Artificial water channels: toward and beyond desalination

Artificial water channels (AWCs) are synthetic mimics of biological water channel proteins, aquaporins. They combine the characteristic features of aquaporins, including a transmembrane orientation in biomimetic membrane matrices and the possibility of combining high water permeability with high water/solute selectivity, with higher processability and stability compared to protein channels. AWCs have thus emerged as a platform for biomimetic membrane development. During the last few years, remarkable progress has been made in AWC synthesis and characterization but bridging these advances to practical membrane development still remains a significant challenge. In this article, we review some recent concepts regarding permeability in water channels and its relevance to AWCs, common misconceptions and need for better clarity in permeability and selectivity characterization of AWCs, and prospective applications of channel-based membranes beyond desalination.