These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Molecular properties and intermolecular forces--factors balancing the effect of carbon surface chemistry in adsorption of organics from dilute aqueous solutions.
    Author: Terzyk AP.
    Journal: J Colloid Interface Sci; 2004 Jul 01; 275(1):9-29. PubMed ID: 15158374.
    Abstract:
    Presented paper recapitulates the results of 6 years' study concerning the effect of carbon surface chemical composition on adsorption of paracetamol, phenol, acetanilide, and aniline from dilute aqueous solutions on carbons. Adsorption-desorption isotherms, enthalpy, and kinetics of adsorption data are shown for the measurements performed at three temperatures (300, 310, and 320 K) at two pH levels (1.5 and 7) on commercial activated carbons. The data were obtained for four carbons: the initial carbon D43/1 and forms modified by applying concentrated HNO3, fuming H2SO4, and gaseous NH3. The modification procedures do not change the porosity in a drastic way, but lead to drastic changes of the composition of carbon surface layer. By applying MOPAC (a general-purpose semiempirical molecular orbital package), the physicochemical constants characterizing the molecules of adsorbates are calculated, including the distribution of the Mulliken charges, the dipole moments and ionization potentials, and the energies of interaction with the unique positive and negative charges. They are correlated with the parameters characterizing the adsorption (and kinetics) process of studied molecules on the mentioned above carbons. The mechanisms proposed in the literature for the description of adsorption from dilute aqueous solutions are verified, and a general mechanism of adsorption is proposed.
    [Abstract] [Full Text] [Related] [New Search]