【作者】 邢翠娟；

【导师】 张志明；

【作者基本信息】 中国海洋大学 ， 海洋化学工程与技术， 2014， 博士

【摘要】 导电聚合物因其结构多样化、独特的掺杂机制、可调的电导率、环境稳定性以及可加工性等特点，已广泛地应用于各种领域：导电材料、电极材料、防腐涂料、电磁屏蔽材料、微波吸收材料以及非线性光学器件等。其中，将聚苯胺用于防腐涂料已有较长的历史，科研工作者将聚苯胺溶解涂覆、电化学聚合成膜或做成涂料涂于金属表面来研究聚苯胺的防腐蚀效果和机理。另外，近年来超疏水材料的迅速发展使其在腐蚀与防护领域的应用越来越多，由于超疏水的表面能够有效地抑制腐蚀性物质向电极表面扩散，也能抑制腐蚀产物向溶液中扩散，因此，超疏水表面能够提高对基体金属的保护效率。本论文在导电聚合物和超疏水性材料在防腐蚀领域应用的基础上，结合超疏水材料的超疏水性能和导电聚合物优异性的防腐蚀性能，将超疏水性的导电聚合物用于碳钢电极的防护，围绕导电聚合物的浸润性对防腐蚀性能的影响展开研究，并取得了以下主要成果：1.借助“无模板”法，通过改变掺杂剂，实现了从亲水性到超疏水性聚苯胺微/纳米结构的可控制备。例如，当掺杂剂为十二酸(LA)和乙酸(AA)时，聚苯胺为亲水性的，当掺杂剂为全氟辛酸(PFOA)时，制备的聚苯胺为超疏水性的。采用Tafel极化曲线和电化学阻抗(EIS)研究了具有不同浸润性的聚苯胺微/纳米结构在0.1mol/L H2SO4溶液中对碳钢的腐蚀防护作用，探讨了聚苯胺微/纳米结构的表面浸润性对腐蚀防护性能的影响。研究结果表明，随着聚苯胺微/纳米结构疏水性的增强，其对碳钢电极的腐蚀防护作用增强，当掺杂剂为PFOA时所制备的超疏水聚苯胺微/纳米结构表现出最佳的防腐蚀性能(η=94.70%)。2.采用“无模板”法，通过苯胺与苯胺衍生物的共聚制备了不同浸润性的苯胺共聚物，研究了苯胺衍生物对共聚物浸润性的影响，探讨了苯胺共聚物的防腐蚀性能与浸润性的关系。首先以苯胺和3-氨基苯磺酸为单体，在共聚物主链上引入亲水性的-SO3H，发现-SO3H的引入不利于其防腐蚀性能的提高；然后以苯胺和2-乙基苯胺为单体，在共聚物的主链上引入不同含量的-C2H5，制备了不同浸润性的共聚物微/纳米结构,电化学测试结果表明，共聚物疏水性的增强有利于防腐蚀性能的提高，防腐蚀效率与接触角的关系为：=132.04–128.62exp (-/137)；最后选用四种苯胺衍生物，使其与苯胺单体比为1:1时，在共聚物的主链上引入不同的疏水性基团，结果表明，疏水性基团的引入有利于共聚物疏水性的提高和防腐蚀性能的提高。对共聚物的防腐蚀效率与接触角的关系进行拟合得到：=102.22–102.78exp (-/84)。3.分别通过不同用量的全氟辛酸(PFOA)和十二烷基磺酸钠(SDS)对已制备的聚苯胺微/纳米纤维进行再掺杂，成功地制备了形貌基本一致，浸润性不同的聚苯胺，并得到超疏水性的聚苯胺。Tafel极化曲线和电化学阻抗(EIS)的结果表明：聚苯胺的疏水性越强，其防腐蚀效率越高。PFOA和SDS再掺杂聚苯胺的防腐蚀效率与接触角的关系为：=234.32–205.31exp (-/442)和=5.971–7.10exp (-/84)。更多还原

