DDA在硫酸介质中的存在状态与缓蚀行为的关系

利用电化学方法、物理检测技术及表面分析技术，针对十二烷基胺（DDA）作用于FeNiSiB非晶合金表面时，在不同浓度范围内，缓蚀效率与缓蚀剂浓度存在不同的对应关系的现象，探讨了DDA的存在状态与其缓烛行为的关系．利用物理测量技术对临界浓度前后DDA的存在状态进行了分析，利用扫描隧道显微镜捕获了高浓度时DDA在非晶合金表面的典型结构，详细阐述了DDA对非晶合金的微观缓蚀机制．     

磷酸溶液中DDA在锌表面的吸附及其缓蚀作用

采用失重法及电化学法研究了锌在含或不含十二烷基胺（DDA）的磷酸溶液中的腐蚀作用，得出相应的动力学方程，求得有关的动力学及热力学参数.用光电子能谱（XPS）检测发现，在40～70 ℃区间，锌在磷酸溶液中生成Zn(OH)x覆盖层，表现出较强的自缓蚀效果，而在30～40 ℃区间，因DDA以及, 等微粒同时吸附在锌表面，DDA在磷酸溶液中表现出较强的缓蚀作用.用吸附理论讨论了这种缓蚀作用产生的原因.     

DDA在碱酸介质中的存在状态与缓蚀行为的关系

利用电化学方法、物理检测技术及表面分析技术，针对十二烷基胺（ＤＤＡ）作用于ＦｅＮｉＳｉＢ非晶合金表面时，在不同浓度范围内，缓蚀效率与缓蚀剂２在不同的对应关系的现象、探讨了ＤＤＡ的存在状态与其缓蚀行为的关系，利用物理测量技术对临界浓度前后ＤＤＡ的存在状态进行了分析，利用扫描隧道显微镜捕获了高浓度时ＤＤＡ在非晶合金表面的典型结构，详细阐述了ＤＤＡ对非晶合金的微观缓蚀机制。     

两种席夫碱缓蚀剂对碳钢材料的缓蚀性能探究

采用了电化学方法研究了2种席夫碱缓蚀剂水杨醛基邻苯甲酸亚胺(SB-I)和N,N’-二水杨醛基-1,2-邻苯二亚胺(SB-II)在1 mol/L盐酸溶液中对20#碳钢的缓蚀性能。通过极化曲线和交流阻抗谱研究该席夫碱对碳钢的缓蚀效果表明:席夫碱对碳钢材料具有良好的缓蚀作用,其最大缓蚀率可达到83%。研究了席夫碱在碳钢表面的吸附模式,结果表明,席夫碱在碳钢表面上的吸附吉布斯自由能在-30 kJ/mol之间,表现为混合型缓蚀剂,即通过化学吸附和物理吸附之间的一种混合吸附在碳钢工作电极的表面,通过抑制、阻止延缓金属的电化学过程而起到缓蚀的作用。另外,实验还发现,SB-I比SB-II具有更好的缓蚀性能,该实验结果与理论计算结果相符合。     

阴/阳离子型表面活性剂对A3碳钢缓蚀的协同效应

采用电化学方法、静态失重法和观察法研究了阳离子双子表面活性剂(12-2-12)和阴离子表面活性剂十二烷基苯磺酸钠(SDBS)及其复合体系在1M HCl溶液中对A3碳钢的缓蚀性能。研究结果表明:二者具有很好的离子协同效应,在较低浓度下即具有很好的缓蚀效果,属于阴极/阳极混合型抑制剂,当二者复合摩尔比为1:0.8时,协同效应最佳,缓蚀率达到99.9%。通过实验所得数据对其缓蚀机理进行推导,结果表明其缓蚀机理符合Langmuir吸附模型。     

向日葵盘果胶对碳钢的缓蚀性能研究

以向日葵盘为原料,利用纤维素酶制备果胶(SFP)。采用静态失重、极化曲线和交流阻抗技术研究SFP在1mol/L HCl及0.5mol/L H_2SO_4溶液中对碳钢的缓蚀性能,并探讨其在碳钢表面的吸附机理。结果表明,缓蚀效率随SFP浓度增大而增大,随温度升高而降低。在HCl和H_2SO_4溶液中,SFP的吸附方式分别服从Langmuir和Temkin等温式,属于物理吸附;极化曲线测试显示SFP是一种混合型缓蚀剂。本文的研究表明,向日葵盘果胶是碳钢的绿色高效缓蚀剂,且在HCl溶液中的缓蚀性能优于在H_2SO_4溶液中。     

