Study on thermo-kinetic modeling of green route synthesized inorganic loading on PVDF membrane for Cr(VI) removal and its optimization

Mathematical modeling of a phase inversion membrane was studied to predict the morphology. The effect of different concentrations of TiO 2 nanoparticles on the thermodynamic and kinetic properties of polyvinylidene fluoride (PVDF) membrane casting solutions was investigated. The addition of green synthesized TiO 2 increases the viscosity, and a sufficient amount results in the formation of two phases. Thermodynamics enhances the demixing rate, whereas kinetics delays the demixing rate; this trade-off between thermodynamic and kinetic parameter will affect the membrane morphology. A quadratic phase diagram for PVDF/ TiO 2 /solvent/Water system was drawn experimentally at different concentrations of TiO 2 using a new method. Synthesized membranes were characterized by the contact angle, porosity, and permeability. Surface morphologies at different compositions were also examined using High Resolution scanning electron microscope (HRSEM). At TiO 2 concentration of 2 wt% in the polymer casting solution, thermodynamics parameter dominates kinetics parameter; thus, maximum porosity with enhanced permeability was achieved experimentally. The importance of thermo-kinetic parameters was further assessed using response surface optimization. The study suggested an optimum value of 2.165% of weight% TiO 2 at 5.125 pH giving excellent agreement to the experimental data.