Conductive polyaniline–polythiophene/poly(ethylene terephthalate) composite fiber: Effects of pH and washing processes on surface resistivity

A conductive polyaniline (PAn)–polythiophene (PTh)/poly(ethylene terephthalate) (PET) composite fiber was prepared by polymerization of aniline and thiophene in the presence of PET fibers in an organic medium with FeCl₃. The effects of polymerization conditions, such as polymerization medium, mol ratios of aniline/thiophene and FeCl₃/aniline‐thiophene as well as polymerization temperature and time, were investigated on PAn–PTh content (%) and surface resistivity of the composite. The composite with the lowest surface resistivity (1.30 MΩ/cm²) was obtained by polymerization of aniline and thiophene (1/3 mol ratio) in acetonitrile/chloroform (1/5 volume ratio) at 20°C. The surface resistivity of the PAn–PTh/PET composite containing 4.8% PAn–PTh was increased from 1.9 MΩ/cm² to 270 MΩ/cm² at pH 11. The washing durability of the composites was determined with domestic and commercial laundering processes by monitoring the surface resistivity and morphology. The composite was also characterized with FTIR, TGA, elemental analysis, optic microscope and SEM techniques. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41979.     

Conductive fibers based on poly(ethylene terephthalate)–polyaniline composites manufactured by electrochemical polymerization

A novel method of manufacturing composite conductive fibers was developed through electrochemical polymerization with an apparatus consisting of insulating fibers, cotton fabrics as electrolytic solution holders, an electrolytic solution, and planer electrodes. By this method, poly(ethylene terephthalate) (PET) fibers coated with polyaniline (PAN) were prepared readily and yielded PET–PAN composite conductive fibers (PPCFs). The content of PAN in PPCFs increased with an increase in both the aniline concentration in the electrolytic solution and the polymerization voltage, although it did not depend on the load applied to the electrodes. Observations of the PPCF surface by scanning electron microscopy confirmed that the formation processes of PPCFs could be divided into three steps: (1) fine (nanometer‐size) granular PAN was generated from the anode and adsorbed onto the PET fiber surface, (2) the size of the granular PAN increased up to about 90 nm in a short time, and (3) the granular PAN was linked together to form networks. The conductivity of PPCFs increased with an increasing content of PAN networks. The surface resistance of the PPCF fabric was about 3 × 10⁵ Ω/□ at a PAN content of approximately 2 wt %. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 87: 1073–1078, 2003     

Preparation of aqueous polyaniline dispersions by micellar‐aided polymerization

Polyaniline (PAn) dispersed in water was prepared with sodium dodecylsulfonate (SDS) as a surfactant with varying concentrations of aniline and HCl and molar ratios of SDS/aniline. The PAn dispersion was homogeneous and stable, and its pH value could be adjusted. The conductivity of PAn powder, precipitated from this dispersion, was as high as 20 S/cm. The transmission electron microscopy morphology of PAn assembled in the dispersion was particle‐like, fiber‐like, or coil‐like, depending on the initial concentration of SDS and aniline. The polymerization of aniline was accelerated by SDS, which was confirmed by open‐circuit potential measurement during the polymerization process. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 1550–1555, 2003     

原位乳液聚合制备导电性聚苯胺/氯磺化聚乙烯复合材料及其性能

以十二烷基苯磺酸为乳化剂及掺杂剂,由二甲苯及水组成乳液,在氯磺化聚乙烯存在下,采用一步原位乳液聚合法制备了聚苯胺／氯磺化聚乙烯(PAn／CSPE)导电复合材料。研究了用熔融法(MP)或溶液法(SP)加工复合物材料的导电性及力学性能,并进行了表征。结果表明,MP法制得的复合材料在导电性及力学性能方面优于SP法制得的复合材料;当PAn质量分数为12％～18％时,MP法复合材料呈现热塑性弹性体行为,拉伸强度为6～8MPa,扯断伸长率大于400％,永久变形小于30％。当PAn质量分数小于18％时,SP法复合材料用闻甲酚二次渗杂后的导电率比原复合材料高出6个数量级,且其导电渗滤阈值由PAn质量分数22％降至3％。     

