复合钒钛酸掺杂聚苯胺湿敏特性的正交实验

采用sol-gel法制备钒钛酸并掺杂聚苯胺制备湿敏元件,通过正交实验的方法,探索出较优越的实验条件及组装最佳的湿敏元件。测试了元件在不同湿度下的电阻,结果表明:当钒钛酸掺杂聚苯胺在浸渍2次,掺杂45min,氧化剂用量为40mL时具有灵敏度高、湿敏性好的特点。     

功能酸二次掺杂聚苯胺的防腐蚀性能

聚苯胺具有独特的掺杂脱掺杂特性,能在特定的反应条件下合成出形貌较好的纳米纤维,使得通过脱掺杂和二次掺杂能制备出拥有特殊防腐官能团的新型纳米材料。将硫酸体系中合成的聚苯胺纳米纤维经氨水脱掺杂,再用磷酸、对甲苯磺酸和酒石酸等功能酸在脱掺杂态聚苯胺基础上制备出二次掺杂态聚苯胺,测试了聚苯胺/环氧树脂复合涂层的防腐蚀性能,并与功能酸一次掺杂态聚苯胺进行了对比。结果表明,功能酸掺杂的聚苯胺都有一定的防腐蚀效果;功能酸二次掺杂态聚苯胺比一次掺杂态聚苯胺有更好的防腐蚀性能,二次掺杂态聚苯胺涂层拥有更高的阻抗,其中酒石酸二次掺杂态聚苯胺涂层的阻抗最高,浸泡120 d后为3.48×10⁷ Ω·cm²,较其一次掺杂态聚苯胺涂层高出一个数量级。     

功能酸二次掺杂聚苯胺的防腐蚀性能

聚苯胺具有独特的掺杂脱掺杂特性,能在特定的反应条件下合成出形貌较好的纳米纤维,使得通过脱掺杂和二次掺杂能制备出拥有特殊防腐官能团的新型纳米材料。将硫酸体系中合成的聚苯胺纳米纤维经氨水脱掺杂,再用磷酸、对甲苯磺酸和酒石酸等功能酸在脱掺杂态聚苯胺基础上制备出二次掺杂态聚苯胺,测试了聚苯胺/环氧树脂复合涂层的防腐蚀性能,并与功能酸一次掺杂态聚苯胺进行了对比。结果表明,功能酸掺杂的聚苯胺都有一定的防腐蚀效果;功能酸二次掺杂态聚苯胺比一次掺杂态聚苯胺有更好的防腐蚀性能,二次掺杂态聚苯胺涂层拥有更高的阻抗,其中酒石酸二次掺杂态聚苯胺涂层的阻抗最高,浸泡120 d后为3.48×107?·cm2,较其一次掺杂态聚苯胺涂层高出一个数量级。     

钒酸基/聚苯胺修饰薄膜的制备及湿敏性能研究

采用交替沉积法制备了钒酸基/聚苯胺薄膜,讨论酸种类和不同层数对薄膜湿敏性能的影响,实验结果表明:钒钛酸/聚苯胺复合膜的湿敏性能优于钒酸/聚苯胺薄膜,双层钒钛酸/聚苯胺薄膜的湿敏性能均优单层,该湿敏薄膜的湿滞为5%RH,灵敏度变化了三个数量级,响应时间为8s,恢复时间为13s,线性度和稳定性均较理想。     

钒钛酸-聚苯胺薄膜电极的制备及电化学性能

以苯胺和自制钒钛酸为原料,ITO导电玻璃为基底,利用一步法和两步法分别制备了钒钛酸-聚苯胺薄膜修饰电极,系统地研究了该复合薄膜的成膜机理和电化学行为。实验结果表明,一步法比两步法制备过程简单,且钒钛酸能逐层固定在聚苯胺薄膜里。该修饰电极不仅保持了钒钛酸的电化学活性和电催化性能,并具有良好的稳定性。两种方法制备的薄膜修饰电极对酸性水溶液中的碘酸钾均具有显著的的电催化还原作用。     

浸渍吸附聚合法合成聚氨酯/聚苯胺抗静电材料

用浸渍吸附聚合法合成了聚氨酯/聚苯胺抗静电复合材料。研究了复合材料的结构、聚苯胺含量对复合材料抗静电性能的影响,并探讨了复合材料的抗静电稳定性。结果表明,浸渍吸附合成的聚氨酯/聚苯胺复合材料,保持了聚氨酯的力学性能,同时也赋予材料抗静电性能,但其抗静电稳定性较差。     

导电聚苯胺的合成与表征

采用微乳液聚合法,以苯胺为单体、十二烷基苯磺酸(DBSA)/盐酸(HCl)复合酸掺杂制备了导电聚苯胺,通过红外光谱对其结构进行了表征,考察了合成工艺条件对聚苯胺导电性能的影响,探讨了有机无机复合酸体系对聚苯胺热稳定性的影响。在复合酸十二烷基苯磺酸与盐酸物质的量比为3∶2、复合酸与单体物质的量比为2.0∶1、聚合温度为20℃、聚合时间为10h的优化条件下,所得到的掺杂态聚苯胺导电性能最佳。适当配比的有机无机复合酸掺杂后,导电聚苯胺的热稳定性显著提高。     

