土酸溶液中溴化十六烷基吡啶对锌的缓蚀作用及吸附热力学研究

用失重法研究了土酸溶液中溴化十六烷基吡啶对锌的缓蚀作用，发现溴化十六烷基吡啶在锌表面上的吸附是产生缓蚀作用的重要原因，且吸附规律服从Langmuir吸附等温式。用Sekine方法处理实验数据，从而获得了吸附过程△H^0、△S^0和△G^0等一系列重要热力学参数。     

氨基磺酸溶液中肉桂醛对碳钢的缓蚀作用和吸附热力学研究

采用失重法考察不同温度下5％氨基璜酸中,不同浓度的肉桂醛对碳钢的缓蚀作用;并对氨基璜酸介质中肉桂醛在碳钢表面吸附热力学进行了研究。肉桂醛低浓度时,随浓度增大,缓蚀作用增强;当其浓度达到一定值后,缓蚀作用基本保持不变。实验结果表明,肉桂醛在碳钢表面产生单分子层吸附,并且满足Langmuir吸附规律。△G°〈0吸附过程可以自发进行,并且随着温度的升高础增大,吸附作用降低。△H°〈O表明反应是放热过程。△S°〈0表肉桂醛在碳钢表面的吸附过程为熵减少的过程。     

盐酸液中溴化十六烷基吡啶对锌的缓蚀作用及吸附热力学性能

为了研究阳离子表面活性剂在盐酸溶液中对锌的吸附及缓蚀作用,用失重法研究了盐酸溶液中溴化十六烷基吡啶对锌的缓蚀作用,并应用吸附理论和Sekine方法对静态挂片试验数据进行处理.结果表明,溴化十六烷基吡啶对锌在盐酸介质中的腐蚀具有良好的抑制作用,是一种吸附型缓蚀剂,低浓度下在锌表面的吸附基本符合Langmuir等温式,相关系数大于0.998.缓蚀率随缓蚀剂浓度增加或温度升高而增大.通过对试验数据的处理,获得了吸附过程△H0、△S0和△G0等重要热力学参数,△H0=14.00 kJ/mol,△S0随温度升高而增加,△G0随温度升高而下降.本研究为后续工作提供了参考.     

土酸溶液中六次甲基四胺对碳钢的缓蚀作用及吸附热力学研究

采用失重法研究了土酸溶液中六次甲基四胺在不同温度和浓度下对碳钢的缓蚀作用,发现六次甲基四胺能较好地抑制碳钢的腐蚀。六次甲基四胺在碳钢表面上的吸附是产生缓蚀作用的重要原因,且吸附规律服从Langmuir吸附等温式。用Sekine方法处理实验数据,获得了吸附过程相关的重要热力学参数,吸附过程是吸热过程,熵值增大,吉布斯自由能减小;随温度升高,吉布斯自由能变增加,熵变减少,缓蚀率降低。     

烷基吡啶盐对铝的缓蚀作用

通过阳离子表面活性剂烷基吡啶盐在铝表面上的吸附，研究了不同温度下的酸碱介质中烷基吡啶盐对金属铝的缓蚀作用。     

马齿苋提取液对盐酸溶液中Q235碳钢的缓蚀作用

为了开发新型环境友好的天然缓蚀剂,采用索氏提取法提取马齿苋中的有效成分,采用失重法、动电位极化曲线和交流阻抗研究了不同浓度马齿苋提取液在1.0 mol/L盐酸溶液中对Q235碳钢的缓蚀作用及机理。结果表明:马齿苋提取液在盐酸介质中对碳钢具有良好的缓蚀效果,缓蚀效率随缓蚀剂浓度增大而升高,30℃下当提取液的浓度达到0.16 g/m L时,其缓蚀效率可达91%以上;随温度升高,马齿苋提取液对碳钢的缓蚀效率降低;马齿苋提取液是一种抑制阴阳极反应的混合型缓蚀剂,有效成分吸附在碳钢表面形成一层保护膜,吸附过程遵循Langmuir等温方程式,其在碳钢表面的吸附属于自发过程,是以化学吸附为主的物理和化学吸附共同作用的过程。     

烷基三唑类缓蚀剂的合成及对N80碳钢的缓蚀性能

目前,对引入长链烷基的三唑类缓蚀剂在盐酸中对金属缓蚀性能的研究尚存在着较大的空白。合成并探讨了烷基三唑类缓蚀剂对碳钢的缓蚀作用机理,采用失重法和电化学法测试评价了3种不同碳链长度的三唑类缓蚀剂对N80碳钢在盐酸中的缓蚀性能,采用扫描电镜(SEM)观察了其缓蚀前后的表面形貌。结果表明:3种缓蚀剂均能有效抑制盐酸对N80碳钢的腐蚀,为阴极抑制型缓蚀剂,在N80碳钢表面的吸附服从Langmuir等温吸附模型;在较低温度下,缓蚀剂碳链越长,缓蚀性能越好;缓蚀剂分子中吸附基团的比例随着碳链的增长而降低,随着温度的增加,缓蚀剂分子热运动加剧,吸附能力降低,碳链较短的缓蚀剂高温条件下能达到更高的缓蚀率。     

硫脲和溴代十六烷基吡啶对X70钢在30%乳酸溶液中的协同缓蚀

目前,对X70钢在乳酸溶液中的缓蚀行为少有报道.采用交流阻抗法和极化曲线法研究硫脲(TU)和溴代十六烷基吡啶(CPB)复配前后对X70钢在30%乳酸溶液中的缓蚀作用.研究发现:在30%乳酸体系中,TU和CPB对X70钢均有缓蚀作用;硫脲和溴代十六烷基吡啶复配后,缓蚀性能增强.当缓蚀剂的总浓度为20 mg/L,TU和CPB质量浓度比为1:1时缓蚀效果最佳.     

