新型铝系缓蚀剂的研究

本文研究了铝盐为主要成份的NH_1缓蚀剂对A_3钢在南京自来水及硬水中的缓蚀性能。研究结果表明:NH_1能有效地抑制A_3钢在水中的腐蚀。在50℃条件下缓蚀剂NH_1用量为60ppm时,A_3钢缓蚀率可达96％以上。经预膜后,温度条件不变,低剂量NH_1缓蚀剂在弱碱性介质条件下运转,也保持上述缓蚀效率。为进一步评价NH_1缓蚀剂的缓蚀特性,作者利用恒电位法测定其极化曲线,结果表明:缓蚀剂NH_1同时抑制铁在水中的阴极过程与阳极过程,低浓度时它是以阴极型为主的混合型缓蚀剂。其缓蚀机理主要由于它在金属表面上生成了一层牢固的不溶性化合物膜,使氧到达金属表面的过程变得困难,因而阻滞了阴极过程。其次,带负电荷的氢氧化铝胶粒集中于带正电荷的铁离子处,并形成了氢氧化铝和氢氧化铁保护膜,这种保护膜阻止铁的阳极溶解过程。由于阴极与阳极过程同时受阻,而达到有效地抑制了铁在水中腐蚀的目的。     

盐酸介质中Tw-20与聚丙烯酸对铁腐蚀的协同缓蚀作用

运用稳态极化曲线、电化学阻抗谱和恒电位方波测极化阻力 (Rp)等电化学测试方法 ,研究了 0 .5mol·L-1HCl介质中非离子表面活性剂吐温 - 2 0 (Tw - 2 0 )在铁表面的吸附特征及其与聚丙烯酸 (PAAC)对铁腐蚀的协同缓蚀作用 ,证明Tw - 2 0在铁表面的吸附遵循修正的Langmuir吸附等温式 ,探讨了铁 /盐酸体系中Tw - 2 0与PAAC协同缓蚀作用的特点和机理     

HEDP镀铜体系中铜阳极的电化学溶解行为

通过循环伏安、阳极极化曲线等方法研究了羟基乙叉二膦酸(HEDP)镀铜液中铜阳极的电化学行为,分析了不同阳极材料的溶解行为差异及对镀层质量的影响.结果表明,溶液环境的改变会显著影响铜阳极溶解的电化学行为,HEDP体系中加入23CO?可促进铜阳极的溶解及提高Cu还原电势;在HEDP镀铜液中,铜的阳极溶解过程主要包括Cu2O的形成、Cu2+的溶出、浓差极化阻滞溶解、Cu(OH)2和CuCO3的生成及氧气的析出.HEDP镀铜体系中,磷铜阳极反应活性低,表面易钝化;电解铜阳极的溶解过快,易产生"铜粉"Cu2O而影响镀层质量;冷轧紫铜作为阳极最适宜.     

纯铝在盐酸中的腐蚀及缓蚀

本文采用失重法和荧光分析法研究了铝在盐酸中的腐蚀以及CaSO_4对其腐蚀的影响。结果表明,CaSO_4是缓蚀性能颇佳的铝的缓蚀剂。并由电化学测量得到它是阴极型的缓蚀剂。同时,对其缓蚀机理及腐蚀动力学进行了初步的探讨。研究铝的腐蚀及缓蚀,一方面可以减轻由于腐蚀而造成的巨大损失;另一方面,抑制铝的阴极过程的缓蚀对于铝代替化学电源中的锌阳极和牺牲阳极保护法中的应用具有非常重要的现实意义。     

超分子缓蚀剂对凝结水中铁含量的抑制机理

在实验室与现场环境下考察了超分子缓蚀剂CDDA对工业锅炉蒸汽凝结水中铁含量的抑制效应,并通过重量法、电化学与表面分析探讨了CDDA对碳钢的缓蚀机理。结果表明,CDDA可有效抑制蒸汽凝结水中的铁含量。现场监测显示,投加CDDA后,总铁质量浓度维持在60～70μg/L,符合回水标准。CDDA以客体十八胺为有效缓蚀组分吸附于碳钢表面,并抑制阳极溶解过程,以减少腐蚀产物侵入凝结水,缓蚀率最高可达93.84%。处理后的凝结水与部分软化水混合后可用作锅炉补水,利于实现节能减排。     