碱性条件下聚苯胺的合成及电化学腐蚀行为

在碱性条件下合成出导电聚苯胺粉末,测定了聚苯胺的红外光谱、电导率、粒径分布、极化曲线及电化学阻抗谱。结果表明,当pH为12.18时,电导率可达到8.35×10-2S/cm;聚苯胺粉末粒径分布范围为0.44~43.57μm;聚苯胺涂层可使钢铁的腐蚀电位正移,腐蚀电流密度下降,阻抗值变大,提高了钢铁的防腐蚀性能。     

聚苯胺和聚吡咯纳米颗粒的制备及其电化学性能研究

采用低温化学氧化法合成了聚苯胺和聚吡咯纳米颗粒,并以聚苯胺和聚吡咯纳米颗粒为电极材料,组装成电化学电容器,利用测试循环伏安、交流阻抗和恒流充放电性能研究两者的电化学性能。结果表明,低温下合成的聚苯胺和聚吡咯呈纳米颗粒堆积状,粒径分别为200,300 nm;当电流密度为1 mA/cm2时,在1 mol/L H2SO4电解液中,聚苯胺比电容达480.30 F/g,聚吡咯比电容达205.51 F/g。     

浸渍吸附聚合法合成聚氨酯／聚苯胺抗静电材料

用浸渍吸附聚合法合成了聚氨酯一聚苯胺抗静电复合材料。研究了复合材料的结构、聚苯胺含量对复合材料的抗静电性能的影响，并探讨了复合材料的抗静电稳定性。     

Performance evaluation of polyaniline pigmented epoxy coating for corrosion protection of steel in concrete environment

Corrosion protection of mild steel reinforcement offered by a newly developed epoxy based coating system containing inherently conducting polyaniline as one of the pigments has been studied. The synthesis of polyaniline and preparation of epoxy based coating system containing this polyaniline are described here. The corrosion resistant property of epoxy polyaniline system, coated on mild steel was evaluated by various techniques such as electrochemical impedance spectroscopy, potential time studies, cathodic disbondment test, anodic polarization study, salt spray test and chemical resistance test. The corrosion resistance of epoxy polyaniline coating system coated on reinforcement bars embedded in concrete was also studied by an accelerated time to cracking study. The formation of polyaniline was characterized using FTIR, UV, GPC, particle size analyzer and fineness studies. Electrochemical impedance studies reveal that the resistance of the coating decreased initially and then increased due to passivating ability of the polyaniline pigment. Based on the results of different techniques, it is found that epoxy coating with polyaniline pigment is effective in corrosion protection of steel in concrete environment.     

Electropolymerised polyaniline films on AA 7075 alloy and its corrosion protection performance

Polyaniline has been electrodeposited on AA 7075 alloy and its corrosion protection ability has been studied by Tafel and impedance techniques in 1% NaCl. Pure polyaniline film is not found to protect the aluminium alloy due to galvanic interaction of polyaniline and aluminium surface exposed through pinholes and cracks. However, it is found that the corrosion resistance property of the polyaniline film can be substantially increased by post-treatment in cerium salt solution.     

Corrosion protection of steel by polyaniline blended coating

Phosphate doped polyaniline was synthesized from aqueous phosphoric acid containing aniline by chemical oxidation method using ammonium persulphate as oxidant. The polymer was characterized by UV–vis and FT-IR spectroscopic techniques. Using this polymer, a paint with 1% polyaniline was prepared with epoxy binder. The corrosion resistant property of the polymer containing coating on steel was found out by open circuit potential measurements and electrochemical impedance spectroscopic method in 0.1 N HCl, 0.1 N H₃PO₄ and 3% NaCl for a duration of 50 days. The coating was able to protect the steel more in 0.1 N H₃PO₄ and 3% NaCl media than in 0.1 N HCl.     

聚苯胺膜对X70钢防腐性能的研究

采用电化学极化曲线和交流阻抗方法,研究了聚苯胺膜分别在酸性(质量分数为5%的HNO3)、弱碱性(饱和Na2CO3)、碱性(质量分数为5%的KOH)溶液中对X70钢的防腐性能。结果表明:聚苯胺膜在3种溶液中对X70钢都有防腐作用,但短时间内以酸性溶液中的防腐性能为最适宜。同时以饱和Na2CO3溶液模拟常规的弱碱性土壤环境,考察了此环境中聚苯胺膜对X70钢电极防腐作用的持久性。结果表明聚苯胺膜在弱碱性环境中对X70钢具有长效防腐性能,并初步证实其防腐机理为聚苯胺的屏蔽作用和阳极保护作用(钝化作用)。     

