Ag/WO3纳米复合膜的制备及其电致变色性质和器件的研究

通过真空镀膜方法制备的纳米Ag薄膜均匀致密, 表面光滑. 然后通过电化学方法在Ag纳米薄膜上沉积一层三氧化钨(WO3), 制备纳米Ag/WO3复合膜. 并在此基础上构筑五层式玻璃/ITO/纳米Ag-WO3复合膜/固态电解质/聚(3-甲基噻吩)/ITO/玻璃电致变色器件. 实验结果表明, 与传统的WO3膜相比, 纳米Ag/WO3复合膜具有更好的电化学活性、更高的对比度、更短的响应时间, 以及更好的稳定性. 由该复合膜组装的电致变色器件工艺简单, 电致变色性能良好.     

Pd纳米粒子敏化的纳米单层TiO_2-Ru(Ⅱ)螯合物修饰电极对单磷酸鸟苷的电催化氧化行为

利用LB膜技术可控制备了纳米单层的二氧化钛-有机钌螯合物杂化膜,并研究了上述无机-有机杂化膜修饰电极在Pd纳米粒子敏化后对单磷酸鸟苷(GMP)的电催化氧化行为.实验结果表明:(1)纳米单层TiO2/[Ru(phen)2(dC18bpy)]2+(简称为TiO2-Ru)杂化膜的平均厚度为(3.2±0.5)nm;(2)在光照条件下TiO2-Ru杂化膜能有效催化还原[Pd(NH3)4]2+形成粒径位于20～200nm之间的Pd纳米粒子;(3)纳米单层TiO2-Ru/Pd杂化膜能高效催化氧化具有供电子能力的单磷酸鸟苷(GMP),与纳米单层TiO2-Ru杂化膜修饰的ITO电极(ITO/TiO2-Ru)相比,当工作电压为1200mV时,ITO/TiO2-Ru/Pd电极在含有1×10-3molL-1GMP的磷酸盐缓冲液中,单位面积的催化氧化电流提高了约36倍;(4)Pd纳米粒子的引入消除了金属钌螯合物中配体对电子传递的阻碍作用,改变了电子传递途径,从而有效减少了电子空穴对的复合,提高了杂化膜修饰电极(ITO/TiO2-Ru/Pd)的电子传递效率.     

Poly(St-co-DMC)/SiO_2杂化及空心杂化纳米粒子的合成及表征

采用无皂乳液聚合法合成了聚(苯乙烯-co-甲基丙烯酰氧乙基三甲基氯化铵)(poly(St-co-DMC))纳米粒子,平均粒径约为100 nm.以此纳米粒子为模板,在接近室温及p H为中性的温和条件下,以四甲氧基硅烷(TMOS)为硅源,合成了poly(St-co-DMC)/Si O2杂化纳米粒子,TEM结果显示该纳米粒子具有明显的核壳结构,Si O2主要沉积在壳层.进一步通过四氢呋喃溶解制备得到具有空心结构的纳米粒子,这种空心结构纳米粒子的FTIR图谱中既有Si O2的信号,也有poly(St-co-DMC)的信号,说明空心纳米粒子的壳层不完全是Si O2,对空心纳米粒子的TGA结果分析计算得到Si O2的含量仅为69.7%,说明纳米粒子的壳层为杂化壳层,并且,这种壳层的厚度随着反应温度的升高、反应时间的延长、TMOS用量的增加及聚合物模板中DMC含量的增加而增大.     

磷钨酸盐修饰的氧化钨薄膜的制备与电致变色性质研究

为了提高WO_3纳米粒子薄膜的光学对比度,利用层接层自组装方法,将Keggin型结构的磷钨酸盐H_3[α-PW_(12)O_(40)]与WO_3纳米粒子复合,制备[PEI/PW_(12)/PEI/WO_3]_(20)复合膜.采用扫描电镜、紫外光谱和电化学工作站对复合膜的形貌及电致变色性能进行研究,结果表明:该复合膜与单纯的WO_3纳米粒子薄膜相比,光学对比度提高了117.28%,且这种复合膜提供了较大的H~+扩散系数,可以获得更好的电致变色性能.     

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.     

纳米Fe3O4/PVDF磁性复合膜的原位制备及表征

通过膜相渗透原位化学沉积法制备了聚合物基Fe3O4/聚偏氟乙烯（PVDF）磁性纳米复合膜，研究了复合膜制备的适宜条件，采用红外光谱（FT-IR）、差热分析（DSC）、X射线衍射、扫描电镜（SEM）等手段对复合膜的组成、结构进行了表征和分析，通过气体渗透法测定了复合膜的孔径随制备条件的变化情况. FT-IR和XRD图谱结果表明，在基膜中原位生成Fe3O4后不影响基膜PVDF的分子结构；复合膜中的Fe3O4粒子尺寸为68 nm左右，复合膜的磁化率达0.044 cm3•g－1；复合膜的磁化率、平均孔径、最大孔径及孔径分布范围随反应条件的改变而有明显变化.     

