摘要
通过实验对不同温度条件下半胱氨酸抑制盐酸对碳钢腐蚀的性能进行评价,并采用分子动力学模拟(Molecular Dynamics Simulation,简称MD)方法,从缓蚀剂膜抑制腐蚀粒子扩散的角度对其缓蚀机理进行深入研究.静态失重实验显示:随温度的升高(25～65℃),半胱氨酸缓蚀剂的缓蚀效率呈逐渐下降趋势,其数值从88.36%降至61.64%.MD模拟发现:随温度升高,半胱氨酸缓蚀剂膜的自由体积逐渐增大,且腐蚀粒子与缓蚀剂膜的相互作用也逐渐减弱,更有利于腐蚀粒子在膜中的主动扩散;同时膜内半胱氨酸分子的自扩散能力也随温度升高而增强,腐蚀粒子在缓蚀剂膜携带下被动迁移的过程也随之加剧.主动扩散和被动迁移两方面的变化表明,腐蚀粒子在缓蚀剂膜中扩散能力随温度升高而增大;也就是说,随温度升高,半胱氨酸缓蚀剂膜对腐蚀粒子的扩散抑制能力逐渐降低,腐蚀粒子更易扩散运移至金属表面,导致半胱氨酸缓蚀剂缓蚀效率的降低.
The inhibition performance of cysteine for carbon steel of hydrochloric acid corrosion under various temperatures was evaluated by experiments. And the inhibition mechanism was explored by investigation of diffusion inhibition of corrosive particles by inhibitor membrane through molecular dynamics （MD） simulation. Results of static weight-loss experiments indicated that the inhibition efficiency of cysteine decreased from 88.36% to 61.64%, with the increase of temperature from 25 to 65 ℃. MD simulations showed that the free volume of cysteine membrane increased, and the interaction between corrosive particles and inhibitor membrane weakened, with the increase of temperature. While the self-diffusion of cysteine molecules within the membrane increased with temperature rise, and the passive diffusion of corrosive particles by inhibitor membrane enhanced. Analysis of both active and passive aspect of diffusion process reveals that the diffusion ability of corrosive particles in inhibitor membrane increases with temperature. And with temperature rise, the inhibitive efficiency of cysteine membrane for corrosive particles decreases, and diffusion of these particles could be facilitated, which results in decrease of inhibition performance of cysteine.
出处
《化学学报》
SCIE
CAS
CSCD
北大核心
2010年第18期1807-1812,共6页
Acta Chimica Sinica
基金
中国石油中青年创新基金(Nos.07E1021和2008D-5006-02)
山东省自然科学基金(No.Y2006B35)资助项目
关键词
半胱氨酸
缓蚀效率
失重法
分子动力学模拟
扩散系数
cysteine
inhibition efficiency
weight-loss method
molecular dynamics simulation
diffusion coefficient
