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A slow-release organophosphate-filled trilayer polyolefin film
Dissertation (MEng)--University of Pretoria, 2017.
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| Format: | Thesis |
| Language: | English |
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University of Pretoria
2018
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| _version_ | 1867613652949925889 |
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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 | © 2018 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 (MEng)--University of Pretoria, 2017. |
| format | Thesis |
| id | oai:repository.up.ac.za:2263/66215 |
| institution | University of Pretoria (South Africa) |
| language | English |
| last_indexed | 2026-06-10T12:39:33.692Z |
| license_str | Other — see source repository |
| provenance_str_mv | Harvested via OAI-PMH from UPSpace — University of Pretoria Institutional Repository |
| publishDate | 2018 |
| publishDateRange | 2018 |
| publishDateSort | 2018 |
| 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:2263/66215 A slow-release organophosphate-filled trilayer polyolefin film Focke, Walter Wilhelm u12222934@tuks.co.za Sibanda, Mthokozisi Mayibongwe Madzorera, Tatenda Panashe UCTD Malaria Mosquitoes Insecticide Trilayer film Controlled release Engineering, built environment and information technology theses SDG-03 Engineering, built environment and information technology theses SDG-09 Engineering, built environment and information technology theses SDG-12 Engineering, built environment and information technology theses SDG-17 Dissertation (MEng)--University of Pretoria, 2017. The development of pyrethroid resistance in mosquitoes threatens the goal of malaria elimination in Africa. Alternative insecticides, e.g. organophosphates, can be considered to control pyrethroid resistant mosquitoes. The problem associated with the deployment of organophosphate-based insecticides is their high volatility. Conventional application forms have a fairly short residual efficacy. This study aimed at extending the residual efficacy of an organophosphate insecticide by using a polymer matrix as a slow release device. A multilayer film blower was used to produce a trilayer film. The middle layer comprised poly(ethylene-co-vinyl acetate), i.e. EVA polymer, impregnated with malathion. This was sandwiched by two low density polyethylene (LDPE) outer layers. These acted as semi-permeable membrane-like barriers that slowed down the release of the contact insecticide to the surfaces of the film. In theory, such a film could be deployed as a long-lasting insecticide-treated wall lining in pyrethroid resistant settings. Scanning electron microscopy (SEM) confirmed the trilayer film structure of the blown film. The malathion release from the film was tracked with Fourier transform infrared spectroscopy (FTIR). The malathion absorption band in the FTIR spectra disappeared gradually over time. Confocal Raman analysis showed a malathion concentration gradient across the thickness of the polyethylene layers. These results suggested diffusion-controlled transport through the LDPE membranes. Bioassays indicated that the residual efficacy of the malathion, against mosquitoes, was increased to about six months. This means that trilayer films, impregnated with an organophosphate, may have potential as alternative mosquito control interventions in pyrethroid resistant settings. mi2026 Chemical Engineering MEng Unrestricted SDG-03: Good health and well-being SDG-09: Industry, innovation and infrastructure SDG-12: Responsible consumption and production SDG-17: Partnerships for the goals 2018-08-17T09:42:42Z 2018-08-17T09:42:42Z 4/19/18 2017 Dissertation Madzorera, TP 2017, A slow-release organophosphate-filled trilayer polyolefin film, MEng Dissertation, University of Pretoria, Pretoria, viewed yymmdd <http://hdl.handle.net/2263/66215> A2018 http://hdl.handle.net/2263/66215 en © 2018 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 | UCTD Malaria Mosquitoes Insecticide Trilayer film Controlled release Engineering, built environment and information technology theses SDG-03 Engineering, built environment and information technology theses SDG-09 Engineering, built environment and information technology theses SDG-12 Engineering, built environment and information technology theses SDG-17 A slow-release organophosphate-filled trilayer polyolefin film |
| title | A slow-release organophosphate-filled trilayer polyolefin film |
| title_full | A slow-release organophosphate-filled trilayer polyolefin film |
| title_fullStr | A slow-release organophosphate-filled trilayer polyolefin film |
| title_full_unstemmed | A slow-release organophosphate-filled trilayer polyolefin film |
| title_short | A slow-release organophosphate-filled trilayer polyolefin film |
| title_sort | slow release organophosphate filled trilayer polyolefin film |
| topic | UCTD Malaria Mosquitoes Insecticide Trilayer film Controlled release Engineering, built environment and information technology theses SDG-03 Engineering, built environment and information technology theses SDG-09 Engineering, built environment and information technology theses SDG-12 Engineering, built environment and information technology theses SDG-17 |
| url | http://hdl.handle.net/2263/66215 |