Rare earth metal oxides smart modifiers in 3D re-entrant surface architecture for efficient membrane separation

The membrane with significantly improved transport, separation, and stability in membrane distillation were generated. The thorough material and physicochemical characterization allows to understand how the introduction of 3D re-entrant surface nanoarchitecture impacts the membrane performance in desalination and removal of hazardous volatile organic compounds (VOCs) performance. Based on PVDF, the 3D construction with rare earth metal oxides (REMOs) smart modifiers (CeO2 and Lu2O3) was successfully accomplished via stable covalent bonds, ensuring stable membranes during the separation process, even during the long-lasting tests (> 50 days). The REMOs were linked on the likers, giving them additional features, i.e., movement of the nanoparticles inspired by Cilia movement in biological membranes. Such biomimicry enhanced transport turbulency and separation features, keeping the membrane surface free from salt deposition. The membranes exhibiting high hydrophobicity also displayed superhydrophobic behavior at a micro-scale, attributed to the formation of fractal-like structures on the surface of the inorganic domain. It is the first example where REMO was applied, causing a substantial enhancement in separation efficiency owing to the affinity between the membrane and the separated system described and analyzed by Hansen Solubility Parameters and Pearson's hard–soft acid–base (HSAB) theory. An improvement in process separation index (PSI) and separation factor β was followed for PVDF (PSI = 5, β = 1.7), and PVDF-thiol-CeO2 (PSI = 279, β = 9.7). MD membranes possessing exceptional resistance to wetting (with a critical surface tension of approximately 15 mN m−1) were fabricated by integrating hierarchically structured membranes with re-entrant texture. [Display omitted]