导电聚苯胺膜的合成及其防腐性能

为了增强不锈钢(SS)双极板的耐腐蚀性能,采用循环伏安法(CV)在316L不锈钢(SS)表面电合成聚苯胺(PANI)薄膜。以0.2 M H_2SO_4+x NaCl水溶液为腐蚀介质,通过测量开路电位(OCP)、Tafel极化曲线和电化学阻抗谱(EIS),研究Cl-浓度对PANI/316L SS复合体系腐蚀行为的影响。结果显示:随着CV循环次数的增加PANI薄膜逐渐变厚;Cl~-浓度对PANI/316L SS耐腐蚀性能影响显著,随Cl~-浓度的增大,PANI/316L SS体系的耐蚀性降低。     

医用不锈钢表面沉积类金刚石薄膜的电化学腐蚀性能研究

医用316L不锈钢植入物植入体内后,体内环境可导致其产生腐蚀和Ni离子的析出。利用双放电腔微波等离子体源全方位离子注入设备,采用等离子体源离子注入(plasmasourceionimplantation,PSII)和等离子体增强化学气相沉积(plasmaenhancedchemicalvapordeposi tion,PECVD)复合工艺在医用316L不锈钢表面沉积类金刚石薄膜,进行表面改性,以提高其在模拟体液环境中的腐蚀阻抗。扫描电子显微镜和原子力显微镜观察发现,薄膜由纳米粒子构成,膜层连续光滑。电化学腐蚀测试表明:采用PSII+PECVD复合工艺制备的类金刚石薄膜与316L不锈钢改性体系在(37±1)℃的Troyde’s模拟体液中的自腐蚀电位约为120mV,体系的击穿电位超过1.9V,与基体316L不锈钢相比,其热力学稳定性与抗腐蚀性能得到增强,改性效果优于单独的PECVD工艺。     

氧气对聚苯胺/316L不锈钢体系耐腐蚀性能的影响

为了防止不锈钢双极板在质子交换膜燃料电池(PEMFC)工作环境下发生腐蚀,在由0.1 mol/L苯胺单体与0.2 mol/L H_2SO_4组成的水溶液中采用循环伏安法在316L不锈钢(SS)表面电化学合成了导电聚苯胺(PANI)薄膜。采用傅里叶变换红外光谱(FT-IR)分析了PANI的化学结构,采用扫描电镜(SEM)观察了表面形貌,发现所合成的PANI具有苯-醌交替的中间氧化态结构,PANI膜呈现纤维状形貌特征。采用极化曲线和电化学阻抗谱(EIS)对比研究了在0.2 mol/L H_2SO_4中氧气对PANI/316L SS和无涂层316L SS耐腐蚀性能的影响。结果表明,氧气促进了PANI/316L SS界面处保护性氧化膜的形成,使PANI/316L SS体系的耐腐蚀性能提高。     

聚苯胺-TiO2复合膜对316L不锈钢耐蚀性能的影响

以苯胺单体和纳米TiO₂胶体溶液为电解液,采用电化学聚合法在316L不锈钢表面合成了聚苯胺(PANI)膜和PANI-TiO₂复合膜,并利用扫描电镜、X射线衍射等检测手段对PANI-TiO₂复合膜的316L不锈钢表面进行了表征,用循环伏安法和动电位极化曲线研究不同pH值下苯胺聚合的效果及不同TiO₂含量对316L不锈钢耐蚀性能的影响。结果表明,在pH为2.5的条件下,聚苯胺的聚合效果最好;相比于单一聚苯胺膜,PANI-TiO₂复合膜对316L不锈钢具有更好的保护性能。当TiO₂添加量为1.5 g时,制备的复合膜对提高316L不锈钢的耐蚀性效果最佳,其腐蚀电位为-0.55 V。     

