醋酸十二铵的吸附和SiO2悬浮液的稳定性

（1）测定了醋酸十二烷基铵（DAA）在CAB－O－SIL上的吸附，其等温线属双平台或LS型[1－3，5]；（2）NaCl的存在使DAA的吸附增加．但不影响其低浓度下第一平台的吸附量；HCl的存在则在全浓度范围内抑制了DAA的吸附，（3）测定了CAB－O－SIL颗粒在上述各溶液中的悬浮液的稳定性；（4）根据表面形成小胶团的吸附理论（即二步模型产）[2，3，5，]，并借助电导跟踪溶液中发生的变化，满意地解释了吸附和聚沉的实验结果．

Effects of Adsorption and Surface Micellization of Dodecylammonium Acetate on the Stability of Silica Suspension

(1) The adsorption of dodecylammonium acetate (DAA) on CAB-O-SIL has been investigated, the adsorption isotherm of DAA shows two plateaus (i.e. LS-type).(2) The addition of sodium chloridc increases the adsorption of DAA, but no significant change can be found in the first plateau at low concentrations; while the addition of hydrochloricacid decreases the adsorption of DAA in the experimental concentration region. (3) The stability of CAB-O-SIL suspension has been determined for the corresponding solutions.(4)Based on the two-step model of the surfactant adsorption theory proposed previously,and with the aid of conductivity measurements, the coagulation regularity of CAB-O-SILsuspension can be explained satisfactorily.