Phosphorylated hybrid silica-sulfonated polyethersulfone composite proton-exchange membranes: Magnetic resonance investigation for enhanced proton-exchange dynamics

Abstract The understating of hydrated proton activity and its dynamics inside the ion exchange channel of proton exchange membranes (PEMs) are one of the basic need to develop quality membranes for desalination and energy applications. In this work, sulfonated polyethersulfone (SPES), hybrid Silica-SPES and phosphorylated hybrid Silica-SPES composite PEMs are prepared; and membrane properties are characterized with appropriate analytical tools. The enhanced conductivity is described effectively with 1H spin-lattice (T1), spin-spin (T2) relaxation and diffusion weighted imaging and their corresponding value determined by magnetic resonance imaging (MRI) technique. This study gives useful insight on variation in the interactions and dynamics of hydrated protons confining inside the membrane channel with the incorporation of silica and its further phosphorylation. Obtained spin-lattice (T1), spin-spin (T2) relaxation and diffusion results relate that silica and phosphorylation have facilitated the formation more hurdle free organized pathway for proton conduction.