316L不锈钢表面电化学合成聚苯胺及其防护特性

在0.3 M草酸与0.1 M苯胺单体组成的水溶液中,用循环伏安法(CV)在316 L不锈钢(SS)表面电化学合成了导电聚苯胺(PANI)薄膜。用傅里叶变换红外光谱(FTIR)对聚苯胺膜进行结构分析,用扫描电子显微镜(SEM)观察表面形貌。结果发现所合成的PANI为具有苯-醌交替的中间氧化态结构,PANI膜呈现细圆颗粒堆积形态。在0.2 M H2SO4中研究了聚苯胺的耐腐蚀性能,结果表明,电化学沉积的聚苯胺膜,其耐腐蚀性能明显高于316L不锈钢,能够对不锈钢基体提供腐蚀保护。     

聚苯胺/凹凸棒土环氧复合防腐涂料的制备及性能研究

以聚苯胺/凹凸棒土纳米复合材料(PANI/ATP)作为填料,以环氧树脂为成膜物质,制备了PANI/ATP环氧复合防腐涂料.研究了PANI/ATP的状态、PANI/ATP的添加量、固化比等对涂层的防腐性能的影响.采用傅里叶红外光谱(Fr-IR)、开路电位(OCP)及极化曲线(Tafel)等测试手段对复合涂层进行了结构表征和防腐性能研究.Tafel极化曲线和开路电位显示,在填料量为5%的情况下,复合涂层的防腐性能较佳,腐蚀电位为-1.098 V,较纯环氧涂层高327 mY;添加了PANI/ATP的涂层较纯环氧涂层的力学性能有很大的提高.     

聚吡咯/聚苯胺复合膜的制备及耐腐蚀性能

采用循环伏安法在304不锈钢表面电沉积聚苯胺(PANI)、聚吡咯(PPY)及其复合膜(PANI/PPY)。用扫描电镜(SEM)和红外光谱(FT-IR)观察膜的表面形貌和组成,通过动电位极化曲线和电化学阻抗谱(EIS)研究了空白钢片、纯PAN膜、纯PPY膜以及苯胺(AN)与吡咯(PY)不同用量所得复合膜在0.30mol/LH2SO_4+3.5%NaCl溶液中的腐蚀行为,并利用三氯化铁点腐蚀试验印证了最优条件下所制复合膜对不锈钢的保护作用。结果表明:苯胺与吡咯的浓度比、扫描速率和循环次数对PANI/PPY复合膜的耐蚀性影响显著。当苯胺与吡咯的浓度比为7:3,扫描速率为50mV/s,循环次数为30圈时,可制得致密度高、表面均匀和结合力良好的PANI/PPY复合膜,该复合膜在0.30 mol/L H2SO_4+3.5%NaCl溶液中具有良好的耐蚀性,可以明显改善不锈钢在氯离子环境中的耐孔蚀能力。     

不锈钢双极板表面合成导电聚苯胺膜的耐腐蚀性能

在0.2 mol/L H_2SO_4和0.1 mol/L苯胺组成的溶液体系中,采用循环伏安法在316L不锈钢双极板表面合成导电聚苯胺(PANI)薄膜。采用红外光谱技术研究聚苯胺薄膜的化学结构。以1 mol/L H_2SO_4及2 ppm NaF混合液作为腐蚀介质,采用电化学技术,研究不同循环周期合成聚苯胺的耐腐蚀性能。结果表明:在不锈钢基底上形成的聚合物为聚苯胺,循环周期为20圈时合成的聚苯胺具有较好的耐蚀性。     

