The model structure of kaolinite in relation to surface complexation

Markus Olin, Eini Puhakka, Jarmo Lehikoinen

Research output: Chapter in Book/Report/Conference proceedingConference abstract in proceedingsScientific

Abstract

Surface complexation modelling using the FITEQL software was applied to explain the surface acidity of kaolinite. In this context, a number of different models and modelling approaches were tested. Further, a density functional method, CASTEP (Accelrys, 2001), was used to investigate the crystal and surface structures of kaolinite, and to calculate surface charge densities. To enable the interpretation of adsorpti-on results with surface complexation modelling, an adequate characterization of the surface charging of the adsorbent is needed. In general, titration experiments are capable of providing this information for ionisable interfaces. However, results based on experimental data give only average values of surface charge densities. Therefore, in this study, molecular modelling was used to calculate surface charge den-sities of likely the most reactive kaolinite crystal faces separately. Based on this information, an attempt will be made to constrain the number of surface sites and magnitude of surface hydrolysis constants, of-ten considered as adjustable parameters devoid of deeper understanding, in surface complexation models. The molecular-level modelling produced invaluable background information of the kaolinite surface for further development of surface complexation models in terms of the surface charging and the adsorption of metal cations.
Original languageEnglish
Title of host publicationGoldschmidt Conference Abstracts 2007
Publication statusPublished - 2007
EventGoldschmidt 2007 - "atoms to planets" - Cologne, Germany
Duration: 19 Aug 2007 → …

Conference

ConferenceGoldschmidt 2007 - "atoms to planets"
CountryGermany
CityCologne
Period19/08/07 → …

Fingerprint

complexation
kaolinite
modeling
den
crystal structure
acidity
hydrolysis
cation
crystal
adsorption
software

Cite this

Olin, M., Puhakka, E., & Lehikoinen, J. (2007). The model structure of kaolinite in relation to surface complexation. In Goldschmidt Conference Abstracts 2007 [A737]
Olin, Markus ; Puhakka, Eini ; Lehikoinen, Jarmo. / The model structure of kaolinite in relation to surface complexation. Goldschmidt Conference Abstracts 2007. 2007.
@inbook{0b4a9a46671e4d5baecfbd1c3fb17ad7,
title = "The model structure of kaolinite in relation to surface complexation",
abstract = "Surface complexation modelling using the FITEQL software was applied to explain the surface acidity of kaolinite. In this context, a number of different models and modelling approaches were tested. Further, a density functional method, CASTEP (Accelrys, 2001), was used to investigate the crystal and surface structures of kaolinite, and to calculate surface charge densities. To enable the interpretation of adsorpti-on results with surface complexation modelling, an adequate characterization of the surface charging of the adsorbent is needed. In general, titration experiments are capable of providing this information for ionisable interfaces. However, results based on experimental data give only average values of surface charge densities. Therefore, in this study, molecular modelling was used to calculate surface charge den-sities of likely the most reactive kaolinite crystal faces separately. Based on this information, an attempt will be made to constrain the number of surface sites and magnitude of surface hydrolysis constants, of-ten considered as adjustable parameters devoid of deeper understanding, in surface complexation models. The molecular-level modelling produced invaluable background information of the kaolinite surface for further development of surface complexation models in terms of the surface charging and the adsorption of metal cations.",
author = "Markus Olin and Eini Puhakka and Jarmo Lehikoinen",
note = "Project code: 13320",
year = "2007",
language = "English",
booktitle = "Goldschmidt Conference Abstracts 2007",

}

Olin, M, Puhakka, E & Lehikoinen, J 2007, The model structure of kaolinite in relation to surface complexation. in Goldschmidt Conference Abstracts 2007., A737, Goldschmidt 2007 - "atoms to planets", Cologne, Germany, 19/08/07.

The model structure of kaolinite in relation to surface complexation. / Olin, Markus; Puhakka, Eini; Lehikoinen, Jarmo.

Goldschmidt Conference Abstracts 2007. 2007. A737.

Research output: Chapter in Book/Report/Conference proceedingConference abstract in proceedingsScientific

TY - CHAP

T1 - The model structure of kaolinite in relation to surface complexation

AU - Olin, Markus

AU - Puhakka, Eini

AU - Lehikoinen, Jarmo

N1 - Project code: 13320

PY - 2007

Y1 - 2007

N2 - Surface complexation modelling using the FITEQL software was applied to explain the surface acidity of kaolinite. In this context, a number of different models and modelling approaches were tested. Further, a density functional method, CASTEP (Accelrys, 2001), was used to investigate the crystal and surface structures of kaolinite, and to calculate surface charge densities. To enable the interpretation of adsorpti-on results with surface complexation modelling, an adequate characterization of the surface charging of the adsorbent is needed. In general, titration experiments are capable of providing this information for ionisable interfaces. However, results based on experimental data give only average values of surface charge densities. Therefore, in this study, molecular modelling was used to calculate surface charge den-sities of likely the most reactive kaolinite crystal faces separately. Based on this information, an attempt will be made to constrain the number of surface sites and magnitude of surface hydrolysis constants, of-ten considered as adjustable parameters devoid of deeper understanding, in surface complexation models. The molecular-level modelling produced invaluable background information of the kaolinite surface for further development of surface complexation models in terms of the surface charging and the adsorption of metal cations.

AB - Surface complexation modelling using the FITEQL software was applied to explain the surface acidity of kaolinite. In this context, a number of different models and modelling approaches were tested. Further, a density functional method, CASTEP (Accelrys, 2001), was used to investigate the crystal and surface structures of kaolinite, and to calculate surface charge densities. To enable the interpretation of adsorpti-on results with surface complexation modelling, an adequate characterization of the surface charging of the adsorbent is needed. In general, titration experiments are capable of providing this information for ionisable interfaces. However, results based on experimental data give only average values of surface charge densities. Therefore, in this study, molecular modelling was used to calculate surface charge den-sities of likely the most reactive kaolinite crystal faces separately. Based on this information, an attempt will be made to constrain the number of surface sites and magnitude of surface hydrolysis constants, of-ten considered as adjustable parameters devoid of deeper understanding, in surface complexation models. The molecular-level modelling produced invaluable background information of the kaolinite surface for further development of surface complexation models in terms of the surface charging and the adsorption of metal cations.

M3 - Conference abstract in proceedings

BT - Goldschmidt Conference Abstracts 2007

ER -

Olin M, Puhakka E, Lehikoinen J. The model structure of kaolinite in relation to surface complexation. In Goldschmidt Conference Abstracts 2007. 2007. A737