中与光矢量方向匹配的光敏基团发生[2+2]环加成反应, 形成表面张力各向异性的薄膜. 用该薄膜作为向列相液晶的取向膜制成平行液晶器件, 在偏光显微镜下观察, 发现获得了均一、稳定的取向效果.     

功能性超薄有序分子沉积膜的制备及其结构研究

1991年G.Decher等首次探讨了阴阳离子与聚电解质交替沉积制备有机超薄膜的方法。我们在完善成膜技术和发展成膜基质的基础上,详细研究了其成膜过程与膜的结构,并定义这种新的自组装超薄有序膜为分子沉积膜——MD膜。MD膜是利用阴阳离子的静电吸附反应特性,通过相反离子体系的交替分子沉积制备的层状有序自组装多层超薄膜。需要指出的是,分子沉积既是有机超薄膜的制备技术,本身又是一种自组装超薄有序膜。MD膜制备工艺简单,热稳定性和长期稳定性好,不受基体形状与面积限制。     

聚4-重氮基苯乙烯与聚苯乙烯磺酸钠的自组装

1991年Ｄｅｃｈｅｒ等将带相反电荷的聚电解质 ,于水溶液中交替沉积在片基上 ,制备了多层超薄膜[1] ,这种制膜方法现称为静电自组装 .它操作简单 ,无需专用设备 ;一般在水体系进行 ,对环境友好 ;静电力比范德华力强 ,使它比ＬＢ膜稳定 ,所以近年来有很大发展[2 ] .现在自组装成膜驱动力已从静电力扩展到氢键力、电荷转移相互作用、疏水相互作用等 ,用于组装的组分也从聚电解质扩展到多官能团小分子、胶体粒子、无机纳米颗粒 ,ＤＮＡ、蛋白质等生物大分子等[3～ 11] .虽然自组装膜比ＬＢ膜稳定 ,但它也不耐极性溶剂、电解质水溶液等侵蚀 .如…     

超支化聚负离子/超支化聚正离子自组装膜的制备及反应

自1991年以来,静电吸附自组装已发展成为制备具有特定纳米微结构聚电介质多层超薄膜的有效技术。近年来,由于树枝状聚合物和超支化聚合物独特的物理化学性质,文献中已将它们与线性聚电解质一起用于静电吸附自组装过程,但完全基于超支化聚合物分子间的自组装过程还鲜见报道,超支化聚合物所具有的大量末端和内部（如叔胺基）官能团,不仅可以用于调节自组装行为及组装膜的表面形貌,     

自组装超薄膜修饰Ta2O5介质膜及其特性研究

采用静电自组装方法在五氧化二钽(Ta2O5)介质氧化膜上制备了聚二烯丙基二甲基氯化铵(PDDA)/聚苯乙烯磺酸钠(PSS)和聚二烯丙基二甲基氯化铵/聚-3,4-乙烯二氧噻吩-聚苯乙烯磺酸钠(PEDOT-PSS)超薄膜.研究了两种自组装超薄膜在Ta2O5介质氧化薄膜上的组装特性.结果表明两种自组装膜能够稳定地组装于Ta2O5介质膜表面,并有效降低薄膜的表面粗糙度.进一步研究了两种自组装超薄膜修饰的Ta2O5电容结构的电性能.结果表明静电自组装膜对Ta2O5介质膜表面进行修饰后,有效地隔离了介质氧化膜中的缺陷,降低了电容的漏电流并提高耐电压能力;研究还发现不同厚度的超薄膜对Ta2O5电容结构的耐压特性有不同程度的影响,较厚的薄膜可以更好地提高电容的耐压能力并降低漏电流,但会增加电容的等效串联电阻(ESR).另外,在相同薄膜层数的情况下,聚合物电解质PEDOT-PSS良好的导电性能降低了复合超薄膜的电阻,使得PDDA/PEDOT-PSS修饰的电容结构ESR值较低.     

静电自组装铁电超薄膜及其性能研究

利用静电自组装方法在石英玻璃表面交替沉积聚二烯丙基二甲基氯化铵(PDDA)和聚偏氟乙烯(PVDF)超薄膜,制得PDDA/PVDF铁电复合超薄膜.通过石英晶体微天平实时监测超薄膜的沉积,研究了超薄膜的表面形貌、结构及电性能.结果表明,自组装每层PVDF超薄膜的厚度为7.5 nm;PDDA/PVDF铁电复合超薄膜的表面平整、均匀,其中C1s的光电子能谱与极化处理后充负电荷的PVDF铁电聚合物一致,但F1s由于溶解再组装过程而降低了0.3 eV;静电自组装材料纳米级的薄膜厚度和聚合物的络合作用导致了铁电复合超薄膜的非晶结构和高的表面电阻率.     

