Acid-induced structural regulation of spiropyran-modified mixed matrix membranes for enhanced CO2/CH4 separation

Abstract

This study presents a biomimetic, acid-responsive membrane developed by blending PIM-1 with a spiropyran-based polymer (TSP-1) to enhance CO₂ separation performance. TSP-1 optimizes the pore structure of PIM-1, and the acid treatment induces a change in the pore microenvironment and polarity, resulting in a CO₂ permeability of 13 659 Barrer and a CO₂/CH₄ selectivity of 36.5, surpassing the 2019 Robeson upper bound.