氧化铜/钒酸铋异质结薄膜的制备及其光电性能研究

采用电化学沉积法在FTO玻璃上制备了具有纳米多孔网状结构的氧化铜/钒酸铋薄膜。利用X射线衍射（XRD）、拉曼光谱（Raman）、扫描电子显微镜（SEM）、能谱分析（EDS）对薄膜做成分及结构分析,采用线性伏安扫描（LSV）、频率阻抗测试（EIS）对薄膜做光电性能测试。氧化铜的掺入能够提高钒酸铋薄膜的光电性能,在1.23 Vvs.RHE时,40 mmol/L 氧化铜/钒酸铋薄膜的光电流密度为1.39 mA/cm²,比纯钒酸铋薄膜的光电流密度（0.7 mA/cm²）增大了1倍左右。结果表明,纳米多孔的网状结构,提高了薄膜对光的利用效率,同时也增加了薄膜和电解液的接触面积。氧化铜和钒酸铋复合形成异质结后,抑制了光生电子-空穴对的复合,从而提高了氧化铜/钒酸铋薄膜的光电流密度。     

09MnNiDR与不锈钢在3.5%的NaCl溶液中的电偶腐蚀行为研究

对比了电偶对材料的自腐蚀电位和各自的极化曲线,以及同一阴阳极面积比下,偶接后的混合电位和电流密度,研究了09MnNiDR和不锈钢(316L、304冷轧板、304热轧板、201)电偶对在3.5%的Na Cl溶液中的电偶腐蚀特性。结果表明,09MnNiDR处于活化状态,4种不锈钢则比较稳定;不锈钢的自腐蚀电位高于09MnNiDR,偶接后不锈钢作为阴极被保护,而09MnNiDR作为阳极腐蚀加剧。电偶腐蚀效应的大小为:09MnNiDR/316L09MnNiDR/20109MnNiDR/304热轧板09MnNiDR/304冷轧板。     

Accelerating effect and mechanism of passivation of polyaniline on ferrous metals

To investigate the corrosion protection mechanism of polyaniline (PANI) films on ferrous metals, this work presents preparation method of a separate protonated PANI film electrode and results of its open-circuit potential (OCP) in 0.5 M NaClO₄ and 0.5 M Na₂SO₄ solutions with different pH and the galvanic interaction between the PANI film electrode and ferrous metals. X-ray photoelectron spectroscopy (XPS) shows the lower pH corresponds to higher protonation level of H⁺ in the film, and a more positive OCP of PANI film. The PANI film accelerated the corrosion of 20A carbon steel slightly with a PANI to steel area ratio less than 25:1, while the PANI films maintained passivity for a ratio above to 25:1 for the 20A steel. For the coupling of 2Cr13 stainless steel/PANI, an equal area PANI film could maintain 2Cr13 in a passive state. The results suggest that corrosion protection of 20A carbon steel and 2Cr13 stainless steel by PANI film in the acid solution is due to passivity protection. The excess oxidative charge stored in the PANI and the equilibrium activity of protonated PANI with the acid environment provide a persistent driving force for carbon steel and 2Cr13 stainless steel passivity.     

Protection of stainless steel by polyaniline films against corrosion in aqueous environments

Polyaniline (PANI) thin films were electrochemically deposited by cyclic voltammetry on stainless steel electrode previously covered by a thin film of polyvinyl acetate (PVAc). The corrosion resistance of PANI covered stainless steel substrates was estimated by using potentiodynamic polarization curves and its linear polarization resistance (LPR) was measured in 0.5 M H₂SO₄, 0.5 M NaCl and 0.5 M NaOH aqueous solutions at room temperature. The results indicate that the PANI-PVAc films did improve the corrosion resistance of the stainless steel in NaOH, behaving even worst, in the case of PANI film, than the uncoated substrate. In H₂SO₄ both PANI and PANI-PVAc coatings gave good protection for the stainless steel electrode, with a slightly better performance of PANI-PVAc than PANI. In NaCl solution both PANI and PANI-PVAc films provided a good protection against corrosion. The better performance of PANI-PVAc coatings for corrosion protection in basic media may be due to its major chemical stability compared to simple PANI films, which lose their conductivity in high pH solutions. The E _corr (free corrosion potential) value of the coated substrate was in the passive region of the uncoated substrate in acidic environment but in the active region in neutral or basic environment.     