Photo-induced polymerization in ionic liquid medium: 1. Preparation of polyaniline nanoparticles

Photo-induced polymerization is employed to prepare polyaniline (PAN) nanoparticles in ionic liquid for the first time. Photons and photoactive ionic liquid cations replace conventional oxidants and metal complexes to promote the polymerization of aniline monomer. The diameter of the resulted PAN is confirmed in nano-scale by SEM. With increase of protonic acid in medium, the yield of the PAN increased, the UV absorption of the PAN strengthened, and a blue shift of the π-polaron absorption was observed. And the conductivity of the PAN also increased with the acid content in medium. The potential mechanism of photo-induced polymerization of aniline is proposed. Moreover, after the ionic liquid is separated from the reaction mixture and reused for five times, no obvious decrease in catalytic activity could be found in photo-induced polymerization of aniline. The method may open a new pathway to prepare nano-scale conducting polymers with sunlight.     

Potassium persulfate-mediated preparation of conducting polypyrrole/polyacrylonitrile composite fibers: Humidity and temperature-sensing properties

Conducting polypyrrole (PPy)/polyacrylonitrile (PAN) composite fibers were prepared by the polymerization of pyrrole in the presence of PAN fibers with potassium persulfate in an acidic aqueous solution. We obtained composite fibers containing concentrations of PPy as high as 1.14% and having surface resistivities as low as 0.6 kΩ/cm² by changing the polymerization parameters, including the temperature and concentrations of pyrrole and oxidant. The tensile strength of 10.02 N/m² and breaking elongation of 32.68% for the pure PAN fiber increased up to 10.45 N/m² and 33.23%, respectively, for the composite fiber containing 0.13% PPy. The change in the resistivity of the PPy/PAN composite fiber during heating–cooling cycles in the temperature range of +5 to 120°C was examined. Scanning electron microscopy and optical microscopy images of the composite fibers showed that the PPy coating was restricted to the surfaces of the PAN fibers. Surface resistivity measurements, Fourier transform infrared spectroscopy, and thermogravimetric analysis techniques were also used to characterize the composite fibers. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Preparation of conductive polyaniline/chlorosulfonated polyethylene composites via in situ emulsion polymerization and study of their properties

The conductive composites of polyaniline (PAn) and chlorosulfonated polyethylene (CSPE) were prepared by polymerization of aniline in the presence of CSPE, using a direct, one‐step in situ emulsion polymerization method. The polymerization of aniline was performed in an emulsion comprising water and xylene containing CSPE in the presence of dodecylbenzene sulfonic acid, which acts both as a surfactant and a dopant for PAn. The composites can be processed by either melt method (MP) or solution method (SP). Conductivity of the composites obtained by different processing methods shows different percolation thresholds: 14 wt % for MP samples and 22 wt % for SP samples. At the same content of PAn, the conductivity of MP composites is higher than that of SP composites. The relationships between mechanical properties and PAn content obtained by the two different processing methods were also investigated. When PAn content of MP samples is between 12 and 18 wt %, the composites behave like a thermoplastic elastomer with tensile strength at 6–8 MPa, ultimate elongation > 400% and permanent set < 30%. The conductivity of composites obtained by SP method after secondary doping with m‐cresol is about 6 orders of magnitude higher than the original at below 18 wt % PAn content and the percolation threshold for conductivity is lowered to 3 wt % PAn content. The composite shows no electrochromic activity in acidic solution of LiClO₄ in propylene carbonate, but after secondary doping exhibits electrochromic activity even in neutral electrolyte. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 76: 845–850, 2000     

