Experimental and theoretical analysis of alginate-based hydrogel kinetics on sorption and desorption of atmospheric water vapor

Hydrogels are highly versatile polymer networks with the remarkable capability to uptake and release substantial amounts of water vapor, making them well-suited for utilization in atmospheric water harvesting applications. This investigation examines an alginate-based hydrogel from both experimental and theoretical perspectives, with a focus on identifying the key factors that contribute to the optimization of sorption/desorption cycles, including water capacity, kinetics, temperature, and vapor diffusion. The impact of the concentration of alginate networks and the reticulation initiator, calcium chloride, was assessed through an experimental investigation in which the material experienced controlled desorption and sorption cycles. The results revealed that higher concentrations of salt and lower levels of alginate within the composition led to enhanced sorption kinetics. The acquired data was subjected to fitting via three distinct models to quantify and compare the transport properties of various samples.