Direct Ink Write 3D Printed Cellulose Nanofiber Aerogel Structures with Highly Deformable, Shape Recoverable, and Functionalizable Properties

Recent advancements in cellulosic aerogels have been extensive, but the lack of reproducible customization over the aerogel's overall 3D structure has limited their ability to adapt to different application requirements. In this paper, high pressure homogenization and 2,2,6,6-tetramethyl-1-piperidinyloxy (TEMPO) modified cellulose nanofiber (T-CNF) was printed using direct-ink-write (DIW) into customizable 3D structures. After freeze-drying and cross-linking, highly deformable and shape recoverable T-CNF aerogel 3D structures were obtained. The 3D printed parts have a porosity of 98% and density of 26 mg/cm3. Due to their sustainability, biocompatibility, ultralight weight with high porosity, and deformability, the resultant aerogels have great potential for applications in thermal insulation, shock/vibration damping, and tissue engineering. In addition, the 3D printed T-CNF aerogels were templated to impart hydrophobicity and electromechanical properties. The resultant aerogels demonstrated potential for oil/water separation, and electronic related applications.