【Abstract】 Conductive polyaniline has a wide range of applications because of its specificproperties, such as highly conjugated molecular structure, controllable conductivity,environmental stability, easy synthesis, low cost and so on. One of the applications iscorrosion protection. In order to obtain information on the inhibition mechanism ofpolyaniline, the polyaniline were usually coated on metal surface as solution-castpolymer coating, electrodeposited coating and additives of resins coating. Recently,considerable interest has been given to the development of superhydrophobic films asanticorrosion coatings. Water serves as a medium for the diffusion of corrosivechemicals from reaching the metal-coating interface, so increasing the water repellantproperty of the coating increases its ability to protect the underlying substrate fromcorroding. On the basis of using conductive polyaniline and superhydrophobic filmsas protective coatings, our research of this thesis was focused on the correlationbetween the contact angle (θ) of the polyaniline micro/nanostructures coatings and thecorrosion protection efficiency (η) of the polyaniline micro/nanostructures. The mainresults are summarized as follows:1. A “template-free” method was used to prepare the polyanilinemicro/nanostructures with different wettability by changing the dopant. The corrosionprotection performance of the PANI with different wettability was evaluated in0.1mol/L H2SO4using the potentiodynamic polarization curves and electrochemicalimpedance spectroscopy (EIS). The effect of the wettability on the anticorrosionperformance was investigated. Superhydrophobic PANI micro/nano structures showgood anticorrosion properties. This is due to the superhydrophobic conducting PANIcoating not only inhibited water from being absorbed by the coating, thus preventingthe corrosive chemicals and corrosion products from diffusing through the coating,but also promoting a thin oxide film on the electrode surface.2. Firstly, sulfonic acid groups (-SO3H) which were strongly hydrophilic substituent group were introduced into the polyaniline molecular structure by thecopolymerization of aniline (ANI) and3-aminobenzenesulfonic acid (metanilic acid,MA). The anti-corrosion behavior of PANIMA coated carbon steel electrodes wasinvestigated in1mol/L H2SO4solutions by the potentiodynamic polarizationtechnique and electrochemical impedance spectroscopy (EIS). Results show that lowsulfur content in the PANIMA coatings afforded the best protection, though theperformance of all PANIMA coatings was inferior to PANI itself under the appliedtesting conditions. Secondly, a hydrophobic group, ethyl groups (-C2H5) wereintroduced into the polyaniline molecular structure by the copolymerization of aniline(ANI) and o-ethylaniline (OEA). The results of potentiodynamic polarization curvesand electrochemical impedance spectroscopy (EIS) indicate that corrosion protectionefficiency depends on the water repellent property of the PANIOEA copolymersmicro/nanostructures. And there is a well-fitting correlation between the contact angle() of the PANIOEA copolymers micro/nanostructures coatings and the corrosionefficiency () of the PANIOEA copolymers micro/nanostructures coatings which canbe expressed as=132.04–128.62exp (-/137). The POEA polymer showed thelargest static water contact angle (CA=145°) and the most effective protection withinhibition efficiency of87.29%. Lastly, a series of polyaniline (PANI) copolymersmicro/nanostructures were prepared by copolymerization of aniline (ANI) and3-aminobenzenesulfonic acid,3-aminobenzoic acid,3-toluidine and2-ethylaniline.The corrosion protection of PANI or PANI copolymers increased with increasingwater repellent property of the PANI or PANI copolymers micro/nanostructures. Awell-fitting correlation between the contact angle () of the PANI or PANIcopolymers micro/nanostructures coatings and the corrosion protection efficiency ()of the PANI or PANI copolymers micro/nanostructures coatings was found and can beexpressed as=102.22–102.78exp (-/84). The PANI copolymer with thehydrophobic-C2H5group (PANI-C2H5) showed the largest static water contact angle(CA=125°) and the most effective protection with an inhibition efficiency of78.98%.3. Polyaniline micro/nano fibers with different wettability was obtained byre-doping with Sodium Dodecyl Sulfonate (SDS) and perfluoro caprylic acid (PFOA). It was found that the wettability of the polyaniline micro/nano fibers was controlledby the content of SDS and PFOA. Standard electrochemical measurements revealedthat the corrosion protection of PANI increased with increasing the water repellentproperty of the PANI micro/nano fibers. And there are well-fitting correlationsbetween the contact angle () of the PANI micro/nano fibers coatings and thecorrosion efficiency () of the PANI micro/nano fibers coatings which can beexpressed as=234.32–205.31exp (-/442)(re-doped with PFOA) and=5.971–7.10exp (-/84)(re-doped with SDS).更多还原