纤维素/全硫化弹性纳米粒子复合膜的制备与性能

利用碱脲溶剂低温溶解纤维素,在该体系中掺杂一定比例的全硫化羧基丁苯弹性纳米粒子,制备了纤维素/全硫化弹性纳米粒子复合膜.通过透射电镜、扫描电镜、WAXD、固体核磁共振、热分析和力学性能测试等对该复合膜的结构和性能进行了表征.结果表明,全硫化羧基丁苯弹性纳米粒子(CSB ENP)均匀的分散在具有微纳孔洞结构的纤维素基体中.CSB ENP的引入对纤维素再生过程中的结晶性影响不大.纤维素/全硫化弹性纳米粒子复合膜具有良好的透光性,并且热稳定性也有所提高.加入少量的CSB ENP可以增韧纤维素膜,且能保持良好的力学性能.当CSB ENP的含量为5 wt%时复合膜的断裂拉伸强度和断裂伸长率同时得到了提高.     

基于静电纺丝技术的PET/PVA复合超滤膜制备条件的探索

采用多喷头静电纺丝技术制备了复合超滤膜,该复合超滤膜是以聚对苯二甲酸乙二酯(PET)无纺布为支撑层,PET/PVA复合纳米纤维膜为分离层,再用丙酮和水的混合溶剂处理得到致密分离层.采用扫描电镜法(SEM)、红外光谱法(FTIR)对复合膜表面进行表征,测试了复合超滤膜的抗水解性能.SEM结果表明,复合膜表面的PET纳米纤维的直径为960 nm,PVA纳米纤维的直径为320 nm,用不同比例的混合溶剂对复合超滤膜进行处理会产生不同的表面形貌,最佳的比例是w(丙酮)/w(水)=30/70.抗水解性能实验结果显示比较适宜的交联剂加入量为2 wt%,用该含量对复合膜进行交联,复合膜具有较好的抗水解性能,其中重量损失率为2.12%,溶胀度为3.62%.红外光谱分析表明,交联处理后,复合膜表面的—OH量大大减少,耐水性能提高,交联前后膜表面在—C O和C—O—C处的吸收峰有很大的区别.     

多酸/Pt-Ni合金纳米粒子复合膜电极的制备及其对H_2O_2电催化性能研究

选用Dawson型多酸K_6[P_2W_(18)O_(62)]·14H_2O (P_2W_(18))和Pt-Ni合金纳米粒子作为电化学活性组分,制备了P_2W_(18)/Pt-Ni合金纳米粒子复合膜电极,采用循环伏安法研究了复合膜电极的电化学行为。实验结果表明,P_2W_(18)/Pt-Ni合金纳米粒子复合膜电极具有良好的重复性和稳定性,并展现出较P_2W_(18)电极更好的对H_2O_2的电催化活性。     

聚丙烯腈纳米纤维载银复合膜绿色制备及其催化性能

采用静电纺丝技术和化学镀方法相结合的方法,用聚丙烯腈(PAN)纳米纤维作为载体,以绿色环保的胺化改性替代化学镀传统的敏化、活化前处理,再化学镀银制备胺化聚丙烯腈纳米纤维载银复合膜(Ag/APAN).SEM、XPS、XRD、FTIR等结果表明,银离子能够吸附在经胺化处理后的PAN纳米纤维表面,且能够在纤维表面生成少量单质银;单质银作为催化活性中心,有效地促进化学镀银的进行,在PAN纳米纤维表面生成均匀致密的银纳米粒子层,制备出了以PAN纳米纤维为核,银层为壳的核壳结构复合膜.银纳米粒子附着在纳米纤维表面,可以使银纳米粒子的催化性能得到充分发挥.通过对催化邻-硝基苯胺与硼氢化钠之间氧化还原反应的研究表明,所制备的Ag/APAN纳米纤维复合膜具有很好的催化效果,且不会造成反应体系的二次污染.     