Investigation of corrosion performance of epoxy coating containing polyaniline nanoparticles

An emulsion polymerization of aniline was performed in a solution of dodecylbenzenesulfonic acid emulsifier, benzoyl peroxide oxidant and tartaric acid as dopant. The polyaniline-containing coating was applied over carbon steel panels and the polyaniline content in the coating was 1?%. The influence of reactants concentration on the morphological and anti-corrosive properties of polyaniline was investigated to determine the optimum conditions for the synthesis of polyaniline nanoparticles. The average size of particles determined by X-ray diffraction measurement was 70?C104?nm, which is found to be in agreement with the scanning electron microscopy results. Corrosion resistance of coatings was obtained using electrochemical techniques (electrochemical impedance spectroscopy and open circuit potential measurements) in 3.5?% sodium chloride solution. Nyquist diagrams showed two capacitance loops, one at high frequency range followed by a larger one at low frequencies due to coating and charge transfer resistance. The corrosion resistance values were found to decrease due to the corrosion of carbon steel in pinholes of the coating. For longer immersion times, the coating resistance values were found to increase due to the passivation effect of polyaniline. The results showed that epoxy coating with doped polyaniline nanoparticles is able to offer protection in sodium chloride solution.     

聚苯胺微乳液合成及其电致变色性

用 (NH4) 2 S2 O8为氧化剂 ,在功能质子酸 水 正丁醇三元体系中 ,用微乳液法合成了聚苯胺。以聚苯胺的电导率和电致变色性能为标准 ,讨论了引发剂、DBSA、反应温度和反应时间对聚苯胺性能的影响 ,并对影响聚苯胺 /聚乙烯醇复合膜的性能因素作了初步探讨。结果表明 :与用常规乳液法合成的聚苯胺相比 ,用微乳液法合成的聚苯胺与聚乙烯醇所成的膜 ,其电导率提高了 2个数量级 ,电致变色性能也更好。     

Electrochemical behavior and anticorrosion properties of modified polyaniline dispersed in polyvinylacetate coating on carbon steel

Conducting polyaniline (Pani) was prepared in the presence of methane sulfonic acid (MeSA) as dopant by chemical oxidative polymerization. The Pani-MeSA polymer was characterized by FT-IR, UV-vis, X-ray diffraction (XRD) and impedance spectroscopy. The polymer was dispersed in polyvinylacetate and coated on carbon steel samples by a dipping method. The electrochemical behavior and anticorrosion properties of the coating on carbon steel in 3% NaCl were investigated using open-circuit potential (OCP) versus time of exposure, and electrochemical techniques including electrochemical impedance spectroscopy (EIS), potentiodynamic polarization and cyclic voltammetry (CV). During initial exposure, the OCP dropped about 0.35 V and the interfacial resistance increased several times, indicating a certain reduction of the polymer and oxidation of the steel surface. Later the OCP shifted to the noble direction and remained at a stable value during the exposure up to 60 days. The EIS monitoring also revealed the initial change and later stabilization of the coating. The stable high OCP and low coating impedance suggest that the conducting polymer maintains its oxidative state and provides corrosion protection for carbon steel throughout the investigated period. The polarization curves and CV show that the conducting polymer coating induces a passive-like behavior and greatly reduces the corrosion of carbon steel.     

Corrosion protection of steel by polyaniline (PANI) pigmented paint coating

The corrosion performance of polyaniline (PANI) pigmented coating on steel has been studied by electrochemical impedance spectroscopy (EIS) in 3% NaCl and 0.1N HCl solutions. Initially, the impedance values were found to decrease due to the corrosion of steel in pin holes of the coating. However, on increased exposure time, the impedance values were found to increase due to the formation of passive film on the exposed steel in pin holes. These studies have shown that the polyaniline pigmented coatings are able to protect the steel both in acid and neutral media.     

The electrochemical deposition of polyaniline at pure aluminium: electrochemical activity and corrosion protection properties

Polyaniline films were electrodeposited at pure aluminium from a tosylic acid solution containing aniline. These polymer films exhibited similar characteristics as pure polyaniline electrosynthesized at an inert platinum electrode, when removed from their respective substrates and dissolved in NMP. Both polymers had similar molecular weights and similar UV-visible absorption spectra. However, the aluminium substrate had a considerable effect on the electrochemical activity of the films. The polyaniline films deposited at aluminium appeared to lose electroactivity and the electrochemical impedance data were governed by the oxidized aluminium substrate. This is consistent with a galvanic interaction between the polymer and the aluminium substrate, giving rise to oxidation of the aluminium and reduction of the polymer. The polyaniline deposits appeared to offer only a slight increase in the corrosion resistance of aluminium. Surface potential measurements, using a scanning vibrating probe, showed that attack initiated underneath the polymer under anodic polarization conditions, indicating that chloride anions diffuse across the polymer to react at the underlying aluminium substrate.