Fig. 3: Controllable crystallization and Janus surfaces of the NCC membrane.

Raman spectra (a) and mapping (b) of the two sides of the NCC-6 membrane. Modulus images and distributions of the rear (c, d) and top (e, f) surfaces of the NCC-6 membrane, as measured by AFM based indentation. g WCAs of the two sides of the NCC-6 membrane. h Surface XPS spectrum of the two sides of the NCC-6 membrane. Error bars represent the standard deviation from three duplicate experiments.