关于钢在酸性溶液中的钝化

在酸性溶液中，钢是活泼的，随着阳极过程的进行而发生腐蚀，但是，由于一些因素的作用，使阳极过程受到强烈的阻滞，同样可进入钝化状态，微酸性除铜钝化利用在亚硝酸的－柠檬酸溶液中，钢的钝化区间扩大，钝化电流变小，钝化电位负移，同时铜溶解产生的强氧化电流使钢的阳极过程受到阻滞，从而进入钝化状态。     

非织造布

20013249用电晕诱导的方法对合纤非织造布表面进行聚丙烯酸链接枝改性Seto Fusako…;Angew.Makromol.Chem.,2999,266,P.56一62(英)本文研究了合纤非织造布在电晕下放射处理后进行高聚物接枝的过程。被接枝的对象为PE、PA一6非织造布基布,接枝体为丙烯酸(AAC)。研究发现PAAC的接枝量主要依赖于接枝时间,经过20分钟后,基布表面的纤维已完全被PAAC接枝,而用于PA一6的接枝时间长于PE。用XPS分析了被PAAC接枝的基布表面,测定了静电荷从基布中的泄漏量,在PAAC的接枝过程中,电势能迅速下降至最初的1/2。用甲基兰对基布染色,发现所接…     

关于钢在酸性溶液中的钝化

在酸性溶液中,钢是活泼的,随着阳极过程的进行而发生腐蚀．但是,由于一些因素的作用,使阳级过程受到强烈的阻滞,同样可进入钝化状态．微酸性除铜钝化工艺是利用在亚硝酸钠－柠檬酸溶液中,钢的钝化区间扩大,钝化电流变小,钝化电位负移,同时铜溶解产生的强氧化电流使钢的阳极过程受到阻滞,从而进入钝化状态．     

酸性硫酸盐体系镀铜中铜阳极的电化学行为

通过测量阳极极化曲线、循环伏安曲线等电化学方法研究了酸性硫酸盐镀铜溶液中铜阳极的电化学行为,分析了镀液组成和工艺条件对铜阳极溶解和钝化过程的影响。结果表明,纯铜阳极在酸性硫酸盐溶液中发生电化学溶解的电势范围较窄,容易发生钝化,在阳极电势达3.0 V(相对于饱和甘汞电极)后仍无过钝化或析氧现象。完全钝化的铜阳极重新通电后依然能发生正常的电化学溶解。磷铜阳极的电化学溶解性能稍好于纯铜阳极。增大硫酸铜质量浓度和加入添加剂HN-Super-A使铜阳极更易钝化,而增大硫酸质量浓度、加入添加剂HN-Super-Mμ和升温有利于铜阳极的电化学溶解。电镀过程中的电流密度不应超过铜阳极的临界钝化电流密度,否则铜阳极容易钝化。     

物理因素对电镀过程的影响

在电镀过程中,阳极过程与阴极过程是同时发生的既矛盾又统一的过程.阳极过程影响电镀槽液的稳定(主盐的浓度),因而也就影响电镀过程.因此,必须重观对阳极过程的研究.对于理想的阳极过程,即金属可以很成功地进行溶解的过程,在动力学上已做了详尽的研究.正是基于这种研究,才使我们有可能在工艺实践中选择适当的阳极材料和电流密度,以及某些阳极活性物质,以保证阳极在电镀过程中的     

