Membrane Science and TechnologyPublished 17 October 2025Transport in perfluorosulfonic acid (PFSA) membranes: effects of pretreatment, side-chain length, and alkali metal cationSebastian Castro · Dennis Ssekimpi · Youneng Tang · Daniel HallinanFrontiers in Membrane Science and Technologydoi 10.3389/frmst.2025.1681118