吐温-60对钢在H2SO4中的缓蚀性能

用失重法研究了非离子表面活性剂吐温-60对冷轧钢在0.5-7.0 mol/L H2SO4溶液中的缓蚀作用。结果表明：吐温-60对冷轧钢在1.0 mol/L H2SO4溶液中具有良好的缓蚀作用,且在钢表面的吸附符合校正的Langmuir吸附模型。缓蚀率随缓蚀剂浓度的增加而增大,但随温度和硫酸浓度的增加而减小。求出了相应的吸附热力学（吸附自由能ΔG^0, 吸附焓ΔH^0, 吸附熵ΔS^0）和动力学参数（腐蚀速率常数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。     

盐酸介质中锌缓蚀剂的电化学研究

采用电化学极化曲线法研究了在盐酸介质中盐酸吖啶、苯扎溴铵、溴代十六烷基吡啶、丙炔醇等对锌的缓蚀作用。结果表明，它们的加入提高了腐蚀反应的活化能，均为阴极型缓蚀剂，缓蚀率排序为盐酸吖啶〉苯扎溴铵〉溴代十六烷基吡啶〉丙炔醇。     

葡萄糖与甘氨酸反应产物对碳钢的缓蚀效果

为了解葡萄糖与甘氨酸反应产物对碳钢的缓蚀效果,采用失重法、电化学法并结合扫描电镜观察,研究了葡萄糖与甘氨酸反应产物(PGG)对碳钢在1 mol/L HCl溶液中的腐蚀抑制作用。结果发现:PGG对碳钢表现出很好的缓蚀效果,缓蚀效率随添加浓度的增加而增加,在最大浓度250 mg/L时,表现出最好的缓蚀效果,缓蚀效率为94.7%,且缓蚀效率随温度升高而降低。PGG同时抑制了碳钢腐蚀的阴极还原反应和阳极氧化反应过程,为混合型缓蚀剂,是通过多组分的物理和化学联合吸附,在碳钢表面上形成保护性覆盖层,将碳钢与酸溶液隔离,从而起到缓蚀作用,其吸附行为遵循Langmuir吸附等温模型。葡萄糖与甘氨酸反应产物(PGG)是碳钢在1 mol/L HCl溶液中的优良缓蚀剂。     

Effect of NaBr on the corrosion of cold rolled steel in 1.0 M phosphoric acid

The inhibition of NaBr on the corrosion of cold rolled steel in 1.0 M phosphoric acid was studied by using weight loss method and polarization method. It was found that the adsorption of bromide ion can prevent steel from corrosion and the adsorption follows the Langmuir adsorption isotherm. Polarization studies showed that NaBr is a mixed-type inhibitor for steel corrosion in 1.0 M phosphoric acid. Thermodynamic parameters such as adsorption heat, adsorption entropy and adsorption free energy were obtained from the experimental data of temperature studies for the inhibition process at four temperatures ranging from 30 to 45°C. The kinetic data such as apparent activation energies and pre-exponential factors at different concentrations of the inhibitor were calculated, and the effects of the apparent activation energy and pre-exponential factor on the corrosion rate of cold rolled steel were discussed. The inhibitive action was satisfactorily explained by using thermodynamic and kinetic models. The results obtained from polarization experiment were in good agreement with those obtained from weight loss measurement.     

Inhibition of Corrosion of Mild Steel in Hydrochloric Acid Solution Using Akee Apple Seed Extract

The inhibiting action of Akee apple (Blighia sapida) seed extract (AASE) on corrosion of mild steel was investigated in 2 M hydrochloric acid solution using weight loss and thermometric measurements. The study was carried out at temperatures of 30 and 60 °C with concentration of inhibitor varied from 0.1 to 0.5 g/l in the acidic medium. The results of the study showed that the corrosion rate of mild steel decreased in the presence of the inhibitor but increased with increase in temperature. The inhibitor exhibited excellent inhibition efficiency on mild steel corrosion as 86.90 and 75.87% of inhibition efficiency were achieved with addition of 0.5 g/l concentration of the inhibitor at 30 and 60 °C temperature, respectively. The inhibitive adsorption parameters established that the AKEE obeyed the Langmuir adsorption isotherm with physical adsorption mechanism and the result of Gibbs free energy of adsorption (?G_ads) revealed an endothermic reaction and spontaneous process of adsorption.     

