Redispersibility of cellulose nanoparticles modified by phenyltrimethoxysilane and its application in stabilizing Pickering emulsions

Because of irreversible agglomeration in the dehydrating process, the wet storage and transport of cellulose nanofibres (CNF) are the serious issues that need to be resolved in the commercialization and application of CNF. In this study, silanized cellulose nanofibres (Si-CNF) were prepared by modifying CNF with phenyltrimethoxysilane (PTS). Moreover, a mixture of redispersed Si-CNF and mineral oil was treated by combining ultrasound and high-pressure homogenizer to prepare Pickering emulsions. Different ratios of CNF/PTS were prepared and redispersed, and their morphological characteristics, thermal performance, rheological properties, zeta potential, and size distribution were analysed to evaluate the changes occurring during modification. The results show that the obtained Si-CNF demonstrates excellent redispersibility in water. The viscosity of the redispersed product exhibits the best suspension stability with the particle distribution uniform at the nanoscale when the addition amount of PTS is 0.18 mmol/g. Rheological and dynamic light scattering results have shown that the Pickering emulsion maintains the best dispersion stability at a concentration of 0.02% and remains stable after 7 days of storage. PTS modified the hydrophobicity of the CNF and provided alternative routes for application of CNF and Pickering emulsions.