导电聚苯胺/聚乙烯醇复合乳液的制备研究

以聚乙烯醇为树脂基体 ,通过乳液氧化聚合同步搀杂有机酸 ,研究了聚苯胺 /聚乙烯醇复合乳液的制备。结果表明 ,过硫酸铵的用量对聚苯胺的产率影响较大 ,当氧化剂 /苯胺的摩尔比达到 2时 ,产率为95% ,高于溶液法的原料比例。十二烷基苯磺酸和聚乙烯醇 (88%醇解度 )对聚苯胺乳胶的粒径亦有影响。在聚苯胺 /聚乙烯醇复合膜中 ,当聚苯胺含量超过 2 0 %后 ,电导率趋向稳定 ,可达 2 .3 s/ cm     

Removal of Cd(II) from aqueous solution by using polyaniline/polystyrene nanocomposite

One of the suitable methods for removing heavy metals from water and waste water is the use of a surface adsorption process. In this study, polyaniline/polystyrene (PAn/PS) nanocomposite was prepared in aqueous solution by the polymerization of styrene and aniline using potassium iodate and ammonium peroxydisulfate as oxidants in the presence of surfactive dopant sodium dodecylbenzenesulfonate and poly(vinyl pyrrolidone) as surfactant. The capability of separating Cd(II) ions was studied, and the results were compared with those obtained with other adsorbents. The results indicated that removal percentage was increased by increasing the concentration of adsorbent, contact time, and the pH of the solution. J. VINYL ADDIT. TECHNOL.,, 2012. © 2012 Society of Plastics Engineers     

Preparation of conductive polyaniline‐sulfonated EPDM ionomer composites from in situ emulsion polymerization and study of their properties

The composites of polyaniline (PAn) and zinc sulfonated ethylene–propylene–diene rubber (EPDM) ionomer were made by polymerization of aniline in the presence of the ionomer by using a direct, one‐step in situ emulsion polymerization technique. The ionomers were prepared by sulfonation of EPDM rubber with acetyl sulfate in petroleum ether, followed by neutralization with zinc acetate solution. The ionomers with sulfonate contents of 10, 24, and 42 mmol SO₃H/100 g were used for preparation of PAn/ionomer composites. The in situ polymerization of aniline was carried out in an emulsion comprising water and xylene containing the ionomer in the presence of dodecyl benzene sulfonic acid, acting as both a surfactant and a dopant for PAn. The composite was characterized by IR and WAXD. The composite obtained can be processed by melt method. The conductivity of the composite with lower sulfonate content was higher than that with higher sulfonate content. Conductivity of the composites exhibits a percolation threshold at about 13 wt % PAn. When the sulfonated content is 10 or 24 mmol SO₃H/100 g and PAn content is 4–10 wt %, the composites behave as a thermoplastic elastomers with high ultimate elongation and low permanent set. The conductivity of the composite after secondary doping with m‐cresol is higher than the composite before secondary doping by about one order. Addition of zinc stearate as an ionic plasticizer lowers both the conductivity and the mechanical strength of the composites. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 2211–2217, 2004     

铅电极上电聚合聚苯胺及其析氧电催化性能研究

在苯胺-硫酸电解液中,采用电化学阳极氧化法在纯铅表面电沉积制备聚苯胺(PAn)膜层。探讨了苯胺电聚合过程的影响因素及其规律,并考察了所得Pb/PAn膜电极材料的析氧电催化特性。结果表明,在一定的恒电流密度下,聚苯胺的沉积量与时间成正比;与空白Pb电极相比,Pb/PAn膜电极的析氧电位负移0.13~0.36V,交换电流密度提高2~4个数量级,显示出良好的析氧电催化特性。作为析氧阳极,Pb/PAn膜电极在有色金属电解提取等方面具有潜在应用价值。     

Electrochemically oxidative polymerization of aniline in aromatic copolyamide matrix

Composite films from polyaniline (PAn) and a copolyamide, poly(p-phenylene terephthalamide/diphenylether terephthalamide) (PPDTA), have been obtained by the electrochemical polymerization of aniline on a PPDTA/Pt (or Ni, stainless steel) working electrode in water or a mixed-solvent electrolyte solution. This PAn/PPDTA composite has higher mechanical properties than does the PPDTA matrix and the electrical conductivity close to pure PAn. The electrochemical polymerization of aniline can be carried out only in the electrolyte solution with PH < 2. The PAn/PPDTA film is electroactive material and very stable in air. © 1993 John Wiley & Sons, Inc.     

