Tert-Butanol as a Structuring Agent for Cellulose Nanocrystal Fluids and Foams

Artikel i vetenskaplig tidskrift, 2025

Nanocelluloses are uniquely valued for their high surface area and controllable assembly. This study elucidates the assembly of cellulose nanocrystals (CNCs) in tert-butanol (TBA) and water mixtures. We emphasize the influence of TBA on the structure of suspensions and freeze-dried foams. Although the length-scale of CNC organization is large relative to water-TBA structures, adding more than 30 wt % TBA shifted ordered CNC packing into an isotropic network. The change was attributed to the disruption of ionic interactions and adsorption of TBA to hydrophobic CNC interfaces; manifesting as a 5-fold increase in viscosity at 50 wt % TBA content. The freeze-dried foams' morphology was transformed due to TBA-modulated crystal growth during the freezing process. This led to the intriguing capability to control foams' mechanical strength and surface area, achieving up to 3 and 15-fold increases, respectively. The investigations highlight TBA's potential as a structuring agent in solvent-mediated design of nanomaterial systems.