四铁取代的夹心型钨砷酸盐的合成及玻碳电极表面多层膜组装与电催化性质研究

碳电极表面的修饰在电化学和材料科学中很重要 .最近 ,通过层与层电子间的相互作用来自组装修饰玻碳电极已引起人们的关注 [1] .运用这种方法可将一些功能团修饰到电极表面 ,赋予电极一些新的功能 [2 ] .过渡金属取代的多金属氧酸盐不仅在配位环境 ,而且在催化活性方面都类似于金属卟啉和其它大环配体金属配合物 [3] .将其修饰到玻碳电极表面已有文献报道 [4 ] .由于修饰电极的厚度可控、成分可调及具有良好的电催化活性 ,在生物传感器和电子器件等方面具有潜在的应用前景 .取代型夹心型多金属氧酸盐具有大摩尔质量和高电荷密度 ,表现出优秀…     

银纳米修饰电极的制备及电化学行为

金属纳米粒子由于其小的体积和大的比表面积而具有独特的电子、光学和异相催化特性,是目前表面纳米工程及功能化纳米结构制备的一种理想研究对象[1]。银纳米粒子可广泛应用于催化剂材料、电池的电极材料、低温导热材料和导电材料等,成为近年来人们研究的热点[2,3]。在电化学方面,银纳米粒子具有比其他纳米粒子更为优异的导电性能和电催化性能。因此,研究银纳米粒子修饰电极有重要的应用价值和前景[4]。1实验部分1.1仪器CHI660电化学工作站(USA);TU-1901型双光束紫外可见分光光度计(北京普析通用仪器公司);KQ-100型超声清洗器(昆山市超声…     

预混合自组装辣根过氧化物酶生物活性膜及其催化活性研究

以阳离子化的辣根过氧化物酶 (HRP)和阴离子聚苯乙烯磺酸钠 (PSS)的预混合溶液 ,与阳离子聚电解质聚二甲基二烯丙基氯化铵 (PDDA)通过逐层组装 ,在阴离子化聚对苯二酸乙二酯 (PET)表面构建了多层生物活性膜 .用紫外 可见光谱仪 (UV Vis)和原子力显微镜 (AFM)研究了交替自组装膜的结构和表面形膜 ,并测定了自组装膜的生物催化活性 .结果表明 ,预混合溶液中的PSS与HRP一起沉积在PDDA膜层上组装成 (PSS+HRP)膜层 ,且每层中PSS和HRP的比例一致 ;(PSS +HRP)膜层呈条状分布 ,膜表面较为平整 ;多层膜中的HRP催化H2 O2 与 4 氨基安替比林的显色反应的表观米氏常数为 9 7× 10 - 5mol·L- 1 (相对于H2 O2 底物 ) ,较溶液中 (1 5 2× 10 - 4mol·L- 1 )的小 .     

Preparation of Y2O3 nanoparticulate thin films using an emulsion liquid membrane system

Y2O3 nanoparticulate thin films have been prepared using an emulsion liquid membrane (water-in-oil-in-water (W/O/W) emulsion) system, consisting of Span 83 (sorbitan sesquioleate) as a surfactant and VA-10 (2-methyl-2-ethylheptanoic acid) as an extractant (cation carrier). Yttrium ions were extracted from the external water phase and stripped into the internal water phase to make precursor oxalate nanoparticles. Y2O3 nanoparticulate thin film was prepared by casting the W/O emulsion, separated from the external phase and containing the Y oxalate nanoparticles, on a Si substrate, followed by calcination in air. Well-arranged thin-layer nanoparticulate film, consisting of Y2O3 nanoparticles smaller than 20 nm, was obtained via spin coating of the W/O emulsion. A multilayer nanoparticulate thin film was also fabricated via a simple procedure of repeated coating and subsequent calcination.     

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.     

层层静电自组装构筑壳聚糖/磷钨酸复合膜的研究

将正电荷的壳聚糖与负电荷的磷钨酸溶液通过静电作用交替沉积在基底上组装复合多层膜。使用紫外可见光谱(UV-Vis)、红外光谱(FTIR)、X-射线光电子能谱(XPS)、原子力显微镜(AFM)和循环伏安法(CV)等手段对复合膜进行了表征。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和FTIR结果证实了壳聚糖和磷钨酸被组装到膜上，AFM图形显示膜表面有一定的粗糙度，CV结果说明多层膜保留了磷钨酸的电化学性质。     

Fabrication and Electrochemical Behavior of Vanadium‐Substituted Keggin‐Type Polyoxometalates Multilayer Films on 4‐Aminobenzoic Acid Modified Glassy Carbon Electrodes

Two Vanadium‐substituted Keggin‐type polyoxometalates, K₃H₂[α‐SiVW₁₁O₄₀]?6H₂O (SiVW₁₁) and K₄H₂[γ(1, 2)‐SiV₂W₁₀O₄₀]?4H₂O (SiV₂W₁₀) were first successfully immobilized on 4‐aminobenzoic acid modified glass carbon electrodes respectively by layer‐by‐layer assembly with poly (ethylenimine) (PEI) as counterions. The regular growth processes were monitored by cyclic voltammetry (CV), and it was proved that the multilayer films were uniform and stable. The cyclic voltammetry results indicated that the electrochemical behavior of two multilayer films was similar, and their redox couples are pH‐ and scan rate‐dependent. The multilayer films show favorable electrocatalytic active toward the reduction of NO₂^?, IO₃^? and H₂O₂.     

