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。     

磷酸二次掺杂聚苯胺纳米纤维的合成及其性能的研究

采用无模板直接混合法制备了硫酸一次掺杂聚苯胺,经氨水解掺杂得到本征态聚苯胺,然后在磷酸体系中对本征态聚苯胺进行二次掺杂。研究了不同的磷酸浓度,反应时间,搅拌时间等对二次掺杂聚苯胺电导率和产率的影响,得到磷酸二次掺杂聚苯胺合成的优化条件,并通过四探针测试仪、扫描电镜、红外光谱、紫外光谱以及电化学测试技术,对掺杂态聚苯胺进行了研究与表征。结果表明,室温下磷酸浓度为1 mol·L-1,搅拌反应24 h时,磷酸二次掺杂聚苯胺的电导率以及产率达到最大值,电导率为0.25 S·cm·1,产率达到138.7%。扫描电镜表征显示,磷酸二次掺杂可获得形貌良好的聚苯胺纳米纤维,其长度可达400~600 nm,且纤维直径均匀;紫外谱图和红外谱图表明磷酸能有效的掺杂到本征态聚苯胺中,改善其电导率及产率;电化学测试结果表明磷酸二次掺杂聚苯胺较一次掺杂聚苯胺有着更好的防腐蚀性能。     

不同态煤基聚苯胺的结构与性能

采用溶液再掺杂法制备了DBSA二次掺杂态煤基聚苯胺(CBP-R-DBSA),得出较佳的二次掺杂条件:时间24 h,温度30℃,酸浓度1.2 mol/L,所得产物电导率为6.08×10-2 S/cm.分析探讨了煤基聚苯胺的掺杂-脱掺杂过程及不同态煤基聚苯胺的结构与性能,结果表明:原位聚合引入的外加酸与煤大分子酸对聚苯胺具有协同掺杂效应,煤基聚苯胺的掺杂-脱掺杂不完全可逆,煤表面酸性基团的掺杂作用相应减少了聚苯胺链上的掺杂活性点,这限定了DBSA对U-CBP的有效二次掺杂,其掺杂效果逊于乳液聚合原位掺杂.     

防腐蚀涂料

正201603009具有不同组成的聚苯胺复合涂层及其在低碳钢上的防腐性能研究[刊,英]/Grgur,B.N.等//Progress in Organic Coatings.-2015,79.-17~24采用电化学和化学方法研究了聚苯胺复合涂层对低碳钢的防腐蚀性能。采用化学脱掺杂和掺杂的方法制备了氧化态聚苯胺和苯甲酸盐形式的聚苯胺粉末。采用不同工艺,以聚苯胺粉末为原料制备了复合涂层。并     

聚苯胺在环氧树脂涂层中防蚀性能研究

采用直接混合氧化法分别在磷酸和硫酸体系中制备了掺杂态聚苯胺,通过研磨把聚苯胺分散到环氧树脂中制备复合涂层,研究了不同酸掺杂的聚苯胺在环氧树脂中的耐蚀性能以及聚苯胺用量对耐蚀性能影响.电化学阻抗谱研究发现,聚苯胺的加入提高了环氧涂层屏蔽保护效果并能提供钝化保护作用,合适的添加量为0.6％;盐雾试验结果表明,磷酸掺杂的聚苯胺在环氧树脂涂层中可以对基体提供较好的保护,而硫酸掺杂的聚苯胺保护效果较差.     

聚苯胺纳米纤维的合成及其在环氧树脂中对Q235钢的防腐蚀性能

分别采用直接混合氧化法和界面聚合法在四种不同的无机酸体系中制备了聚苯胺纳米纤维。扫描电镜表征发现采用直接混合氧化法可以得到高品质的聚苯胺纳米纤维,且在硫酸体系中可以得到直径均匀,长度达几个微米的优异的纤维形貌;通过红外光谱和紫外光谱对聚苯胺产物进行结构表征显示所得产物为掺杂态聚苯胺。进一步,选择硫酸掺杂的聚苯胺与环氧树脂共混制备了复合涂层,电化学阻抗谱研究发现,聚苯胺的加入提高了环氧涂层对Q235钢的初始屏蔽保护效果,但浸泡后,保护效果迅速下降。     

