Fabrication\nof PBAT\nMembranes with High Separation\nAccuracy Based on Inverse-Opal-Structural Photonic Crystals

Membrane\ntechnology is one of the most effective ways\nto cope with\nthe filtration and separation. However, most polymer membranes are\nnot uniform in pore size and have wide pore size distributions and\nlow porosities, which restrict their application. A high-porosity\nhomogeneous membrane with high filtration accuracy is an effective\nsolution. Photonic crystals (PCs) with an inverse-opal (IO) structure\nprovide a new way for preparing high-porosity homogeneous porous membranes.\nIn this study, a rapid shear-induced assembly method for preparing\nbiodegradable poly(butylene adipate-<i>co</i>-terephthalate)\n(PBAT) membranes based on PCs with an IO structure was proposed, and\nthe design principles of the IO-structured PBAT membrane were investigated.\nMoreover, the effects of polymer solution concentrations, solvent\nevaporation temperature, and SiO<sub>2</sub>/PBAT mass ratio on the\nSiO<sub>2</sub>/PBAT PC structure, formation mechanism of shear-induced\nassembly, and the filtering efficiency of resultant PBAT membranes\nfor solid–liquid separation were investigated. The study underscored\nthe point that when the polymer concentration is in the range of 15–20\nwt % and the drying temperature is at 80 °C, as the SiO<sub>2</sub>-to-PBAT mass ratio increases, the pore of the membrane increases,\nthe porosity is as high as to 84.11%, and pure water flux is up to\n756.19 L m<sup>–2</sup> h<sup>–1</sup>. After five cycles,\nthe rejection rate of PBAT membranes for the contaminant still reached\nmore than 99%. This study proposes a simple and rapid method for constructing\nan IO-structured membrane that is expected to address challenges encountered\nin achieving efficient and high-precision separation.