十二烷基苯磺酸钠在纳米CaCO_3表面的吸附

Adsorption of sodium dodecylbenzenesulfate on nano-sized CaCO_3

为了更好地分析十二烷基苯磺酸钠(SDBS)作为分散剂时纳米CaCO3在水中分散的机制,研究水性体系中SDBS在纳米CaCO3表面的吸附情况。采用紫外可见分光光度法测定SDBS在纳米CaCO3表面的吸附量,讨论吸附SDBS后分散体系Zeta电位的变化,研究吸附的稳定性。实验结果表明:SDBS在纳米CaCO3表面的吸附量随着SDBS溶液质量浓度的增大而增加,当质量浓度大于2 g/L时,吸附达到饱和吸附;pH值对吸附量有一定影响,pH=7时的吸附量大于pH=11时的吸附量;吸附SDBS后,分散体系的Zeta电位有很大变化;SDBS在纳米CaCO3表面的吸附是一个自发过程,吸附比较稳定。

The adsorption of sodium dodecylbenzenesulfate （SDBS） on nano-sized CaCO3 in aqueous system was studied so as to＇further analyze the dispersing mechanism of the nano-sized CaCO3 in aqueous system with SDBS as dispersant. The adsorption amount of SDBS on ＂nano-sized CaCO3 was determined by using UV/VI spectrometry. The change of Zeta potential of dispersion after adsorption of SDBS and the stability of adsorption were discussed. The experimental results showed that the adsorption amount of SDBS on nano-sized CaCO3 increased with increasing the concentration of SDBS solution and reached saturated adsorption when the concentration exceeded 2 g/L. pH value had an impact on the adsorption amount and the amount of adsorption at pH = 7 was larger than that at pH = 11. After SDBS was adsorbed on nano-sized CaCO3, a great change of Zeta potential of the dispersion was observed. The adsorption of SDBS on nano-sized CaCO3 was a spontaneous process and this adsorption was rather stable.