An environmentally friendly and highly efficient PBS composite membrane prepared by TiO2 hybridization and PDA surface coating

Abstract

The biodegradable membrane, due to its intrinsic biodegradable properties, has been recognized as a sustainable material with environmental benefits. However, it faces challenges related to poor mechanical strength and insufficient permeation separation performance. In this work, poly (butylene succinate) (PBS)/TiO₂/polydopamine (PDA) composite membrane has been fabricated through TiO₂ hybridization and PDA surface coating. As the duration of dopamine coating increases, the membrane displays a reduction in pore size, a narrower pore distribution, and a slight decrease in overall porosity. The tensile strength of the composite membrane is increased to 4.1 ± 0.3 MPa, which is about 3.8 times greater than that of the pure PBS membrane. Moreover, the contact angle of the membrane surface decreases to 28.7°, indicating a notable improvement in hydrophilicity. After coating with 2 g/L dopamine for 6 h, the PBS/TiO₂/PDA composite membrane achieves a maximum pure water flux of 152.4 L·m⁻²·h⁻¹ and a bovine serum albumin (BSA) rejection rate of 94.3 %. After experiencing two instances of BSA contamination, the pure water flux remains higher than that of the PBS/TiO₂ hybrid membrane. Furthermore, the PBS/TiO₂/PDA composite membrane exhibits notable long-term stability and is capable of degradation in the lipase degradation solution post-service. The environmentally friendly and highly efficient PBS/TiO₂/PDA composite membrane presented in this study offers theoretical framework and practical assistance for the development and utilization of biodegradable membranes.