Synergistic inhibition between OP and NaCl on the corrosion of cold-rolled steel in phosphoric acid

The effects of single OP and the mixture of various concentrations of OP and 0.1 M NaCl on the corrosion of cold-rolled steel in 1.0–3.5 M phosphoric acid have been investigated by using weight loss method and polarization method. This study revealed that cold-rolled steel in phosphoric acid has been more efficiently inhibited by OP in the presence of NaCl than single OP, and inhibition efficiency increases with increasing concentration of OP at the same temperature, but decreases with increasing temperature studied. A synergistic effect exists when OP and chloride ion are used together to prevent cold-rolled steel corrosion in 1.0–3.5 M phosphoric acid at every experimental temperature. The polarization curves showed that OP is a cathodic inhibitor, while the complex of OP and NaCl is a mixed-type inhibitor that mainly inhibits the cathodic corrosion of the steel. The experimental results suggested that the presence of chloride ion in the solution stabilized the adsorption of OP molecules on the metal surface and improved the inhibition efficiency of OP. The adsorption of single OP follows the Langmuir adsorption isotherm, and the adsorption of the complex accords with the Langmuir adsorption isotherm too. Some thermodynamic parameters such as adsorption heat, adsorption entropy and adsorption free energy have been calculated by employing thermodynamic equations. Kinetic parameters such as apparent activation energy and pre-exponential factor have been calculated and discussed. In 1.5–3.5 M phosphoric acid, the concentration pre-exponential factor and acid concentration constant have been calculated, and the synergistic effect has been observed too.     

Adsorption and corrosion inhibition effect of 2-((5-mercapto-1,3,4-thiadiazol-2-ylimino)methyl)phenol Schiff base on mild steel

In this study, the inhibition effect of 2-((5-mercapto-1,3,4-thiadiazol-2-ylimino)methyl)phenol Schiff base (MTMP) on mild steel corrosion in 0.5 M HCl solution was studied. For this aim, electrochemical techniques such as potentiodynamic polarization curves, weight loss (WL), electrochemical impedance spectroscopy (EIS) and linear polarization resistance (LPR) were used. It was shown that, the MTMP Schiff base has remarkable inhibition efficiency on the corrosion of mild steel in 0.5 M HCl solution. Polarization measurements indicated that, the studied inhibitor acts as mixed type corrosion inhibitor with predominantly control of cathodic reaction. The inhibition efficiency depends on the concentration of inhibitor and reaches 97% at 1.0 mM MTMP. The remarkable inhibition efficiency of MTMP was discussed in terms of blocking of electrode surface by adsorption of inhibitor molecules through active centers. The adsorption of MTMP molecules on the mild steel surface obeys Langmuir adsorption isotherm.     

Green approach to corrosion inhibition of mild steel in hydrochloric acid and sulphuric acid solutions by the extract of Murraya koenigii leaves

The inhibition of the corrosion of mild steel in hydrochloric acid and sulphuric acid solutions by the extract of Murraya koenigii leaves has been studied using weight loss, electrochemical impedance spectroscopy (EIS), linear polarization and potentiodynamic polarization techniques. Inhibition was found to increase with increasing concentration of the leaves extract. The effect of temperature, immersion time and acid concentration on the corrosion behavior of mild steel in 1 M HCl and 0.5 M H₂SO₄ with addition of extract was also studied. The inhibition was assumed to occur via adsorption of the inhibitor molecules on the metal surface. The adsorption of the extract on the mild steel surface obeys the Langmuir adsorption isotherm. The activation energy as well as other thermodynamic parameters (Q, ΔH^*, and ΔS^*) for the inhibition process was calculated. These thermodynamic parameters show strong interaction between inhibitor and mild steel surface. The results obtained show that the extract of the leaves of M. koenigii could serve as an effective inhibitor of the corrosion of mild steel in hydrochloric and sulphuric acid media.     

Corrosion inhibition of mild steel in hydrochloric acid solution by methylene blue dye

The corrosion inhibition of mild steel in hydrochloric acid solution by methylene blue dye (MB) was investigated by gravimetric techniques at 30 and 60 °C as well as thermometric technique. MB was shown to be an inhibitor in the acidic corrodent. Inhibition efficiency increased with MB concentration but decreased with rise in temperature, with maximum value of 94–95% obtained for 5.0 mM MB at 30 °C. Corrosion inhibition is attributed to the adsorption of MB on the mild steel surface via a physical adsorption mechanism. These results were further corroborated by kinetic and activation parameters for corrosion and adsorption processes evaluated from experimental data.     

Corrosion inhibition of mild steel using naphthalene disulfonic acid

The corrosion inhibition of mild steel is the subject of tremendous technological importance due to the increased industrial applications of this material. This paper reports the results of mass loss and potentiodynamic polarization measurements on the corrosion inhibition of mild steel in 0.5 M H₂SO₄ in the temperature range 30–60 °C using sodium naphthalene disulphonic acid (NDSA) as an inhibitor. The inhibition efficiency increased with the increase in concentration of NDSA till a critical value which is independent on temperature. The adsorption of inhibitor at 30 °C followed Flory–Huggins adsorption isotherm and the value of standard free energy of adsorption suggests that it is chemisorption.