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Adsorption of L-lysine on montmorillonite

Citation

Parbhakar, A and Cuadros, J and Sephton, MA and Dubbin, W and Coles, BJ and Weiss, D, Adsorption of L-lysine on montmorillonite, Colloids and Surfaces A, 307 pp. 142-149. ISSN 0927-7757 (2007) [Refereed Article]

Copyright Statement

Copyright 2007 Elsevier B.V.

DOI: doi:10.1016/j.colsurfa.2007.05.022

Abstract

Amino acid adsorption on smectite is relevant to prebiotic processes involving possible catalytic reactions in the early Solar System, as implied by the clay-organic correlation found in meteorites, and the generation and modification of organic components essential for the origin of life. Here we report the results of a study investigating the adsorption of l-lysine (0.025–0.4 M) onto montmorillonite. The reaction products were studied using X-ray diffraction, chemical analysis and infrared spectroscopy.We find that lysine adsorption is first dominated by cation exchange and then by adsorption of electrically neutral lysine (as a zwitterion), as indicated by chemical and FTIR evidence. At the maximum concentration, lysine displaces only ∼1/3 of the original interlayer cations. The d-spacing of the smectite–lysine complex increases from 1.2 to 2.1 nm as more lysine enters the interlayer space, and water is expelled. We propose a structural model of lysine sorption in the interlayer in which lysine is oriented at >45–90◦ to the plane of siloxane O atoms.

Item Details

Item Type:Refereed Article
Keywords:lysine, smectite, amino acid, origin of life
Research Division:Earth Sciences
Research Group:Geology
Research Field:Geology not elsewhere classified
Objective Division:Expanding Knowledge
Objective Group:Expanding Knowledge
Objective Field:Expanding Knowledge in the Earth Sciences
Author:Parbhakar, A (Dr Anita Parbhakar-Fox)
ID Code:100616
Year Published:2007
Web of Science® Times Cited:33
Deposited By:Earth Sciences
Deposited On:2015-05-22
Last Modified:2015-09-07
Downloads:0

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