Pressure-induced hydration explained

Pressure-induced hydration (PIH), also known as “super-hydration”, is a special case of pressure-induced insertion whereby water molecules are injected into the pores of microporous materials. In PIH, a microporous material is placed under pressure in the presence of water in the pressure-transmitting fluid of a diamond anvil cell.^{[1] [2]}

Early physical characterization^[3] and initial diffraction experiments^[4] in zeolites were followed by the first unequivocal structural characterization of PIH in the small-pore zeolite natrolite (Na₁₆Al₁₆Si₂₄O₈₀·16H₂O), which in its fully super-hydrated form, Na₁₆Al₁₆Si₂₄O₈₀·32H₂O, doubles^[5] the amount of water it contains in its pores.

PIH has now been demonstrated in natrolites containing Li, K, Rb and Ag as monovalent cations^{[6] [7]} as well as in large-pore zeolites,^[8] pyrochlores,^[9] clays^[10] and graphite oxide.^[11]

Using the noble gases Ar, Kr, and Xe as well as CO₂ as pressure-transmitting fluids, researchers have prepared and structurally characterized the products of reversible, pressure-induced insertion of Ar^[12] Kr,^[13] and CO₂^[14] as well as the irreversible insertion of Xe and water.^[15]

Notes and References

1. Web site: Crystal's Strange Behavior Could Enable Chemical Cleanup. Scientific American.
2. Frameworks under pressure. 10.1038/nmat805. 2003. Baur. Werner H.. Nature Materials. 2. 1. 17–18. 12652666. 137248079.
3. Moroz et al., Microporous and Mesoporous Materials 42 113 (2001)
4. R. M. Hazen, Science, 219, 1065 (1983)
5. Y. Lee, J.A. Hriljac, T. Vogt, J. B. Parise, G. Artioli, J. Am. Chem. Soc. 2001, 123, 12732-12733
6. D. Seoung, Y. Lee, CC Kao, T. Vogt, Y. Lee, Chem. Eur. J. 2013, 19, 10876-10883
7. Y. Lee, D. Seoung, Y-N Jang, T. Vogt, Y. Lee, Chem. Eur. J. 2013, 19, 5806-5811
8. M. Colligan, P.M. Forster, A.K. Cheetham, Y. Lee, T. Vogt, J.A. Hriljac J. Am. Chem. Soc. 2004, 126, 12015-12022
9. P.W. Barnes, P.M. Woodward, Y. Lee, T. Vogt, J.A. Hriljac J. Am. Chem. Soc., 2003, 125 (15), pp 4572–4579
10. Shujie You, Daniel Kunz, Matthias Stöter, Hussein Kalo, Bernd Putz, Josef Breu, Alexandr V. Talyzin. Angewandte Chemie International Edition, 2013; 52 (14): 3891
11. Alexandr V. Talyzin, Vladimir L. Solozhenko, Oleksandr O. Kurakevych, Tams Szab, Imre Dekany, Alexandr Kurnosov, and Vladimir Dmitriev Angew. Chem. Int. Ed. 2008, 47, 8268 –8271
12. Y. Lee, J.A. Hriljac, T. Vogt J. Phys. Chem. C 114, 6922-6927 (2010)
13. Donghoon Seoung, Yongmoon Lee, Hyunchae Cynn, Changyong Park, Kwang-Yong Choi, Douglas A Blom, William J Evans, Chi-Chang Kao, Thomas Vogt, Yongjae Lee, Nature chemistry 6(9), 835-829 (2014)
14. Y. Lee, D. Liu, D. Seoung, Z. Liu, CC Kao, T. Vogt J. Am. Chem. Soc. 2011, 133(6), 1674 - 1677
15. Yongjae Lee, Thomas Vogt, Joseph A. Hriljac, John B. Parise, Jonathan C. Hanson & Sun Jin Kim, Nature 420, 485-489 (2002)