Synthesis of amphiphilic dumbbell-like Janus nanoparticles through one-step coupling

In this study, amphiphilic Janus nanoparticles with dumbbell-like structure have been synthesized by connecting two silica nanospheres with differential wettability. In this method, silica nanospheres were modified to be hydrophobic and hydrophilic respectively and then the nanospheres with different wettability were covalently connected together on a one-to-one basis simply by chemical bonds generating between surface groups. The dumbbell-like structure of particles can be observed clearly under scanning electron microscope and transmittance electron microscope. Results showed that 58% of the nanospheres were successfully coupled to build the dumbbell-like structure. Since these anisotropic nanoparticles were based entirely on inorganic materials and owned well-defined surface areas of different wettability, they may have a highly potential for many application fields such as optical and electrical engineering.