Mihail Barboiu, Institut Europeen des Membranes, Montpellier France
Highly Selective Biomimetic Ion/Water Channels
Written by Akshay Phadnis
Naturally occurring biological water channels have very fast water transport while separating the ions contained in it due to aquaporins (AQPs). Making such channels artificially imposes numerous challenges, but will be very helpful for desalination applications. Hitherto efforts on making such channels include bilayer membranes, reverse osmosis membranes, and single molecule channels like carbon nanotubes (CNTs) providing fast transport but not as high as AQPs and not as effective for ion separation. Mihail Barboiu proposed an artificial imidazole-quartet water channels with a pore size of 2.6 Å. These channels with chirality can transport ~106 water molecules per second. Although these channels can separate all the ions from water, they cannot filter out the protons. This difficulty is solved using artificial ion-channel of H-bonded hexyl-benzoureido-15-crown-5-ether. These channels prefer K+ ions over Na+, making them a polarizing membrane and resulting in very high transport rates.