Date of Award
Ionic Liquids, Absorption, Activated Carbon
Ionic liquids (ILs) were investigated for functionalization of activated carbon (AC) adsorbents for the filtration of warfare toxins. Preliminary steps were taken by testing absorption capacity of neat ILs and tethering ionic liquids to the surface of AC. AC is known to have good adsorption ability for warfare agents. Functionalizing the AC with ILs could enhance the capture ability significantly. ILs have been found to be good absorbents for a variety of gaseous species. The absorption selectivity and capacity can be tuned by changing the anion-cation pair. By tethering ILs to AC, the beneficial properties of gas absorption from ILs can be integrated into a solid system. The simulant dimethylmethylphosophnate (DMMP) was utilized in gas capture investigations as a model for sarin gas. In order to understand the impact of the cation-anion pair selection in the IL, DMMP absorption tests were conducted in neat ILs. This was done by flowing argon saturated in DMMP through the ionic liquids and monitoring the DMMP detection via a Residual Gas Analyzer (RGA). The highest absorption capacity of DMMP in the ILs tested of 0.68 mmol DMMP/mol IL was achieved using 1-butylpyridinium bis(trifluoromethylsulfonyl)imide ([Bpi][NTf2]). The ILs [Bpi][NTf2] and choline bis(trifluoromethylsulfonyl)imide ([ChO][NTf2]) were tethered to the AC using physisorption techniques. The technique was effective in tethering the ILs to the surface and allowing the ILs to remain partially tethered after independently being washed with deionized water and going through temperature programmed desorption (TPD) tests.
Peck, Devin, "Ionic Liquids Tethered to Activated Carbon for Capture of Airborne Toxins" (2017). CUNY Academic Works.