skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Hydrogen bonding between acetone and silica gel, as studied by NMR

Abstract

{sup 13}C NMR spectra and relaxation parameters (T{sub 1}{sup H}, T{sub 1}{sup C}, T{sub 1{rho}}{sup H}, T{sub CH}) were measured via CP-MAS and DP-MAS techniques as a function of acetone loading level in acetone/SiO{sub 2} samples at 25 C. T{sub 1}{sup H} and T{sub 1{rho}}{sup H} values were also measured via {sup 29}Si CP-MAS experiments. Peak positions and relaxation parameters are averaged by rapid exchange between different acetone interaction sites on the surface. The data were analyzed in terms of a surface equilibrium of adsorbed acetone units between hydrogen-bonding and non-hydrogen-bonding sites. Data analysis by this model yielded the surface concentration of hydrogen-bonding (silanol) sites (1.5 nm{sup {minus}2}) and the equilibrium constant (K = 3.0 nm{sup 2}). Variable-temperature experiments (124--297 K) at three loading levels yielded values of {Delta}H{degree} ({minus}5.8 {+-} 0.3 kJ mol{sup {minus}1}) and {Delta}S{degree} ({minus}12.5 {+-} 0.7 J K{sup {minus}1} mol{sup {minus}1}). A self-consistent qualitative interpretation of measured relaxation parameters is made in terms of the relative mobilities of hydrogen-bonded (less mobile) and non-hydrogen-bonded (more mobile) acetone on the SiO{sub 2} surface.

Authors:
; ; ;  [1]
  1. Colorado State Univ., Fort Collins, CO (United States). Dept. of Chemistry
Publication Date:
Sponsoring Org.:
USDOE, Washington, DC (United States)
OSTI Identifier:
691304
DOE Contract Number:  
FG03-95ER14558
Resource Type:
Journal Article
Journal Name:
Journal of Physical Chemistry B: Materials, Surfaces, Interfaces, amp Biophysical
Additional Journal Information:
Journal Volume: 103; Journal Issue: 33; Other Information: PBD: 19 Aug 1999
Country of Publication:
United States
Language:
English
Subject:
40 CHEMISTRY; BONDING; SILICA GEL; NUCLEAR MAGNETIC RESONANCE; ACETONE; HYDROGEN; CARBON 13

Citation Formats

Pan, V.H., Tao, T., Zhou, J.W., and Maciel, G.E. Hydrogen bonding between acetone and silica gel, as studied by NMR. United States: N. p., 1999. Web. doi:10.1021/jp990912r.
Pan, V.H., Tao, T., Zhou, J.W., & Maciel, G.E. Hydrogen bonding between acetone and silica gel, as studied by NMR. United States. doi:10.1021/jp990912r.
Pan, V.H., Tao, T., Zhou, J.W., and Maciel, G.E. Thu . "Hydrogen bonding between acetone and silica gel, as studied by NMR". United States. doi:10.1021/jp990912r.
@article{osti_691304,
title = {Hydrogen bonding between acetone and silica gel, as studied by NMR},
author = {Pan, V.H. and Tao, T. and Zhou, J.W. and Maciel, G.E.},
abstractNote = {{sup 13}C NMR spectra and relaxation parameters (T{sub 1}{sup H}, T{sub 1}{sup C}, T{sub 1{rho}}{sup H}, T{sub CH}) were measured via CP-MAS and DP-MAS techniques as a function of acetone loading level in acetone/SiO{sub 2} samples at 25 C. T{sub 1}{sup H} and T{sub 1{rho}}{sup H} values were also measured via {sup 29}Si CP-MAS experiments. Peak positions and relaxation parameters are averaged by rapid exchange between different acetone interaction sites on the surface. The data were analyzed in terms of a surface equilibrium of adsorbed acetone units between hydrogen-bonding and non-hydrogen-bonding sites. Data analysis by this model yielded the surface concentration of hydrogen-bonding (silanol) sites (1.5 nm{sup {minus}2}) and the equilibrium constant (K = 3.0 nm{sup 2}). Variable-temperature experiments (124--297 K) at three loading levels yielded values of {Delta}H{degree} ({minus}5.8 {+-} 0.3 kJ mol{sup {minus}1}) and {Delta}S{degree} ({minus}12.5 {+-} 0.7 J K{sup {minus}1} mol{sup {minus}1}). A self-consistent qualitative interpretation of measured relaxation parameters is made in terms of the relative mobilities of hydrogen-bonded (less mobile) and non-hydrogen-bonded (more mobile) acetone on the SiO{sub 2} surface.},
doi = {10.1021/jp990912r},
journal = {Journal of Physical Chemistry B: Materials, Surfaces, Interfaces, amp Biophysical},
number = 33,
volume = 103,
place = {United States},
year = {1999},
month = {8}
}