Structures of Surfactant System Studied by Positron Annihilation Lifetime Spectroscopy

Surfactant system has many applications in industry. Many investigations have been carried out on surfactants using various methods such as small-angle neutron scattering (SANS), small-angle x-ray scattering(SAXS),conductivity freeze-fracture electron microscopy and nuclear magnetic resonance(NMR...

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Main Author: Ibrahim, Rosdi
Format: Thesis
Language:English
English
Published: 1996
Subjects:
Online Access:http://psasir.upm.edu.my/id/eprint/8605/
http://psasir.upm.edu.my/id/eprint/8605/1/FSAS_1996_3_A.pdf
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author Ibrahim, Rosdi
author_facet Ibrahim, Rosdi
author_sort Ibrahim, Rosdi
building UPM Institutional Repository
collection Online Access
description Surfactant system has many applications in industry. Many investigations have been carried out on surfactants using various methods such as small-angle neutron scattering (SANS), small-angle x-ray scattering(SAXS),conductivity freeze-fracture electron microscopy and nuclear magnetic resonance(NMR).In the positron annihilation lifetime spectroscopy technique, the lifetime ('t2)of positron that interacts with surfactant medium is measured using fast coincidence system. The intensity of formation of orthopositronium(12), when positron interact with aggregate of surfactant system are sensitive to phase changes. In amphiphilic system with bicontinous character geometry of periodic phase can be explained using minimal surfaces. Factors influencing the topology includes the length of surfactant and cosurfactant tails and the aqueous volume fraction. Positron are readily attracted to these centres. Changes in the geometry of the interfacial layer thus will influence the lifetime and intensity of the orthopositronium atom formed. These parameters are obtainable using the POSITR ON FIT programme. In this study, three surfactant systems were investigated. Firstly, the intensity (12) and lifetime ("(2) of the Didodecyl DimethylAmmonium Bromide (ODAB) - Water - Octane system were measured at various amount of water content in the surfactant system in the diamond and body centred cubic phases. A symmetry transitions from diamond phase to body-centred cubic phase was observed in this system.
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English
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publishDate 1996
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spelling upm-86052012-06-11T07:22:57Z http://psasir.upm.edu.my/id/eprint/8605/ Structures of Surfactant System Studied by Positron Annihilation Lifetime Spectroscopy Ibrahim, Rosdi Surfactant system has many applications in industry. Many investigations have been carried out on surfactants using various methods such as small-angle neutron scattering (SANS), small-angle x-ray scattering(SAXS),conductivity freeze-fracture electron microscopy and nuclear magnetic resonance(NMR).In the positron annihilation lifetime spectroscopy technique, the lifetime ('t2)of positron that interacts with surfactant medium is measured using fast coincidence system. The intensity of formation of orthopositronium(12), when positron interact with aggregate of surfactant system are sensitive to phase changes. In amphiphilic system with bicontinous character geometry of periodic phase can be explained using minimal surfaces. Factors influencing the topology includes the length of surfactant and cosurfactant tails and the aqueous volume fraction. Positron are readily attracted to these centres. Changes in the geometry of the interfacial layer thus will influence the lifetime and intensity of the orthopositronium atom formed. These parameters are obtainable using the POSITR ON FIT programme. In this study, three surfactant systems were investigated. Firstly, the intensity (12) and lifetime ("(2) of the Didodecyl DimethylAmmonium Bromide (ODAB) - Water - Octane system were measured at various amount of water content in the surfactant system in the diamond and body centred cubic phases. A symmetry transitions from diamond phase to body-centred cubic phase was observed in this system. 1996 Thesis NonPeerReviewed application/pdf en http://psasir.upm.edu.my/id/eprint/8605/1/FSAS_1996_3_A.pdf Ibrahim, Rosdi (1996) Structures of Surfactant System Studied by Positron Annihilation Lifetime Spectroscopy. Masters thesis, Universiti Pertanian Malaysia. Surface active agents. Positron annihilation. Spectrum analysis. English
spellingShingle Surface active agents.
Positron annihilation.
Spectrum analysis.
Ibrahim, Rosdi
Structures of Surfactant System Studied by Positron Annihilation Lifetime Spectroscopy
title Structures of Surfactant System Studied by Positron Annihilation Lifetime Spectroscopy
title_full Structures of Surfactant System Studied by Positron Annihilation Lifetime Spectroscopy
title_fullStr Structures of Surfactant System Studied by Positron Annihilation Lifetime Spectroscopy
title_full_unstemmed Structures of Surfactant System Studied by Positron Annihilation Lifetime Spectroscopy
title_short Structures of Surfactant System Studied by Positron Annihilation Lifetime Spectroscopy
title_sort structures of surfactant system studied by positron annihilation lifetime spectroscopy
topic Surface active agents.
Positron annihilation.
Spectrum analysis.
url http://psasir.upm.edu.my/id/eprint/8605/
http://psasir.upm.edu.my/id/eprint/8605/1/FSAS_1996_3_A.pdf