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(英文)

Highly Stable Foams Generated by the Gemini Surfactant Ethanediyl-α,ω-bis(tetradecyldimethylammonium bromide)

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961min,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(754min),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 ethanediyl-α,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-α,ω-bis（dodecyldimethyl-ammonium 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.