聚苯胺/铬酸锶复合材料的制备及其环氧涂层防腐蚀行为研究

利用原位聚合的方法合成了不同质量比的聚苯胺/铬酸锶复合材料,使用扫描电镜(SEM)、透射电镜(TEM)、傅里叶变换红外光谱(FT-IR)和X射线衍射(XRD)对复合材料进行了表征,并在不锈钢片上制备了聚苯胺/铬酸锶复合材料的环氧涂层,利用电化学工作站和盐雾试验箱测试其防腐性能.测试结果表明:聚苯胺/铬酸锶复合材料的防腐效果优于聚苯胺,且当复合材料中聚苯胺与铬酸锶的质量比为1∶1时,防腐蚀性能最好,该复合材料环氧涂层的腐蚀电位较聚苯胺环氧涂层提高30 mV,腐蚀电流密度下降一半,降低成本的同时提高了其防腐性能.     

植酸掺杂聚苯胺/环氧防腐涂层的研究

目前,聚苯胺防腐涂料已成为导电高分子材料的应用和涂料研究开发领域的一个新的热点。为了研究聚苯胺对涂层防腐性能的影响,制备了聚苯胺质量分数分别为0%,1%,3%,5%及10%的植酸掺杂聚苯胺/环氧防腐涂层,应用电化学阻抗谱和Tafel极化曲线等方法对比了其在3.5%Na C1溶液中的防腐性能。研究表明,聚苯胺在涂层中的含量对涂层的防腐性能有较大影响,聚苯胺质量分数为3%时,涂层具有最佳的防腐性能。     

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     

二氧化锰氧化法合成聚苯胺/二氧化硅复合粒子用于防腐涂料的研究

以二氧化锰代替过硫酸铵氧化苯胺单体,并在聚合反应体系中添加适当比例的二氧化硅粒子,制备出不同酸掺杂的聚苯胺包覆二氧化硅复合粒子.扫描电子显微镜(SEM)观察表明,二氧化硅表面及其粒子之间明显包覆一层聚苯胺(PANI);并比较不同酸掺杂的聚苯胺复合粒子的傅里叶变换红外光谱(FT-IR),证明了掺杂的有效性.将合成的聚苯胺复合粒子作为防腐填料,加入环氧树脂作为成膜物,制备出的聚苯胺/环氧树脂复合涂料涂覆在碳钢基体上,采用加速浸泡实验、开路电位法、Tafel极化曲线研究其防腐性能.实验结果表明:H2SO4掺杂的聚苯胺复合涂层具有优良的防腐性能,该复合涂层的腐蚀电位较环氧树脂涂层提高400 mV,腐蚀电流下降4～5个数鼍级,是一种低成本、高性能防腐涂料.     

聚苯胺/蒙脱土/水性氟碳树脂复合防腐涂料的研究

合成了聚苯胺/蒙脱土/水性氟碳树脂三元复合防腐涂层,测量了其电化学阻抗谱和塔菲尔曲线,发现其具有较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),通过扫描电镜照片也发现复合涂层在低碳钢表面形成致密的膜层,从而具有良好的防腐蚀效果.     

聚苯胺改性涂料的防腐性能研究

将聚苯胺与聚酯树脂、环氧树脂溶液共混制备防腐蚀涂料.用腐蚀电位时效法考察了饱和聚酯、环氧-低相对分子质量聚酰胺固化体系和环氧-二乙烯三胺固化体系中聚苯胺的加入量对防腐性能的影响.结果表明:对聚苯胺进行适当的还原处理,有利于改善其溶解性和在涂料中的分散性,提高涂层的防腐性能.涂料的最佳配方为:聚苯胺溶液中苯肼用量为1%,环氧树脂、聚酰胺固化剂和聚苯胺的质量比为1:1:0.06.涂覆该涂料的电极腐蚀电位可达-305 mV.     

