Inverse Pickering Emulsions Stabilized by Cinnamate Modified Cellulose Nanocrystals as Templates To Prepare Silica Colloidosomes

A facile method to prepare colloidosomes at room temperature from inverse water-in-oil (w/o) Pickering emulsions containing silica precursors and stabilized by cinnamate modified cellulose nanocrystals (Cin-CNC) is proposed. Cin-CNC Pickering emulsifiers were prepared by acylation with an excess of cinnamoyl chloride. The Cin-CNC surface displayed partial wettability with both toluene and water, which allowed the stabilization of w/o inverse Pickering emulsions. The Cin-CNC particles around the droplets were subsequently locked by cross-linking TEOS or TBOS silica precursors at the water/toluene interface, leading to an intricate network of polysiloxane within the Cin-CNC shell. In optimized conditions, the Cin-CNC/silica colloidosomes obtained displayed a robust and compact shell, which ensured a long-term encapsulation of rhodamine B or biological molecules such as fluorescent deoxyribonucleic acid (DNA).