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中性红在盐酸溶液中对冷轧钢的缓蚀作用 总被引:1,自引:0,他引:1
用失重法和动电位极化曲线法研究了酸碱指示剂中性红对冷轧钢在1.0~8.0 mol/LHCl溶液中的缓蚀作用.结果表明:中性红对冷轧钢在1.0 moL/L HCl溶液中具有良好的缓蚀作用,为混合抑制型缓蚀剂,且在钢表面的吸附符合校正的Langmuir吸附等温式,缓蚀率随缓蚀剂浓度的增加而增大,但随温度和盐酸浓度的增加而减小.通过吸附理论求出了相应的吸附热力学(吸附自由能△G°,吸附热△H°,吸附熵△S°)和动力学参数(腐蚀速度常数k,腐蚀动力学常数B),并根据这些参数讨论了缓蚀作用机理. 相似文献
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以乙醇水溶液为提取溶剂,采用回流提取法从核桃青皮中提取制备了核桃青皮缓蚀剂(WGHI),并用失重法、动电位极化曲线、EIS、UV、FTIR和SEM测试了WGHI对冷轧钢在0.5 mol/L HCl溶液中的缓蚀性能。结果表明:乙醇体积分数为40%时,提取制备出的WGHI产率和缓蚀率均较佳,分别为14.2%和90.3%。WGHI对冷轧钢在0.5 mol/L HCl溶液中的腐蚀具有明显抑制作用,且随着WGHI质量浓度的增加缓蚀性能逐渐增强,但随温度的升高有所下降,20℃时100 mg/L WGHI的缓蚀率为90.3%。WGHI通过物理和化学吸附方式在钢表面发生吸附,吸附过程中会释放出热量,同时混乱度减小,该吸附规律遵循Langmuir吸附方程。添加WGHI后同时抑制了钢的阴极和阳极腐蚀反应,为混合抑制型缓蚀剂;Nyquist呈单一弥散容抗弧,其阻抗值随WGHI质量浓度的增加而显著增大。SEM结果显示:WGHI能有效减缓钢表面在HCl溶液中的腐蚀并且降低了其表面粗糙度。 相似文献
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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 mol8226;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 mol8226;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. 相似文献
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Gemini型表面活性剂在HCl溶液中的缓蚀性能研究 总被引:1,自引:0,他引:1
利用静态失重法和动态电化学方法对gemini型季铵盐缓蚀剂C10-4-C10,C12-4-C12,C14-4-C14和C16-4-C16在1mol/L HCl介质中对45#钢片的缓蚀性能进行了研究,结果表明,在1mol/L的HCl溶液中,gemini型季铵盐缓蚀剂在45#钢片表面上形成单分子层吸附,对45#钢片有优异的缓蚀性能,缓蚀率随缓蚀剂浓度增加而升高;极化曲线表明,gemini型季铵盐缓蚀剂在HCl溶液中是以抑制阴极过程为主的阴极型缓蚀剂。 相似文献
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通过动电位扫描测量极化曲线,研究了钼酸盐系缓蚀剂在含5 g/L C1-溶液中对Q 235铜的缓蚀性能.分析结果表明:由钼酸盐为主盐,与硅酸盐、磷酸盐、有机胺A复配而成的缓蚀剂,可以达到成本低、高缓蚀率的效果.通过失重法实验,对该配方进行了验证,复配缓蚀剂的缓蚀率接近88.4%,明显高于单组分缓蚀剂的. 相似文献
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通过电导率测量、pH测量、同步热分析(STA)、Tafel极化曲线法和电化学交流阻抗谱法研究了不同浓度和温度下过期药呋塞米在1 mol/L的醋酸溶液中对冷轧钢缓蚀作用。实验结果表明:过期药呋塞米在1 mol/L的醋酸溶液中对冷轧钢有较好的缓蚀效果,且缓蚀率随着缓蚀剂浓度和温度的增加而增大。该缓蚀剂在醋酸中对钢是一种抑制阴极和阳极的混合型缓蚀剂。缓蚀剂在冷轧钢表面的吸附符合Langmuir吸附等温式,其吸附是自发、物理吸附过程。同步热分析还说明了该缓蚀剂易稳定吸附在冷轧钢表面。 相似文献
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The corrosion inhibition of cold rolled steel (CRS) in 7.0 mol·L-1 H2SO4 solution by red tetrazolium (RTZ) was carefully investigated using both experimental procedures and theoretical techniques. The results show that RTZ acts as an effective inhibitor for the corrosion of CRS in 7.0 mol·L-1 H2SO4, and the maximum inhibition efficiency is higher than 95% with a RTZ concentration of 2.0 mmol·L-1. The adsorption of RTZ on CRS surface follows Langmuir isotherm. RTZ effectively retards both cathodic and anodic reactions, and acts as a mixed-type inhibitor. EIS exhibits two capacitive loops, and their resistances increase drastically in the presence of RTZ. SEM and AFM confirm that the addition of RTZ could significantly retard the corrosion of CRS surface. A series of characterizations like FTIR, RS, XRD and XPS reveal that the corrosion CRS surface is composed of the corrosion products of iron sulfates, iron oxides and iron hydroxide, as well as inhibitor. Theoretical results of quantum chemical calculation and molecular dynamics (MD) indicate that the adsorption center of RTZ+ (organic cationic part of RTZ) mainly relies on its tetrazole ring, and the adsorption of RTZ+ on Fe (001) surface is in a nearly flat orientation mode. 相似文献
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钼酸盐对镁合金在模拟冷却水中腐蚀的抑制作用 总被引:5,自引:2,他引:3
采用Tafel极化曲线、电化学阻抗谱方法研究了钼酸钠对AZ40镁合金在模拟冷却水中腐蚀的抑制作用,利用扫描电子显微镜(SEM)和能量色散谱(EDS)表征了试样的形貌及组成。结果表明,钼酸钠对镁合金在模拟冷却水中的腐蚀具有一定的抑制作用,钼酸钠浓度为1000 μg·g-1时缓蚀效果最佳。钼酸钠的加入减弱了腐蚀性Cl-在试样/介质界面的吸附,同时参与镁合金试样在模拟冷却水中表面膜的生成,使表面膜变得致密,从而较好地抑制镁合金的腐蚀;其缓蚀作用属于阳极抑制型缓蚀作用。 相似文献
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The inhibition effect of Jasminum nudiflorum Lindl. leaves extract (JNLLE) on the corrosion of cold rolled steel (CRS) in 1.0 M hydrochloric acid (HCl) was investigated
by weight loss, potentiodynamic polarization, and electrochemical impedance spectroscopy (EIS) methods. The results show that
JNLLE acts as a very good inhibitor, and the inhibition efficiency increases with the concentration of JNLLE. The adsorption
of JNLLE obeys Langmuir adsorption isotherm. Values of inhibition efficiency obtained from weight loss, potentiodynamic polarization,
and electrochemical impedance spectroscopy (EIS) are in good agreement. Polarization curves show that JNLLE behaves as a mixed-type
