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Optimisation of water-in-oil microemulsion formulation stabilised by nonylphenol ethoxylated phosphate ester
Dissertation (MSc (Chemistry))--University of Pretoria, 2007.
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University of Pretoria
2013
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| _version_ | 1867613482925424640 |
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| access_status_str | Open Access |
| author2 | Focke, Walter Wilhelm |
| author_browse | Focke, Walter Wilhelm |
| author_facet | Focke, Walter Wilhelm |
| collection | Thesis |
| dc_rights_str_mv | © 2005, University of Pretoria. All rights reserved. The copyright in this work vests in the University of Pretoria. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of the University of Pretoria. |
| description | Dissertation (MSc (Chemistry))--University of Pretoria, 2007. |
| format | Thesis |
| id | oai:repository.up.ac.za:2263/22973 |
| institution | University of Pretoria (South Africa) |
| last_indexed | 2026-06-10T12:36:51.610Z |
| license_str | Other — see source repository |
| provenance_str_mv | Harvested via OAI-PMH from UPSpace — University of Pretoria Institutional Repository |
| publishDate | 2013 |
| publishDateRange | 2013 |
| publishDateSort | 2013 |
| publisher | University of Pretoria |
| publisherStr | University of Pretoria |
| record_format | dspace |
| source_str | UPSpace — University of Pretoria Institutional Repository |
| spelling | oai:repository.up.ac.za:2263/22973 Optimisation of water-in-oil microemulsion formulation stabilised by nonylphenol ethoxylated phosphate ester Focke, Walter Wilhelm upetd@ais.up.ac.za Mdhlovu, Johan Water-in-oil microemulsion Didodecyldimethyl ammonium chloride Surfactant Nonylphenol ethoxylated phosphate ester Alcohol Amine Ionic strength UCTD Dissertation (MSc (Chemistry))--University of Pretoria, 2007. Water-in-oil (w/o) microemulsion systems, stabilised by either an anionic surfactant or a cationic surfactant were studied. The anionic system consisted of ethoxylated nonylphenol phosphate esters (Atpol), Shellsol oil and an alcohol. These microemulsions tolerated an increase in ionic strength of the water phase up to a point: Beyond this point no microemulsion could be obtained. However, adding amine salts, e.g. diethanolamine nitrite, improved the emulsification of the aqueous phase. Increasing the alcohol (cosurfactant) chain length up to octanol also increased the uptake of the aqueous phase. Thus octanol yielded the best results in terms of emulsifying large volumes of the water-phase, particularly at high salt concentrations. A key objective was to prepare stable microemulsions with high nitrite content. The maximum microemulsion nitrite contents (expressed as NaNO2equivalent by mass) achieved were: -- About 10% when a 30% NaNO2solution was emulsified -- 23% when neat diethyl ethanolamine nitrite (DEEAN) was solubilized, and -- 23% for mixtures of diethanolamine nitrite (DEtOHAN) and NaNO2 in water. The cationic microemulsion system was based on the double-chain cationic surfactant, didodecyldimethyl ammonium chloride (DDAC). In this case the solubilization of the following acetate salts were investigated: ammonium, sodium, magnesium, zinc and manganese. As with the Atpol system, it was found that increasing the ionic strength is detrimental to microemulsification of the aqueous phase. In the DDAC system, an increase in the alcohol chain length beyond butanol led to reduced aqueous phase uptake. Thus the natures and concentrations of the surfactant and the cosurfactant as well as the ionic strength of the aqueous phase determine the stability and the emulsification of large volumes of aqueous phase. In general there is an optimum ionic strength at which the salt content of the microemulsion formulation is maximised. Chemistry unrestricted 2013-09-06T14:11:19Z 2006-03-06 2013-09-06T14:11:19Z 2005-02-17 2007-03-06 2006-03-06 Dissertation Mdhlovu, J 2005, Optimisation of water-in-oil microemulsion formulation stabilised by nonylphenol ethoxylated phosphate ester, MSc dissertation, University of Pretoria, Pretoria, viewed yymmdd < http://hdl.handle.net/2263/22973 > http://hdl.handle.net/2263/22973 http://upetd.up.ac.za/thesis/available/etd-03062006-093400/ © 2005, University of Pretoria. All rights reserved. The copyright in this work vests in the University of Pretoria. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of the University of Pretoria. application/pdf University of Pretoria |
| spellingShingle | Water-in-oil microemulsion Didodecyldimethyl ammonium chloride Surfactant Nonylphenol ethoxylated phosphate ester Alcohol Amine Ionic strength UCTD Optimisation of water-in-oil microemulsion formulation stabilised by nonylphenol ethoxylated phosphate ester |
| title | Optimisation of water-in-oil microemulsion formulation stabilised by nonylphenol ethoxylated phosphate ester |
| title_full | Optimisation of water-in-oil microemulsion formulation stabilised by nonylphenol ethoxylated phosphate ester |
| title_fullStr | Optimisation of water-in-oil microemulsion formulation stabilised by nonylphenol ethoxylated phosphate ester |
| title_full_unstemmed | Optimisation of water-in-oil microemulsion formulation stabilised by nonylphenol ethoxylated phosphate ester |
| title_short | Optimisation of water-in-oil microemulsion formulation stabilised by nonylphenol ethoxylated phosphate ester |
| title_sort | optimisation of water in oil microemulsion formulation stabilised by nonylphenol ethoxylated phosphate ester |
| topic | Water-in-oil microemulsion Didodecyldimethyl ammonium chloride Surfactant Nonylphenol ethoxylated phosphate ester Alcohol Amine Ionic strength UCTD |
| url | http://hdl.handle.net/2263/22973 http://upetd.up.ac.za/thesis/available/etd-03062006-093400/ |