“…Aerogels, often referred to as “frozen smoke” or “blue smoke”, represent a class of materials with exceptional properties that have garnered significant attention in recent years. These materials are characterized by an ultralow density, high porosity, and unique physical and chemical attributes, making their application in diverse fields, including aerospace, , oil spill recovery, , thermal insulation, , and biomedical engineering. , In recent years, many environmentally friendly aerogels based on poly(vinyl chloride), , graphene and carbon nanotubes, , polyimides, , and cellulose nanofibers , have been developed using freeze-drying technology. Compared with supercritical CO 2 drying, which requires high operating pressures, freeze-drying is a more environmentally friendly, cost-effective, and feasible method for extracting solvents from wet gels without damaging the gel structure.…”