Dispersion of bacterial cellulose bundles in organic solvents and their assembly as ultra-low grammage coating on woven fabric

Water is commonly considered as the optimal dispersing medium for nanocellulose given its hydrophilic nature. However, studies have also proven otherwise that alternative organic solvents may give better dispersion quality. Herein, a thermodynamic approach is used to estimate the Hansen solubility parameters of bacterial cellulose (BC) and understand the dispersion of BC bundles in selected organic solvents (i.e. ethyl acetate, acetone and ethanol-water mixtures). The correlation between the BC dispersion in different solvents and the aerosol particulate filtration performance of the resultant BC coated woven fabric is also presented. It is discovered that the best dispersion was achieved in a 60 % ethanol-water mixture, resulting in enhanced aerosol particulate filtration performance. At a BC coating grammage of 0.5 g m⁻², the filtration efficiency exceeded 80 %, outperforming the BC coating produced from a water dispersion. These findings highlight the potential of understanding nanocellulose dispersion from a solubility parameter approach.