掺杂态聚苯胺涂层微波辐射水蒸气生成性能研究

通过化学聚合法合成盐酸掺杂聚苯胺(PANI-HCl)与硫酸掺杂聚苯胺(PANI-H_2SO_4)构建微波吸收器,用于水处理。XRD、SEM、FTIR、接触角表征结果显示,两种掺杂态聚苯胺具有一定的结晶度与亲水性,其纳米纤维状聚苯胺单元呈三维多孔网络结构。VNA测试结果表明,PANI-HCl具有良好的微波吸收性能。70 W微波辐射下,PANI-HCl涂层组的蒸发速率为7.34 kg/(m²·h),为空白对照组的1.71倍,且除盐、染料废水净化实验表现出良好的脱盐性能、水净化性,并能多次重复使用。这种节能、低成本、稳定且结构简单的掺杂态聚苯胺涂层所组装的3D蒸发装置可用于海水淡化与废水处理,在水处理方面具有广阔应用前景。     

聚苯胺/钯纳米复合材料的原位还原法制备及表征

本文采用原位还原法,利用聚苯胺本身的还原性,对硝酸钯进行了还原和负载,制得了聚苯胺/钯纳米复合材料,考察了掺杂态及脱掺杂态聚苯胺对原位还原反应的影响,通过红外光谱、紫外光谱、扫描电镜和X射线衍射对所得复合材料的结构进行了表征,并用循环伏安法测定了复合材料对甲酸的催化性能。结果表明所制备的复合材料对甲酸具有一定的催化性能,且脱掺杂态聚苯胺复合材料的性能要优于掺杂态聚苯胺复合材料的性能。     

叔碳改性硅丙乳液复合涂层的防腐蚀性能研究

利用叔碳酸乙烯酯和乙烯基三甲氧基硅烷为功能单体,合成叔碳酸乙烯酯-硅烷改性丙烯酸酯(叔硅丙)乳液,并添加纳米Si O2和纳米蒙脱土等无机材料制备复合防腐蚀涂层。通过接触角、吸水率、电化学阻抗谱、极化曲线、盐雾试验等测试研究了乳液种类及无机纳米材料种类对涂层耐水性和防腐蚀性能的影响。结果表明,叔碳酸乙烯酯和乙烯基三甲氧基硅烷的引入可以有效提高涂层的耐水性和防腐蚀性能,无机纳米材料的加入,尤其是蒙脱土的加入可以进一步提高涂层的防腐蚀性能。复合涂层的吸水率仅为0.7%,腐蚀电流密度为2.91×10-9A/cm2,电化学阻抗可达1.9×108Ω,盐雾试验240 h后无腐蚀扩散现象。     

聚苯胺/环氧复合阴极电泳涂料防腐蚀性能的研究

运用插层聚合的方法制备了蒙脱土／聚苯胺复合材料，并进行了表征。将该复合材料通过共混的方式加入聚酰胺／环氧阴极电泳（CED）涂料中配制成聚苯胺／环氧复合阴极电泳涂料，并利用电化学阻抗谱方法对各电泳涂层的防腐性能进行了分析。研究发现：在3．5％NaCl溶液中浸泡10d后，腐蚀介质不能到达涂层／基底金属界面，金属表面没有发生腐蚀反应。随着聚苯胺含量的增加，复合电泳涂膜的阻抗值增加，具有较好的防腐性能。当聚苯胺含量相同时，与掺杂态聚苯胺复合电泳涂膜相比，本征态聚苯胺复合电泳涂膜具有很高的阻抗值，表现出更好的防腐性能。     

