Octadecane-Encapsulated,Emulsion-Based Alginate Fibers:Enhanced Mechanical Property and Heat Density

Alginate-based, phase change fibers are promising, but their relatively low heat density and mechanical properties hinder them from real applications. Here, we report the fabrication of octadecane-encapsulated, alginate-based fibers with enhanced mechanical property and heat density from wet spinning of cellulose nanocrystal-stabilized Pickering emulsions via formation of hierarchically and physically cross-linked interpenetrating polymer networks that have never been reported to emulsion-based hydrophilic polymers. The fibers could be prepared continuously with high reproducibility, and the resulting fibers exhibit good flexibility (even at temperatures slightly below the melting point of the encapsulated octadecane), high stretchability, low leakage, high heat density (up to 173.6 J/g) that is usually impossible for alginate-based fibers, and high reusability (without significant decrease in heat density after 100 cooling–heating cycles). This facile preparation, combined with flexibility, stretchability, high heat density, and reusability, makes the alginate-based phase change fibers an excellent candidate for personal temperature regulation and latent heat storage.