Hostname: page-component-7479d7b7d-fwgfc Total loading time: 0 Render date: 2024-07-12T13:16:20.274Z Has data issue: false hasContentIssue false
  • English
  • Français

Molecular Orbital Modeling of Water Adsorption on a Tetrasiloxane Ring

Published online by Cambridge University Press:  28 February 2011

J. K. West  and
S. Wallace
J. K. West
Affiliation:
Advanced Materials Research Center, University of Florida, One Progress Blvd. #14, Alachua, Fl 32615.
S. Wallace
Affiliation:
Advanced Materials Research Center, University of Florida, One Progress Blvd. #14, Alachua, Fl 32615.
Get access

Abstract

A water molecule hydrogen bonded to a surface SiOH group produces an IR vibrational transmission peak (ν3) at 2.82 μm. Water was adsorbed into the pores of a metal alkoxide derived silica gel monolith, and the increase in the wavelength of the first vibrational overtone (2ν3) of this peak was measured as a function of the adsorbed water content W (g H2O/g SiO2). The peak shifted from 1.390 to 1.420 μm as W increased by 0.14 g/g. Intermediate Neglect of Differential Overlap (INDO) Molecular Orbital (MO) theory was used to model this process. The effect of a H2O molecule, hydrogen bonded to a hydroxylated tetrasiloxane ring, on the structure of the ring and the water molecule was investigated. The bond length of the O-H group H-bonded to the water molecule increased, as expected from the increase in wavelength of the 2ν3 IR peak.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 180: Symposium A – Better Ceramics Through Chemistry IV , 1990 , 255
Copyright
Copyright © Materials Research Society 1990

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

1. Wang, S.H., Ph.D Dissertation, University of Florida, 1988.Google Scholar
2. Perry, C.C. and Li, X., “N.I.R. Studies of Monolithic Silica Gels,” to be published in J. Chem. Soc. Faraday I Trans.Google Scholar
3. West, J.K., Zhu, B.F., Cheng, Y.C. and Hench, L.L., “Quantum Chemistry of sol-Gel Silica Clusters,” 5th International Workshop on Glasses and Glass Ceramics from Gels, Aug. 1989, Rio De Janeiro, Brazil.Google Scholar
4. Hench, L.L and West, J.K., Chemical Reviews 90, 33–72 (1990).Google Scholar
5. Zhu, B.F., Wang, G.F. and Hench, L.L., “Dilatometry of Gel-Silica,” 4th International Conference on Ultrastructure Processing of Ceramics, Glasses and Composites February 1989 Tucson, Arizona.Google Scholar
6. Zerner, M.C., Loew, G.H., Kirchner, R.F. and Mueller-Westerhoff, U.T., J. Am. Chem. Soc. 102, 589 (1980).Google Scholar
7. Zerner, M. et al. , QTP, Univ. of Florida, Gainesville, Fl, Pgm No. 010183.Google Scholar
8. Wright, A.C. and Erwin Desa, J.A., Phys. Chem. Glasses 19, 140 (1978).Google Scholar
9. Brinker, C.J., Tallant, D.R., Roth, B.P. and Ashley, C.S., MRS Symp. Proceedings 61, 387 (1986).Google Scholar