Dependency of highest occupied molecular orbital (homo) electron density on freundlich exponent

摘要

In this study chloro- and nitrophenols were used as the test adsorbates, and modified, non-modified granular activated carbon (GAC), and macroreticular synthetic resin were used as the adsorbent. These adsorbents have carbonaceous structure, with different surface properties. The isotherms for all three systems were determined by the so-called batch bottle technique. The Highest Occupied Molecular Orbital (HOMO) electron density at the adsorption site was estimated by CAChE program, because it is suggested that the electron density will affect the adsorption isotherm. A qualitative relationship between Freundlich 1/n and the HOMO density of adsorbent was found by combining the experimental and computational results for modified GAC. The value of Freundlich 1/n for all adsorbent systems including modified GAC was decreasing linearly with an increase in "adsorbent" HOMO density. The HOMO electron density of both the adsorbate and the adsorbent was one of the major factors that determined the Freundlich Exponent, 1/n, for phenolic adsorbates - carbonecious adsorbents systems.