INHIBITION OF THE CORROSION OF NICKEL AND ITS ALLOYS BY NATURAL CLOVE OIL

The corrosion behavior of nickel, Inconel 600, and Inconel 690 in different concentrations of HCl solutions and its inhibition by clove oil was studied using potentiostatic polarization measurements. As the acid concentration increases, the rate of corrosion increases, indicating that HCl accelerates the dissolution of nickel and its alloys. The inhibition efficiency of the clove oil was found to increase with increase of its concentration. The inhibitive action of this oil was discussed in view of adsorption onto the metal surface. The adsorbed layer acts as a barrier between the metal surface and aggressive solution, leading to a decrease in corrosion rate. The adsorption process follows Langmuir adsorption isotherms. It was found that the clove oil provides good protection to nickel and its alloys against pitting corrosion in chloride-containing solution using potentiodynamic anodic polarization techniques.     

Influence of H+ and Cl− ions on inhibitive performance of poly(aniline) for iron corrosion in acid

The inhibition effect of poly(aniline) on pure iron corrosion in 1M HCl and with various H⁺ ions and Cl^? ions concentrations was investigated by the polarization and electrochemical impedance spectroscopy methods. The results showed that poly(aniline) suppressed both cathodic and anodic processes of iron dissolution in 1M HCl by its adsorption on the iron surface according to Langmuir's adsorption isotherm. The inhibition efficiency of poly(aniline) was found to increase with the inhibitor concentrations. Further, it was observed that, there was no significant variation in corrosion potential (E_corr) values in the presence of inhibitors suggesting that, this polymer behaved as mixed type inhibitor. Similar studies for the inhibitor at 500 ppm in various concentrations of H⁺ and Cl^? ions, have shown that the inhibition efficiency decreases with decrease in concentrations of H⁺ ions and Cl^? ions in aqueous solution. It reveals that, the adsorption of inhibitor on iron surface is by more cationic form of inhibitor and higher efficiency at higher H⁺ and Cl^? ions is due to enhanced adsorption of cat ionic form of inhibitor molecules. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007     

Effect of ascorbic acid on mild steel dissolution in sulphuric acid solution investigated by electrochemical polarization and surface probe techniques

The effect of ascorbic acid (AA) on the corrosion of mild steel in sulphuric acid solution has been investigated by open circuit potential (OCP) and polarization measurements. AA was observed to shift the OCP to more positive potentials with increasing concentration. The polarization curves revealed that AA inhibited the anodic metal dissolution reaction, although this effect became negligible at high anodic overpotentials. The trend of inhibition efficiency with concentration showed that efficiency increased rapidly at low concentrations, remained almost steady at intermediate concentrations and increased again at high concentrations. The mechanism of inhibition was considered in terms of initial chemisorption of AA according to the Temkin isotherm, followed by formation of chelate compounds with Fe²⁺ ions at high concentrations. EDS and AFM analyses of the electrode surface support the proposed inhibition mechanisms.     

Effect of some polymeric materials on the corrosion behaviour of tin in succinic acid solution

The anodic behaviour and corrosion of tin in various concentrations (0.05–0.7M) of succinic acid were studied using cyclic voltammetry. The potentiodynamic anodic polarization curves exhibit active/passive transition. The active dissolution of tin involves one anodic peak. The cathodic curve exhibits one cathodic peak corresponding to the reduction of the passive layer. The ratio of the anodic charge/cathodic charge is more than unity indicating that the passive layer is very thin and the dissolution products are mainly soluble species. Additions of some polyethylene glycols to the succinic acid solution decrease the anodic peak current and shift the peak potential in the negative direction. These changes depend on the concentration and molecular weight of the polyethylene glycol added. The effect of the inhibitors decreases in the following order: (PEG)₆₀₀₀ > (PEG)₄₀₀₀ > (PEG)₁₂₀₀. The inhibition efficiency decreases with increase in temperature, suggesting physical adsorption.     

