壳聚糖及衍生物掺杂聚苯胺在0.5mol·L~(-1)HCl溶液中对碳钢的缓蚀性能

采用化学氧化法合成了壳聚糖掺杂聚苯胺(CTS-PANI)、羟丙基壳聚糖掺杂聚苯胺(HPCS-PANI)及羧甲基壳聚糖掺杂聚苯胺(CMC-PANI);利用红外光谱法(FTIR)对合成产物进行表征,用腐蚀试验和电化学测试研究了掺杂态聚苯胺对Q235钢在0.5mol·L~(-1) HCl溶液中的缓蚀性能。结果表明:本征态聚苯胺及掺杂态聚苯胺的缓蚀率随缓蚀剂含量的增加先增大后减小,当缓蚀剂的质量浓度达到50mg·L~(-1)时缓蚀率最大;四种缓蚀剂对Q235碳钢在0.5mol·L~(-1) HCl溶液中的缓蚀率从大到小顺序为CMC-PANIHPCS-PANICTS-PANIPANI,羧甲基壳聚糖掺杂聚苯胺的缓蚀性能最好,缓蚀率可达91.9%。     

有机酸二次掺杂超疏水聚苯胺的制备及其耐蚀性

利用化学氧化法在硫酸体系中合成掺杂态聚苯胺,用氨水脱掺杂得到本征态聚苯胺,再采用对甲苯磺酸(TSA)、柠檬酸(CA)及十二烷基苯磺酸(DBSA)对本征态聚苯胺进行二次掺杂得到超疏水聚苯胺。通过傅里叶红外光谱(FTIR)、扫描电镜(SEM)等对聚苯胺进行了结构表征和形貌观察,通过电化学测试研究了在3.5%NaCl溶液中超疏水性聚苯胺的耐蚀性。结果表明:三种有机酸二次掺杂均能够有效提高聚苯胺的疏水性及耐蚀性,并且随着聚苯胺疏水性的增强,其对不锈钢的腐蚀防护效果提高;其中,TSA二次掺杂的聚苯胺的疏水性和耐蚀性最强。     

掺杂态和本征态聚苯胺对不锈钢的保护作用

用电化学方法在不锈钢表面制备了磷酸掺杂的聚苯胺,将掺杂态聚苯胺浸在1mol/L氨水中脱掺杂得到本征态聚苯胺。用扫描电子显微镜和红外光谱对掺杂态和本征态聚苯胺进行了表征,采用动电位极化曲线和电位-时间曲线研究了它们对不锈钢在1mol/L硫酸钠溶液中的保护性能。结果表明,掺杂态和本征态聚苯胺表面都有孔,使不锈钢的自腐蚀电位显著正移;本征态聚苯胺起机械隔离作用,掺杂态聚苯胺主要使不锈钢钝化;掺杂态聚苯胺对不锈钢的保护时间比本征态的长很多。     

对甲苯磺酸掺杂聚苯胺对镁的防腐蚀性能

    对甲苯磺酸掺杂化学合成的本征态聚苯胺,得到对甲苯磺酸掺杂聚苯胺,并用紫外可见光光谱和红外光谱对其结构进行了确证;以对甲苯磺酸掺杂聚苯胺为功能成分,羟基丙烯酸树脂为成膜物质,按一定配方涂覆于镁表面,利用开路电位和Tafel极化曲线方法研究了对甲苯磺酸掺杂聚苯胺对金属镁的防腐性能.结果表明,对甲苯磺酸掺杂聚苯胺与羟基丙烯酸树脂混合涂抹的涂料相对本征态聚苯胺与羟基丙烯酸树脂混合涂抹的涂料以及与甲苯磺酸掺杂聚苯胺与环氧树脂混合涂抹的涂料而言,显示了更好的防腐能力.     

二次掺杂聚苯胺的防腐蚀性能

采用不同的功能质子酸对化学氧化法合成的聚苯胺进行二次掺杂,比较了不同掺杂态聚苯胺的溶解性能;采用开路电位法和极化曲线法考查聚苯胺/环氧复合涂膜的防腐蚀性能。结果表明,用十二烷基苯磺酸钠(DBSA)掺杂的聚苯胺涂料具有很好的防腐蚀性能,涂覆该涂料的平衡开路电位比空白试样提高了近100 mV。     

聚苯胺/环氧涂层对AZ91D镁合金耐蚀性能的影响

通过化学氧化法合成本征态及氢氟酸掺杂态聚苯胺(PANI),用红外光谱对其结构进行表征。以环氧树脂为成膜物质,在AZ91D镁合金基体上制备了本征态及氢氟酸掺杂的 PANI/环氧涂层,用EIS方法研究涂层在3.5%NaCl溶液中的耐蚀性,并用SEM对浸泡后基体表面形貌进行观察。实验结果表明,与环氧清漆相比,本征态PANI的加入明显改善了环氧涂层的耐蚀性,而氢氟酸掺杂后进一步提高了PANI/环氧涂层的性能。用XPS对基体表面分析,发现添加聚苯胺的涂层在镁合金表面形成了具有保护作用的产物膜。     

