两性离子聚合物防污机制的多尺度模拟研究

生物污损已经成为海洋科学等学科的重要问题，造成大量经济损失。通过以两性离子为代表的材料对表面进行修饰有较好的防污效果，但是其防污机理例如分子结构和防污性能的关系，以及不同组分的相互作用，目前仍不清晰。通过分子模拟，可以研究两性离子及其聚合物防污的微观机制，但现阶段的模拟主要局限于较小尺度的全原子模拟，很难观察两性离子及其聚合物对一定数量蛋白质的防污机制。为了突破模拟尺度限制，本项目拟以MARTINI粗粒化力场为基础，建立并发展两性离子及其聚合物的粗粒化模型，并结合全原子模拟构成多尺度模拟的框架，探索两性离子及其聚合物在材料表面防污的性能和机理。重点研究两性离子及其聚合物抗蛋白质吸附的热力学机理，分子组成、分子量、拓扑结构、接枝密度等因素对其抗蛋白质吸附的影响。所得研究结果对阐明两性离子聚合物分子拓扑结构、热力学相互作用对其防污的影响机制具有重要意义，并为相关防污材料的分子设计提供理论依据。

Biofouling has been a crucial problem in many research areas, like marine science and so on, and it causes extreme economic penalties. Zwitterions are excellent representative materials for antifouling application, but the underlying mechanisms, for instance, the relationship between molecular topology and antifouling performance, as well as the interactions between different components, are still ambiguous. The microscopic mechanisms of zwitterions antifouling could be investigated using molecular simulations, but most of the current studies are atomistic scale level, which is difficult to study the adsorption of many proteins on the surfaces with zwitterions and polyzwitterions, due to the time scale and length scale limits. To overcome the challenge, we are going to utilize coarse-grained simulation technique in this project, which is based on MARTINI force field, to construct the coarse-grained model of zwitterions and polyzwitterions, and build the multiscale simulation framework by combining atomistic simulations. We will investigate the thermodynamic mechanism for the antifouling of zwitterions and polyzwitterions, as well as their antifouling performances under different compositions, molecular weights, molecular topologies and grafting densities. We hope the outcome of this project will clarify the influence from molecular topologies, thermodynamic mechanism of polyzwitterions on their antifouling performance, and serve as a promising design of corresponding antifouling materials.