聚苯胺/聚乳酸复合纳米纤维表面形貌对生物相容性的影响

外加电场作用下聚苯胺能够调节细胞附着、增殖、迁移和分化,在体液环境下发生脱掺杂会使聚苯胺基导电可降解纳米纤维电活性减弱,但在一定程度上仍能促进细胞的黏附、生长和增殖。本文选择酒石酸作为聚苯胺在等离子体处理后的聚乳酸纳米纤维表面原位聚合过程中的酸掺杂剂,考察酒石酸与苯胺摩尔比分别在1∶1, 1∶2和1∶4下不同形貌的聚苯胺/聚乳酸复合纳米纤维对生物相容性的影响。采用SEM、TEM和FTIR表征聚苯胺形貌及化学成分,接触角评价其润湿性,MTT、ALP和免疫荧光染色评价聚苯胺/聚乳酸复合纳米纤维生物相容性。结果表明,酒石酸与苯胺摩尔比在1∶1、1∶2和1∶4下的聚苯胺形貌分别为纳米颗粒状、纳米纤维状和纳米空心管状,聚苯胺附着在聚乳酸纳米纤维表面,不会对静电纺丝的多孔结构基体产生影响;聚苯胺/聚乳酸复合纳米纤维表面润湿性良好,有助于细胞的黏附和生长;纳米纤维状的聚苯胺对生物相容性的增强效果明显优于纳米颗粒状聚苯胺,而纳米空心管状结构的聚苯胺对生物相容性增强作用更佳。     

聚苯胺-氟碳乳液复合防腐蚀涂料研究

以聚苯乙烯磺酸(PSSA)为掺杂剂,利用原位插层聚合方法制备了聚苯胺(PANI)-蒙脱土(MMT)复合材料,对其结构进行了XRD表征,测试了变温电导率;并以水性氟碳乳液为成膜物,制备了水分散体PANI-氟碳乳液复合防腐涂料,利用电化学交流阻抗谱和Tafel曲线考察了对Q235的防腐蚀性能.试验结果表明:PANI-MMT复合材料中的蒙脱土以片层剥离状态存在的;PSSA-PANI-MMT复合材料具有稳定的变温电导率;PANI-MMT-FC复合涂料具有最高的阻抗和腐蚀电位(-0.42 V)以及最低的腐蚀电流密度(10-8.6 A/cm2).对Q235有很好的防腐蚀效果.     

Investigation of corrosion protection performance of epoxy coatings modified by polyaniline/clay nanocomposites on steel surfaces

In this study, polyaniline (PANI) and polyaniline/clay nanocomposites were prepared via in situ oxidative polymerization. The morphology of nanocomposites structures was investigated by X-ray diffraction (XRD). The chemical structures of PANI and PANI/clay nanocomposites were examined via Fourier transform infrared (FT-IR) spectroscopy. Polyaniline-based pigments were introduced into epoxy paint and applied on steel substrates. The effect of clay addition and the type of clay cation, including Na⁺ in natural clay (MMT) and alkyl ammonium ions in organo-modified montmorillonite (OMMT), on the anticorrosion performance of epoxy-based coatings was investigated through electrochemical Tafel test, electrochemical impedance spectroscopy and immersion measurements in NaCl solution. The stability of the adhesion of the neat and modified epoxy coatings to the steel surface was also examined. The results indicated that introduction of PANI/OMMT nanocomposite into epoxy paint results in improved anticorrosion properties in comparison with PANI/MMT and neat PANI.     

聚苯胺颗粒对水性环氧树脂涂层防腐性能的影响

以盐酸为掺杂剂、过硫酸铵为氧化剂、咪唑类离子液体为稳定剂,采用化学氧化聚合法合成了导电聚苯胺(PANI)颗粒,将其分散到水性环氧树脂(ER)中制成聚苯胺水性环氧防腐涂层,研究了聚苯胺颗粒对涂层防腐性能和机械性能的影响。结果表明,添加聚苯胺显著提高了水性环氧涂层的阻隔性能,信号频率f=0.01 Hz时,PANI/ER涂层的阻抗(|Z|f=0.01Hz)均高于纯ER涂层。添加5.0wt% PANI时ER涂层阻隔性能最好,浸泡0~168 h时|Z|f=0.01Hz稳定在约8.0×108 Ω?cm2,浸泡168 h后|Z|f=0.01Hz=7.5×108 Ω?cm2,远高于ER和其它PANI/ER体系。中性盐雾实验结果表明,聚苯胺赋予了涂层钝化腐蚀的能力,显著提高了涂层的防腐性能,且其添加量越高,防腐性能越好。弯曲和冲击实验结果表明,涂层的机械性能随聚苯胺含量增加先上升后降低,当聚苯胺添加量不超过5.0wt%时,涂层的机械性能优异,附着力和韧性均较好;PANI添加量增至7.0wt%时,ER涂层的脆性明显变大,机械性能下降。聚苯胺在水性环氧体系中的最宜添加量为5.0wt%,此时涂层的机械性能良好,综合防腐性能最优。     