新型建筑用铸态硅橡胶/聚苯胺屏蔽复合材料的研究

随着电磁渡干扰的日益加重，电磁功能材料在建筑业也越来越受到重视。本文分析了以掺杂态聚苯胺为填料、硅橡胶为基体的铸态复合材料的导电性以及在300～1500MHz频段下的屏蔽效能。研究结果表明，当聚苯胺与基体以1：1复合时，屏蔽效能达到16．0～19．3dB，体电阻率与原橡胶相比下降13个数量级．可以作为很好的建筑暗室用新型屏蔽材料来应用。     

基于聚苯胺的光固化防腐蚀涂层

利用十二烷基苯磺酸 (DBSA) 对本征态的聚苯胺 (PANI) 进行掺杂,将不同含量的掺杂后的聚苯胺分别加入到光固化树脂聚氨酯丙烯酸酯 (6071) 中,制备了一种低VOC排放的光固化聚苯胺防腐蚀涂层。通过实时红外以及漆膜性能的测试选择了合适的光引发剂,通过电化学阻抗谱、盐雾实验以及极化曲线对涂层的防腐蚀性能进行了测试。结果表明,加入0.4%DBSA-PANI的光固化涂层具有最佳的防腐蚀性能。     

聚苯胺纳米纤维超声合成及其防腐蚀性能

在超声场下用直接混合法合成了聚苯胺纳米纤维。将聚苯胺纳米纤维与环氧树脂共混浸涂于304不锈钢表面,研究涂层对不锈钢的的防腐蚀效果。结果表明,在3.5%NaCl和0.5 mol/L HCl溶液中,比较本征态聚苯胺/环氧树脂涂层,掺杂态聚苯胺/环氧树脂涂层具有较好的防腐蚀效果,环氧树脂涂层对304钢也有一定的防腐蚀效果。     

聚苯胺微乳液及其对水性防腐涂料防腐性能的影响

目的用不同酸掺杂的聚苯胺微乳液制备水性防腐涂料,提高马口铁表面涂层的耐腐蚀性能。方法采用扫描电子显微镜、傅立叶变换红外光谱和热重分析表征聚苯胺性能,通过动电位极化法及耐水性、耐盐雾和耐盐水实验检测聚苯胺微乳液水性防腐涂层的防腐性能,用铅笔硬度和划格法表征涂层的硬度和附着力。结果磷酸掺杂聚苯胺微乳液、本征态聚苯胺微乳液制备的水性防腐涂层都对马口铁起到良好保护作用。含有盐酸掺杂聚苯胺微乳液和不含聚苯胺微乳液的水性防腐涂层在浸泡过程中很快失去保护作用。掺杂态聚苯胺使马口铁表面钝化和屏蔽,本征态聚苯胺起机械屏蔽作用。通过把聚苯胺微乳液添加到水性防腐涂料中,发现涂层的硬度和附着力均没有发生明显下降,表明聚苯胺微乳液在水性防腐涂料中分散均匀,对涂层的性能影响较小。结论当水性防腐涂料中的聚苯胺质量分数为0.3%时,磷酸掺杂的聚苯胺微乳液具有最佳的耐腐蚀性能,其腐蚀电流密度Jcorr=7.359×10-7 A/cm2,腐蚀电位Ecorr=-0.527 V。     

Thermal stability of polyaniline

Thermal stability data for neutral (emeraldine base) and doped polyaniline with various counter anions are reported. The emeraldine base is a highly heat-stable polymer, with thermal stability up to 420 °C. The thermal stability of doped polyaniline is dependent on the counter anion. The methane sulfonic acid doped polyaniline is stable up to 250 °C. The decomposition of the doped polyaniline is seen as a two-step process. The first step is the loss of the dopant and the second step corresponds to the decomposition of the backbone.     

Self-assembled necklace-like polyaniline nanochains from elliptical nanoparticles

High quality necklace-like polyaniline nanochains assembled by elliptical nanoparticles have been synthesized in chitosan aqueous solution by a facile dispersion polymerization method. The synthetic procedure is very simple and easy to scale up. The necklace-like nanochains coated by a layer of chitosan are typical doped polyaniline in its emeraldine salt form, which is easy to form stable polyaniline dispersion in water. Open-circuit potential measurements show that the rate of polymerization of aniline has a substantial decrease due to the steric effects of chitosan. The synthetic parameters, such as reaction times, and the concentrations of chitosan, aniline, and dopant acid, have profound influences on the sizes and morphologies of polyaniline nanostructures. A new self-assembly process of elliptical nanoparticles has been proposed for the formation of necklace-like polyaniline nanochains with fluctuant diameters, which is different from that of other one-dimensional polyaniline nanostructures including nanofibers and nanotubes.     

