Constructing superhydrophobic surface of PES/PES-SiO2 mixed matrix membrane contactors for efficient SO2 capture

Abstract Obtaining high SO2 absorption flux for membrane contactor is noticeably vital for fule gas desulfurization, and superhydrophobic surface is essential to reach excellent desulfurization performance. The development of a generic and low budget strategy for membrane contactors preparation is important in indisturial application. In this study, a superhydrophobic polyethersulfone-silica (PES/PES-SiO2) gas-liquid membrane contactor is fabricated using a facile spin coating method. PES substrate is prepared by a facile non-solvent induced phase separation (NIPS), and then the superhydrophobic surface of PES/PES-SiO2 is formed on the PES substrate by spin coating method. The solubility parameters of mixed solvent, PES concentration, and SiO2 content are regulated to investigate the morphology of membrane contactors. On one hand, the surface structure of MMMCs is regulated, and constructs lotus-leaf like morphology, which noticeably elevate surface roughness. On the other hand, SiO2 nanoparticles enhance hydrophobic characteristic with water contact angle 159o and anti wetting resistance with liquid entry pressure of water (LEPw) 1.389 bar. Moreover, the SiO2 nanoparticles help to significantly improve the stability of desulfurization performance, which is much higher than PES control membrane after 12 h test. The SO2 absorption fluxes and SO2 removal efficiencies are 1.24×10-3 mol·m-2·s-1 and 63.8%, respectively. Besides, the membrane phase transfer coefficient (Km) and membrane phase transfer resistance (H/Km) are explored.