涂料和涂膜的检验、分析及评价

法测定水性涂料中的游离甲醛;氟碳防腐面涂层缺陷分析;防腐涂料——抗氯离子渗透性测试方法;聚苯胺改性涂料的防腐性能研究;最新船舶涂料特性检测方法介绍     

水性聚苯胺防腐涂料研究

将聚苯胺水性微乳液和环氧树脂共混作为底漆、与环氧树脂面漆复合制成防腐涂料，采用开路电位法评价复合涂层的防腐性能。结果表明，合成聚苯胺水性微乳液所使用的酸介质、聚苯胺乳液的用量和腐蚀介质等对涂层的防腐性能均有影响。以十二烷基苯磺酸(DBSA)为酸性介质合成的聚苯胺水性微乳液，当其用量为50％时，复合涂料的防腐性能最佳，与裸露钢板相比，该复合涂层的平衡开路电位可提高245mV左右。该复合涂料不使用任何有机溶剂，是一种环境友好型绿色涂料。     

聚苯胺/纳米碳酸钙复合物的制备及其防腐性能

以苯胺单体为原料、过硫酸铵为氧化剂,采用化学氧化法制备了本征态聚苯胺,将其与纳米CaCO3通过溶液共混法制备了聚苯胺/CaCO3复合物。采用扫描电镜(SEM)、X射线衍射(XRD)、紫外–可见光谱(UV–Vis)和红外光谱(IR)对聚苯胺/CaCO3复合物进行了形貌观察和结构表征。分别以聚苯胺、聚苯胺/CaCO3复合物为填料,加入到环氧树脂(EP)/聚酰胺固化剂体系中,在碳钢表面制备了EP/聚苯胺和EP/聚苯胺/CaCO3复合涂层,通过开路电位、极化曲线和交流阻抗谱等电化学方法对比研究了裸钢以及含EP涂层、EP/聚苯胺涂层、EP/聚苯胺/CaCO3复合涂层的碳钢试片在3.5%NaCl溶液中浸泡不同时间的腐蚀行为。结果表明,聚苯胺膜较好地包覆在CaCO3纳米粒子表面;CaCO3的加入增强了涂层的致密性,提高了聚苯胺分子对金属基体的粘附力。含有聚苯胺/纳米CaCO3复合物的环氧涂层具有最强的抗腐蚀能力,其次为环氧/聚苯胺涂层;两者相比,EP/聚苯胺/CaCO3复合涂层的腐蚀电位正移了59 mV,腐蚀电流密度降低了63%。     

聚苯胺/SiO_2复合粒子的制备及其防腐性能

以二氧化锰代替常规的过硫酸铵氧化体系,并在化学氧化聚合反应体系中添加适当比例的二氧化硅粒子,制备出盐酸掺杂的聚苯胺包覆二氧化硅复合粒子。扫描电子显微镜(SEM)观察表明,二氧化硅表面及其粒子之间明显包覆一层聚苯胺(PANI);傅立叶变换红外光谱(FTIR)证明了其掺杂的有效性。将复合粒子作为防腐填料,加入环氧树脂做成膜物,制备出的聚苯胺/环氧树脂复合涂料在碳钢基体上进行涂层,采用加速浸泡实验、开路电位法、Tafel极化曲线考察了其防腐性能。结果表明,盐酸掺杂的聚苯胺复合涂层具有优良的防腐性能,该复合涂层的腐蚀电位较环氧树脂涂层提高400mV,腐蚀电流下降4～5个数量级,有望成为一种低成本、高性能防腐涂料。     

铜在硝酸介质苯并三唑抛光液中化学-机械抛光时的电化学行为

用电化学测试技术研究了硝酸、苯并三唑及H2O2浓度对铜表面的成膜及铜抛光过程的影响.测试了各种体系中铜的交流阻抗及其影响因素，探讨了腐蚀电流密度与抛光压力、抛光转速的关系，考察了化学-机械抛光过程中腐蚀电位及极化曲线的变化规律. 用腐蚀电流密度及腐蚀电位等电化学变量的变化解释了抛光过程的电化学机理，证明在硝酸溶液介质中，以苯并三唑为成膜剂、H2O2为助剂、纳米g -Al2O3为磨粒的抛光液配方是可行的.     

