Journal of the Mineralogical Society of Korea (한국광물학회지)

The Mineralogical Society of Korea (한국광물학회)
권호 표지
DOI QR코드

DOI QR Code

Application of Computational Mineralogy to Studies of Hydroxyls in Clay Minerals

전산광물학을 이용한 점토광물 내의 수산기 연구 가능성

  • 채진웅 (강원대학교 자연과학대학 지질학과) ;
  • 권기덕 (강원대학교 자연과학대학 지질학과)
  • Received : 2014.11.26
  • Accepted : 2014.12.16
  • Published : 2014.12.30
Download PDF
⟨ Previous Next ⟩

Abstract

The physicochemical properties of clay minerals have been investigated at the atomistic to nano scale. The microscopic studies are often challenging to perform by using experimental approaches alone. In particular, hydroxyl groups of octahedral sheets in 2:1 clay minerals have been hypothesized to impact the sorption process of metal cations; however, X-ray based techniques alone, a common tool for mineral structure examination, cannot properly test the hypothesis. The current study has examined whether computational mineralogy techniques can be applied to examine the hydroxyl structures of clay minerals. Based on quantum-mechanics and molecular-mechanics computational methods, geometry optimizations were carried out for representative dioctahedral and trioctahedral phyllosilicate minerals. Both methods well reproduced the experimental lattice parameters; however, for structural distortion occurring in the tetrahedral or octahedral sheets, molecular mechanics showed significant deviations from experimental data. The orientation angle of the hydroxyl with respect to (001) basal plane is determined by the balance of repulsion between the hydroxyl proton and Si cations of tetrahedral sites; the quantum-mechanics method predicted $25-26^{\circ}$ for the angle, whereas the angle predicted by the molecular-mechanics method was much higher by $10^{\circ}$ (i.e., $35^{\circ}$). These results demonstrate that computational mineralogy techniques are a reliable tool for clay mineral studies and can be used to further elucidate the roles of hydroxyls in metal sorption process.

점토광물의 물리화학적 특성에 대한 분자 또는 원자 스케일의 연구 중요성이 강조되고 있다. 그러나 실험만으로는 광물의 미시적 현상을 이해하기 어려운 경우가 많다. 특히 2:1 점토광물 팔면체에 존재하는 수산기(hydroxyl)가 금속 양이온 흡착과정에 큰 역할을 한다는 가정은 X-ray를 이용하는 실험만으로는 명확하게 테스트하기 어렵다. 이번 논문에서는 점토광물 내의 수산기 연구에 대한 전산광물학(computational mineralogy) 이용 가능성에 대하여 조사하였다. 점토광물의 기본구조인 팔면체 층만으로 구성된 광물, 1:1 구조를 갖는 광물, 2:1 구조를 갖는 광물 중 대표적인 이팔면체 및 삼팔면체 층상규산염 광물을 선별하여 구조최적화를 실시하였다. 분자역학적(molecular mechanics) 계산과 양자역학적(quantum mechanical) 계산 모두 실험값의 격자상수(lattice parameters)를 잘 재현할 수 있었다. 그러나, 사면체층과 팔면체의 구조적 뒤틀림(structural distortion) 등 광물 내부구조를 기존 실험결과와 비교했을 때, 양자역학적 계산결과가 분자역학적 방법을 이용한 결과 보다 더 낮은 오차를 보였다. 파이로필라이트(pyrophyllite) 수산기가 (001)면과 이루는 각은, 수산기의 H(proton)과 사면체의 Si 양이온 간의 척력으로 결정되는데, 양자역학적 방법은 약 $25-26^{\circ}$로 예측하였고, 분자역학적 방법은 약 $35^{\circ}$ 정도로 양자역학계산 결과와 무려 $10^{\circ}$의 큰 차이를 보였다. 전산광물학은 점토광물 구조연구에 신뢰성이 매우 높은 연구방법으로 양이온 흡착과정 중 수산기의 역할 규명에 사용될 수 있다.

