TY - JOUR
T1 - Toward modeling clay mineral nanoparticles
T2 - The edge surfaces of pyrophyllite and their interaction with water
AU - Martins, David M S
AU - Molinari, Marco
AU - Goncalves, Mário A.
AU - Mirão, José P.
AU - Parker, Stephen C.
N1 - No record of this in Eprints. HN 21/11/2017
PY - 2014/11/26
Y1 - 2014/11/26
N2 - The basal surfaces of phyllosilicate minerals have been widely studied, whereas the edge surfaces have received little attention. However, in order to simulate complete clay particles at the atomic level, the modeling of edge surfaces becomes crucially important, and such surfaces are likely to be far more active. We used a combination of quantum and potential based techniques to evaluate the structure of the edge surfaces of pyrophyllite and their interaction in an aqueous environment. These include {110}, {100}, {010}, {110}, {130}, and {130}. We found that the CLAYFF force field is an effective model for reproducing the DFT results. Furthermore, the results show that, for this notorious natural hydrophobic clay, all edge surfaces show hydrophilic behavior and that the precise structure of water above these surfaces is in fluenced by both the presence of hydroxyl groups and under-coordinated surface Al atoms; this will impact both geological processes where natural clays are involved and processes where such clays act as primary retention barriers to the dispersion of contaminants. (Figure Presented).
AB - The basal surfaces of phyllosilicate minerals have been widely studied, whereas the edge surfaces have received little attention. However, in order to simulate complete clay particles at the atomic level, the modeling of edge surfaces becomes crucially important, and such surfaces are likely to be far more active. We used a combination of quantum and potential based techniques to evaluate the structure of the edge surfaces of pyrophyllite and their interaction in an aqueous environment. These include {110}, {100}, {010}, {110}, {130}, and {130}. We found that the CLAYFF force field is an effective model for reproducing the DFT results. Furthermore, the results show that, for this notorious natural hydrophobic clay, all edge surfaces show hydrophilic behavior and that the precise structure of water above these surfaces is in fluenced by both the presence of hydroxyl groups and under-coordinated surface Al atoms; this will impact both geological processes where natural clays are involved and processes where such clays act as primary retention barriers to the dispersion of contaminants. (Figure Presented).
UR - http://www.scopus.com/inward/record.url?scp=84913559684&partnerID=8YFLogxK
U2 - 10.1021/jp5070853
DO - 10.1021/jp5070853
M3 - Article
AN - SCOPUS:84913559684
VL - 118
SP - 27308
EP - 27317
JO - Journal of Physical Chemistry C
JF - Journal of Physical Chemistry C
SN - 1932-7447
IS - 47
ER -