Polymer-CNT Membrane for Water Filtration/Desalination

Background: The American University in Cairo\'s researchers have developed a novel polymer carbon Nanotube Membrane suited to a variety of applications in water filtration & Purification. The membrane combines the advantages of the traditionally used hydrophilic cellulose acetate material with the outstanding fluid transport properties of CNTs. Being a single layer the membrane can be easily prepared and the process scaled up to commercial production. Technology Description: Polymer-CNT membranes for water filtration/desalination have been the subject of recent research interests worldwide due to the observed super-fast transport of water through CNTs. Membranes that have been prepared so far entail multi-layers with primarily a polymer porous layer attached to which is an impermeable polymer layer in which open-ended CNTs are embedded in a way such that they protrude from this impermeable layer. Other examples include thin film composite membranes prepared by the interfacial polymerization technique in which a thin film composite membrane incorporating CNTs is formed on the surface of a porous base membrane. This invention entails polymer-CNT membranes composed of only one porous asymmetric polymer layer in which the CNTs are randomly dispersed. This \"nanocomposite\"" membrane is prepared by the established phase inversion method after the functionalized CNTs are dispersed in a polymer-solvent solution (i.e. the preparation of the membrane is much simpler). The membrane was tested and the presence of the CNTs was observed to lead to improved permeability (up to 50%) without reducing salt retention properties. Applications: 1) water filtration 2) desalination applications"


1) The primary advantage of the invention is the improved water permeability though the membrane with no adverse effects on salt retention properties. 2) Water permeability and salt retention are the two significant properties of membranes used in filtration/desalination. They vary in opposing trends: high salt retention is associated with low water permeability which requires significant pressure differentials across the membrane. 3) Improved water permeability reduces these required pressures thus reducing energy requirements.

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