Patterned Cellulose Nanocrystal Aerogel Films with Tunable Dimensions and Morphologies as Ultra-Porous Scaffolds for Cell Culture

Aerogel films are interesting as coatings due to their unique properties including high surface area, sorption capacity and insulating properties. To date, silica-based aerogel films have been most widely explored due to their ultra-high surface areas and well-known chemistry. However, the fragile nature of silica aerogels coupled with the limited control over film thickness and dimensions when using traditional deposition techniques limits their use in applications requiring films with good mechanical stability (e.g., in flexible devices). To address these challenges, we present a pressure-aided freeze casting method to pattern, on a variety of substrates (e.g., glass or flexible polyethylene terephthalate), mechanically robust aerogel films composed of covalently cross-linked cellulose nanocrystals (CNCs) with controlled dimensions and internal morphology. To accomplish this, a film of the desired aerogel thickness was deposited on the substrate and a mold with the specific shape for the aerogel was fab...