Fig. 2. Surface properties of different membranes. (a) ATR-FTIR spectra of the PES substrate, the COF-deposited PES substrate and the PA composite membrane. (b) Zeta potentials of the PES substrate, the COF-deposited PES substrate and the PA composite membrane. (c) Digital photos of water droplets penetrating through different membranes with the same duration (on the left the optical images of the corresponding membranes are shown).
