层层自组装聚烯丙胺盐酸盐/Pd纳米复合薄膜的制备及其电催化特性

利用层层静电自组装技术将聚烯丙胺盐酸盐(PAH)和四氯合钯酸根离子( )交替沉积在基底上, 然后用硼氢化钠还原, 构筑了含钯纳米粒子的PAH/Pd纳米复合薄膜. 通过紫外-可见吸收光谱(UV-Vis)、扫描电子显微镜(FESEM), X射线光电子能谱(XPS)和循环伏安(CV)等手段对复合膜的组装、成分、微结构、表面形貌和光学性能进行了测试分析. FESEM图形显示膜表面有一定的粗糙度, 膜上生成了粒径在50～100 nm 范围的钯纳米粒子; UV-Vis结果显示多层膜在特征吸收峰处的吸光度数值随膜双层数增加逐渐增大, 呈良好的线性关系, 表明多层膜是均匀组装的; XPS结果证实了复合膜上有Pd生成, CV结果说明复合薄膜对尿酸的氧化具有较好的电催化活性, 有望用于电化学传感器.     

基于多壁碳纳米管/二茂铁接枝壳聚糖的核/壳结构组合物多层膜电极的组装及其电催化

以聚二烯丙基二甲基氯化铵(PDDA)修饰的玻碳电极(GCE)为基础电极, 利用静电层-层自组装的方法将多壁碳纳米管/二茂铁接枝壳聚糖的核/壳结构组合物(MWCNTs@CHIT-Fc)和聚苯乙烯磺酸钠(PSS)在该电极表面进行交替多层组装. 用循环伏安(CV)、紫外-可见光谱(UV-Vis)和扫描电子显微镜(SEM)等方法对组装过程进行了跟踪表征. 用CV方法研究了抗坏血酸(AA)在该多层膜电极上的电催化氧化. 研究结果表明, 当MWCNTs@CHIT-Fc为6个双层时, AA在该修饰电极上的氧化峰电位与裸GCE相比降低了约0.4 V. 用控制电位电流法研究了不同MWCNTs@CHIT-Fc双层时AA的电流响应. 用该电极测定了AA的灵敏度, 检测限及线性范围等性能参数可通过控制组装的MWCNTs@CHIT-Fc双层数进行调节.     

四种α,α'-二氧代烯酮环二硫代缩酮类化合物的电化学性质及光谱研究

本文应用循环伏安法(CV)、UV-Vis、交流阻抗(EIS)和X射线光电子能谱(XPS)等技术研究了4种α-羰基二硫缩烯酮化合物在有机溶剂中的电化学和光谱性质及其在金电极上的自组装膜行为, 根据循环伏安数据计算了此类化合物在DMSO溶液中的扩散系数和电极反应速率常数.     

以DDAB为模板的银纳米粒子多层膜制备及其表面增强拉曼效应

通过离子交换和静电相互作用, 将银纳米粒子引入双十二烷基二甲基溴化铵(DDAB)模板中, 获得了有序的银纳米粒子多层膜. 用紫外-可见光谱(UV-Vis)、循环伏安(CV)和原子力显微镜(AFM)对其进行了表征, 并用小角X射线衍射(XRD)研究了DDAB模板和银纳米粒子多层膜的有序性结构. 以4-巯基吡啶(4-MPY)为探针分子研究了银纳米粒子多层膜在表面增强拉曼(SERS)方面的应用, 结果表明, 4-MPY吸附在银纳米粒子多层膜上呈现很强的SERS信号, 说明该多层膜可以用作高活性的SERS基底.     

钒取代多金属氧酸盐/聚酰胺-胺多层膜的制备及其电催化性能

用层接层自组装的方法制备了过渡金属钒取代的多金属氧酸盐PMo11VO4-40/聚酰胺-胺多层纳米复合膜. X射线光电子能谱(XPS)、紫外-可见光谱(UV-Vis)、循环伏安(CV)测定和分析结果表明, PMo11VO4-40和聚酰胺-胺通过静电相互作用形成了纳米交替多层膜,且膜的增长均匀. 复合膜的循环伏安图呈现出四对氧化还原峰(一个V的单电子和三个Mo的双电子), 峰电流与扫描速率成正比, 其式量电位随着pH 的增加而线性负移, 表明电极过程属于表面控制过程, 电荷传递很快且有氢离子参与多金属氧酸盐的氧化还原反应. 该方法制备的多层膜修饰电极稳定性好, 对NO-2、BrO-3及H2O2具有良好的催化还原活性.     

