Imperial College London
Alternate

ProfessorMatthewJackson

Faculty of Engineering, Department of Earth Science & Engineering

Chair in Geological Fluid Dynamics
 
 
 
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Contact

 

+44 (0)20 7594 6538m.d.jackson

 
 
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Location

 

1.34Royal School of MinesSouth Kensington Campus

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Summary

 

Publications

Citation

BibTex format

@article{Al:2016:10.1016/j.cis2016.12.006,
author = {Al, Mahrouqi D and Vinogradov, J and Jackson, MD},
doi = {10.1016/j.cis2016.12.006},
journal = {Advances in Colloid and Interface Science},
pages = {60--76},
title = {Zeta potential of artificial and natural calcite in aqueous solution},
url = {http://dx.doi.org/10.1016/j.cis2016.12.006},
volume = {240},
year = {2016}
}
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RIS format (EndNote, RefMan)

TY  - JOUR
AB  - Despite the broad range of interest and applications, controls on calcite surface charge in aqueous solution, especiallyat conditions relevant to natural systems, remain poorly understood. The primary data source to understandcalcite surface charge comprises measurements of zeta potential. Here we collate and review previousmeasurements of zeta potential on natural and artificial calcite and carbonate as a resource for future studies,compare and contrast the results of these studies to determine key controls on zeta potential and where uncertaintiesremain, and report new measurements of zeta potential relevant to natural subsurface systems.The results show that the potential determining ions (PDIs) for the carbonate mineral surface are the lattice ionsCa2+, Mg2+ and CO32−. The zeta potential is controlled by the concentration-dependent adsorption of these ionswithin the Stern layer, primarily at the Outer Helmholtz Plane (OHP). Given this, the Iso-Electric Point (IEP) atwhich the zeta potential is zero should be expressed as pCa (or pMg). It should not be reported as pH, similarto most metal oxides.The pH does not directly control the zeta potential. Varying the pH whilst holding pCa constant yields constantzeta potential. The pH affects the zeta potential only by moderating the equilibrium pCa for a given CO2 partialpressure (pCO2). Experimental studies that appear to yield a systematic relationship between pH and zeta potentialare most likely observing the relationship between pCa and zeta potential, with pCa responding to the changein pH. New data presented here show a consistent linear relationship between equilibrium pH and equilibriumpCa or pMg irrespective of sample used or solution ionic strength. The surface charge of calcite is weakly dependenton pH, through protonation and deprotonation reactions that occur within a hydrolysis layer immediatelyadjacent to the mineral surface. The Point of Zero Charge (PZC) at which the surface charge is zero could b
AU  - Al,Mahrouqi D
AU  - Vinogradov,J
AU  - Jackson,MD
DO  - 10.1016/j.cis2016.12.006
EP  - 76
PY  - 2016///
SN  - 0001-8686
SP  - 60
TI  - Zeta potential of artificial and natural calcite in aqueous solution
T2  - Advances in Colloid and Interface Science
UR  - http://dx.doi.org/10.1016/j.cis2016.12.006
UR  - http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000395220400004&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=1ba7043ffcc86c417c072aa74d649202
UR  - http://hdl.handle.net/10044/1/49483
VL  - 240
ER  -
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