聚苯胺/阴离子聚醚型聚氨酯导电复合膜的制备

常压下,采用化学氧化现场吸附聚合法制备了聚苯胺/阴离子型聚氨酯导电复合膜。该复合膜不仅表现出良好的导电性,其表面电阻为103Ω/cm,而且导电性较为耐久和稳定;同时复合膜也兼有良好的力学性能及良好的透气性。     

催化剂制备与研究 石墨烯/聚苯胺复合材料的制备及其光催化性能

以苯胺和氧化石墨烯溶液为原料,采用乳液聚合法,根据m(氧化石墨烯)∶m(苯胺)为0∶10、1∶20和1∶10合成不同石墨烯/聚苯胺复合材料。采用紫外可见分光光度计、SEM、XRD及FT-IR对复合材料进行表征。XDR和FT-IR表明,乳液聚合合成了石墨烯/聚苯胺复合材料。SEM表明,聚苯胺以氧化石墨烯为载体,分散在其表面。光催化结果表明,石墨烯/聚苯胺复合材料的光催化性能较纯聚苯胺明显提高,m(氧化石墨烯)∶m(苯胺)=1∶20的石墨烯/聚苯胺复合材料的光催化性能高于m(氧化石墨烯)∶m(苯胺)=1∶10,原因可能在于微观结构的不同。     

Electromagnetic interference shielding with polyaniline nanofibers composite coatings

Hydrochloric acid doped polyaniline (PANI) nanofibers were synthesized by an interfacial polymerization with tetrachloride as the organic solvent and with a relatively higher aniline concentration. The doped PANI nanofibers were dispersed in cyclohexanone and the dispersion was mixed with solution of polyacrylate to prepare PANI nanofibers composite coatings. It was found that the yield of the doped PANI nanofibers can be as high as 23%, though a small amount of irregular shaped PANI particles and PANI nanofibers with relatively larger diameter were also obtained. The conductivity of the PANI nanofibers based composite coatings increased with the PANI nanofibers contents and a percolation threshold of 0.2 was demonstrated. The shielding effectiveness of the PANI nanofibers based coatings increased with PANI nanofibers loadings and shielding effectiveness as high as 63 dB can be achieved with PANI nanofibers loadings of 45%. POLYM. ENG. SCI., 2008. © 2007 Society of Plastics Engineers     

Electrically conductive textiles by in situ polymerization of aniline

Two methods of obtaining electrically conductive fabrics by in situ polymerization of aniline were compared. Conductive fabrics were prepared by immersing the nylon 6 fabrics in 100% aniline or an aqueous hydrochloride solution of aniline followed by initiating successive polymerization in a separate bath (DPSB) or in a mixed bath (DPMB) of oxidant and dopant solution with aniline. In each case, the polymerization conditions were optimized to obtain the maximum quality of polyaniline (PAn) on the fabrics. The higher conductivity of composite fabrics, whose value reached up to 0.6 × 10⁻¹ s/cm, was obtained by the DPMB process. Moreover, this method induced the least decrease in the degree of crystallinity as compared to the DPSB process. The serviceability of the PAn–nylon 6 composite fabrics was also evaluated. No significant changes in the conductivity were observed after abrading the composite fabrics over 50 cycles and multiple acid and alkali treatment. The stability of conductivity was slightly decreased by less than 1 order after exposure to light for 100 h, but it was significantly decreased after washing with detergent. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 74: 2094–2101, 1999     

Electrochemical characteristics and catalytic activity of polyaniline doped with ferrocene perchlorate

