Carbohydrate Polymers, 2026,

Cellulose nanocrystals (CNCs)-stabilized oil-in-water Pickering emulsion has been widely studied, while the reports on the CNC-stabilized inverse water-in-oil emulsion are quite limited, and the interfacial behavior of CNCs in this system has not yet been fully clarified. Herein, a water-in-castor oil system stabilized with CNCs was prepared as a template for the study. The results showed that the emulsifying capacity of CNCs was not monotonically dependent on the degree of substitution (DS), and the emulsion stabilized by moderately modified CNCs (DS=0.308~0.353, with water contact angle θ_w=117^o~128^o) had better interfacial structure and emulsion stability. The interfacial adsorption/desorption and emulsion rheology tests were performed to probe the effect of DS of CNCs on the interfacial activity. The CNCs with low DS (≤0.267, θ_w<103^o) had less interfacial adsorption, whereas the CNCs with higher DS (>0.353, θ_w>130^o) were prone to desorption from the water/oil interfaces. Only those with moderate DS (0.308~0.353) could promote the formation of robust interface. As a result, the inverse emulsion stabilized with moderately modified CNCs presented a minimum interfacial dissipation and the best resistance to a strain-driven bulk deformation. This study can provide a specific guidance for regulating inverse Pickering emulsions by tailoring the surface wetting properties of CNCs.

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