Do material discontinuities in silica affect vibration modes?

Volkov, VV ORCID: https://orcid.org/0000-0003-2990-3580, Belton, DJ and Perry, CC ORCID: https://orcid.org/0000-0003-1517-468X, 2018. Do material discontinuities in silica affect vibration modes? The Journal of Physical Chemistry A. ISSN 1089-5639

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Abstract

Structural properties of bioinorganic composites are of current interest in the areas of drug delivery, bone repair and biomimetics. In such composite systems, structural analysis is enhanced when we combine methods of spectroscopy and simulation. Depending on size and shape, structural discontinuities of inorganic matter may modulate the optical response of a bound molecule. Using Density Functional Theory we explore the effects of a local field next to the surface of a silica cluster on frequencies of methyl stretching modes of associated methanols. Computation results predict that the electrostatic potential modulated by structural discontinuities of silica should not contribute to any systematic frequency shifts for normal modes of a guest molecule. Regardless of position, the methyl stretching modes of methanol demonstrate sensitivity only to the local chemistry of bonding with silanols, which may lead either to a low or to high frequency shift for vibrations. In support, experimental studies of deuterated methanol at impurity levels in water show uniform broadening of resonances of Carbon–Deuterium stretching modes in the presence of both crystalline and amorphous silica nanoparticles. The significance of these findings is that the spectral responses of guest molecules on such surfaces should not be subject to bias introduced by edge effects.

Item Type:	Journal article
Publication Title:	The Journal of Physical Chemistry A
Creators:	Volkov, V.V., Belton, D.J. and Perry, C.C.
Publisher:	American Chemical Society
Date:	8 May 2018
ISSN:	1089-5639
Identifiers:	Number Type 10.1021/acs.jpca.8b01688 DOI
Divisions:	Schools > School of Science and Technology
Record created by:	Jonathan Gallacher
Date Added:	14 May 2018 10:14
Last Modified:	07 Feb 2022 14:53
URI:	https://irep.ntu.ac.uk/id/eprint/33554

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