A new‐doped method based on electrochemical polymerization of aniline in the presence of ferrocene perchlorate and perchloric acid was presented. Polyanilines (PAn and PAnFc) were polymerized in the solution of perchloric acid and the solution containing ferrocene perchlorate and perchloric acid, respectively. Both flame atomic absorption spectrometry and infrared spectrum indicated that ferrocene perchlorate was assured to be doped into the polyaniline. We presumed that ferrocene perchlorate was combined via electrostatic adsorption onto the chain of polyaniline. The effect of pH on the electrochemical characteristics of PAn and PAnFc was studied by cycle voltammetry. Compared with PAn prepared in the absence of ferrocene perchlorate, PAnFc prepared in the presence of ferrocene perchlorate has a rather high electrochemical activity at pH > 4. The electrochemical oxidation of ascorbic acid (AA) on both PAn film and PAnFc film modified Pt electrode was also performed. The results indicated that the catalytic activity of the PAnFc film to AA was better than that of the PAn film. The anodic peak currents of AA (measured by constant potential amperometry) increased linearly with the concentration of AA in the range of 8.0 × 10^?5–1.0 × 10^?2 mol/L. The detection limit (S/N = 3) obtained was 1.0 × 10^?5 mol/L. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 5633–5639, 2006     

聚苯胺修饰电极对甲醇的电催化氧化研究

应用电化学方法制备了Pt/PAn/GC电极,优化了苯胺在玻碳电极上的聚合条件,并对其进行了表征.结果表明,铂微粒在聚苯胺膜电极上具有很高的分散度,电极具有很大的比表面积,Pt/PAn/GC电极对甲醇电氧化的催化活性明显高于Pt/GC电极和Pt电极,在该电极上甲醇正向扫描和反向扫描时的氧化峰电流为58.68mA/cm2和50.00mA/cm2,为Pt/GC电极的1.6倍和1.7倍,为Pt电极的3.0倍和3.1倍,从而有效地提高了铂的催化活性,并得到在玻碳电极上聚合苯胺的最佳条件为扫描速度50mV/s,扫描上限1.2V.     

Adsorption behavior of monomers and formation of conducting polymers on polyester fibers

In situ adsorption of monomers on fibers plays a key role in fabricating highly conductive polyaniline (PANI)‐based textiles by two‐stage oxidation polymerization. Experiments were conducted in aniline monomer and hydrochloric acid solution with the variables such as contact time, initial concentration, and temperature, which can enhance the equilibrium adsorption capacity to aniline of poly(ethylene terephthalate) (PET) fibers. Equilibrium data were fit well by a Henry partition‐type isotherm equation. It was found that the kinetics of the adsorption of aniline onto PET fibers at different operating conditions was best described by the pseudo‐second‐order model. The rate parameters of the intraparticle diffusion model for adsorption were also evaluated and compared to identify the adsorption mechanisms. The monomer exhaustion increased with increasing the temperature. The value of electrical surface resistance of conductive textiles about 3.2 kΩ was obtained when the padder squeeze step was introduced, and the molar ratio of 0.6 between the oxidant concentration and the exhausted concentration of monomers at the adsorption equilibrium was applied. Scanning electron micrographs of PANI/PET composite surfaces were observed, conforming that smooth films were produced by surface polymerization of aniline monomers adsorbed previously on fibers. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

二次掺杂聚苯胺的PAN复合纤维抗静电性能研究

将苯胺与聚丙烯腈(PAN)纤维接枝聚合,第一次采用5-磺基水杨酸(SSA)掺杂制得PAN/聚苯胺(PANI)复合纤维,再以盐酸(HCl)第二次掺杂制得PAN/PANI复合纤维;研究了第二次掺杂的反应条件及PAN/PANI复合纤维的抗静电性能。结果表明:红外光谱分析证明了PAN/PANI复合纤维中有PANI存在;HCl第二次掺杂最佳条件为HCl浓度2 mol/L,反应温度0℃,反应时间6 h,PAN/PANI复合纤维的比电阻约2 kΩ.cm;第二次用HCl掺杂的复合纤维的抗静电性能比第一次用SSA掺杂的抗静电性能更好。