Interfacial polymerization of polyaniline and its layer‐by‐layer assembly into polyelectrolytes multilayer thin‐films

The layer‐by‐layer (LbL) self assembly deposition technique was used to prepare multilayer thin films of anionic polyaniline‐blend‐poly(sodium 4‐styrenesulfonate) (PANI‐PSS) and cationic poly(diallydimethylammonium chloride) (PDADMAC). Anionic polyaniline was prepared by the interfacial polymerization of aniline monomer in the presence of PSS which acted as template to provide water solubility. The PSS to PANI concentration ratios used in the synthesis step was found to have a major effect on the final PANI‐PSS synthesis, its self assembly and the electrical properties of the prepared films. The optical and electrical properties of the films were measured by ultraviolet‐visible spectroscopy (UV‐Vis) and a 4‐point probe setup, respectively while the thickness of the films was measured by atomic force microscopy (AFM). Results showed that the optimum condition for the film growth and optimal conductivity were obtained with different synthesis conditions. These results suggest that the PSS concentration used for interfacial synthesis of PANI must be finely tuned depending on the type of application aimed by the user. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Fabrication of DBSA‐doped polyaniline nanorods by interfacial polymerization

An interfacial polymerization was used to fabricate dodecybenzenesulfonic acid (DBSA)‐doped polyaniline (DBSA‐PANI) nanorods with diameter range from 40 nm to 1 μm. The molar ratio of aniline to ammonium peroxydisulfate (APS), the concentrations of DBSA and reaction temperature had an effect on the morphology and size of products. It was found that lower concentration of DBSA and lower temperature will be helpful to the formation of rod‐like PANI nanostructures with a relative small diameter. UV–vis and FTIR measurements were used to characterize the chemical structure of the obtained samples. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

纳米聚苯胺改性聚哌嗪酰胺纳滤膜的制备

以导电态纳米聚苯胺(PANI)为添加剂, 哌嗪和均苯三甲酰氯(TMC)为反应单体, 通过界面聚合反应在聚砜超滤膜上形成复合层制备纳滤膜。采用扫描电子显微镜(SEM)和原子力显微镜(AFM)等对复合膜的性能和结构分别进行了测试和表征。SEM照片证实PANI含量低时, 可以在复合膜上分布得比较均匀;AFM图像看出膜表面粗糙度的增加;膜性能的测试结果证实了添加PANI的复合膜水通量得到了提高, 同时脱盐率也有变化。最优实验条件下, 膜对Na₂SO₄、MgSO₄、MgCl₂和NaCl的截留率分别为99.4%、98.5%、85.4%和59.2%。试验结果表明, 加入PANI能够提高膜的水通量, 并提升了膜的脱盐性能。     

Exploration of the morphological transition phenomenon of polyaniline from microspheres to nanotubes in acid‐free aqueous 1‐propanol solution in a single polymerization process

Polyaniline micro‐ or nanostructures have been widely investigated due to their unique physical and chemical properties. Although several studies have reported the synthesis of polyaniline microspheres and nanotubes, their mechanisms of formation remain controversial. This study reports our observation of the morphological transition of polyaniline from microspheres to nanotubes in a single polymerization process and also tries to propose their mechanisms of formation. The polymerization of aniline monomer in acid‐free aqueous 1‐propanol solutions (1 and 2 mol L^?1) produces polyaniline microspheres and nanotubes at different reaction stages through a morphology transition process with treatment using ultrasound. In the initial reaction stage, Fourier transform infrared spectra indicate that the aniline monomers form phenazine‐like units, producing polyaniline microspheres with an outside diameter of 1–2 µm. The hydrogen bonds between 1‐propanol and polyaniline serve as the driving force for the polyaniline chains to build microspheres. As the reaction continues, observation indicates the microspheres decompose and reform one‐dimensional nanotubes. In this stage, a structure consisting of a head of phenazine‐like units and a tail of acid‐doping para‐linked aniline units develops. The protonation of the para‐linked aniline units provides the driving force for the formation of nanotubes through a self‐curling process. We report here the unique morphology transition of polyaniline from microspheres to nanotubes in a single polymerization process. The results indicate that the structural change of polyaniline leads to this morphological change. The mechanisms of formation of the microspheres and nanotubes in a polymerization process are also well explained. Copyright © 2010 Society of Chemical Industry     

原位聚合法制备聚苯胺/改性羰基铁粉复合材料

采用正硅酸乙酯(TEOS)对羰基铁粉(CIP)表面改性,通过原位聚合法制备了聚苯胺(PANI)/改性CIP复合材料。傅里叶变换红外光谱验证了SiO2和CIP表面形成了化学键。耐酸性实验表明:TEOS可在较长时间内保护CIP不被酸腐蚀,保证了制备PANI/CIP复合材料过程中CIP处于SiO2的有效保护下。所得复合材料为CIP表面包覆直径约20 nm均匀致密的PANI微粒,复合效果明显改善。复合材料电导率与CIP未改性前处于相同数量级。     

聚苯胺的合成与聚合机理研究进展

近年来,聚苯胺因其优良的性能而备受关注,其合成方法与合成机理一直是聚苯胺研究的重要内容之一.本文详细阐述了聚苯胺的化学氧化和电化学合成方法,并对两类合成方法的反应机理进行了综述.     

