Swelling dynamics of a ternary interpenetrating polymer network (IPN) and controlled release of potassium nitrate as a model agrochemical

An interpenetrating polymer network (IPN) of carboxymethyl cellulose (CMC), polyethylene glycol (PEG) and crosslinked polyacrylamide (PAM) has been prepared and dynamic water sorption properties have been investigated as a function of chemical architecture of the IPN, pH and temperature of the swelling medium and presence of salt ions in the bathing medium. Based on the Fick's law the swelling exponent (n) and diffusion constant (D) were evaluated suggesting possible modes of water transport through the IPN's. The IPN's synthesized were loaded with KNO3 as a representative agrochemical and its release dynamics was studied conductometrically. The influences of percent loading and chemical composition of the IPN were also observed on the release rate and released amounts of KNO3.