金电极上β-环糊精单层膜的组装与表征

采用分步组装法将合成的β-环糊精对甲苯磺酸基衍生物(oTs-β-CD)直接与组装在金电极上的半胱胺于80℃下反应24小时以上，成功地制得β-CD单层膜修饰电极(SAM-β-CD)。分别用循环伏安法(CV)、X-射线光电子能谱(XPS)和原子力显微镜(AFM)对该修饰电极进行了表征。实验结果表明，所制得的SAM-β-CD修饰电极对铁氰化钾(K3[Fe(CN)6]，和氢醌(QH2)表现出有效的主客体响应，并具有良好的稳定性。其制备方法简单、操作方便、成功率高。     

壳聚糖氧化自组装膜的制备及其性能

由高碘酸钠和壳聚糖溶液反应,成功制备出壳聚糖氧化自组装膜。采用傅立叶变换红外光谱(FTIR)和X射线衍射法对氧化自组装膜进行了结构表征,并对膜的吸水率及其力学性能进行了测试。当壳聚糖为3 g,而高碘酸钠加入量等于0.010 g时,得到壳聚糖氧化自组装膜的最佳的抗张强度,干膜为54.32 MPa,湿膜为29.11 MPa,相对壳聚糖膜分别提高了17.52%和26.78%;并且得到了最佳的阻水性,其吸水率为78.51%,相对于壳聚糖膜降低了6.88%。     

(肝素/壳寡糖/Pluronic(R))静电组装多层膜的构建

以壳寡糖/Pluronic(R)聚合物纳米聚集体(COPNs)、肝素为组装基元构建仿(肝素/壳聚糖)多层膜,验证多层膜负载疏水药物的可行性.Pluronic(R)P123与1,3-丙烷磺内酯反应合成末端磺酸化的Pluronic(R)聚合物,其与Pluronic(R)F127在水溶液中自组装形成表面带负电荷的混合胶束.利用壳寡糖与混合胶束的静电作用,获得COPNs,粒径与表面电位分析、透射电镜表征COPNs为直径(27.61±2.46) nm、表面zeta电位(6.12±1.82)mV、稳定的球形结构.石英晶体微天平(QCM)跟踪检测证明COPNs与肝素可在基材表面实现交替沉积;原子力显微镜(AFM)表征多层膜表面拓扑形貌,证明COPNs在表面沉积过程中稳定.将疏水的荧光探针芘载入COPNs参与多层膜的构建,荧光光谱实验结果表明多层膜可成功包载芘,且多层膜内芘的载入量与组装层数相关.以葛根素为模型药物,载药量测定与体外释药实验结果表明多层膜具有包载和缓释疏水药物的能力.     

[PCu(H2O)Mo11O39]5－/PAMAM多层复合膜的制备及电化学性质研究

通过电化学扫描法在玻碳电极和导电玻璃基底上组装制备过渡金属铜取代多金属氧酸盐[PCu(H₂O)Mo₁₁O₃₉]^5－和4代聚酰胺-胺(G4-PAMAM)交替沉积的复合膜. X射线光电子能谱(XPS), 原子力显微镜(AFM), 循环伏安法(CV)结果表明复合膜成功制备且有好的均匀性. 多层膜中的[PCu(H₂O)Mo₁₁O₃₉]^5－与其在溶液中的氧化还原行为相比, 电子转移控制速率不同, 该多层膜修饰电极稳定性好, 对 的还原及抗坏血酸的氧化具有较好的电催化性能.     

