Modeling the swelling kinetics of preformed particle gels coated with a silicate layer

This study presented an organic–inorganic hybrid preformed particle gels (PPG) by coating a tetramethyl orthosilicate layer on acrylamide-based PPG to control the swelling rate of PPG in simulated aqueous media. The coated silicate layer on the PPG delayed the equilibrium swelling time by several hours. Furthermore, jump boundary conditions at interfaces were applied to develop a mathematical model for the swelling kinetics of hybrid PPG with three distinct regions and three moving boundaries. The proposed model results showed that the diffusion coefficient of distilled water and saltwater in the coated layer and its thickness control the swelling process of these hybrid gel particles. Furthermore, the error percentages of predictive results by the proposed mathematical model for experimental swelling kinetic measurements of coated PPG were less than 5.25%. The experimental results also showed that the silicate layer controlled PPG swelling kinetics and improved hybrid PPG's strength and thermal stability.