Spatial Distribution of Interfacial Carboxymethyl Chitosan Modulates Network Architecture and Properties of Dynamic Cross-linked Emulsion Gel

This study elucidates how the spatial distribution of carboxymethyl chitosan (CMCS) governs the architecture and properties of emulsion gels formed via reversible Schiff base linkages. A methodology centered on regulating the oil-water interfacial area was employed to manipulate CMCS distribution between the interface and the continuous phase. Multiscale characterization revealed that the macroscopic properties of this polysaccharide-based dynamic gel are predominantly governed by the continuous phase network, which is fundamentally distinct from interface-dominated protein-based gel systems. Specifically, increasing the interfacial area drove CMCS migration to the interface, reducing the effective cross-linking density in the continuous phase. This led to prolonged gelation, weaker gel strength, a more porous network, and enhanced water mobility. Interestingly, the reduced network density facilitated polymer chain diffusion, significantly accelerating the self-healing process. This work clarifies the dominant role of the continuous phase network in dynamic polysaccharide gels. It establishes a general methodology for programming material properties by controlling polymer spatial distribution. These insights provide a new paradigm for the rational design of functional soft materials.