A SANS study of the interfacial curvatures and the phase behavior in bicontinuous microemulsions

Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Nuclear Engineering, 1998.

Bibliographic Details
Main Author: Choi, Sung-Min, 1965-
Other Authors: Sow-Hsin Chen.
Format: Thesis
Language:eng
Published: Massachusetts Institute of Technology 2009
Subjects:
Online Access:http://hdl.handle.net/1721.1/50069
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author Choi, Sung-Min, 1965-
author2 Sow-Hsin Chen.
author_facet Sow-Hsin Chen.
Choi, Sung-Min, 1965-
author_sort Choi, Sung-Min, 1965-
collection MIT
description Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Nuclear Engineering, 1998.
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spelling mit-1721.1/500692020-03-31T14:25:01Z A SANS study of the interfacial curvatures and the phase behavior in bicontinuous microemulsions Small-angle neutron scattering study of the interfacial curvatures and the phase behavior in bicontinuous microemulsions Choi, Sung-Min, 1965- Sow-Hsin Chen. Massachusetts Institute of Technology. Department of Nuclear Science and Engineering Nuclear Engineering Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Nuclear Engineering, 1998. Includes bibliographical references (leaves 104-108). A microemulsion is a three-component system in which oil and water are solubilized via an interfacial surfactant monolayer. Depending on the composition and various external conditions, it exhibits a wide variety of phases with corresponding mesoscopic scale interfacial structures. For scientific as well as industrial purposes, knowledge of the relation between the interfacial structure and the phase behavior is crucial but its quantitative measure is lacking. To identify the relation in a quantitative way, the natural parameters to be measured are the interfacial curvatures : Gaussian, mean, and square mean curvatures. A new small-angle neutron scattering (SANS) data analysis method to extract the interfacial curvatures was developed and applied to various microemulsions. The method involves the use of a clipped random wave model with an inverse 8th order polynomial spectral function. The spectral density function contains three basic length scales : the inter-domain distance, the coherence length, and the surface roughness parameter. These three length scales are essential to describe mesoscopic scale interfaces. A series of SANS experiments were performed at various phase points of isometric and non-isometric microemulsions. Using the developed model, the three interfacial curvatures at each phase point were determined for the first time in a practical way. In isometric bicontinuous microemulsions, the Gaussian curvature is negative and has a parabolic dependence on the surfactant volume fraction. In non-isometric systems, based on the measured interfacial curvatures, a characteristic structural transformation was identified. As the water and oil volume ratio moves away from unity, the bicontinuous structure transforms to a spherical structure through an intermediate cylindrical structure. by Sung-Min Choi. Ph.D. 2009-12-10T19:08:01Z 2009-12-10T19:08:01Z 1998 1998 Thesis http://hdl.handle.net/1721.1/50069 43080391 eng 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. http://dspace.mit.edu/handle/1721.1/7582 136 leaves application/pdf Massachusetts Institute of Technology
spellingShingle Nuclear Engineering
Choi, Sung-Min, 1965-
A SANS study of the interfacial curvatures and the phase behavior in bicontinuous microemulsions
title A SANS study of the interfacial curvatures and the phase behavior in bicontinuous microemulsions
title_full A SANS study of the interfacial curvatures and the phase behavior in bicontinuous microemulsions
title_fullStr A SANS study of the interfacial curvatures and the phase behavior in bicontinuous microemulsions
title_full_unstemmed A SANS study of the interfacial curvatures and the phase behavior in bicontinuous microemulsions
title_short A SANS study of the interfacial curvatures and the phase behavior in bicontinuous microemulsions
title_sort sans study of the interfacial curvatures and the phase behavior in bicontinuous microemulsions
topic Nuclear Engineering
url http://hdl.handle.net/1721.1/50069
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AT choisungmin1965 sansstudyoftheinterfacialcurvaturesandthephasebehaviorinbicontinuousmicroemulsions