反相微乳液聚合法合成聚苯胺

以环已烷为溶剂,十二烷基硫酸钠(SDS)为乳化剂,H<,2>O<,2>为氧化剂,过硫酸钾(KPS)为引发剂,浓盐酸使苯胺质子化,采用反相微乳液聚合法合成聚苯胺.研究了SDS,KPS,浓盐酸,反应时间对聚苯胺产量的影响,用循环伏安法、差热分析法对聚苯胺进行了表征.结果表明,较佳的工艺条件:SDS用量为0.50 g,KPS...     

Emulsion polymerization of styrene using mixtures of hydrophobically modified inulin (polyfructose) polymeric surfactant and nonionic surfactants

Polystyrene latex dispersions were prepared by emulsion polymerization, using a mixture of hydrophobically modified Inulin (INUTEC® SP1) and various nonionic surfactants (cosurfactants). Two series of nonionic surfactants were used, namely Synperonic A (C_13–15 alkyl chain with 7, 11, and 20 moles of ethylene oxide, EO) and Synperonic NP (nonylphenol with 10 and 15 moles of EO). For 5 wt % latex, the INUTEC SP1 concentration was kept constant at 0.0165 wt % and the initiator concentration was also kept constant at 0.0125 wt %, whereas the cosurfactant concentration was varied between 0.1 and 0.5 wt %. With the exception of Synperonic A20, all other cosurfactants showed an initial increase in particle diameter followed by a decreased reaching a value comparable with that obtained using INUTEC SP1 alone. However, A20 produced a continuous reduction in particle diameter with increase of surfactant concentration, reaching a value of 100 nm at 0.5 wt % which is lower than the value obtained using INUTEC SP1 alone (188 nm). In all cases, addition of a cosurfactant enhanced the stability of latexes by co‐adsorption at the solid–liquid interface. The enhanced stability produced by the addition of cosurfactants to INUTEC SP1 could be illustrated by using the mixture of INUTEC SP1 and Synperonic A7 at 40 wt % of styrene latex concentration. In this case, the mixture produced lower particle size, much lower polydispersity index and much higher stability. These results are of significant value for industrial applications. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

乳液聚合法制备聚苯胺及其导电性能

以十二烷基苯磺酸(DBSA)为乳化剂,十六醇(CA)为助乳化剂,盐酸和十二烷基苯磺酸（DBSA）为掺杂剂, 过硫酸铵为引发剂,采用乳液聚合法合成了导电聚苯胺（PAn）.研究了反应温度、反应时间及苯胺、十二烷基磺酸、十六醇、盐酸和过硫酸铵配比对聚苯胺电导率的影响.研究结果表明,较佳的工艺条件为：反应温度为7 ℃,反应时间为6 h,较佳的原料物质的量的比为苯胺∶十二烷基苯磺酸∶十六醇∶盐酸∶ 过硫酸铵=0.05∶0.028∶0.04∶0.01∶0.05;以十六醇为助乳化剂,采用十二烷基苯磺酸和盐酸为掺杂剂,提高了聚苯胺的导电性.同时对聚苯胺导电机理进行了分析.     

Synthesis of polyaniline/MCM‐41 composite through surface polymerization of aniline

Polyaniline (PANI)/porous silica MCM‐41 (MCM‐41) composite was synthesized according to surface polymerization theory, and it was confirmed through comparing with PANI/solid silica (SiO₂) by TGA and XPS techniques. The morphology and composition of the composite were also characterized by some techniques such as small‐angle XRD, N₂‐adsorption isotherm, SEM, FTIR, and UV–vis. The thermal stability for the PANI/MCM‐41 composite was enhanced when compared with that of pure PANI. With the increase in the concentration of HCl, the doping degree increased and UV‐absorption peak at about 700 nm showed a red shift. The conductivity of the composite was enhanced by increasing the concentration of HCl. The results of FTIR showed that there was a strong interaction between PANI and MCM‐41. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 2088–2094, 2006     

