Freeze-casting method in membrane technologies; process parameters, advantages, limitations and recent applications in water, wastewater and energy applications

Freeze-casting is a promising and adaptable fabrication method for producing porous materials such as ceramics and biomaterial scaffolds. However, this review specifically highlights the application of freeze-casting in membrane technologies, with a focus on ceramic and polymeric membranes, as well as its relevance to the fabrication of electrodes, hydrogels, and aerogels. Ice-templating allows for precise control over pore morphology, making it especially suitable for membrane applications requiring tailored structures. The process is also environmentally favorable, as it can utilize green solvents like DMSO and water and reduce dependency on chemical additives. The performance of freeze-cast membranes strongly depends on several key parameters, including the type and concentration of raw materials, freezing rate, and post-treatment conditions. These factors directly influence the structural and functional properties of the final product. Freeze-cast membranes have shown potential in various fields such as desalination, oil and water separation, gas separation, fuel cells, and pollutant removal. However, challenges remain in scaling up production and a better understanding of the process. Future efforts should focus on advanced modifications and pilot-scale validation to enhance the industrial applicability and sustainability of freeze-casting in membrane technologies.