Keywords

References

  1. Bish, D.L. (1993) Rietveld refinement of the kaolinite structure at 1.5 K. Clays and Clay Minerals, 41, 738-744. https://doi.org/10.1346/CCMN.1993.0410613
  2. Bridgeman, C.H., Buckingham, A.D., Skipper, N.T., and Payne, M.C. (1996) Ab-initio total energy study of uncharged 2:1 clays and their interaction with water. Molecular Physics, 89, 879-888. https://doi.org/10.1080/00268979609482512
  3. Clark, S.J., Segall, M.D., Pickard, C.J., Hasnip, P.J., Probert, M.J., Refson, K., and Payne, M.C. (2005) First principles methods using CASTEP. Zeitschrift fur Kristallographie, 220, 567-570.
  4. Cygan, R.T. (2001) Molecular modeling in mineralogy and geochemistry. Modelling in Mineralogy & Geochemistry, 42, 1-28. https://doi.org/10.2138/rmg.2001.42.1
  5. Cygan, R.T., Liang, J., and Andrey, G.K. (2004) Molecular models of hydroxide, oxyhydroxide, and clay phases and the development of a general force field. Journal of Physical Chemistry B, 108, 1255-1266. https://doi.org/10.1021/jp0363287
  6. Cygan, R.T., Romanov, V., and Myshakin, E. (2012) Molecular simulation of carbon dioxide capture by montmorillonite using an accurate and flexible force field. Journal of Physical Chemistry C, 116, 13079-13091. https://doi.org/10.1021/jp3007574
  7. Ewald, P.P. (1921) The computation of optical and electrostatic lattice potentials. Annals of Physics, 64, 253.
  8. Francis, G.P. and Payne, M.C. (1990) Finite basis set corrections to total energy pseudopotential calculations. Journal of Physics-Condensed Matter, 2, 4395-4404. https://doi.org/10.1088/0953-8984/2/19/007
  9. Franzini, M. (1969) Tha A and B mica layers and the crystal structure of sheet silicates. Contributions to Mineralogy and Petrology, 21, 203-224. https://doi.org/10.1007/BF00371751
  10. Giese, R.F. (1973) Hydroxyl orientation in pyrophyllite. Nature Physical Science, 241, 151-151.
  11. Gonzalez, M.A. (2011) Force fields and molecular dynamics simulations. Collection SFN, 12, 169-200. https://doi.org/10.1051/sfn/201112009
  12. Kohn, W. and Hohenberg, P. (1964) Inhomogeneous electron gas. Physical Review, 136, B864-B871. https://doi.org/10.1103/PhysRev.136.B864
  13. Kohn, W. and Sham, L.J. (1965) Self-consistent equations including exchange and correlation effects. Physical Review, 140, A1133-A1138. https://doi.org/10.1103/PhysRev.140.A1133
  14. Laurora, A., Brigatti, M.F., Malferrari, D., and Galli, E. (2011) The crystal chemistry of lizardite-1T from north apennines ophiolites near modena, italy. Canadian Mineralogist, 49, 1045-1054. https://doi.org/10.3749/canmin.49.4.1045
  15. Lee, J.H. and Guggenheim, S. (1981) Single crystal X-ray refinement of pyrophyllite-1tc. American Mineralogist, 66, 350-357.
  16. McCauley, J.W. and Newnham, R.E. (1971) Origin and prediction of ditrigonal distortions in micas. American Mineralogist, 56, 1626-1638.
  17. Mookherejee, M. and Stixrude, L. (2006) High-pressure proton disorder in brucite. American Mineralogist, 91, 127-134. https://doi.org/10.2138/am.2006.1886
  18. Murray, H.H. (2000) Traditional and new applications for kaolin, smectite, and palygorskite: a general overview. Applied Clay Science, 17, 207-221. https://doi.org/10.1016/S0169-1317(00)00016-8
  19. Perdew, J.P., Burke, K., and Ernzerhof, M. (1996) Generalized gradient approximation made simple. Physical Review Letters, 77, 3865-3868. https://doi.org/10.1103/PhysRevLett.77.3865
  20. Perdikatsis, B. (1981) Strukturverfeinerung am talk $Mg_3[(OH)_2Si_4O_{10}]$. Zeitschrift fur Kristallographie, 156, 177-186. https://doi.org/10.1524/zkri.1981.156.3-4.177
  21. Refson, K., Park, S., and Sposto, G. (2003) Ab initio computaional crystallography of 2:1 clay minerals: 1. pyrophyllite-1Tc. Journal of Physical Chemistry B, 107, 13376-13383. https://doi.org/10.1021/jp0347670
  22. Saalfeld, H. and Wedde, M. (1974) Refinement of the crystal structure of gibbsite, $Al(OH)_3$. Zeitschrift fur Kristallographie, 139, 129-135. https://doi.org/10.1524/zkri.1974.139.1-2.129
  23. Sposito, G., Skipper, N.T., Sutton, R., Park, S., Soper, A.K., and Greathouse, J.A. (1999) Surface geochemistry of the clay minerals. National Academy of Sciences Colloquium, 96, 3358-3364. https://doi.org/10.1073/pnas.96.7.3358
  24. Stackhouse, S., Coveney, P.V., and Sandre, E. (2001) Plane-wave density functional theoretic study of formation of clay-polymer nanocomposite materials by self-catalyzed in situ intercalative polymerization. Journal of the American Chemical Society, 123, 11764-11774. https://doi.org/10.1021/ja015808d
  25. Teppen, B.J., Rasmussen, K., Bertsch, P.M., Miller, D.M., and Schafer, L. (1997) Molecular dynamics modeling of clay minerals. 1. gibbsite, kaolinite, pyrophyllite, and beidellite. Journal of Physical Chemistry B, 101, 1579-1587. https://doi.org/10.1021/jp961577z
  26. Thompson M. and Ukrainczyk L. (2002) Soil Mineralogy with Environmental Applications. SSSA Book Series, 7, 431-466.
  27. Tunega, D., Bueko, T., and Zaoui, A. (2012) Assessment of ten DFT methods in predicting structures of sheet silicates: Importance of dispersion corrections. Journal of Chemical Physics, 137, 1-8.
  28. Vanderbilt, D. (1990) Soft self-consistent pseudopotentials in a generalized eigenvalue formalism. Physical Review B, 41, 7892-7895. https://doi.org/10.1103/PhysRevB.41.7892
  29. Voora, V.K., Al-Saidi, W.A., and Jordan, K.D. (2011) Density functional theory study of pyrophyllite and M-montmorillonites (M = Li, Na, K, Mg, and Ca): Role of dispersion interactions. Journal of Physical Chemistry A, 115, 9695-9703.
  30. Yi, Y.S. and Lee, S.K. (2014) Qunatum chemical claculations of the effect of Si-O bond length on X-ray raman scattering features for $MgSiO_3$ perovskite. Journal of the Mineralogical Society of Korea, 27, 1-15 (in Korean with English abstract). https://doi.org/10.9727/jmsk.2014.27.1.1

Cited by

  1. Effects of Fe Substitution on Lithium Incorporation into Muscovite vol.28, pp.2, 2015, https://doi.org/10.9727/jmsk.2015.28.2.127