Interfacial assembly and electrochemical properties of nafion-modified-graphene/polyaniline hollow spheres

A novel strategy has been developed to prepare hollow structured Nafion-modified-graphene/polyaniline (NGP) composites via interfacial assembly polymerization between an aqueous phase containing oxidant and an organic phase containing aniline monomers and Nafion-modified graphene. Fourier transform infrared (FTIR), Ultraviolet-visible (UV-vis) and X-ray diffraction (XRD) analyses confirmed the generation of polyaniline (PANI) on graphene during the interfacial polymerization. The morphological evolution of the product had been investigated by scanning electron microscopy (SEM) with respect to the reaction time, based on which a conceivable interpretation of the growth mechanism of the sphere architectures with composite component were given. The as-prepared hollow structured composites showed a good rate capability as electrode material for supercapacitor, and the as-designed interfacial assembly preparation strategy for such composites may provide a generic guideline in developing other graphene-base composite hollow spheres with different compositions.     

Oxidative degradation of polyaniline during the chemical oxidative polymerization of aniline in aqueous methanol medium

The course of chemical oxidative polymerization of aniline using ammonium persulfate as the initiator in acidic (1 M HCl) aqueous methanol (30 to 70 vol%) was studied spectrophotometrically. It was found that at temperatures greater than about 10 °C the reaction leads to degradation of polyaniline, the effect being greater with increasing methanol concentration. This is quite unlike the situation in aqueous ethanol where the product is the usual emeraldine hydrochloride form of polyaniline. Copyright © 2005 Society of Chemical Industry     

Preparation of phenolic hollow microspheres via in situ polymerization

BACKGROUND: Phenolic hollow microspheres with a closed structure have a set of outstanding thermal characteristics. In the work reported here, a facile method is introduced to fabricate phenolic closed hollow microspheres by in situ polymerization in oil‐in‐water emulsion. Although in situ polymerization has been widely used to prepare hollow microspheres, it has not been utilized for the preparation of phenolic hollow microspheres. RESULTS: The average particle size of the produced microspheres was about 500 µm. Fourier transform infrared spectroscopy indicated that the phenolic microspheres were partially cured during preparation and a significant number of hydroxymethyl groups remained in the microspheres. Thermogravimetric analysis showed that the thermal decomposition temperature of the phenolic hollow microspheres was 420 °C, and residual weight at 800 °C was 62%. Differential thermal analysis showed that the glass transition temperature of the phenolic hollow microspheres was 200 °C. CONCLUSION: Using in situ polymerization, high thermal performance phenolic hollow microspheres are produced. The resultant product possesses a satisfactory closed hollow structure with controlled morphology. Copyright © 2009 Society of Chemical Industry     

Facile synthesis of hollow microspheres of polyaniline using poly(sodium 4‐styrenesulfonate) as dopant

In a conventional chemical oxidative polymerization of aniline in poly(sodium 4‐styrenesulfonate) aqueous solution, hollow microspheres of polyaniline were easily prepared, instead of common particles. The morphology of the hollow microspheres was studied and confirmed using scanning electron microscopy and transmission electron microscopy. The molecular structure, room temperature conductivities and thermal stability of the resulting polyaniline were characterized using Fourier transform infrared spectroscopy, the standard DC four‐probe method, thermogravimetric analysis and differential thermal analysis. The influence of poly(sodium 4‐styrenesulfonate) and aniline on the morphology and physical properties of the resulting polymer were investigated. The results showed that the proper ratio of poly(sodium 4‐styrenesulfonate) and aniline was a critical factor in the synthesis of hollow microspheres, which may be related to the chemical structure of poly(sodium 4‐styrenesulfonate) as polyanion and of polyaniline as polycation and the electrostatic interaction between them in the doping process. A possible formation mechanism is proposed in this work. © 2013 Society of Chemical Industry     

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     

Synthesis of conducting polyaniline/TiO2 composite nanofibres by one‐step in situ polymerization method

Conducting polyaniline (PANI)/titanium dioxide (TiO₂) composite nanofibres with an average diameter of 80–100 nm were prepared by one‐step in situ polymerization method in the presence of anatase nano‐TiO₂ particles, and were characterized via Fourier‐transform infrared spectra, UV/vis spectra, wide‐angle X‐ray diffraction, thermogravimetric analysis, and transmission electron microscopy, as well as conductivity and cyclic voltammetry. The formation mechanism of PANI/TiO₂ composite nanofibres was also discussed. This composite contained ～ 65% conducting PANI by mass, with a conductivity of 1.42 S cm^?1 at 25°C, and the conductivity of control PANI was 2.4 S cm^?1 at 25°C. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 2007     

