Different types of superabsorbent polymers (SAP) exhibiting varied absorbency properties were investigated for their performances at varying concentrations of an electrolyte. Water chemical potential, which is a function of concentration and pressure, was interpreted as a major parameter for absorbency and swelling properties of SAP. Superabsorbent polymers that were investigated gave different values of permeability which was carried out in a layer of swelled superabsorbent polymer. This result revealed differences on the structure of the superabsorbent polymers particularly on the crosslinking density. SAP’s absorbency properties were further tested and a correlation between the quantity of absorption and the chemical potential of water in terms of sodium chloride concentration was developed using experimental data on free swelling capacity and absorption under pressure. Results showed decreasing quantity of absorption by the superabsorbent polymers with decreasing chemical potential of water with higher reduction in the absorbency at higher pressure applied on the swelled SAP.