盐酸介质中吐温-60对冷轧钢的缓蚀作用机理

用失重法及电化学法研究了非离子表面活性剂吐温-60对冷轧钢在1.0～8.0 mol•L^-1盐酸溶液中的缓蚀作用. 结果表明：吐温-60对冷轧钢在1.0 mol•L^-1盐酸溶液中具有良好的缓蚀作用,且其在钢表面的吸附符合Langmuir吸附模型. 缓蚀率随缓蚀剂浓度的增加而增大,但随盐酸浓度和温度的增加而减小. 动电位极化曲线表明,吐温-60为混合抑制型缓蚀剂,但主要是抑制阴极反应. 通过吸附理论和动力学公式求出了相应的吸附热力学参数和动力学参数,并根据这些参数详细讨论了缓蚀作用机理.     

盐酸中原儿茶醛在钢表面的吸附及缓蚀作用

用失重法和动电位极化曲线法研究了在1.0mol/L HCl中20~50℃原儿茶醛(3,4-二羟基苯甲醛)在冷轧钢表面上的吸附及缓蚀作用.结果表明:原儿茶醛具有中等程度的缓蚀作用,为混合抑制型缓蚀剂,缓蚀率随原儿茶醛的浓度增加而增大,但随温度的增加而减小;原儿茶醛在钢表面的吸附符合Freundlich吸附模型.通过吸附理论和动力学Arrhenius公式求出了相应的吸附热力学参数(吸附自由能ΔG°,吸附热ΔH°,吸附熵ΔS°)和动力学参数表观活化能Ea,并根据这些参数详细讨论了缓蚀作用机理.     

Synergistic corrosion inhibition effect of 1-ethyl-1-methylpyrrolidinium tetrafluoroborate and iodide ions for low carbon steel in HCl solution

Investigation into the corrosion inhibition of low carbon steel in 0.1-M HCl solution by 1-ethyl-1-methylpyrrolidinium (EMTFB) and the effect of KI addition on the inhibition efficiency was carried out using potentiodynamic polarization (PDP) and electrochemical impedance spectroscopy and surface analysis (scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDAX)) techniques. Results show that EMTFB suppresses low carbon steel dissolution in the corrosive environment. Inhibition efficiency increased with the increase in EMTFB concentration. Addition of iodide ions to EMTFB raises inhibition efficiency from 75 to 98%. PDP results indicate that EMTFB affects majorly anodic reactions while EMTFB + KI act as cathodic-type inhibitor. The adsorption of EMTFB onto low carbon steel surface is by physical adsorption mechanism and follows Langmuir adsorption isotherm model. SEM and EDAX results confirm the adsorption of EMTFB alone and in combination with KI onto the steel surface.     

Electrochemical behaviour of iron electrode in acidic acetonitrile solutions

Iron dissolution as well as hydrogen evolution was studied in HCl and HBr acetonitrile solutions in a concentration range between 2·8 × 10^?4 M. Halide concentration was changed by adding lithium halide to some of the previous solution. Measurements were performed at 0·0°C.Current efficiency for a two-electron transfer was about 100 per cent for both anodic and cathodic reactions.Corrosion and kinetic parameters were obtained from the polarization curves performed under different experimental conditions. Tafel slopes of 2·3 × 2 RT/F were found for both anodic and cathodic reactions.A reaction mechanism for the anodic reaction is postulated on the basis of anion adsorption. An inhibitory effect, probably due to solvent adsorption at the electrode, occurs as the acid concentration decreases, affecting both the anodic and cathodic polarization curves.     

棉竹竹叶提取物在HCl中对钢和铝的缓蚀作用

采用失重法和动电位极化曲线首次研究了棉竹竹叶提取物在1.0 mol/LHCl溶液中对冷轧钢和工业纯铝的缓蚀作用。结果表明：棉竹竹叶提取物对冷轧钢具有非常好的缓蚀作用,最大缓蚀率达95%,且在钢表面的吸附符合Langmuir吸附等温式;对铝具有中等程度的缓蚀作用,最大缓蚀率仅为55%,在铝表面的吸附也服从Langmuir吸附模型。极化曲线表明竹叶缓蚀剂为混合抑制型缓蚀剂。