曲唑酮的两步法制备及对碳钢的缓蚀机理

以3-氯苯胺、N-氯丙基二乙醇胺和吡啶三唑酮为原料,两步法制备出曲唑酮（TZD）.通过动态失重、极化曲线与电化学阻抗谱研究了TZD在0.5 mol/L盐酸溶液中对20#钢的缓蚀性能;借助扫描电子显微镜、原子力显微镜、衰减全反射红外光谱与吸附活化参数分析研究了TZD在碳钢表面的作用机理.结果表明,TZD可显著降低碳钢在盐酸溶液中的腐蚀速率,缓蚀率随TZD添加浓度的增加而增大,随温度升高而降低;298 K下,添加6 mmol/L TZD时,缓蚀率达95.8%;TZD可自发吸附组装于碳钢表面,同时抑制腐蚀反应的阴、阳极过程,显著增加界面极化阻抗;吸附为放热过程,符合Langmuir等温式.理论计算结果显示,TZD倾向以平行取向组装于碳钢表面.     

盐酸中十二烷基硫酸钠在铝表面的吸附及缓蚀性能

采用失重法、动电位极化曲线、电化学阻抗谱(EIS)和扫描电子显微镜(SEM)系统研究了1.0 mol·L^-1 HCl中阴离子表面活性剂十二烷基硫酸钠(SDS)在铝表面的吸附及缓蚀性能。结果表明:SDS对铝的腐蚀产生显著减缓作用,20℃时最高缓蚀率可达99.0%,缓蚀率随SDS浓度的增大而上升,但随温度的上升而下降。SDS在铝表面的吸附符合Langmuir等温式,吸附方式为包含物理作用和化学作用的混合吸附。添加SDS后,表观活化能、表观活化焓、表观活化熵均增大。动电位极化曲线表明SDS为抑制阴极为主的混合抑制型缓蚀剂;Nyquist图谱在高频区为弥散容抗弧,在低频区呈感抗弧,添加SDS后铝的电荷转移电阻增加,但铝/溶液界面的常相位角元件数值下降。SEM表明SDS有效抑制了铝表面在HCl的腐蚀,使铝表面的粗糙程度急剧下降。     

绿色聚天冬氨酸复配缓蚀剂对A3碳钢的缓蚀抑雾作用

采用失重法和极化曲线法研究了聚天冬氨酸(PASP)和十二烷基酚聚氧乙烯醚(OP-10)复配对A3碳钢在6mol·L-1HCl腐蚀介质中的协同吸附行为及缓蚀抑雾作用.结果表明:复配缓蚀剂可有效抑制A3碳钢在HC1介质中的腐蚀,当PASP浓度为20g·L-1,缓蚀率可达94%,抑雾率83%;随着温度的升高,复配缓蚀剂的缓蚀性能下降.复合缓蚀剂在钢表面的吸附符合校正的Langmuir模型,吸附过程为放热、熵减的自发过程;复配体系属于阳极型缓蚀剂.     

Effect of pH Value on the Adsorption Behavior and Inhibition Mechanism of Dodecylamine on Carbon Steel

The effect of pH value on the adsorption behavior and inhibition mechanism of dodecylamine for carbon dioxide corrosion of carbon steel was investigated by electrochemical methods and scanning electron microscopy (SEM). The results indicated that the pH value of the solution played the crucial role to the adsorption behavior and inhibition mechanism of dodecylamine. The inhibition performance of dodecylamine on carbon steel was dependent on the pH value and the inhibition efficiency increased with the increase of pH value. At pH 4.9, dodecylamine mainly inhibited the cathode process of the corrosion. The adsorption energy of dodecylamine on the metal surface was lower. The adsorption of dodecylamine on the metal surface was not stable and an anode desorption phenomenon could be observed. Hence, dodecylamine did not provide effective inhibition to the corrosion. While at pH 6.9, it had much higher adsorption energy. Dodecylamine adsorbed on the metal surface tightly and formed the effective diffusion barrier which inhibited both the cathode and anode processes effectively.     

