Electronic Supplementary Information Polymer membrane wearing a mineral coating for enhanced curling resistance and surface wettability

Materials Polypropylene microfiltration membranes were obtained from Membrana GmbH (Germany) and Beijing Normal University (China), respectively. One was prepared by thermally induced phase separation with mean pore size of 0.2 μm and porosity of 75%, another was prepared by biaxially orientation with mean pore size of 0.20.02 μm and porosity of 45%. Poly(vinylidene fluoride) (PVDF) microfiltration membranes (mean pore size ~0.45 μm) were purchased from Yibo Co., Ltd. (China). The membranes were cut into rounds with a diameter of 25 mm and rinsed by acetone under oscillation overnight. Then the membrane samples were dried in a vacuum oven at 40 °C. Dopamine hydrochloride and PEI (Mw=600 Da) were procured from Sigma-Aldrich and Aladdin Co. respectively. Other reagents such as zirconium sulfate (Zr(SO4)2), tris(hydroxymethyl) aminomethane, hydrochloric acid, ethanol and acetone were obtained from Chemical Reagent Co., Ltd. (China) and used without further purification.