Study of slow dynamics in supercooled water by molecular dynamics and quasi-elastic neutron scattering

The slow dynamics of supercooled water is studied by modelling the spectrum of test particle fluctuations: intermediate scattering function (ISF). The theoretical models are compared with experimental measurements by quasi-elastic neutron scattering (QENS) and molecular dynamics (MD) simulation results. The dynamics of supercooled water can be decoupled into a product of translational and rotational dynamics. While the translational dynamics is modelled well by a product of a ISF representing short time in-cage vibrations and long time cage relaxation processes, the rotational dynamics is an aspect we shall study in this thesis. We introduce a model for the first, second and third order rotational correlation functions, which are required for the computation of the rotational intermediate scattering function corresponding to the incoherent QENS spectra from supercooled water. The model is tested against MD data generated from an extended-simple-point-charge (SPC/E) model of water and is found to be satisfactory. The analysis can be used as a practical method for extracting rotational relaxation parameters from QENS spectra measured at large Q from supercooled bulk water or interfacial water in porous materials.

Department dc:contributor.department

Massachusetts Institute of Technology. Department of Nuclear Engineering

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2005

Author dc:creator

• Liu, Li

Advisor dc:contributor.advisor

• Sow-Hsin Chen.

• Nuclear Engineering.

Statement dc:rights

• M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/34440
• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

eng

Identifier URI

http://dspace.mit.edu/handle/1721.1/34440

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/34440