pH-responsive pickering foam created from self-aggregate polymer using dynamic covalent bond

•Dynamic imine bond introduced between PAH and aldehyde compounds.•Hydrophobicity of PAH controlled by dynamic covalent bonds responsive to pH.•Aggregation of amphipathic PAH-aldehyde at neutral pH stabilizes Pickering foams.•Decomposition of PAH-aldehyde at acidic condition destructs foams.•Reversible foaming and defoaming achieved by alternatively changing pH.