Electrical conductivity response of polyaniline films to ethanol–water mixtures

Polyaniline emeraldine base was chemically synthesized and converted to polyaniline emeraldine salts through the protonation doping process using HCl and CH₃COOH as the acid dopants. The doped polyanilines were characterized by ultraviolet–visible (UV–VIS) spectroscopy, Fourier transform-infrared (FT-IR) spectroscopy, TGA, GPC. The four-point probe technique was used to evaluate the effect of dopant type and doping molar ratio on the specific conductivity. Weak acid doping, by CH₃COOH, produces films with the specific conductivity which depends solely on the degree of protonation, or the number of charge carriers. On the other hand, stronger acid doping by HCl can induce crystalline domains, a greater electron mobility and hence a greater specific conductivity value. The specific conductivity of the HCl-doped and CH₃COOH-doped polyaniline films responds with positive increments upon exposed to water and ethanol. The interchain H-transfer is suggested to be a common mechanism which increases electron mobility upon exposure to water and ethanol, whereas additional protonation occurs only with the exposure to water. No evidence for ethanol molecules to interact chemically with the doped polyaniline films was found. The film electrical conductivity sensitivity is inversely proportional to ethanol concentration, with a higher sensitivity to concentration found in the film doped with the acid with a lower pK_a value.     

一种新型聚苯胺涂层的防腐蚀性能

在酸性环境下用化学氧化法合成了聚苯胺;制备了不同含量的本征态和掺杂态聚苯胺涂覆的碳钢试样,利用塔菲尔曲线比较了它们在质量分数为3.5%的NaCl和1 mol/L HCl溶液中的腐蚀行为.结果表明:当间甲酚固化剂作为溶剂、磷酸作为催化剂时,本征态聚苯胺涂层具有良好的防腐蚀性能;不同状态聚苯胺的防腐蚀性能与腐蚀介质有关,与聚苯胺的含量有关.     

Solid phase mechanochemical synthesis of polyaniline branched nanofibers

A polyaniline supramolecular structure composed of polyaniline nanofibers, has been prepared by a simple solid-state mechanochemical reaction and template-free method. XRD analysis confirmed the good crystallinity of the product, and FTIR and UV–vis analysis indicated that the product was a highly doped emeraldine salt. Electrochemical cyclic voltammetry confirmed the electrocatalytic effect of the branched nanofiber to dopamine and hydroquinone. The growth mechanism of the unique supramolecular structure in mechanochemical reaction was discussed, together with the effect of the crystalline water of the oxidant.     

Electrochemical and physical characterization of lithium ionic salt doped polyaniline as a polymer electrode of lithium secondary battery

Polyaniline films doped with lithium ionic salts such as LiPF₆ and LiBF₄ were prepared by using the electrolyte solution mixture of ethylene carbonate and dimethyl carbonate. The doping level of the polyaniline films was confirmed by X-ray photoelectron spectroscopy and dc conductivity experiments. A doping mechanism of lithium ion through the interaction with a nitrogen at imine site is proposed. Electrochemical cells of Lipolyaniline-LiPF₆ or Lipolyaniline-LiBF₄ were assembled to investigate electrical capacity and its trends over the repeated charge/discharge cycles. The capacity of Lipolyaniline cell was increased and then saturated over 15 cycles. However, it did not reach the half of theoretical capacity of polyaniline material. The mechanism of electrochemical reaction during charge/discharge process of Lipolyaniline cell is presented.     

Synthesis of polyaniline-type thin layer structures under low-pressure RF-plasma conditions

Macromolecular thin layers were deposited under continuous and modulated aniline-RF-plasma conditions, and by Ar-, NH₃, and I₂-plasmas-enhanced crosslinking of pre-deposited N-phenyl-1,4-phenylenediamine (PPD) films on optically smooth quartz substrates. Survey and high-resolution ESCA, Fourier transform infrared spectroscopy (FT-IR), UV–VIS analyses were used for the investigation of the chemical structure of the deposited films. The thermal behavior of deposited (undoped and doped) plasma-treated PPD films was characterized by TG/DTA and DSC analysis and their electrical conductivities were evaluated by using a commercial four-probe system. It was found that gas phase aniline-plasma environments induce intense molecular fragmentation processes, which result in the formation of structures that are significantly different in comparison to that of conjugated polyaniline. The plasma-mediated crosslinking approach allows the synthesis of macromolecular layers, which retain most of the structure of the starting component, and their doped versions exhibit electrical conductivities comparable to the electrical conductivities of doped conventional polyaniline.     

Pattern replication in polyaniline–polystyrene thin films

Blends of polyaniline doped with camphorsulfonic acid (PANI(CSA)) and polystyrene (PS) were spin-cast from chloroform onto gold substrate patterned with a hydrophobic self-assembled monolayer (CH₃-SAM). As a result, the replication of the substrate pattern into the formed thin films was obtained, observed as pattern-directed variation of both film thickness and polyaniline distribution. The thin films were examined by means of optical microscopy, atomic force microscopy (AFM) and secondary ion mass spectrometry (SIMS).