Ultrastrong aerogels based on aramid nanofiber composites and membrane devices made therefrom

A composite nanofiber aerogel (CNA) comprising aramid nanofibers (ANFs) combined with polyvinyl alcohol (PVA),

• wherein the composite nanofiber aerogel is created by
• forming a dispersion of about 3% wt of the ANFs dissolved in dimethyl sulfoxide (DMSO) in about 7 days,
• forming a dispersion of about 15% wt of the PVA dissolved in the DMSO in about 7 days,
• mixing the ANF dispersion with the PVA dispersion in a mass ratio of 1:1 to form a precursor liquid,
• conducting a solvent exchange in deionized (DI) water leading to solid hydrogels and immersing the hydrogels in ethanol for about another 24 hours, and
• conducting critical point drying (CPD), whereby a solid foam aerogel with nanoscale porosity is formed, and
• wherein nanoscale constituents of the aerogel form 3D networks with nodal connectivity and welded connectivity nodal joints between fibrils so that the aerogel has a fracture energy of about 4,697 Jm−2, a 76% porosity and a toughness of about 1,050 kJ/m3 and wherein successive breakage of crosslinks at the connectivity nodal joints affords energy dissipation while maintaining the overall structural integrity.