Conducting polymer based hybrid nano-composites for enhanced corrosion protective coatings

Hybrid composite coatings containing zinc oxide (ZnO) and polyaniline (PANI) as nano-additives dispersions were prepared with poly(vinyl acetate) (PVAc) as the major matrix. The steel plates dip-coated with these formulations were tested for corrosion protection by immersion in saline water over long periods. The Tafel plots for the determination of open circuit potential (OCP) and corrosion current (I_corr) were recorded. The coatings containing both ZnO and PANI showed improved corrosion resistance as compared to the single component coating. The I_corr values of PVAc–ZnO–PANI are found to be two-order magnitude lower than that of PVAc and PVAc–ZnO coatings. The results are explained on the basis of enhancement in barrier properties due to nano-particulate additives in PVAc–ZnO–PANI film together with the redox behaviour of PANI and protective oxide layer formation near the substrate.     

Conducting polymer based hybrid nano-composites for enhanced corrosion protective coatings

Hybrid composite coatings containing zinc oxide (ZnO) and polyaniline (PANI) as nano-additives dispersions were prepared with poly(vinyl acetate) (PVAc) as the major matrix. The steel plates dip-coated with these formulations were tested for corrosion protection by immersion in saline water over long periods. The Tafel plots for the determination of open circuit potential (OCP) and corrosion current (I_corr) were recorded. The coatings containing both ZnO and PANI showed improved corrosion resistance as compared to the single component coating. The I_corr values of PVAc–ZnO–PANI are found to be two-order magnitude lower than that of PVAc and PVAc–ZnO coatings. The results are explained on the basis of enhancement in barrier properties due to nano-particulate additives in PVAc–ZnO–PANI film together with the redox behaviour of PANI and protective oxide layer formation near the substrate.     

Styrene butadiene co-polymer based conducting polymer composite as an effective corrosion protective coating

Electroactive conducting polymer composite coatings of polyaniline (PANI) are electrosynthesized on styrene–butadiene rubber (SBR) coated stainless steel electrode by potentiostatic method using aqueous H₂SO₄ as supporting electrolyte. The protective behaviour of these coatings in different corrosion media (3.5% NaCl and 0.5 M HCl) is investigated using Tafel polarization curves, open circuit potential measurements and electrochemical impedance spectroscopy. The results reveal that SBR/PANI composite coating is much better in corrosion protection than simple PANI coating. The corrosion potential of composite films shifts to more noble values indicating that SBR/PANI composite coating act as an effective corrosion protective layer.     

Epoxy/polyaniline–ZnO nanorods hybrid nanocomposite coatings: Synthesis,characterization and corrosion protection performance of conducting paints

The objective of this research is the production of an epoxy coating blended with organic–inorganic hybrid nanocomposite as a corrosion inhibiting pigment applied over carbon steel grade ST37. A series of conducting polyaniline (PANI)–ZnO nanocomposites materials has been successfully prepared by an in situ chemical oxidative method of aniline monomers in the presence of ZnO nanorods with camphorsulfonic acid (CSA) and ammonium peroxydisulfate (APS) as surfactant and initiator, respectively. The synthesized polymers were characterized by X-ray diffraction pattern (XRD), Fourier transform infrared (FTIR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), thermal gravimetric analysis (TGA) and electrical conductivity techniques. Synthesized nanocomposites were solved in tetraethylenpentamine (TEPA), and then prepared solution was mixed with epoxy and then was applied as a protective coating on carbon steel plates. The anti-corrosion behavior of the epoxy binder blended with PANI–ZnO nanocomposites were studied in 3.5% NaCl solution at a temperature of 25 °C by electrochemical techniques including electrochemical impedance spectroscopy (EIS) and chronopotentiometry at open circuit potential (OCP). It was observed that the epoxy coating containing conducting PANI–ZnO nanocomposites exhibited higher corrosion resistance and provided better barrier properties in the paint film in comparison with pure epoxy and epoxy/PANI coatings. In the case of conducting coatings, the OCP was shifted to the noble region due to presence of PANI pigments. Additionally, the possibility of formation of a passive film in the presence of PANI was reinforced at the substrate–coating interface. SEM studies taken from surface of the coatings showed that epoxy/PANI–ZnO hybrid nanocomposite coating systems (EPZ) are crack free, uniform and compact. Furthermore, it was found that the presence of ZnO nanorods beside PANI can significantly improve the barrier and corrosion protection performance of the epoxy coating due to the flaky shaped structure of the PANI–ZnO nanocomposites.     

