M. S. KARMOUS

Copyright © 2011 SciRes. WJNSE

lower than the constants c alculated along a and b consis-

tent with the crystal structure of kaolinite [22].

4. Conclusions

In summary, these calculations have shown that the

computational techniques are a useful tool for investi-

gating clay structures and mechanical properties. Pre-

dicting the mechanical properties of minerals that are

difficult to obtain experimentally because of their small

particle size (typically <2 micrometers).

5. Acknowledgements

Dr KARMOUS Mohamed Salah is grateful to Dr David

S Coombes for his helpful discussion. Dr Julian Gale

(Imperial College, University of London) is also grate-

fully acknowledged for providing GULP and for useful

discussions.

6. References

[1] R. A. Young and A. W. Hewat, “Verification of the Tric-

linic Crystal Structure of Kaolinite,” Clays and Clay

Minerals, Vol. 36, No. 3, 1988, pp. 225-232.

doi:10.1346/CCMN.1988.0360303

[2] D. L. Bish, and C. T. Johnston, “Rietveld Refinement and

Fourier Transform Infrared Spectroscopic Study of the

Dickite Structure at Low Temperature,” Clays and Clay

Minerals, Vol. 41, No. 31, 1993, pp. 297-304.

doi:10.1346/CCMN.1993.0410304

[3] S. Naamen, H. B. Rhaiem, M. S. Karmous and A. B. H.

Amara, “XRD Study of the Stacking Mode of the Na-

crite/Alkali Halides Complexes,” Zeitschrift fur Kristal-

lographie, Vol. 23, No. 2, 2006, pp. 499-504

[4] M. S. Karmous, J. Samira, J.-L. Robert and A. B. H.

Amara, “Nature of Disorder in Synthetic Hectorite,” Ap-

plied Clay Science, Vol. 51, No. 1-2, 2011, pp. 23-32.

doi:10.1016/j.clay.2010.10.018

[5] T. Vanorio, M. Prasad and A. Nur, “Elastic Properties

of Dry Clay Mineral Aggregates, Suspensions and Sand-

stones,” Geophysical Journal International, Vol. 155, No.

1, 2003, pp. 319-326.

doi:10.1046/j.1365-246X.2003.02046.x

[6] K. S. Alexandrov and T. V. Ryzhova, “Elastic Properties

of Rock-Forming Minerals II. Layered Silicates,” Bulletin.

USSR Academy of Science, Geophysics, Vol. 9, No. ,

1961, pp. 165-1168.

[7] P. A. Berge and J. G. Berryman, “ Realizability of Nega-

tive Pore Compressibility in Poroelastic Composites,”

Journal of Applied Mechanics, Vol. 62, No. 4, 1995, pp.

1053-1062. doi:10.1115/1.2896042

[8] K. W. Katahara, “Clay Mineral Elastic Properties,” SEG

Annual Meeting Expanded Technical Programme Ab-

stracts, 1996.

[9] Z. Wang, H. Wang and M. E. Cates, “Effective Elastic

Properties of Solid Clays,” Geophysics, Vol. 66, No. 2,

2001, pp. 428-440. doi:10.1190/1.1444934

[10] C. Tosaya and A. Nur , “Effects of Diagenesis and Clays

on Compressional Velocities in Rocks,” Geophysical Re-

search Letters, Vol. 9, No. 1, 1982, pp. 5-8.

doi:10.1029/GL009i001p00005

[11] J. P. Castagna, D.-H. Han and M. L. Batzle, “Issues in

Rock Physics and Implications for DHI Interpretation,”

The Leading Edge, Vol. 14, No. , 1995, pp. 883-885.

doi:10.1190/1.1437178

[12] D. H. Han, A. Nur and D. Morgan, “Effects of Porosity

and Clay Content on Wave Velocities in Sandstones,”

Geophysics, Vol. 51, No. 11, 1986, pp. 2093-2107.

doi:10.1190/1.1442062

[13] S. Jemai, A. B. H. Amara, J. B. Brahim and A. Plançon,

“Structural Study of a 10 Å Unstable Hydrate of Kaoli-

nite,” Journal of Applied Crystallography, Vol. 33, No. 4,

2000, pp. 1075-1081. doi:10.1107/S0021889800004878

[14] B. Militzer, H.-R. Wenk, S. Stackhouse and L. Stixrude,

“First-Principles Calculation of the Elastic Moduli of

Sheet Silicates and Their Application to Shale Anisotro-

py,” American Mineralogist, Vol. 96, No. , 2011, pp 125-

137. doi:10.2138/am.2011.3558

[15] J. D. Gale, “GULP: A Computer Program for the Sym-

metry-Adapted Simulation of Solids,” Journal of the

Chemical Society - Faraday Transactions, Vol. 93, No. 4,

1997, pp. 629-637. doi:10.1039/a606455h

[16] B. G. Dick and A. W. Overhauser, “Theory of the Di-

electric Constants of Alkali Halide Crystals,” Physical

Review, Vol. 112, No. 1, 1958, pp. 90-103.

doi:10.1103/PhysRev.112.90

[17] K.-P. Schröder, J. Sauer, M. Leslie, C. Richard, A. Cat-

low and J. M. Thomas, “Bridging Hydrodyl Groups in

Zeolitic Catalysts: A Computer Simulation of Their

Structure, Vibrational Properties and Acidity in Proto-

nated Faujasites (HY Zeolites),” Chemical Physics Let-

ters, Vol. 188, No. 3-4, 1992, pp. 320-325.

doi:10.1016/0009-2614(92)90030-Q

[18] D. R. Collins and C. R. A Catl ow, “Computer Simulation

of Structures and Cohesive Properties of Micas,” Ameri-

can Mineralogist, Vol.77, No. 11-12, 1992, pp. 1172-

1181.

[19] D. S. Coombes, C. R. A. Catlow and J. M. Garcés,

“Computational Studies of Layered Silicates,” Modelling

and Simulation in Materials Science and Engineering,

Vol. 11, No. 3, 2003, pp. 301-306.

doi:10.1088/0965-0393/11/3/303

[20] P. H. J. Mercier and Y. Le Page, “Kaolin Polytypes Revi-

sited Abinitio,” Acta Crystallographica, Vol. 64, No. ,

2008, pp. 131-143. doi:10.1107/S0108768108001924

[21] R. B. Neder, M. Burghammer, T. Z. Grasl, H. Schul z, A.

Bram and S. Fiedler, “Refinement of the Kaolinite Struc-

ture from Single-Crystal Synchrotron Data,” Clays and

Clay Minerals, Vol.47, No. , 1999, pp. 487-494.

doi:10.1346/CCMN.1999.0470411