不同工艺对PANI/PAA复合薄膜的电致变色性能影响

采用直接聚合法与逐层镀膜法分别成功制备了聚苯胺(PANI)/聚丙烯酸(PAA)复合薄膜,通过SEM、FTIR考察了两种工艺制备的薄膜的形貌和微结构,并测定了两种复合薄膜的循环伏安性能(CV)、电流响应特性(CA)及电致变色性能。结果表明,SEM与FTIR证实了两种方法制备的PANI/PAA复合薄膜仅在材料结构上有所不同;直接聚合法制备的PANI/PAA复合薄膜(PANI/PAA-DP)表面具有较大颗粒,两对明显的氧化还原峰,氧化态和还原态的响应时间分别为120 ms和226 ms,在600～700 nm波长处的透过率调制幅度为10%;逐层镀膜法制备的PANI/PAA复合薄膜(PANI/PAA-LP)具有多孔的网络结构,3对氧化还原峰,氧化还原反应更明显,电致变色性能更优异,其氧化态和还原态的响应时间分别为45 ms和67 ms,在600～700 nm波长处的透过率调制幅度可达40%。     

RGO/ZnO/PANI复合材料的制备及电致变色性能

在原位聚合制备PANI的同时加入RGO/ZnO得到RGO/ZnO/PANI复合材料,利用扫描电镜(SEM),傅里叶变换红外(FT-IR)光谱,拉曼(Raman)光谱和电化学测试等分析研究了材料的形貌、结构和电致变色性能。结果表明,RGO/ZnO与PANI结合形成均匀的复合物,复合物的电致变色性能比PANI有所增强,可归因于RGO/ZnO在结构稳定性和电子传输方面的贡献。     

静电纺丝法制备聚酰亚胺/聚苯胺导电复合纤维膜

采用原位聚合法制备聚酰氨酸(PAA)和聚苯胺(PANI),使用静电纺丝技术制备PAA/PANI复合纤维膜,经热亚胺化处理后得到聚酰亚胺(PI)/PANI复合纤维膜。通过扫描电子显微镜观察了PI/PANI复合纤维膜的微观形貌,使用红外光谱仪对PI/PANI复合纤维膜的官能团进行了分析,使用高阻计研究了PI/PANI复合纤维膜的导电性能。实验结果表明,PI/PANI复合纤维膜的逾渗阈值为10wt%,在逾渗阈值时,PI/PANI复合纤维膜的体积电阻率为108Ω·cm。     

原位聚合法制备PANI/RGO导电复合材料的性能

采用原位聚合法制备聚苯胺(PANI)、PANI/氧化石墨烯(GO)复合材料和PANI/还原氧化石墨烯(RGO)复合材料。利用四探针测试仪、X射线衍射(XRD)仪、傅立叶变换红外光谱(FTIR)仪、热重(TG)分析仪和扫描电子显微镜(SEM)等对PANI及PANI/GO复合材料和PANI/RGO复合材料进行表征。电导率测试结果表明,当加入GO质量分数为50%时,先还原后聚合法制得PANI/RGO复合材料的导电率可达9.916 S/cm,RGO能有效提高复合材料的导电性;XRD和FTIR分析结果表明,GO和RGO都能较好分散在PANI中;TG分析结果表明,将GO还原为RGO后在小于250℃时能有效提高复合材料的热稳定性。通过原位聚合法能将GO和RGO较好分散在PANI中,形成较好的插层型复合材料,尤其是先还原后聚合法制得的PANI/RGO复合材料具有较好的导电性和热稳定性。     

控电位法制备CdSe/PANI复合薄膜及其光致发光性

采用控电位法,以PANI薄膜作为载体,成功制备出CdSe/PANI复合薄膜。采用扫描电子显微镜(SEM)、X射线衍射(XRD)、荧光光谱仪等仪器对所制备的薄膜进行比较与表征。CdSe/PANI复合薄膜中CdSe微粒粒径约为150~200 nm,且随沉积时间的延长,粒径逐渐增大。复合薄膜中含有聚苯胺和CdSe 2种成分的晶体,并且复合薄膜的晶型结构与沉积CdSe薄膜的厚度无关。与PANI薄膜和CdSe薄膜比较,CdSe/PANI复合薄膜的荧光强度明显增强,PANI增强了CdSe的光致发光性能,光致发光发射峰位置发生红移。     

