Ionizable hydrophobes behind new IBM desalination membrane
US computer giant IBM, Tokyo-based Central Glass and the King Abdul Aziz City for Science & Technology (KACST) unveiled a novel desalination membrane technology at the World Water Forum in Turkey on 16 March 2009.The collaborative research team has designed a membrane material that they claim combines resistance to chlorine damage and high performance separation behavior in mildly basic conditions, making it suitable for arsenic removal in addition to water desalination. Because of its unique chemistry, the membrane contains ionizable hydrophobes that undergo a dramatic change when they encounter mildly basic conditions - they become substantially hydrophilic.
The membrane, which is made with fluorine materials, transforms from a low water transporting filter to a high water transporting state in a basic environment - what the researchers call a "water superhighway." Fortuitously, high pH also causes arsenic to become ionic resulting in a relatively easy separation by desalination membranes. Because of these conditions and reactions, when contaminated water is forced through the membrane, the arsenic is filtered out.
Dr Turki AlSaud, vice-president for research institutes, KACST, says, "Currently, Saudi Arabia is the largest producer of desalinated water in the world, and the kingdom continues to invest in research and development to make access to fresh water more affordable. Our collaborative research with IBM is providing innovative technological solutions and paving the way toward cost effective technologies in the field of membranes for water desalination that will help meet the increasing global demand of fresh, clean water."
A video about the new membrane can be viewed at: http://www.youtube.com/watch?v=M1Mo_rVZVws