(538a) GO-Based Membrane As Barrier Against Toxic Vapors/Gases | AIChE

(538a) GO-Based Membrane As Barrier Against Toxic Vapors/Gases


Sirkar, K. - Presenter, New Jersey Institute of Technology
Peng, C., New Jersey Institute of Technology
Iqbal, Z., New Jersey Institute of Technology
Peterson, G. W., Edgewood Chemical Biological Center
Traditional protective garments loaded with activated carbons to remove toxic gases are bulky. Novel graphene oxide (GO) flake-based composite lamellar membrane was developed for a garment for protection against chemical warfare agent (CWA) simulants: dimethyl methyl phosphonate (DMMP) (a sarin-simulant); 2-chloroethyl ethyl sulfide (CEES) (a simulant for sulfur mustard); yet it has a high moisture transmission rate. GO flakes (300-800 nm, 0.7-1.2 nm thick) dispersed in water were formed into a membrane by vacuum filtration on porous polyethersulfone (PES) or poly (ether-ether-ketone) (PEEK) support membrane for noncovalent π-π interactions with GO flakes. After physical compression, Upright Cup tests indicated: it can block toluene for 3-4 days and DMMP for 5 days while exhibiting excellent water vapor permeation. Further, they have low permeances for small molecule gases/vapors. The GO flakes underwent crosslinking later with ethylenediamine (EDA) during vacuum filtration followed by physical compression and heating. With a further spray-coating of polyurethane (PU), these membranes could be bent without losing barrier properties vis-à-vis DMMP for 5 days; a membrane not subjected to bending blocked DMMP for 15 days. For the PEEK-EDA-GO-PU compressed membranes after bending, the separation factors of H2O over others for low gas flow rates in the dynamic moisture permeation cell (DMPC) were: αH2O-He, 42.3; αH2O-N2, 110; αH2O-ethane, 1800. At higher gas flow rates in the DMPC, moisture transport rate goes up considerably due to reduced boundary layer resistances and exceeds the breathable fabric threshold water vapor flux, 2000 g/m2-day. The membrane displayed considerable resistance to permeation by CEES as well. This behavior has been compared with that of a nanopacked bed of membrane supported nanocrystals of UiO-66-NH2 MOF. The PES-EDA-GO-PU compressed membrane shows good mechanical property under tensile strength tests.