聚氨酯/还原氧化石墨烯聚对苯二胺薄膜的制备与性能

采用Hummers法制备氧化石墨烯（GO）,并在其表面原位聚合聚对苯二胺(PPDA),再经水合肼还原得到还原氧化石墨烯聚对苯二胺(RGO-PPDA)复合体,并用其改性热塑性聚氨酯(TPU)薄膜,最终通过溶液涂膜制得TPU/RGO-PPDA复合薄膜。通过傅里叶变换红外光谱仪、X射线衍射仪、扫描电子显微镜、透射电子显微镜、X射线光电子能谱仪对RGO-PPDA纳米复合体进行表征,并利用氧气透过仪、高阻计对TPU/RGO-PPDA复合薄膜的性能进行测试,并与TPU/GO-PPDA复合薄膜性能进行对比。结果表明,GO上原位聚合PPDA,显著改善了GO的亲油性,这有利于GO在氮氮二甲基甲酰胺(DMF)中的分散,进而有利于实现在TPU基体中的均匀分散;当RGO-PPDA含量为0.8 %(质量分数,下同)时,TPU/RGO-PPDA复合薄膜的氧气透过率降低了73.28 %,导电性能提升了8个数量级,表现出良好的阻隔抗静电性能。     

新型石墨烯/聚苯胺/银基复合材料的制备

通过对石墨烯(GN)制备、结构改性及与聚苯胺(PANI)、银粒子(Ag)的复合,设计了制备GN/PANI/Ag新型电极复合材料的工艺路线。首先利用Hummers氧化还原法将石墨氧化成氧化石墨烯,利用硼氢化钠将氧化石墨烯还原成石墨烯,将石墨烯与聚苯胺、银粒子反应,最后制得了GN/PANI/Ag复合材料。利用扫描电子显微镜(SEM),透射电子显微镜(TEM),热重分析(TG)和电导率测试对GN和GN/PANI/Ag的形貌,热稳定性和电化学性能进行了分析研究。结果表明,聚苯胺类衍生物、石墨烯以及银粒子三相在整个复合材料中共存,材料的复合使体系热稳定性和电化学性能得到提高。     

DNA在GO-PANI复合材料表面上的固定/杂交

采用氧化还原法制备氧化石墨烯(GO),通过原位插层聚合法制备出GO与导电聚苯胺(PANI)复合层状纳米材料。采用旋涂法将GO–PANI复合材料旋涂在自组装有十八烷三甲氧基硅烷的硅片上,对核糖核酸(DNA)在复合材料表面上的固定进行电化学性能测试。结果表明,DNA能够很好地固定在GO–PANI复合材料表面上,对将来开发出易于制备的电化学性能优良的DNA芯片提供了实验基础。     

氧气对聚苯胺/316L不锈钢体系耐腐蚀性能的影响

为了防止不锈钢双极板在质子交换膜燃料电池(PEMFC)工作环境下发生腐蚀,在由0.1 mol/L苯胺单体与0.2 mol/L H_2SO_4组成的水溶液中采用循环伏安法在316L不锈钢(SS)表面电化学合成了导电聚苯胺(PANI)薄膜。采用傅里叶变换红外光谱(FT-IR)分析了PANI的化学结构,采用扫描电镜(SEM)观察了表面形貌,发现所合成的PANI具有苯-醌交替的中间氧化态结构,PANI膜呈现纤维状形貌特征。采用极化曲线和电化学阻抗谱(EIS)对比研究了在0.2 mol/L H_2SO_4中氧气对PANI/316L SS和无涂层316L SS耐腐蚀性能的影响。结果表明,氧气促进了PANI/316L SS界面处保护性氧化膜的形成,使PANI/316L SS体系的耐腐蚀性能提高。     

氧化石墨烯复合TiO2-B薄膜的制备及其电致变色性能

目前具有一维纳米结构的TiO₂薄膜在电致变色领域应用主要受限于材料光调制幅度小、响应时间长、循环稳定性差等缺点。为了解决上述问题,本文采用沉积法将B型二氧化钛纳米管（TiO₂-B）与氧化石墨烯复合,以TiO₂粉末为原料,采用水热法得到钛酸纳米管后,利用沉积法在氟掺杂的氧化锡玻璃（FTO）基底上制备了高透明度、大光调制范围以及优良循环性能的氧化石墨烯复合B型二氧化钛纳米管电致变色薄膜（GO/TiO₂）。借助XRD、XPS、Raman、FESEM、HR-TEM等分析手段研究了氧化石墨烯用量对GO/TiO₂复合薄膜电致变色性能的影响。研究结果表明,当GO与钛酸纳米管的质量比（GO/钛酸）为7％时,GO/TiO₂复合薄膜离子扩散系数为1.46×10^-8cm²/s,着色效率值为38.1cm²/C,具有良好的电致变色性能。在-1.6V、633nm处,GO/TiO₂电致变色薄膜的光调制幅度可达77％,GO/TiO₂薄膜的着色和漂白时间分别为28.6s和4.8s,100次循环后的光调制幅度保持率为96.1％。     

