两亲性分子聚集体的相变及其协同性

两亲性分子聚集体是一类重要的软物质,它们有着丰富而复杂的相行为.本文主要从两个方面综述了作者所在的研究组在两亲性分子聚集体相变研究方面的工作进展.(1)磷脂相关体系相变热力学:归纳了多种小分子(二甲基亚砜、甘油、海藻糖、尿素等)对于磷脂体系相行为的调控,比较并讨论了固醇类分子和葡萄糖神经酰胺分子诱导磷脂分子形成液态有序相的能力,还介绍了计算机模拟磷脂相行为的工作进展.(2)两亲性分子聚集体相变的协同性:先介绍了相变协同性(即分子头部、尾部、界面等基团在相变过程中的一致性)问题的提出,然后通过双十八烷基二甲基溴化铵分子和硬脂酰溶血卵磷脂两个体系的研究实例,说明两亲性分子聚集体相变过程中存在着头尾不一致的现象.对这个问题的研究,将为我们打开挑战相态转变的一系列重大问题(如相变动力学、相态多型性、相态稳定性以及相变可逆性等)的新窗口.

Phase transitions and the molecular cooperativity in amphiphilic aggregates

Amphiphilic aggregates are a family of soft matter.They have very rich phase behavior.In this mini-review,we summarized the research progress in our group.（1） Phase transitions of phospholipid-related systems.We summarized the modulation effects of small cosolutes such as dimethylsulfoxide,glycerol,trehalose,urea,etc,on the phase behavior of phospholipids,discussed and compared the abilities of different sterols in inducing stable liquid-ordered phase in lipid bilayers,and addressed the possibility of glucocerobroside in inducing a stable quasi-crystalline phase in phosphatidylethanolamine.Computing simulation results of the phase behavior of a number of lipid systems have also been described.（2） The cooperativity of the phase transitions of amphiphilic aggregates.First,a rational is given to the possible existence of nonsynchronicity of different groups in the amphiphilic aggregates.Then two examples including dioctadecyldimethylammonium bromide and 1-stearoyllysophosphatidylcholine systems were given to demonstrate the existence of the nonsynchronicity phenomenon.The study on the cooperativity of phase transitions could open a new window to understand a series of important questions such as the reversibility of the phase transitions in amphiphiles.