电镀锌钝化处理耐蚀效果的电化学评估

采用线性极化电阻、开路电位及阳极极化曲线等电化学方法,评估了锌镀层经3种不同钝化液处理后在w=1%的NaCl溶液中的耐蚀性。结果表明,3种电化学方法测得的钝化膜耐蚀性与中性盐雾试验的结果相符,能够用于快速有效地评价电镀锌钝化处理的耐腐蚀效果。     

阴极极化对微生物在电极表面附着的影响

以天然海水作为电解质,利用荧光显微镜、扫描电镜等表征方法和开路电位、恒电位极化等电化学测试手段研究了生物膜附着与电极表面电位的相互影响。结果表明：（1）生物膜在电极表面的附着导致了开路电位正移;（2）阴极极化能有效抑制微生物附着,并且阴极氧还原反应是阴极极化抑制微生物附着的主要原因;（3）搅拌等能促进阴极反应、增大阴极极化电流密度的措施都会在一定程度上利于阴极极化对微生物附着的抑制作用。     

Morphological reason for enhancement of electrochemical double layer capacitances of various acetylene blacks by electrochemical polarization

Enhancement of electrochemical capacitance and morphological variations of various acetylene blacks caused by electrochemical polarization are presented. Acetylene blacks of different mean particle diameters were modified by air-oxidation and heat treatment to diversify the morphologies of the acetylene blacks before electrochemical polarization. The various acetylene blacks were electrochemically oxidized at 1.6 V (vs. Ag/AgCl) for 10 s and the polarization step was repeated until the capacitance values did not change any longer. These polarization steps enhanced the capacitances of the acetylene blacks and the specific enhancement factors range from 2 to 5.5. Such an enhancement is strongly related to morphological modification as revealed by transmission electron microscopic observations. The electrochemical polarization resulted in formation of tiny graphene sheets on the wide graphitic carbon surfaces, which were most responsible for the observed capacitive enhancement. Although the pseudo-capacitance increased after polarization by forming oxygenated species on the surfaces, its contribution to the total capacitance was less than 10%. The mechanism of the formation of the tiny graphene sheets during the electrochemical oxidation is described schematically.     

Influence of substrate on the electrodeposition of nickel-molybdenum alloys

The electrodeposition of nickel-molybdenum alloy has been studied on various substrates, with the aim of determining the influence of hydrogen evolution on the formation of the deposit. Transient electrochemical methods were used. Three types of substrates were used. Glassy carbon in which hydrogen absorption cannot occur, palladium in which hydrogen diffusion is rapid, and nickel. Good and thick deposits were obtained on glassy carbon and annealed ultra pure nickel. On palladium no deposit was formed. The importance of hydrogen in the formation of the deposit was confirmed. Codeposition occurs in the same potential range as hydrogen evolution, and therefore hydrogen is trapped in the expanding lattice as seen by its oxidation during anodic polarization.     

液流电池钛基负极电解液在不同温度下的电化学性能

探究了钛基-盐酸水溶液体系电解液的电化学性能。分别采用循环伏安法、电化学交流阻抗法和动电位扫描法研究了不同温度下电解液电对的电化学反应的可逆性和反应的内部作用机理, 以及TiCl₃的盐酸水溶液体系在石墨电极上的反应平衡电位、交换电流、传递系数等电极反应的动力学参数。循环伏安结果表明温度上升有利于体系的电化学反应的可逆性, 40℃时反应的可逆性最好。交流阻抗实验结果采用LR_s(Q(R_ctW))等效电路模型进行了拟合, 结果显示随着温度由10℃上升至40℃, 电化学阻抗R_ct 值由4.192 W·cm²降低到0.5321 W·cm², 表明温度上升可以显著降低电对在石墨电极上的电化学反应阻抗。动电位测试结果发现Ti(Ⅲ)/Ti(Ⅳ)的平衡电位随温度上升发生正方向的偏移, 可能是由于温度上升使得Ti在HCl溶液中的形态发生变化;交换电流也随温度上升而增加是由于温度上升有促进电极表面电化学反应的电荷传递。各种电化学测试结果显示TiCl₃的HCl水溶液是一种有应用前景的液流电池负极电解液。     