inhibitor in hydrochloric acid. EIS shows that charge-transfer resistance increase and the capacitance of double layer decreases
with the inhibitor concentration, confirming the adsorption process mechanism. The adsorbed film on CRS surface containing
JNLLE inhibitor was also measured by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscope (SEM).
A probable inhibitive mechanism is proposed from the viewpoint of adsorption theory. 相似文献
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The inhibition effect of methyl violet (MV) on the corrosion of cold rolled steel (CRS) in 1.0 M sulfuric acid (H2SO4) was investigated by weight loss, potentiodynamic polarization, and electrochemical impedance spectroscopy (EIS) methods.
The results show that MV is a good inhibitor, and inhibition efficiency increases with inhibitor concentration, while decreases
with the temperature. The adsorption of MV on CRS surface obeys Langmuir adsorption isotherm equation. The thermodynamic parameters
of adsorption enthalpy (ΔH°), adsorption free energy (ΔG°) and adsorption entropy (ΔS°) are calculated and discussed. Potentiodynamic polarization curves show that MV acts as a mixed-type inhibitor in sulfuric
acid. EIS exhibits one capacitive loop which indicates that the corrosion reaction is controlled by charge transfer process.
Inhibition efficiency values obtained from weight loss, polarization and EIS are in reasonably good agreement. The adsorbed
film on CRS surface containing optimum dose of MV was investigated by Fourier transform infrared spectroscopy (FTIR) and scanning
electron microscopy (SEM). Depending on the results, the inhibitive mechanism is proposed from the viewpoint of adsorption
theory. 相似文献
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Mahendra Yadav Sushil Kumar Laldeep Gope 《Journal of Adhesion Science and Technology》2013,27(11):1072-1089
Amino acid derivatives, namely, 2-(2-oxo-2-phenothiazin-10-yl)ethylamino)-3-mercaptopropanoic acid (OPEM) and 2-(2-oxo-2-phenothiazin-10-yl)ethylamino)acetic acid (OPEA) were synthesized and investigated as inhibitors for mild steel corrosion in 15% HCl solution using the weight loss, polarization, and electrochemical impedance spectroscopy (EIS) techniques. The inhibition efficiency of both the inhibitors increased with increasing the temperature and concentration of inhibitor. The inhibitors OPEM and OPEA show corrosion inhibition efficiency of 97.5 and 95.8%, respectively, in 200?ppm concentration, at 333?K. Polarization studies showed that both studied inhibitors were of mixed type in nature. The adsorption of inhibitors on the mild steel surface obeys Langmuir adsorption isotherm and the surface of inhibited and uninhibited specimens were analyzed by scanning electron microscopy (SEM). The semiempirical AM1 method was employed for theoretical calculations and the obtained results were found to be consistent with the experimental findings. 相似文献
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L. Vrsalović E. Oguzie M. Kliškić S. Gudić 《Chemical Engineering Communications》2013,200(11):1380-1393
The purpose of this study was to investigate the efficiency of two phenolic acids, namely p-hydroxybenzoic acid (HBA) and protocatechuic acid (PCA), as corrosion inhibitors for CuNi10Fe alloy in a 0.5 mol dm?3 NaCl solution. In these investigations, open circuit potential measurements, potentiodynamic polarization measurements, and the linear polarization method have been used. It was found that both phenolic acids had similar corrosion inhibition effects on the CuNi10Fe alloy dissolution. The inhibition efficiency (IE) increased with increase in inhibitor concentration. The polarization shows that both compounds functioned as cathodic corrosion inhibitors by adsorption on the surface of CuNi10Fe alloy according to the Freundlich adsorption isotherm. The numerical values of free energies of adsorption indicate physical adsorption of the compounds on the electrode surface. DFT-based quantum chemical computations and molecular dynamics (MD) simulations revealed identical electronic and adsorption structures for both HBA and PCA, which could account for the similarities in the experimentally observed inhibiting effects. 相似文献