Asymmetric polydopamine-modified functional membrane with enhanced water vapor permeability, malodorous gas barrier, and oil fouling resistance for aerobic composting

Although membrane-covered composting (MCC) technology demonstrates significant advantages in malodorous gas barrier and nitrogen retention, existing functional covering membranes still face several challenges in practical applications. Specifically, these membranes are susceptible to contamination by oily aerosols present in compost, while substantial room remains for improving malodorous gas barrier and water vapor permeability. Here, dopamine self-deposition is employed to modify the inner surface of a widely used functional membrane via single-sided deposition. The resulting PDA@2h membrane achieves 7.10% and 6.54% higher NH 3 and H 2 S retention efficiencies, respectively, along with a 10.27% increase in water vapor permeability compared with the pristine membrane, and exhibits excellent underwater superoleophobicity that effectively resists oily aerosol contamination. Density functional theory (DFT) calculations elucidate the weak interactions between polydopamine (PDA) and malodorous gas molecules, while finite element simulations and image analyses highlight altered sub-membrane condensation patterns, collectively enhancing gas barrier performance. Raman spectroscopy confirms that PDA modification could change the condensed water state and partially activate the water, hence facilitating water evaporation. Moreover, benefiting from its outstanding mechanical properties and thermal stability, the membrane is not only suitable for traditional high-temperature aerobic composting but also exhibits great potential for application in hyperthermophilic composting. This study provides novel insights into the development of high-performance functional membranes for MCC systems, significantly contributing to the advancement of sustainable waste resource utilization technologies. • An asymmetric PDA-modified functional membrane was developed for oily composting. • The developed membrane exhibited enhanced water vapor permeability and malodorous gas barrier performance. • DFT calculations elucidated the weak interactions between PDA and malodorous gas molecules, while finite element simulations and image analyses highlighted altered sub-membrane condensation patterns, collectively enhancing gas barrier performance. • Raman spectroscopy confirmed that PDA modification could partially activate water molecules, facilitating water evaporation. • The PDA@2h membrane demonstrated excellent environmental and economic benefits in industrial-scale MCC applications.