棒状病毒的高分子刷修饰及其液晶行为研究

项目名称： 棒状病毒的高分子刷修饰及其液晶行为研究

项目编号： No.21274067

项目类型： 面上项目

立项/批准年度： 2013

项目学科： 数理科学和化学

项目作者： 张珍坤

作者单位： 南开大学

项目金额： 80万元

中文摘要： 多尺度自组装结合活性聚合方法催生了许多结构各异的蠕虫状聚合物纳米粒子（HPN）如聚合物分子刷，其结构特征就是在柔性的有机软物质骨架上接枝有不同密度的高分子刷。由于能够实现分子级别上的结构调控，这类粒子预期有着丰富的溶致液晶行为。 但当前对这类行为的研究处于停滞状态，主要是由于实验模型的缺乏。我们拟以单分散的棒状病毒fd为骨架，在其表面引入不同结构的高分子刷，构建一类尺寸单一和结构确定的HPN模型。利用fd病毒本身超螺旋结构对表面化学改性的敏感性，探讨高分子刷的结构特征如接枝密度、嵌段聚合物刷的塌缩、混合高分子刷构建的疏水微区等对病毒的构象和粒子之间相互作用的影响。通过测量液晶相转变点、胆汁型液晶的指纹结构和螺距等宏观参数， 并结合散射技术来考察高分子刷的结构如何影响HPN的液晶相行为。 本研究有望理解和预测液晶基元与液晶相微观结构之间的关系，以便构建基于HPN的具有不同规整结够的液晶材料。

中文关键词： 高分子接枝；聚合物分子刷；病毒；手性液晶；自组装

英文摘要： Shaped hairy polymer nanoobjects (HPNs) consist of a soft organic backbone, onto which polymer brushes are grafted. One of the classical examples is the so-called cylindrical molecular brush,with a linear or branched polymer as the backbone and terminally tethered polymers as the brush. Due to their worm-like conformation and possibilies to tune the structure on the molecular level, HPNs are expected to exibit rich lyotropic liquid crystal phases (LC). However, systematic invesitigation on such topic is rare, compared to tremendous reports on the fabrication of such objects in the literature. The reason is that there is no reliable and well-defined model system. In this project, we shall construct such system based on a rodlike fd virus. The fd virus has a length of 880 nm and a diameter of 6 nm and mainly consists of a protein capsid. On the surface of the fd virus, there are many functonal groups available for chemical modifications. We plan to use the fd viruses as the backbone and graft them with varied kinds of polymers, resulting in several classical model systems bearing thermoresponsive block polymers, or mixed brush of two dissimilar polymers, and densyly grafted homopolymers. Using the LC of the native virus as the reference, the influence of several characateristics of the grafted polymers on the

英文关键词： Polymer grafting；polymeric brush；Virus；Chiral liquid crystal；self-assembly