题目：Stimuli-responsive Particles Crossing Interfaces

主讲嘉宾：汪大洋教授 (澳大利亚墨尔本皇家理工大学)

讲座时间：2015年12月22日（周二）9:00

讲座地点：国工楼B3112 

欢迎有兴趣的师生前来聆听！

化学与材料工程学院嘉宾简介：王大洋，澳大利亚墨尔本皇家理工大学化学与工程学院教授，皇家化学会会士。2010年至2015年于南澳大利亚大学Ian Wark研究所任物理化学方向研究教授；2003年至2010年于德国马普胶体与界面研究所（Max Planck Institute of Colloids and Interfaces）工作。汪大洋教授在表界面、结晶、自组装、水凝胶以及包埋与释放等研究领域均有较高的造诣，目前撰写专著4本，发表文章120余篇（其中Angew. Chem. 12篇），文章被引用次数多达4,800余次，个人H因子40。 摘要：本报告将介绍纳米粒子穿越水-油界面的研究。利用刺激响应性聚合物对纳米粒子表面进行修饰，在离子强度、pH值或温度等环境因素刺激下，纳米粒子可以响应性越过油水界面，从水相进入油相或从油相进入水相。这种响应性水-油界面穿越行为主要依取决于纳米粒子表面的聚合物刷与水分子间的氢键作用。实验结果和理论研究表明，粒子由水相进入油相的行为与其表面聚合物刷的刺激响应性相关，而由油相进入水相的行为与两相界面上水分子结构有关。粒子从不同方向穿越水-油界面的机理可以帮助我们更好地解释与理解相转变行为。 

This talk will highlight our recent study of nanoparticle (NP) crossing oil/water interfaces. By anchoring stimuli-responsive polymer brushes on their surfaces, NPs can readily transfer between water and oil across oil/water interfaces in response to the environmental change in ionic strength, pH, and temperature for instance. This NP crossing interfaces is obviously associated with the hydration and de-hydration of the NP polymer brush coating, which is determined dominantly by the hydrogen bonding of the polymer brushes with water. Careful experimental and theoretical studies reveal that the water-to-oil NP transfer is correlated directly with the stimuli response of the polymer brushes anchored on the NPs, but the oil-to-water NP transfer mainly with the water structure at the oil/water interfaces. The revealed transfer mechanism disparity for the two directions during NP crossing oil/water interfaces should provide a better thermodynamic picture to describe phase transfer.