基于卤键的选择性吸附层层组装多层膜

以超支化聚乙烯亚胺为构筑基元、以卤键为推动力制备了可以选择性吸附带有负电荷小分子的层层组装多层膜. 为了将超支化聚乙烯亚胺引入多层膜体系中, 我们首先制备了接枝有卤键给体分子-碘全氟苯的超支化聚乙烯亚胺(BPEI-I). 然后将BPEI-I和含有卤键受体的聚(4-乙烯吡啶)(PVPy)在四氢呋喃和三氯甲烷的混合溶剂中组装成膜, 并用紫外可见光谱、AFM和XPS对膜的组装过程、形貌、厚度和推动力进行了表征. 制备得到的BPEI-I和PVPy多层膜可以吸附含有负电荷的2-蒽甲酸钠小分子, 而对有类似结构但带有正电荷的溴化-N-(2-蒽甲基)吡啶盐却没有吸附作用. 这种选择性吸附能力主要得益于包覆在多层膜中的超支化聚乙烯亚胺基元的正电荷空腔和由卤键构筑的弱极性微环境. 本文的研究为制备选择性吸附薄膜提供了一种新的思路, 在传感、富集分离和微接触印刷等领域都有潜在应用价值.     

磷钼钒杂多酸/聚酰胺-胺复合膜修饰电极的制备及电催化性能

通过静电层层自组装方法在预修饰聚二烯丙基二甲基氯化铵的电极基片上制备了Dawson型磷钼钒杂多酸/聚酰胺-胺多层复合膜. 用X射线光电子能谱、紫外-可见光谱、循环伏安法和原子力显微镜分析表征了多层复合膜的形成过程; 用循环伏安法表征了该复合膜修饰电极的电化学性能, 研究结果表明, 该复合膜修饰的电极稳定性好, 对亚硝酸盐、溴酸盐的还原以及抗坏血酸的氧化具有良好的催化活性.     

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.     

氨基酸多金属氧酸盐纳米粒子复合膜的制备及抗菌活性

用水热微乳法制备了Keggin结构(CTA)0.2(HGly)2.8［PMo12O40］·nH2O(1) 纳米粒子(nano-1), 并通过元素分析, XPS, IR, XRD, TEM和CV进行表征. 利用层接层自组装技术, 将已制备的纳米粒子装配成纳米复合膜, 用紫外-可见光谱监测膜的生长, 用电化学方法分析膜的成分. 测定了纳米粒子对致病Escherichia coli(E. coli)的拮抗性， 结果显示, 纳米粒子及其复合膜具有显著的抗菌活性.     

Effects of solar radiation on collagen and chitosan films

Photo-aging and photo-degradation are the deleterious effect of chronic exposure to sun light of many materials made of natural polymers. The resistance of the products on the action of solar radiation is very important for material scientists. The effect of solar radiation on two natural polymers: collagen and chitosan as well as collagen/chitosan blends in the form of thin films has been studied by UV-Vis and FTIR spectroscopy. It was found that UV-Vis spectra, which characterise collagen and collagen/chitosan films, were significantly altered by solar radiation. FTIR spectra of collagen and collagen/chitosan films showed that after solar irradiation the positions of amide A and amide I bands were shifted to lower wavenumbers. There was not any significant alteration of chitosan UV-Vis and FTIR spectra after solar radiation. In the condition of the experiment chitosan films were resistant to the action of solar radiation. The effect of solar UV radiation in comparison to artificial UV radiation has been discussed.     

Na-MMT掺杂对PMA/PVP复合膜结构及光致变色性能的影响研究

将钠基膨润土(Na-MMT)掺入磷钼酸/聚乙烯基吡咯烷酮(PMA/PVP)体系中,利用透射电子显微镜(TEM)、原子力显微镜(AFM)、红外光谱(FTIR)、热重-差热(TG-DTA)、紫外-可见吸收光谱(UV-Vis)、X射线光电子能谱(XPS)等手段对复合薄膜的结构、热稳定性和光致变色性能进行了研究.红外光谱结果表明keggin结构磷钼酸和聚乙烯吡咯烷酮的基本结构在复合膜中仍然存在,复合膜中高分子与质子结合,以阳离子的形式与杂多阴离子成盐.Na-MMT的掺杂未对复合膜中PVP和PMA间的相互作用产生影响,但其掺杂提高了复合膜的热稳定性.在紫外光照下,复合膜由无色变为蓝色,杂多酸被还原产生杂多蓝.Na-MMT的掺杂降低了复合膜的光致变色响应性,这是由于多酸分子与钠基膨润土之间发生阳离子交换作用导致的.     

