We report a general method to synthesize polymeric Janus nanosheets (PJS) by sequential RAFT grafting from a template particle surface. Layer number and composition of the PJS are tunable by feeding sequence and type of monomers. The cPNIPAM-PS PJS is flexible and thermal responsive, which can form a scrolled superstructure. A dually responsive cPAA-PNIPAM PJS is derived by hydrolysis of cPtBA-PNIPAM. Accordingly, stability of the emulsion with the cPAA-PNIPAM PJS is triggered by alternation of pH or/and temperature.