Bio- and bioelectro-catalytic properties of polyaniline/poly(acrylic acid) composite films bearing covalently-immobilized acid phosphatase

Conducting films composed of polyaniline (PANI) and poly(acrylic acid) (PAA) were prepared by electrochemical polymerization of aniline in the presence of various concentrations of PAA. The content of PAA moiety on the surface of the composite films (PANI/PAA films) was estimated by determination of carboxyl groups and found to be controlled by the concentration of PAA in polymerization solution. Acid phosphatase (ACP) was immobilized covalently on the PANI/PAA films by the condensation reaction with the carboxyl groups on the films. It was confirmed that the enzyme activity of the ACP-immobilized PANI/PAA film increased with increasing content of PAA moiety on the surface of the film, accompanying an increase in the amount of the immobilized ACP. The activity of the covalently immobilized ACP was significantly higher than that of the ACP adsorbed on the PANI/PAA film. By use of the ACP-immobilized PANI/PAA film as an enzyme electrode, bioelectrocatalytic oxidation of L-ascorbic acid 2-phosphate (ASA2P) was examined. The enzyme electrode gave the current due to the oxidation of ASA2P in proportion to the content of PAA moiety on the surface of the PANI/PAA film used, which was relevant to the activity of the covalently immobilized ACP.     

Growth mechanism of transparent and conducting composite films of polyaniline

Composites of polyaniline (PANI) with various polymeric matrices as substrates were synthesized by means of diffusion–oxidation of aniline swollen polymeric matrices with FeCl₃ as oxidizer. The conductivity at room temperature, transmittance at 400–800 nm, stability in air, and morphology of PANI composite films depend on the polymerization time, concentration of FeCl₃, and substrate used. A maximum conductivity at room temperature and the highest transmittance at 500–800 nm can be achieved of 10^?1 S/cm and 70–80%, respectively. The growth mechanism of PANI composite films has been discussed. © 1993 John Wiley & Sons, Inc.     

Oxidative graft polymerization of aniline on the modified surface of polypropylene films

A novel method for preparing electrically conductive polypropylene‐graft‐polyacrylic acid/polyaniline (PP‐g‐PAA/PANI) composite films was developed. 1,4‐Phenylenediamine (PDA) was introduced on the surface of PP‐g‐PAA film, and then, chemical oxidative polymerization of aniline on PP‐g‐PAA/PDA film was carried out to prepare PP‐g‐PAA/PANI electrically conductive composite films. After each step of reaction, the PP film surface was characterized by attenuated total reflectance Fourier transform infrared spectroscopy. Static water contact angles of the PP, PP‐g‐PAA, and PP‐g‐PAA/PANI films were measured, and the results revealed that graft reactions took place as expected. The morphology of the PP‐g‐PAA film and the PP‐g‐PAA/PANI composite film were observed by atomic force microscopy. The conductivity and the thickness of the PP‐g‐PAA/PANI composite films with 1.5 wt % PANI were around 0.21 S/cm and 0.4 μm, respectively. The PANI on the PP‐g‐PAA/PANI film was reactivated and chain growing occurred to further improve the molecular weight of PANI. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 2442–2450, 2007     

Electrochemical polymerization of aniline in the presence of poly(acrylic acid) and characterization of the resulting films

Conducting films composed of polyaniline (PANI) and poly(acrylic acid) (PAA) were prepared by electrochemical polymerization of aniline in the presence of PAA. The PAA content in the films (PANI/PAA films) was controlled by the concentration of PAA in polymerization solution, and the properties of the films were investigated in relation to the PAA content. It was demonstrated by means of scanning electron microscopy and cyclic voltammetry that the surface morphology and electrochemical property of the films were affected significantly by the PAA content. In contrast, the conductivity of the films was found hardly dependent on the PAA content up to 18 wt %. The cyclic voltammetry gave an interesting result that the PANI/PAA films showed an electroactivity in neutral solution, which was not observed for the PANI film without PAA, and the electroactivity was closely related to the PAA content in the PANI/PAA films.     