Effect of pH and Temperature on Adsorption of Dimethyl Phthalate on Carbon Nanotubes in Aqueous Phase

Adsorptions of dimethyl phthalate (DMP) on carbon nanotubes (CNTs) in aqueous phase at various pH and temperatures were studied. The increase in pH results in the increase in adsorption coefficient. The adsorption is governed by the π-π electron interaction which is affected by the changes in pH of the medium. The outer diameter of the CNTs greatly influences the adsorption behavior of CNT for DMP. Under the same working temperature, the adsorption capacity of CNTs for DMP is inversely related to the average outer diameter of the CNT: single-walled SWCNT (1.4 nm)>multi-walled MWCNT10 (9.4 nm)>MWCNT30 (27.8 nm)>MWCNT40 (42.7 nm). The larger surface area of CNTs provides many active sites for adsorption of DMP molecules. The Freundlich model can describe well the adsorption isotherms of DMP on CNTs. The thermodynamic parameters of standard free energy, standard enthalpy (ΔH), and standard entropy changes are determined, showing that the adsorption of DMP on CNTs is an endothermic and spontaneous reaction. The ΔH value of 27.8 nm-sized MWCNT (22.69 kJ/mol) is higher than 1.4 nm-sized SWCNT (6.05 kJ/mol), inferring that the adsorption process becomes more endothermic with the increase in the outer diameter of CNTs.     

二氧化碳在金属-有机骨架材料中吸附的阶梯现象

采用巨正则系综蒙特卡罗(GCMC)模拟方法, 对二氧化碳在5种具有相同拓扑结构的金属-有机骨架材料(IRMOFs), 即IRMOF-1, -8, -10, -14, -16中吸附产生的阶梯现象进行了详细的研究. 结果表明: 低温条件下, 孔径越大的IRMOFs越容易发生阶梯现象; 发生阶梯现象的转变压力与能够发生阶梯现象的转变温度都与孔径呈线性关系. 此外, 模拟结果进一步验证了二氧化碳分子之间的静电作用力是阶梯现象发生的关键因素. 这些规律将为金属-有机骨架材料(MOFs)的设计和改性以及二氧化碳在混合气体中的吸附分离提供有用的信息.     

酸性介质中羧甲基纤维素钠在低碳钢表面的吸附和缓蚀作用

The effect of sodiumcarboxymethyl cellulose (Na-CMC) on the corrosion behavior of mild steel in 1.0 mol·L-1 HCl solution has been investigated by using weight loss (WL) measurement, potentiodynamic polarization, linear polarization resistance (LPR), and electrochemical impedance spectroscopy (EIS) methods. These results showed that the inhibition efficiency of Na-CMC increased with increasing the inhibitor concentration. Potentiodynamic polarization studies revealed that the Na-CMC was a mixed type inhibitor in 1.0 mol·L-1 HCl. The adsorption of the inhibitor on mild steel surface has been found to obey the Langmuir isotherm. The effect of temperature on the corrosion behavior of mild steel in 1.0 mol·L -1 HCl with addition of 0.04% of Na-CMC has been studied in the temperature range of 298-328 K. The associated apparent activation energy (E*a) of corrosion reaction has been determined. Scanning electron microscopy (SEM) has been applied to investigate the surface morphology of mild steel in the absence and presence of the inhibitor molecules.     

Adsorption Behavior and Inhibition Corrosion Effect of Sodium Carboxymethyl Cellulose on Mild Steel in Acidic Medium

The effect of sodium carboxymethyl cellulose (Na-CMC) on the corrosion behavior of mild steel in 1.0 mol·L-1 HCl solution has been investigated by using weight loss (WL) measurement, potentiodynamic polarization, linear polarization resistance (LPR), and electrochemical impedance spectroscopy (EIS) methods. These results showed that the inhibition efficiency of Na-CMC increased with increasing the inhibitor concentration. Potentiodynamic polarization studies revealed that the Na-CMC was a mixed type inhibitor in 1.0 mol·L-1 HCl. The adsorption of the inhibitor on mild steel surface has been found to obey the Langmuir isotherm. The effect of temperature on the corrosion behavior of mild steel in 1.0 mol·L-1 HCl with addition of 0.04% of Na-CMC has been studied in the temperature range of 298-328 K. The associated apparent activation energy (E*a ) of corrosion reaction has been determined. Scanning electron microscopy (SEM) has been applied to investigate the surface morphology of mild steel in the absence and presence of the inhibitor molecules.     

