Microencapsulation of phase change materials via interfacial jamming of cellulose nanocrystal surfactants

Phase-change materials (PCMs) possess great potential for latent heat storage and thermal regulation, yet their practical application is often hindered by leakage during phase transitions. Here, we report an efficient strategy for PCM encapsulation based on the co-assembly of cellulose nanocrystals and oil-soluble dimethyl distearylammonium chloride, which stabilizes the water-paraffin wax (PW) interface. Cellulose nanocrystal surfactants (CNCSs) are formed in situ at the interface, where their high interfacial activity and jammed multilayer structure enable the preparation of stable PW-in-water emulsions. Freeze-drying of these emulsions yield PCM microcapsules with robust CNCS shells that can effectively prevent leakage during heating. Polymerization of the emulsion continuous phase produces phase change hydrogels with uniformly distributed PCM microcapsules, exhibiting excellent thermal insulation, heat-regulation, and thermal-protective properties.