Gemini表面活性剂乙烷基-α,ω-双十四烷基二甲基溴化铵产生的高稳定泡沫

摘要

报道了由gemini表面活性剂乙烷基-α,ω-双十四烷基二甲基溴化铵(14-2-14)产生的高稳定泡沫体系泡沫塌陷到初始高度一半所对应的时间(t1/2)用来表征泡沫的稳定性.测得14-2-14体系的t1/2高达961 min,远大于乙烷基-α,ω-双十二烷基二甲基溴化铵(12-2-12)产生泡沫的t1/2(754 min),表明带有一根短联接链和两条长尾链的gemini表面活性剂是高效的泡沫稳定剂.为了揭示界面弹性与泡沫稳定性之间的关联,测量了表面活性剂吸附膜的扩张流变行为.在指定的表面过剩量下,吸附膜的高频极限弹性再一次被发现与泡沫稳定性相关,较大的极限弹性很好地对应更加稳定的泡沫.%This paper reports a highly stable foam system generated by the gemini surfactant ethanediylα,ω-bis(tetradecyldimethylammonium bromide) (referred to as 14-2-14).The time measured for the collapse of the foam to half its initial height was used to characterize the foam stability; it was as high as 961 min for this system and significantly longer than that (754 min) for ethanediyl-o,ω-bis(dodecyldimethylammonium bromide) (12-2-12) foams.Thus the gemini surfactant structure of a short spacer together with two long tails enabled it to be a highly efficient foam stabilizer.The dilational rheology of the adsorbed films revealed the relationship between the interfacial elasticity and the foam stability.The high-frequency limit of elasticity of the adsorbed film at a specific surface coverage was again found to indicate foam stability.A larger limit of elasticity indicated a more stable foam.