Microscopic characteristics of Janus nanoparticles prepared via a grafting-from reaction at the immiscible liquid interface.

The dynamic process of synthesizing Janus nanoparticles (JNPs) at a water/oil two-phase interface using a grafting-from reaction is investigated via dissipative particle dynamics simulations. We find that the interfacial tension, the initial monomer concentration, and the reaction probability can greatly influence the microscopic characteristics of JNP structure. It is difficult to synthesize a symmetric JNP with an equal volume ratio between hydrophilic and hydrophobic parts by grafting-from methods unless the physical chemical conditions in the two phases are strictly symmetric, and there is always a disordered domain on the JNP at a two immiscible solvents interface. Interestingly, for certain routes for synthesizing JNPs with a grafting-from method, the higher interfacial tension between the water and oil phases may enhance the degree of disorder of the grafted chains. The asymmetric initial monomer concentration in solution and the reaction probability can be used to control the syntheses of asymmetric JNPs.