Abstract

Inelastic neutron scattering spectra of silica gel with low concentrations of water, 3 and 10%, were measured at 5 K. The experimental spectrum for the lower fraction of water (3%) in silica gel shows dramatic changes compared to the spectra of other known ice phases in the energy transfer region of 2--140 meV. Its intermolecular librational band ranges from 47 to 102 meV shifted to lower energy by about 20 meV (or by a factor 1.43) compared to ice Ih (67--119 meV), and shows a similar librational band with liquid. A significant excess of low frequency vibration modes (7 meV) over normal ice Ih and a very wide acoustic peak (4--15 meV) were observed. Experimental data indicate that little ${\mathrm{H}}_{2}\mathrm{O}$ (3%) in silica gel exhibits a strong softening of hydrogen bonds compared to bulk normal ice and all other known ice phases.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.