Upcycling CO₂ into an antifouling cellulose acetate membrane for sustainable ultrafiltration

As a major carbon resource, carbon dioxide recycling can effectively address issues of the greenhouse effect and carbon resource shortages. Carbon dioxide based polypropylene carbonate (PPC) is a polymer material produced from carbon dioxide and propylene oxide, with advantages in environmental protection and sustainability. However, its relatively low thermal stability severely limits its application prospects. In this study, a novel cellulose acetate grafted carbon dioxide based polypropylene carbonate (CA-DMC-CO 2 ) ultrafiltration membrane was prepared by epoxidation and high-pressure catalysis of cellulose acetate side chains. The molecular weight of CA-DMC-CO 2 was 428,169 Da, and its thermal decomposition temperature reached 365 °C. The introduction of polycarbonate side chains endowed the CA-DMC-CO 2 ultrafiltration membrane with good hydrophilicity and excellent permeability, reaching 115.9 L/m 2 h, which performed better than the CA ultrafiltration membrane. In addition, good hydrophilicity of CA-DMC-CO 2 provided effective anti-fouling performance. This study highlights the potential for developing environmentally friendly and sustainable ultrafiltration membranes for practical applications.