Development of membrane distillation by dosing SiO₂-PNIPAM with thermal cleaning properties via surface energy actuation

This study evaluates the performance and cleaning efficiency of Direct Contact Membrane Distillation (DCMD) by changing its surface energy via thermal actuation. Thermoresponsive SiO₂-PNIPAM particles were dosed into the DCMD with different surface energy and its thermal cleaning efficiency was evaluated against the model organic foulants namely Bovine Serum Albumin (BSA) and Sodium Alginate (SA). The impact of SiO₂-PNIPAM dosing on the performance of membrane distillation as well as its defouling efficiency were evaluated under thermal actuation effect. Results showed that composite membrane has higher flux recovery (93%–95%) compared to pristine membrane (55%–90%). The composite membranes were analysed for their Surface Free Energy (SFE) to understand their fouling and cleaning behaviour. Based on SFE analysis, it was found that both low and high SFE composite membranes surface that fouled by BSA and SA foulants were able to restore their hydrophobicity after thermal actuation. The stability of the embedded hydrogel could be maintained after thermal actuation which indicated sufficient interactions between the SiO₂-PNIPAM with the PVDF membrane matrix.