Journal of Colloid and Interface Science, Vol.300, No.2, 805-808, 2006
Determining molecule-carbon surface adsorption energies using molecular mechanics and graphene nanostructures
Five model surfaces were developed using molecular mechanics with MM2 parameters. A smooth, flat model surface was constructed of three parallel graphene layers where each graphene layer contained 127 interconnected benzene rings. Four rough surfaces were constructed by varying the separation between a pair of graphene nanostructures placed on the topmost layer of graphene. Each nanostructure contained 17 benzene rings arranged in a linear strip. The parallel nanostructures were moved closer together to increase the surface roughness and to enhance the molecule-surface interaction. Experimental adsorption energy values from the temperature variation of second gas-solid virial coefficients values were available for 16 different alkanes, haloalkanes, and ether molecules adsorbed on Carbopack B (Supelco, 100 m(2)/g). For each of the five different surface models, sets of 16 calculated adsorption energies, E-cal*, were determined and compared to the available experimental adsorption energies, E*. The best linear regression correlation between E* and E-cal* was found for a 1.20 nm internuclei separation of the surfacenanostructures, and for this surface model the calculated gas-solid interaction energies closely matched the experimental values (E*=1.018E(cal)*, r(2) = 0.964). (c) 2006 Elsevier Inc. All rights reserved.
Keywords:adsorption;Henry's law;adsorption;carbon;on;virial coefficients;gas-solid;molecular mechanics surface energy;adsorption energy