乳胶颗粒与硝基重氮树脂的自组装

高分子通过静电、氢键、电荷转移等的自组装 ,尤其是静电自组装已有大量报道[1] .带重氮基(Ｎ+2 )高分子 (重氮树脂 ,ＤＲ)自组装的特点是形成组装膜的弱键 ,光照下能转变为共价键 ,不稳定的膜变成稳定的膜[2 ] .乳胶颗粒的组装 ,因胶体晶体、光子晶体的进展 ,越来越受关注[3 ] ,国内也有一些评述文章[4 ,5] .就胶体晶体而言 ,用它作模板 ,几乎能制备包括无机、有机、金属、陶瓷的各种多孔材料 .自然界的蛋白石 (Ｏｐａｌｓ)是ＳｉＯ2 颗粒有序沉积物中 ,渗入水溶性硅酸盐 ,再在其中固化形成的 .按照自然形成蛋白石的模式 ,从胶体晶体复制 ,…     

重氮树脂与牛血清白蛋白共价结合自组装膜及其表面细胞培养

细胞支架作为组织工程的组成部分为细胞生长提供了最佳微环境 ,并对细胞生长与功能进行控制 .由于细胞对支架表面的生物识别是细胞附着、生长和增殖的基本前提 ,所以对材料表面的功能化是一个重要的课题 [1,2 ] . Shoichet等 [3 ] 通过化学反应或等离子体处理的方法 ,将蛋白质引入到材料表面而使其功能化 .基片在两种带有相反电荷的聚电解质溶液中交替吸附 ,其表面形成致密有序的超薄自组装膜 ,这种层 -层自组装技术不仅制备方法简单 ,无需特殊的设备 ,而且对膜组成和厚度能随意调控 ,以水为介质 ,对环境友好 [4～ 6] ,无疑是一项重要的表…     

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.     

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 (…     

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.     

Fabrication of a Stable Layer‐by‐Layer Thin Film Based on Diazoresin and Phenolic Hydroxy‐Containing Polymers via H‐Bonding

Using the self assembly technique, a stable multilayer films was successfully fabricated from diazoresin (DR) and poly(styrene‐co‐(N‐(p‐hydroxyphenyl)maleimide)) (P(S‐co‐HPMI)) followed by UV irradiation. The driving force of the self‐assembly was confirmed to be H‐bonding attraction between the diazonium group (—N₂⁺) of DR and the phenolic hydroxy group (—Ph—OH) of P(S‐co‐HPMI). A linkage conversion from H‐bond to covalent bond takes place after decomposition of the —N₂⁺ group using UV irradiation. As a result, the stability of the film towards polar solvents increases dramatically.     

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.     

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.     

重氮树脂-聚(4-羧酸苯基)乙炔自组装膜与光电转换

近年来 ,自组装及其形成的多层复合膜已经在导电、生物传感器及非线性光学等领域得到深入研究 ,特别是以聚阴离子与聚阳离子相互作用的静电自组装研究更为深入 .这一技术制备方法简单 ,无需特别的设备 ,对膜层厚度能随意调控 ,并以水作为介质 ,对环境无害 [1～ 3] .共轭高分子 (如聚苯胺、聚吡咯及聚苯亚乙烯等 )通过自组装形成共轭高分子膜 ,对制备具有导电、光电和传输等功能的薄膜半导体器件具有重要意义 .聚乙炔类是最早被发现且理论与应用研究最多的一类共轭高分子材料[4 ,5] .本文以聚 ( 4 -羧酸苯基 )乙炔 ( PCPA)为聚阴离子 ,以重…     

Hydrogen-bonding-directed layer-by-layer assembly of poly(4-vinylpyridine) and poly(4-vinylphenol): effect of solvent composition on multilayer buildup

This paper describes the buildup of hydrogen-bonding-directed poly(4-vinylpyridine)/poly(4-vinylphenol) (PVPy/PVPh) multilayer film that was fabricated by layer-by-layer (LbL) assembly of PVPy and PVPh from an ethanol solution. UV-visible spectroscopy and Fourier transform infrared (FT-IR) spectroscopy revealed a uniform deposition process. The interaction between PVPy and PVPh was identified as hydrogen bonding through FT-IR spectroscopy and temperature-dependent IR spectral changes of the hydrogen-bonded multilayer. Notably, we discussed the effect of solvent conditions on the growth of PVPy/PVPh multilayer films monitored by UV-visible spectroscopy. It was found that increasing the ratio of N,N-dimethylformamide (DMF) in the mixed ethanol/DMF solvents resulted in a marked decrease of the amount of polymers adsorbed, which was attributed to the increased polarity of the adsorption solutions. Furthermore, the solvent stability of PVPy/PVPh multilayer film in mixed ethanol/DMF solvents with different DMF ratios was also investigated. As a result, a new method for tuning the structure of hydrogen-bonding-directed multilayer film was developed.