The development of biocomposites using renewable resources is a cost-effective and long-term solution to environmental and resource issues. Hydrogels [Poly Sodium Acrylate (PSA)] were created by variable percentages of crosslinker concentration, and banana–cellulose microfibril (CMF) was used as a filler in this study for better reinforcement. When the concentration of crosslinker is increased, the number of covalent crosslinks increases, limiting the movement of water molecules and lowering the diffusion coefficient, equilibrium water content, the initial rate of swelling, and the theoretical equilibrium swelling ratio. The swelling behaviour of reinforced PSA with high concentrations of CMF was unexpected; the hydrophilic OH groups of CMF increase the diffusion of water molecules from the swelling medium to inside the PSA, allowing for better mechanical behaviour of gels without sacrificing the swelling response. The swelling behaviour and swelling exponent of a hydrogel were determined at various temperatures, pH levels, and physiological fluid models. The swelling exponent's maximum value was discovered to be 0.5, which suggests that the hydrogel's water diffusion was non-Fickian in nature. The swelling ratio was found to rise with rising temperature and to have a lower value than that at room temperature. It was also proven that elevating the pH of the medium from 1 to 7 improved the PSA/CMF hydrogels' swelling response. The swelling behaviour of PSA/CMF hydrogels was also investigated as the concentration of CMF rose from 0.2 to 1%. The equilibrium water content, swelling kinetics, and water transport mechanisms were all investigated. The Flory–Rehner equation was applied to determine crosslinking density, polymer mesh size, and molecular weight between crosslinks.

High performance polydimethylsiloxane (PDMS) membranes for n-butanol recovery were fabricated using a tri-functional crosslinker containing the phenyl group. In order to understand the role of the functional group structure and cross-linking density in pervaporation performance, PDMS membranes were prepared using tri-functional crosslinker containing other functional groups (hexyl and cyclohexyl) and conventional tetra-functional crosslinker. The relationship between the polymer structure-performance was discussed based on the sorption and diffusion properties of the membranes. As a result, the phenyl-based PDMS membrane exhibited the pervaporation performance owing to the strong hydrophobicity and chain rigidity of the phenyl group compared to other PDMS membranes even at high butanol concentration and high temperature conditions.