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Traditional protective garments loaded with activated carbons to remove toxic gases are very bulky. Novel graphene oxide (GO) flake-based composite lamellar membrane structure is being developed as a potential component of a garment for protection against chemical warfare agents (CWAs) represented here by simulants, dimethyl methyl phosphonate (DMMP) (a sarin-simulant), and 2-chloroethyl ethyl sulfide (CEES) (a simulant for sulfur mustard), yet allowing a high-moisture transmission rate. GO flakes of dimensions 300−800 nm, 0.7−1.2 nm thickness and dispersed in an aqueous suspension were formed into a membrane by vacuum filtration on a porous poly(ether sulfone) (PES) or poly(ether ether ketone) (PEEK) support membrane for noncovalent π−π interactions with GO flakes. After physical compression of such a membrane, upright cup tests indicated that it can block toluene for 3−4 days and DMMP for 5 days while exhibiting excellent water vapor permeation. Further, they display very low permeances for small-molecule gases/vapors. The GO flakes underwent crosslinking later with ethylenediamine (EDA) introduced during the 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 the CWA simulant 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 other species for low gas flow rates in the dynamic moisture permeation cell (DMPC) are: αH2O−He is 42.3; αH2O−N2 is 110; and αH2O−ethane is 1800. At higher gas flow rates in the DMPC, the moisture transmission rate goes up considerably due to reduced boundary layer resistances and exceeds the threshold water vapor flux of 2000 g/(m2·day) that defines a breathable fabric. This membrane displayed considerable resistance to permeation by CEES as well. The PES-EDA-GO-PU-compressed membrane shows good mechanical property under tensile strength tests. 

Direct contact membrane distillation (DCMD) for desalination is attractive for high salt concentrations if low cost steam/waste heat is available and waste brine disposal cost for inland desalination is factored in. A number of innovations have taken place in DCMD in terms of the structure of the porous hydrophobic membrane. Composite membranes are of increasing interest. Composite membrane structures of great interest include a thin hydrophobic porous layer over a porous hydrophilic layer of polyvinylidene fluoride (PVDF) or a thin porous hydrophobic layer over a more conventional hydrophobic porous membrane. These membranes can be in the form of an integral composite or a stacked composite or a laminated composite. A facile method of fabricating such integral composite membranes is plasma polymerization under vacuum. A class of such membranes yielding quite high water vapor fluxes have been characterized using a variety of characterization techniques: Contact angle, liquid entry pressure (LEP), bubble-point pressure, scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), atomic force microscopy (AFM). Stacked composites of a hydrophobic ePTFE membrane over a hydrophilic PVDF membrane or a hydrophobic PVDF membrane over another hydrophobic PVDF membrane were also studied. Novel conditions created lead to very high water vapor fluxes compared to those from conventional hydrophobic membranes supported on a mesh support.