Water vapour-Calcium Alginate equilibrium isotherm

Experimental measurements were obtained using a Dynamic Vapor Sorption (DVS) analyzer (ProUmid) on different sets of calcium–alginate samples, characterized by varying compositions and testing histories (including multiple adsorption/regeneration cycles to simulate material ageing), as well as on silica gel samples used as reference. Mass variation was measured by applying 10% RH steps over a range from 0% to 70% RH. The step analysis was performed in both directions of mass change—increasing during adsorption and decreasing during desorption—in order to evaluate the possible presence of hysteretic behavior.