(131h) Two Recent Developments in Membranes and Membrane Separations

Larger scale separations from solutions/mixtures involve either aqueous solutions, organic solutions or gaseous mixtures. Membranes have an expanding footprint in all three general areas. Aqueous solutions are probably the largest outlet of membrane separation technologies with gas separations coming in second; organic solvent mixture separation is a distant third. Yet organic solvent mixture separation is a dominant activity in chemical / petrochemical process industry consuming a huge amount of energy. I would first present our recent results of separation of binary organic solvent mixtures by reverse osmosis using perfluorocopolymer membranes. We will show examples of a pure solvent coming out as a permeate from binary mixtures with other solvents. The proposed separation mechanism is far from traditional solution-diffusion concepts.
Graphene (GR) and graphene oxide (GO) are being increasingly studied for a variety of separations. I would next present our experimental results focusing on graphene oxide (GO) flake-based membranes that are being developed to protect against toxic gases and vapors as well as chemical warfare agents (CWAs) like 2-chloroethyl ethyl sulfide (CEES) (a simulant for sulfur mustard), dimethyl methyl phosphonate (DMMP) (a sarin-simulant). Such barrier membranes have high moisture permeability; yet they have significant toxic vapor/gas molecule blocking capability and are potentially adaptable to building protective suits.