Electrochemical behaviour of cadmium in NaOH solution

The electrochemical behaviour of cadmium in 1 M NaOH solution was studied. Different electrochemical methods such as potentiodynamic measurements, polarization techniques and electrochemical impedance spectroscopy (EIS) were used. During the course of polarization, several characteristic features were observed, including prepassivation and a relatively wide passive range extending over 1.4 V. Equivalent circuit models for the electrode–electrolyte interface under different applied potentials were proposed. The impedance data measured at steady state were fitted to calculated data according to proposed equivalent circuits. The relevance of the proposed equivalent circuits to the different phenomena occurring at the electrode–solution interface was discussed. The passive film formed on Cd is composed of two layers: a barrier layer in contact with metal and a deposit on the barrier layer. The barrier layer appears to form directly from the metal through a solid state reaction, rather than by a dissolution–precipitation mechanism. For an applied potential >+0.7 V the relative passive film thickness and resistance decrease to lower values indicating transpassive dissolution at this potential.     

Influence of Various Albumin Concentrations on the Corrosion Resistance of Zr-2.5%Nb Alloy

The Zr-2.5% Nb alloy corrosion resistance in four saline solutions with and without albumin was tested through electrochemical measurements of electrochemical impedance spectroscopy (EIS), linear polarization, and cyclic voltammetry at human body temperature.

The EIS measurements were performed at open circuit potential. The impedance spectra were recorded and the equivalent electric circuits were elaborated. From the linear polarization the Tafel slopes were recorded and the corrosion parameters were calculated. From the potentiodynamic polarization curves, the breakdown potential, the protection potential, and the protection domain were observed.

The amount of ions released from the material was quantified using the ICPMS technique and the results concerning the corrosion resistance were compared with those obtained from linear and cyclic polarization.

Before and after potentiodynamic polarization the topographic measurements were performed; the roughness at the samples surface was observed using AFM. The roughness was co-related to the contact angle measurements.     

制氟电解槽阳极极化的控制方法

分析了电解制氟中阳极极化过程的机理,叙述了浓差极化、"前置"化学极化、电化学极化、"后置"化学极化和反向传质极化等5类极化现象。针对每种极化产生的机理,提出了相对应的解决方法,并对采用特殊电解工艺消除极化的方法进行了展望。     

Development of HA-CNTs composite coating on AZ31 Magnesium alloy by cathodic electrodeposition. Part 2: Electrochemical and in-vitro behavior

The carbon nano-tubes (CNTs) reinforced hydroxyapatite (HA), with various functionalized CNTs concentration ranging from 0 to 1.5?wt%, were deposited on AZ31 magnesium alloy by direct and pulse cathodic electrodeposition methods. The corrosion resistance of the coatings was tested in simulated body fluid (SBF) using different electrochemical methods such as open circuit potential, polarization and electrochemical impedance spectroscopy. The in-vitro behavior, changes in solution pH as well as the amount of evolved hydrogen of these coatings were also evaluated during five days immersion in SBF. The results indicated that the pulse deposited HA having 1% CNTs coating was the optimum condition which decreased the corrosion current density of AZ31 magnesium alloy from 44.25?µA/cm² to 0.72?µA/cm². Moreover, it stabilized the alkalization behavior of AZ31 alloy and caused a tenfold decrease in the amount of hydrogen generation in SBF. Additionally, the formation of new hydroxyapatite layer on the surface of the pre-exist coatings after five days immersion in SBF was confirmed by SEM characterization.