Preparation of polyaniline coated polystyrene‐poly(styrene‐co‐sodium 4‐styrenesulfonate) microparticles and the further fabrication of hollow polyaniline microspheres

In this article, the microparticles of polystyrene‐poly(styrene‐co‐sodium 4‐styrenesulfonate) (PS‐PSS) coated by polyaniline (PANI) were prepared and hollow PANI microspheres were further obtained by dissolving the core. First, surface‐sulfonated monodispersed PS was prepared by copolymerization of sodium 4‐styrenesulfonate (SSS) and styrene with dispersion polymerization method. Then aniline was polymerized on the surface of the surface‐sulfonated PS (PS‐PSS) by chemical oxidative polymerization. After purification, we prepared core‐shell (PS‐PSS)/PANI particles. Hollow PANI microspheres were prepared by dissolving the plastic PS core of the (PS‐PSS)/PANI particles in chloroform. The growth process of PANI on the surface of PS‐PSS particles was investigated and the hollow PANI microspheres were characterized. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Water‐dispersible porous polyisoprene‐block‐poly(acrylic acid) microspheres

Two polyisoprene‐block‐poly(tert‐butyl acrylate) (PI‐b‐PtBA) samples and a poly(tert‐butyl acrylate) (PtBA) homopolymer (hPtBA) were prepared by anionic polymerization and characterized by light scattering, size exclusion chromatography, and NMR. The tert‐butyl groups were removed from one of the diblocks to yield amphiphilic polyisoprene‐block‐poly(acrylic acid) (PI‐b‐PAA). PI‐b‐PAA was then used as the surfactant to disperse dichloromethane containing PI‐b‐PtBA and hPtBA at different weight ratios as oil droplets in water. Solid microspheres containing segregated polyisoprene (PI) and PtBA/hPtBA domains were obtained after dichloromethane evaporation. Permanent microspheres were obtained after PI domain crosslinking with sulfur monochloride. Porous microspheres were produced after the hydrolysis of PtBA and the extraction of the homopoly(acrylic acid) chains. The shape and connectivity of the poly(acrylic acid)‐lined pores were tuned by changes in the PtBA/hPtBA content in the precursor microspheres. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 2785–2793, 2003     

Controlled growth of hollow polyaniline structures: From nanotubes to microspheres

Homogeneous and fairly monosized microspherical structures of polyaniline has been synthesized using a simple soft template method with β-naphthalene sulfonic acid (β-NSA) as both the surfactant and dopant, and ammonium persulfate (APS) as the oxidant at 2–5 °C. The morphology of PANI-NSA was successfully controlled from nanotubes to microsphere, by changing the synthesis conditions (i.e. pH, the concentration of surfactant and monomer, and temperature). Some mechanistic aspects of the formation of nanotubes and hollow spheres have been discussed precisely based on SEM, TEM, DLS, FTIR and UV-visible results. Moreover, synthesis was performed under acidic environment to obtain further understanding about the formation mechanisms.     

Surface graft polymerization of conducting polyaniline on waterborne poyurethane‐urea film and its phenol sensing

Waterborne polyurethane‐ureas (pristine WBPUs: WBPU‐19 and WBPU‐24, fixed soft segment content: 60 wt %) containing dimethylol propionic acid (DMPA)/ethylene diamine (EDA) contents (19/16.8 and 24/11.4 mol %) were prepared. The polyaniline (PANI)‐graft‐WBPU (PANI‐graft‐WBPU) films were prepared by oxidative graft polymerization of aniline on the surface layer of WBPU films. This study focused on the effects of reaction conditions (concentrations/treating times/temperatures of aniline and APS) and DMPA content on the %grafting, conductivity, and mechanical properties of PANI‐graft‐WBPU films. To obtain the maximum %grafting (PANI‐graft‐WBPU‐19: 6.2, and PANI‐graft‐WBPU‐24: 7.4) and conductivity (PANI‐graft‐WBPU‐19: 3.6 × 10^?2S/cm, and PANI‐graft‐WBPU‐24: 4.7 × 10^?2S/cm), the optimum concentrations/treating times/temperatures of aniline and APS, were found to be 0.35M/10 min/25°C and 0.2M/10 min/0°C, respectively. The tensile strength of film samples was found to be increased in the order of PANI‐graft‐WBPU‐19>pristine WBPU‐19>PANI‐graft‐WBPU‐24>pristine WBPU‐24. The PANI‐graft‐WBPU‐19 (%grafting: 6.2) films on exposure to 0–10,000 ppm phenol solutions showed a well‐defined response behavior, demonstrating high promise for application in aqueous phenol sensors. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013