Electrochemical formation of Ir oxide/polyaniline composite films

The primary goal of this work has been to electrochemically form and then characterize a composite polyaniline (PANI)/hydrous Ir oxide (IrOx) film. Efforts to electrochemically form IrOx and PANI simultaneously in acidic aniline-containing solutions failed, likely as aniline adsorption on Ir prevents IrOx formation. Successful composite films were therefore made by first forming an anodic IrOx film on bulk Ir and then depositing PANI into its pores. Based on the characteristics of the PANI redox peaks, it is seen that all of the PANI film that is electrochemically active is in direct electrical contact with the Ir surface at the base of the IrOx film pores. This is consistent with the cross-sectional SEM and EDX analyses, showing the formation of films of uniform thickness and composition. Thin films of Ir nanoparticles, subsequently converted to IrOx, were also used as a template for PANI formation within the porous structure. These hybrid films exhibit an enhanced internal porosity, ease of multiple coating formation (up to 20 μm in thickness), high charge densities, unusual electrochromic behavior, and very rapid charge transfer kinetics. The formation of composite IrOx/PANI films also resulted in a widening (by 0.3-0.4 V) of the potential window over which a pseudocapacitive and electrochromic response is seen.     

A study on the electrochromic properties of polyaniline/silica composite films with an enhanced optical contrast

A polyaniline (PANI)/silica (SiO₂) composite film was prepared by a simple in situ electrodeposition method, and its electrochromic (EC) properties were studied. When PANI was electrodeposited in the presence of SiO₂ particles, the resulting PANI/SiO₂ composite films possessed higher surface areas, larger redox charge capacities, and higher doping levels, thus enhanced optical contrasts. By incorporating SiO₂ particles into the PANI film, the transmittance change at 700 nm from 10.7% to 16.4%, or an enhancement of ca. 50%, was achieved when operating between −0.5 V and 0 V. In addition, x-ray photoelectron spectroscopy (XPS) indicated that the formation of the highly oxidized PANI might have been retarded through the addition of SiO₂ particles. Furthermore, the growth mechanism of the PANI/SiO₂ composite film was proposed.     

Layer-by-layer assembly of polyaniline nanofibers/poly(acrylic acid) multilayer film and electrochemical sensing

Polyaniline (PANI) nanofibers are synthesized by dilute polymerization and subsequently used for layer-by-layer assembly with poly(acrylic acid) (PAA). The chemical synthesized PANI nanofibers are characterized by SEM and TEM. In addition, the LBL assembly process is characterized by SEM, UV-vis spectrometry and electrochemical methods. PAA inside the multilayer film can dope nanostructured PANI effectively and shift its electroactivity to a neutral pH environment. Compared with PANI/PAA film co-deposited on the electrode by electropolymerization, the redox behavior of PANI/PAA multilayer via LBL assembly is more reversible, indicating the enhancement of electron transfer. The obtained nanostructured PANI/PAA multilayer films are very stable and show high electrocatalytic ability toward H₂O₂, which makes it an ideal substrate for H₂O₂ detection and offers great promise for biosensing.     

Aqueous in-situ electrosynthesis and electrochromic performance of PEDOT:PSS/Reline film

Poly(3,4-ethylene dioxythiophene) (PEDOT) is a promising electrochromic material in many practical application, such as smart windows and displays. However, there are still difficulties in currently realizing green manufacturing, high coloration efficiency, and rapid response. Herein, in-situ electrochemical polymerization of PEDOT:PSS/Reline films was suggested in aqueous solution. Deep eutectic solvents (DES) composed of choline chloride and urea (Reline) were employed as green solvents in reaction system and used as dopants for the PEDOT:PSS. The as-prepared PEDOT:PSS/Reline films exhibited remarkable electrochromic properties, including great ion diffusion coefficient, fast reaction time (coloration response time was 1.4 s), prominent transmittance modulation (38%), high coloration efficiency (223 cm²/C) and excellent cyclic stability. Impressively, doping of Reline cannot only provide a green polymerization environment, but also significantly boost the electrochromic properties.     

Electrochromic features of hybrid films composed of polyaniline and metal hexacyanoferrate

Hybrid organic/inorganic films, composed of polyaniline (PANI) matrix and Prussian blue-like nickel hexacyanoferrate redox centers, showed reversible electrochromic behavior in acidic potassium salt electrolytes. The system's coloration properties were assessed from various spectroelectrochemical measurements including voltabsorptometry that involved monitoring of the time-derivative signal of absorbance at 700 and 410 nm as a function of linearly scanned potential. Gold-covered foil was used as a conductive, optically transparent, substrate onto which the composite film was electrodeposited by potential cycling in the mixture for modification consisting of aniline monomer, Ni²⁺, Fe(CN)₆³⁻ and electrolyte containing K⁺ and H⁺ ions. An important feature of hybrid (composite) material was that its electrochromic properties were dominated by color changes occurring in the PANI component. Coloration originating from nickel hexacyanoferrate barely affected the system's electrochromic characteristics. But the cyanometallate redox centers distributed in the PANI matrix behaved reversibly as expected for a system capable of fast charge transport.