Electrochemical synthesis and optical properties of helical polyaniline nanofibers

Helical polyaniline (PANI) nanofibers were facilely synthesized via a direct electrochemical method without using any template in the presence of (1S)-(+)-camphor-10-sulfonic acid (d-CSA) or (1R)-(−)-camphor-10-sulfonic acid (l-CSA) as the dopant. The helical morphologies of the PANI nanofibers prepared from potentiostatic deposition were confirmed with SEM and TEM. The helical PANI nanofibers induced by d-CSA and l-CSA exhibited mirror-imaged circular dichroism spectra in the UV-vis range, indicating the stereochemical selectivity of the electrochemical polymerization. The colors and optical activities of these nanofibers can be maintained on an indium-tin oxide (ITO) coated electrode with a dedoping/redoping treatment. The optical activities of the helical PANI nanofibers reversibly varied with different oxidized forms, which were easily controlled by the different potentials applied to the nanofibers.     

Corrosion of mild steel with composite polyaniline coatings using different formulations

The protective abilities of composite coatings based on electrochemically and chemically formed polyaniline powder against the corrosion of mild steel were investigated. A polyaniline powder has been prepared in the form of an emeraldine base and benzoate salt through chemical dedoping and doping. The composite coatings using polyaniline powders, which were obtained through different routes, and base coatings, which were not corrosion-resistant, with different formulations were prepared and applied on mild steel samples. The corrosion was investigated using an electrochemical impedance technique in 3% NaCl, and the atmospheric corrosion was assessed in a humidity chamber. Emeraldine–benzoate salts, which are a chemically synthesized polyaniline, offer the best protection with an optimal polyaniline concentration of approximately 5 wt%. The different corrosion behaviors were assessed relative to the presence of aniline oligomers in the samples after characterization using UV–vis spectrophotometry. Upon comparison between the corrosion behavior in 3% NaCl with commercial primer paint for iron and that with a paint containing 5 wt% PANI, the composite coating has superior anticorrosion characteristics. The mechanism for the protection of mild steel from corrosion through composite polyaniline coatings was also considered.     

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.     

Synthesis of polyaniline nanofiber and anticorrosion property of polyaniline–epoxy composite coating for Q235 steel

Polyaniline (PANI) nanofibers were prepared by direct mixed oxidation in four kinds of inorganic acids. The characterization of scanning electron microscopy (SEM) showed that high quality PANI fibers with uniform diameter and several microns length can be obtained by direct mixed oxidation, especially in a sulfuric acid system. Structural characteristics of PANI products through IR and UV spectra indicated the consistent peak distribution with the classic spectrum of the doped PANI. In addition, composite coatings of PANI–epoxy resin were prepared by mechanical grinding. The effect of PANI’s content on anticorrosion property of the composite coatings for Q235 steel was studied by the electrochemical impedance spectroscopy (EIS). Results showed that the best shielding protective effect was obtained when the amount of PANI was around 0.5% (wt%). More importantly, the effects of four different inorganic acids on anticorrosion property of the composite coatings were studied by the EIS and Tafel polarization curve. Experiments showed that the different composite coatings of PANI doped by different inorganic acids provided different protective abilities for the Q235 steel. It can be concluded that both the morphology and counter-anion would impact the anticorrosion effect of the doped PANI.     

High corrosion protection of a polyaniline/organophilic montmorillonite coating for magnesium alloys

Epoxy coatings containing polyaniline (PANI) and polyaniline/organophilic montmorillonite (PANI/OMMT) powders were prepared on the surface of AZ91D magnesium alloy. The corrosion performance of the coatings was evaluated by electrochemical impedance spectroscopy (EIS) and open-circuit potential analysis in 3.5% NaCl. The results indicate that the PANI/OMMT coating retained its high corrosion protection for AZ91D magnesium alloy after 6000 h of immersion. The protective mechanism conferred by the PANI/OMMT coating was also discussed. The effects of oxygen on the protective mechanism of PANI were evaluated by EIS measurements in a 3.5% deaerated NaCl solution.