Over the last decades, considerable effort has been devoted to synthesizing a number of novel ionic liquids also known as “solvents of the future” or “designer solvents”. Their main advantages are their near-zero vapor pressure and their good chemical and thermal stabilities, having a large temperature range where they are stable with negligible vapor pressure. Nowadays, they are used in a large variety of applications in all areas of chemical industries.

Moreover, ionic liquids can be used as a membrane separation layer and/or a catalytically active site, but for this application it has to be impregnated into a porous support. Additionally, this integrated or even hybrid material is called the supported ionic liquid membrane (SILM). SILM is not only stable because of negligible vapor pressure of the ionic liquid, the possibility of minimizing its solubility in the surrounding phases by adequate selection of the cation and anion, and its high viscosity, but it also has high ion conductivity and high solvent power.

All the above-mentioned advantages of this integration of two media indicate that SILMs have the potential to support the process of chemical reaction and separation in a membrane reactor.

This Special Issue aims to give an overview of the challenges and trends in properties of SILMs. It welcomes both original contributions and reviews related to applications discussing the properties of SILMs in such process as carbon dioxide and other acid gases removal, the separation of organic compounds, the removal of metal ions, and the use SILMs in catalysis and analytical applications including sensors.