Dual Jamming of Biobased CNC-Stabilized Bijel Fibers via Continuous Solvent Transfer Induced Phase Separation

Bicontinuous nanoparticle-stabilized emulsions are formed by mixing two immiscible liquids with a cosolvent, followed by inducing phase separation within the spinodal regime and kinetically arresting the evolving morphology with colloidal nanoparticles. Here, we demonstrate that biobased, rod-like cellulose nanocrystals (CNCs) can stabilize bicontinuous emulsion gels at a low particle loading of 3 wt % through combined inter- and intraphase jamming, yielding characteristic domain sizes of approximately 10 μm. The use of 1-propanol as a cosolvent promotes CNC dispersion prior to and during solvent transfer, enabling the continuous production of CNC-stabilized bicontinuous emulsion gels as the segmented fibers (1-2 cm) and continuous filaments exceeding 25 cm in length. A key finding is that surfactant-specific access to near-neutral wetting is identified as a practical control lever for CNC, and DDAB enables the robust filament formation. The resulting porous, biphasic CNC network supports efficient crossflow mass transfer, providing a promising platform for interfacial transport and reaction processes. This work established a scalable route to sustainable material design from anisotropic nanoparticles.