镀铜导针线材的抗氧化处理

采用盐雾试验、腐蚀极化曲线和大气腐蚀试验方法,综合评价了BTA类化合物对镀铜导针线材的缓蚀效果.最佳抗氧化处理条件为:BTA类化合物质量浓度6 g/L,成膜温度55℃,成膜时间6min.此条件下得到的钝化膜在3%(质量分数)NaC1溶液中的开路电位(OCP)比基材正移250 mV,在大气中暴露180d后成色不变,可焊性...     

Study of PANI-MeSA conducting polymer dispersed in UV-curing polyester acrylate on galvanized steel as corrosion protection coating

Polyaniline (PANI) was synthesized by chemical oxidative polymerization using methane sulfonic acid (MeSA) as dopant and ammonium peroxodisulfate as oxidizer. Coatings of PANI-MeSA dispersed in polyester acrylate resin were applied on galvanized steel and UV-cured. The UV-curing resin base was studied to provide high performance and environmental friendly coating system. Morphology and mechanical properties of the coatings were investigated by scanning electron microscopy (SEM) and microindentation hardness tests. Long-term open-circuit potential (OCP) and electrochemical impedance spectroscopy (EIS) measurements were performed in 3 wt.% NaCl solution. SEM images show dispersion of the PANI particles in the coating, and electrochemical studies show long term active anodic ennoblement introduced to the protective system in the presence of PANI, shifting OCP value to nobler region. The changes in impedance value of the system during long-term exposure to the electrolyte give useful information about the PANI mechanism of action in corrosion protection and indicate the redox action (changing of states) of PANI under the defects healing process.     

Corrosion protective bi‐layered composites of polyaniline and poly(o‐anisidine) on low carbon steel

Bi‐layered composites of polyaniline (PANI) and poly(o‐anisidine) (POA) were investigated for corrosion protection of low carbon steel (LCS). In this work, homopolymers and bi‐layers of PANI and POA were electropolymerized on LCS from an aqueous salicylate solution by using cyclic voltammetry. These coatings were characterized by cyclic voltammetry, Fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM). Corrosion tests were carried out in aqueous 3% NaCl solution for LCS coated with PANI, POA, bi‐layered POA/PANI (POA on top of the PANI) or PANI/POA (PANI on top of the POA) composites using open circuit potential (OCP) measurements, potentiodynamic polarization technique, and electrochemical impedance spectroscopy (EIS). The single layer of PANI and POA protected the LCS in 3% NaCl for 8 and 16 h, respectively. The bi‐layered composite coatings provide effective protection to LCS for a longer time than a single layered PANI or POA coating. However, the corrosion protection offered to LCS depends on the deposition order of polymer layers in the composite. The PANI/POA composite provides better protection to LCS against corrosion than POA/PANI coating. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Electrosynthesis and protection role of polyaniline–polvinylalcohol composite on stainless steel

Polyaniline–polyvinyl alcohol (PANI–PVA) composite has been electrodeposited on stainless steel surface from aqueous sulfuric acid solution of aniline monomer in presence of soluble PVA at different concentrations. The PVA increased the rate of electropolymerization where 4 g/L PVA formed a composite of 37 wt% PANI and 63 wt% PVA composition. The composite layer exhibited more adhesion to the steel surface in comparison with PANI layer but with less thermal stability. It has higher protection role for the stainless steel (SS) against general and pitting corrosion. It enhanced the passivation of the SS surface by increasing the thickness of oxide film and improving the composition.