Membranes, in general, are selective barriers available in different shapes and sizes for separating gases or liquids based on different factors.
An ion-exchange membrane is a semi-permeable membrane that transports certain dissolved ions, while blocking other ions or neutral molecules. They are therefore electrically conductive moving ions from one solution to another with little passage of water.
A proton-exchange membrane, or polymer-electrolyte membrane (PEM), is a semipermeable membrane generally made from ionomers and designed to conduct protons while acting as an electronic insulator and reactant barrier.
In Nordische, PEM membranes are develoved from a polymer and cellulose derivative both by casting and electrospinning for different applications like fuel cells, hydrogen production, metal extraction, gas separation, desalination etc.