Development of Cellulose/Aramid Nanofiber Composites for Ion Exchange Membranes

Abstract

The development of sustainable and eco-friendly energy sources is of utmost importance for reducing pollution and addressing the challenges posed by fossil fuel consumption and global warming. Membrane-based energy generation and storage systems, such as fuel cells, redox flow batteries, and reverse electrodialysis (RED), have emerged as promising alternatives with minimal environmental impacts. Ion-exchange membranes (IEMs) are central to the operation of these systems and play a critical role in enabling selective ion transport. Therefore, there is a growing need for IEMs that exhibit high ionic conductivity and selectivity, as well as desirable mechanical properties and scalability. However, the most widely used ion exchange membranes are made of synthetic polymers, which are difficult to biodegrade and do not agree with the sustainable industry. Waste management is another environmental problem that needs to be addressed. Therefore, in this study, IEMs were fabricated from cellulose, which is recycled from the shells of waste sea squirts that hold the headline owing to difficulties in disposal, leading to landfilling. For better stability, aramid nanofibers (ANFs) are used as reinforcements in the preparation of composite membranes. Various IEMs with different ANF contents were synthesized and characterized in terms of their chemical compositions and electrochemical performances using a half-system RED unit cell. These results highlight the potential of recycled biodegradable cellulose/aramid nanofiber IEMs as ion-exchange membranes for osmotic power generation.