Adsorption Behavior and Inhibition Corrosion Effect of Sodium Carboxymethyl Cellulose on Mild Steel in Acidic Medium

The effect of sodium carboxymethyl cellulose (Na-CMC) on the corrosion behavior of mild steel in 1.0 mol·L⁻¹ HCl solution has been investigated by using weight loss (WL) measurement, potentiodynamic polarization, linear polarization resistance (LPR), and electrochemical impedance spectroscopy (EIS) methods. These results showed that the inhibition efficiency of Na-CMC increased with increasing the inhibitor concentration. Potentiodynamic polarization studies revealed that the Na-CMC was a mixed type inhibitor in 1.0 mol·L⁻¹ HCl. The adsorption of the inhibitor on mild steel surface has been found to obey the Langmuir isotherm. The effect of temperature on the corrosion behavior of mild steel in 1.0 mol·L⁻¹ HCl with addition of 0.04% of Na-CMC has been studied in the temperature range of 298–328 K. The associated apparent activation energy (E^*_a) of corrosion reaction has been determined. Scanning electron microscopy (SEM) has been applied to investigate the surface morphology of mild steel in the absence and presence of the inhibitor molecules.     

溶液的pH值对纳米CeO2晶粒形貌及形成机制的影响

以亚硝酸铈盐和氨水沉淀法合成了二氧化铈纳米粒子. 通过对溶液pH值的调节制备出了形貌各异的纳米CeO2晶粒. TEM和BET结果表明 酸性条件下, 得到的是球形的纳米CeO2晶粒且其比表面为148.1944 m2·g-1;中性时, CeO2晶粒的形貌为球形和棒状的混合形, 比表面为114.7975 m2·g-1;而碱性环境下, 易得到棒状的、比表面为106.2465 m2·g-1 的CeO2晶体. 另外还对各种形貌产物的形成机制进行了研究.     

硫酸溶液中1,1'-硫代羰基二咪唑在碳钢上的吸附及缓蚀影响和碘离子的增强应

The inhibition effect of 1,1'-thiocarbonyldiimidazole (TCDI) on the corrosion behaviors of mild steel impedance spectroscopy(EIS),and linear polarization resistance(LPR)techniques.The effect of immersion time on the inhibition effect of TCDI was also investigated over 72 h.For the long.term tests.hydrogen evolution with immersion time(VH2-t)was measured in addition to the three techniques already mentioned.The thermodynamic parameters.such as adsorption equilibrium constant(Kads) and adsorption free energy(△Gads)values,were calculated and discussed.To clarify inhibition mechanism,the synergistic effect of iodide ion was also investigated.The potential of zero charge (PZC)of the MS was studied by electrochemical impedance spectroscopy method.and a mechanism of adsorption process was proposed.It was demonstrated that inhibition efficiency increased with the increase in TCDI concentration and synergistically increased in the presence of KI.The inhibition efficiency was discussed in terms ofadsorption of inhibitormolecules on the metal surface and protective film formation.     

缓蚀剂吸附行为的电化学及AFM力曲线研究

结合极化曲线,微分电容曲线测试和AFM力曲线技术研究了直链十二胺对氯化钠溶液中铜镍合金的缓蚀行为以及吸附机理。结果表明:十二胺在合金表面形成单分子层吸附膜而起到缓蚀作用。十二胺浓度越大,吸附膜越致密,缓蚀率越高,力曲线上测得的粘附力值也越大。质子化的十二胺在荷负电的合金表面的吸附使电极零电荷电位正移,电荷屏蔽作用使得AFM力曲线上探针与试样之间的长程静电斥力减小。     

硫酸溶液中1,1’-硫代羰基二咪唑在碳钢上的吸附及缓蚀影响和碘离子的增强效应

The inhibition effect of 1,1’-thiocarbonyldiimidazole (TCDI) on the corrosion behaviors of mild steel (MS) in 0.5 mol·L -1 H2SO4 solution was studied with the help of potentiodynamic polarization, electrochemical impedance spectroscopy (EIS), and linear polarization resistance (LPR) techniques. The effect of immersion time on the inhibition effect of TCDI was also investigated over 72 h. For the long-term tests, hydrogen evolution with immersion time (VH2-t) was measured in addition to the three techniques already mentioned. The thermodynamic parameters, such as adsorption equilibrium constant (Kads) and adsorption free energy (⊿Gads) values, were calculated and discussed. To clarify inhibition mechanism, the synergistic effect of iodide ion was also investigated. The potential of zero charge (PZC) of the MS was studied by electrochemical impedance spectroscopy method, and a mechanism of adsorption process was proposed. It was demonstrated that inhibition efficiency increased with the increase in TCDI concentration and synergistically increased in the presence of KI. The inhibition efficiency was discussed in terms of adsorption of inhibitor molecules on the metal surface and protective filmformation.