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: Role of surface oxygen groups in incorporation of nitrogen to activated carbons via ethylmethylamine adsorption.
    Author: El-Sayed Y, Bandosz TJ.
    Journal: Langmuir; 2005 Feb 15; 21(4):1282-9. PubMed ID: 15697272.
    Abstract:
    Coal origin and wood origin activated carbons were used in this study. To broaden the spectrum of surface features, the surface of the initial samples was modified using oxidation with nitric acid or impregnation with urea followed by heat treatment. Boehm and potentiometric titrations, thermal analysis, and sorption of nitrogen were used to characterize the pore structure and surface chemistry. Then adsorption of ethylmethylamine from aqueous solutions was carried out without controlling the pH of the carbon suspension. The isotherms were measured at 299 K and fitted to the Freundlich equation. The results showed that the amount of ethylmethylamine adsorbed on all carbons at a high concentration is dependent on the total number of surface groups whereas at low concentration it depends on the type of surface groups. The latter was observed exclusively for initial and oxidized carbons where acidic groups are present. The ethylmethylamine adsorption is mainly governed by dipole-dipole, hydrogen bonding, or specific acid-base interactions. Those interactions play a crucial role in incorporation of nitrogen to the carbon matrix at elevated temperatures.
    [Abstract] [Full Text] [Related] [New Search]