Cation-anion synergy in constructing κ-carrageenan/konjac glucomannan double-network gels: Performance enhancement and mechanism analysis

Cation–anion synergy boosts KC/KGM double-network gels, breaking single-ion regulation limits. • KGM deacetylation at high temperature and KC helical cross-linking at low temperature. • K + + CO₃ 2− /PO₄ 3− forms dense 3D network with enhanced hardness, water retention and stability. • Synergistic gels show non-Fickian diffusion and excellent water-holding capacity. Binary gels composed of κ-carrageenan (KC) and konjac glucomannan (KGM) possess broad application prospects in the food industry, pharmaceuticals and other fields. Current studies mainly focus on single-ion regulation strategies, which fail to realize the precise performance optimization of binary gels and limit their high-performance applications. This work proposed a cation-anion synergistic enhancement hypothesis and constructed high-performance KC-KGM double-network gels. With multiple characterization techniques, the regulation rules and intrinsic mechanism of different cation-anion combinations on gel properties were systematically explored. The results revealed that the synergistic system followed a two-step gelation pathway: high-temperature deacetylation of KGM and subsequent low-temperature helical cross-linking of KC. The alkaline environment induced KGM deacetylation, while K + strengthened hydrogen bonding between KC and KGM to form a dense and homogeneous three-dimensional network. For the K 2 CO 3 group, gel hardness increased significantly from 308.41 g to 1034.69 g. Moreover, the gel swelling behavior conformed to non-Fickian diffusion ( n  = 0.63) mechanism, exhibiting excellent water retention capacity and structural stability. This study clarified the cation-anion-driven dual-network coupling mechanism of rigid KC network and elastic KGM network, providing theoretical basis and feasible regulation strategies for the precise design and high-performance application of such materials.