Enhanced carbon dioxide capture via amphiphobic PVDF membrane modification for membrane contactors: Overcoming wettability challenges

The membrane contact absorption method is a promising technology for carbon dioxide (CO 2 ) capture, enhancing absorption efficiency and mitigating aerosol emissions. However, membrane wetting, an inevitable issue during the membrane contact absorption process, leads to a rapid decline in absorption rates, thereby limiting the development of this methodology. Focusing on the tendency of organic absorbents to induce membrane wetting, this study reports a novel modification method for amphiphobic polyvinylidene fluoride (PVDF) membranes. This method leverages polydopamine nanoparticles (PDANPs) to construct stable multi-level reentrant structures on the membrane surface, which are further enhanced for their hydrophobic properties through surface fluorination. The resultant amphiphobic membrane exhibits exceptional resistance to both water and organic wetting, with a water contact angle as high as 152.82° and contact angles above 90° for various organic absorbents. Long-term experiments demonstrate that the membrane material prepared by this method facilitates the stable and long-running operation of membrane contactors. Based on these findings, we analyze the structure–property relationship between the membrane surface microstructure and its amphiphobic performance. In conclusion, the fluorinated polydopamine hierarchical structure effectively resists membrane wetting induced by CO 2 absorbents, contributing to the promotion and application of CO 2 membrane absorption technology