稠油组分与十二烷基苯磺酸钠相互作用对油水界面Zeta电势的影响

考察了阴离子乳化剂十二烷基苯磺酸钠(LAS)质量分数、水相pH等因素对稠油及其组分油水界面Zeta电势的影响,并初步探讨了稠油组分与阴离子乳化剂的协同作用。研究表明,孤岛、辽河两种稠油及其胶质、沥青质组分油水界面Zeta电势绝对值,随着LAS质量分数的增加先增大后减小,在质量分数为0.1%附近出现最大值,绝对值大于120 mV。在强酸强碱条件下,Zeta电势受pH影响较大,其绝对值大幅度降低,低于80 mV,体系的电稳定性较差。pH=4~10的中性及弱酸弱碱条件下,LAS在界面上吸附能力减弱,稠油及其极性组分能够竞争吸附在界面上,与LAS发生相互作用,表现出较强的协同作用效应,使Zeta电势绝对值增大至高于120mV,体系的电稳定性明显增强。

Influence of the Interaction between Heavy Crude Oil Components and LAS on Zeta Potential of Oil-water Interface

Influences of the concentration and pH of LAS neopelex on Zeta potential of simulated oil-water interface of heavy crude oil and its polar components were studied by using electrophoreic method.The influences of the synergetic effect between the polar components and anionic emulsifier on Zeta potential were also investigated.The results showed that,with the increasing concentration of LAS,the absolute values of Zeta potential of the simulated oil increased firstly and then decreased.When the LAS mass fraction was 0.1%,the absolute values of Zeta potential was maximizing,as high as 120 mV.In the strong acidic and alkaline conditions,the influence of pH on the Zeta potential of oil-water interface is stronger,the absolute values sharply decrease(less than 80 mV),and the stability of the oil-water system is decreased.In the neutral,weak acidic and weak basic conditions,as the adsorptive capacity of LAS on the interface decreases,the heavy crude and its polar components are adsorbed competitively on the interface,and strong synergetic effect between the polar components and LAS exhbits,which enhances the absolute value of Zeta potential(higher than 120 mV),and electrical stability of the system increases obviously.