Tailoring pore architecture for enhanced hydraulic performance in nanofiller-modified PDMS composites: an integrated micro-CT and CFD study

Abstract

• Porous PDMS composites designed using sugar templating and nanofiller integration. • Micro-CT and BET reveal pore morphology and surface area changes with nanofillers. • CFD and FEM modeling link pore architecture to hydraulic performance. • Bentonite and magnetite enhance flow resistance and MB dye adsorption. • Structure–function relationships inform design of porous composite filters. Porous polydimethylsiloxane (PDMS) composites have gained attention for their diverse applications, particularly as matrices for nanoparticles in pollution remediation. However, the link between pore distribution and hydraulic behaviour in these materials remains insufficiently understood. This study investigates how pore distribution influences the hydraulic properties of porous PDMS composites prepared via the template leaching method, with bentonite and magnetite incorporated as nanofillers. The composites were characterised using scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), Fourier-transform infrared spectroscopy (FTIR), and Brunauer–Emmett–Teller (BET) surface area analysis. To assess fluid dynamics within the porous structure, micro-computed X-ray tomography (micro-CT) was employed to visualise pore architecture, while finite element modeling using Elmer Multiphysics software applied the Navier–Stokes equation to simulate fluid flow. Micro-CT revealed a pore size range from 0.03 to 1.2 mm, and FTIR confirmed successful nanofiller integration. Simulation results showed axial fluid velocities reduced to below 40.0 µm/s, indicating restricted flow due to microstructural complexity. These findings highlight the impact of pore morphology on hydraulic performance and demonstrate the importance of controlled porosity in tailoring PDMS-based composites for water treatment. The study offers valuable insights for designing efficient column filtration systems using porous PDMS as a functional support material.