Freeze-casting multicomponent aerogel membrane with controllable asymmetric multilayer configuration for high flux gravity-driven separation of oil-water emulsion

•Freeze-casting was modified to construct multilayered aerogels from solutions and dispersions.•A multilayered aerogel with asymmetric structural morphologies and wettability was prepared.•The aerogel could demulsified water-in-toluene nano-emulsion at a high permeate flux.•Demulsification was done by solely gravity.