In situ generation of silver nanoparticles in cellulose matrix using Azadirachta indica leaf extract as a reducing agent

In the present work, silver nanoparticles (AgNPs) were in situ generated in cellulose matrix using leaf extract of Azadirachta indica as a reducing agent. The cellulose/AgNP composite films prepared were characterized by FTIR, X-ray diffraction (XRD), scanning electron microscope, and antibacterial tests. The infrared spectra indicated the association of organic materials with silver nanoparticles to serve as capping agents. Scanning electron micrographs showed that synthesized silver nanoparticles were nearly uniform and spherical in shape with diameter in the range of 61–110?nm. XRD confirmed the formation of AgNPs and Ag–O nanoparticles. The nanocomposite films showed good antibacterial activity against Escherichia coli bacteria.     

All-cellulose multilayers: long nanofibrils assembled with short nanocrystals

Self-organized multilayer films were formed by sequential addition of oppositely charged cellulose I nanoparticles. The all-cellulosic multilayers were prepared via adsorption of cationicially modified cellulose nanofibrils (cat NFC) and anionic short crystalline cellulose (CNC) at pH 4.5 and pH 8.3. The properties and build-up behavior of layer-by-layer-constructed films were studied with microgravimetry (QCM-D) and the direct surface forces in these systems were explored with colloidal probe microscopy to gain information about the fundamental interplay between cat NFC and anionic CNC. The importance of the first layer on the adsorption of the consecutive layers was demonstrated by comparing pure in situ adsorption in the QCM-D with multilayer films made by spin coating the first cationic NFC layer and then subsequently adsorbing the following layers in situ in the QCM-D chamber. Differences in adsorbed amount and viscoelastic behavior were observed between those two systems. In addition, a significant pH dependence of cat NFC charge was found for both direct surface interactions and layer properties. Moreover the underlying cellulose layer in multilayer film was established to influence the surface forces especially at lower pH, where the cat NFC chains extensions were facilitated and overall charge was affected by the cationic counterpart within the layers. This enhanced understanding the effect of charge and structure on the interaction between these renewable nanoparticles is valuable when designing novel materials based on nanocellulose.     

Alternate assemblies of polyelectrolyte functionalized carbon nanotubes and platinum nanoparticles as tunable electrocatalysts for dioxygen reduction

A novel method based on electrostatic layer-by-layer self-assembly (LBL) technique for alternate assemblies of polyelectrolyte functionalized multi-walled carbon nanotubes (MWNTs) and platinum nanoparticles (PtNPs) is proposed. The shortened MWNTs can be functionalized with positively charged poly(diallyldimethylammonium chloride) (PDDA) based on electrostatic interaction. Through electrostatic layer-by-layer assembly, the positively charged PDDA functionalized MWNTs (PDWNTs) and negatively charged citrate-stabilized PtNPs were alternately assembled on a 3-mercaptopropanesulfonic sodium (MPS) modified gold electrode and also on other negatively charged surface, e.g. quartz slide and indium–tin-oxide (ITO) plate, directly forming the three-dimensional (3D) nanostructured materials. This is a very general and powerful technique for the assembling three-dimensional nanostructured materials containing carbon nanotubes (CNTs) and nanoparticles. Thus prepared multilayer films were characterized by ultraviolet–visible–near-infrared spectroscopy (UV–vis–NIR), scanning electron microscopy (SEM) and cyclic voltammetry (CV). Regular growth of the mutilayer films is monitored by UV–vis–NIR. SEM provides the morphology of the multilayer films. The PtNPs containing multilayer films exhibit high electrocatalytic activity for the reduction of dioxygen. Furthermore, the electrocatalytic activity of the films could be further tailored by simply choosing different cycles in the LBL process. This assembling method for polyelectrolyte functionalized carbon nanotubes and nanoparticles introduces new opportunities for the incorporation of various functionalities into nanotube devices, which, in turn, opens up the possibility of building more complex multicomponent nanostructures.