中文摘要：

Janus材料集成不同组成/功能于一体,具有明确的空间分区特征,是一类特殊的高分子复合功能材料.有机高分子链提供亲水/亲油及响应特性,无机组成提供丰富的光、电、磁、热等功能性.两亲性的Janus材料在高效稳定界面同时,还能赋予界面功能性并可在外场作用下实现操控.本文重点总结了不同结构和功能的Janus材料在稳定界面和调控界面的近期主要进展,包括聚集行为、固体乳化剂、界面增容、界面催化、功能涂层、细胞诊断与治疗等方面.

英文摘要：

Janus is named after the Roman god who is depicted to have two opposite faces looking at the past and the future. In 1991, de Gennes introduced the Janus particles in his Nobel lecture. Janus materials have triggered extensive research interests in academia and industry. Janus composites possess two different chemical regions and functions that are distinctly compartmentalized onto the same object. While the organic polymer components provide tunable wettability and responsive performances, the inorganic（or metallic） components offer desired functionalities such as magnetic manipulation and light thermal effect. We have developed methods to precisely tune shape, size, microstructure and chemistry of Janus composites and therefore their performance. In analogy to molecular surfactants or copolymers, the amphiphilic Janus composites can stabilize interfaces more effectively. Similarly, the Janus composites can serve as emulsifiers in emulsion polymerization and as compatibilizers for polymer alloys. Moreover, the interfaces stabilized with the Janus composites can be easily manipulated by using external stimuli, and functionalized by delivering desired species thereby. By grafting responsive polymer chains, the emulsions can be de-stabilized by simple changing p H, temperature, light irradiation or exchanging of ions. When Janus composites contain paramagnetic species, the emulsion droplets can be withdrawn with a magnet. The droplets are further coalesced, leading to de-emulsification under a stronger magnetic field. This performance is important to remedy polluted water or soil with organic species in the presence of surfactants. By conjugation of heterogeneous catalysts onto the Janus composites, the catalytic efficiency of the catalysts is greatly enhanced. Functional species such as Fe3O4 or Au nanoparticles（NPs） can be delivered toward an oil/water interface when these NPs are grafted with hydrophobic and thermally responsive chains such as PNIPAM at the opposite sides. The de-emulsification can be ea