Fabrication and hemocompatibility of cell outer membrane mimetic surfaces on chitosan by layer by layer assembly with polyanion bearing phosphorylcholine groups

Three random copolymers poly(2-methacryloyloxyethyl phosphorylcholine-co-methacrylic acid) (PMAs) were synthesized by free radical polymerization of 2-methacryloyloxyethyl phosphorylcholine (MPC) and methacrylic acid (MA) with different monomer ratios under monomer-starved conditions. The synthesized PMA polyanions were assembled on chitosan (CS) film surfaces via electrostatic interactions. Using layer by layer (LbL) assembly with PMA polyanion and chitosan polycation, PMA/CS multilayer thin films with phosphorylcholine groups on the outer surfaces were fabricated. The modified surfaces were characterized by dynamic contact angle (DCA), X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM). Hemocompatibility of the surfaces was estimated by protein adsorption and platelet adhesion measurements. The results indicated that cell outer membrane mimetic structures were formed on the modified surfaces with PMA as the outermost layer, and the hemocompatibility of the modified surfaces was significantly improved. This facile method of fabricating cell outer membrane mimetic surfaces may have potential applications in the fields of hemocompatible coatings, drug delivery, and tissue engineering.     

Multilayer film assembled from charged derivatives of chitosan: physical characteristics and biological responses

Polyelectrolyte multilayer films were successfully assembled from each of the three charged derivatives of chitosan; N-[(2-hydroxyl-3-trimethylammonium)propyl]chitosan chloride (HTACC), N-succinyl chitosan (SCC) and N-sulfofurfuryl chitosan (SFC), paired with one of the two oppositely charged polyelectrolytes, poly(acrylic acid) (PAA) and poly(allylamine hydrochloride) (PAH) on surface-treated poly(ethylene terephthalate) (treated PET) substrates by alternate layer-by-layer adsorption. Surface coverage and wettability of the multilayer films were determined by AFM and water contact angle measurements, respectively. Analysis by quartz crystal balance with dissipation (QCM-D) has suggested that all multilayer films are relatively rigid and have a high water content associated within their structures, accounting for up to 85-90% (w/w) for films having 7-10 layers. In vitro cytocompatibility tests for the fibroblast-like L929 cell line revealed a slight dependency for cell adhesion and proliferation on the outermost layer. The multilayer film containing HTACC exhibited moderate antibacterial activity against E. coli and S. aureus. Bearing negative charges, the multilayer films terminating with SFC and having at least 10 layers were capable of suppressing the adsorption of plasma proteins and platelet adhesion at a comparable level to the multilayer film assembled from heparin, a well-known antithrombogenic polymer.     

修饰Langmuir-Blodget膜法制备聚(3,4-亚乙基二氧噻吩)薄膜结构和导电性能的研究

采用修饰Langmuir-Blodget(LB)膜法以二十烷酸(AA)LB膜为模板,通过3,4-亚乙基二氧噻吩(EDOT)单体在LB膜亲水基团间聚合,制备了二十烷酸/聚(3,4-亚乙基二氧噻吩)(AA/PEDOT)复合LB膜.UV-Vis、FTIR和XPS分析表明EDOT在多层膜中有效聚合,生成了PEDOT导电聚合物;X射线衍射(XRD)和二次离子质谱(SIMS)分析表明薄膜具有较好的层状有序结构,进一步研究发现EDOT在AA多层膜中的聚合破坏了原有LB膜的有序性,这可能与聚合过程对层状结构产生的破坏作用有关;采用四探针仪及半导体测试仪研究了薄膜导电性能,发现AA/PEDOT多层膜的电导率随处理时间的变化产生突变,这与多层膜中导电通道的"逾渗"有关,在有效导电网络连通后电导率发生了突变.测试结果还表明AA层和PEDOT层之间具有较为明显的界面,PEDOT显示出较好的定域性,薄膜具有很好的层状有序结构.