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Preparation of novel functional polymeric nanoparticles and various applications
Thesis (PhD)--Stellenbosch University, 2018.
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| Format: | Thesis |
| Language: | en_ZA |
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Stellenbosch : Stellenbosch University
2018
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| _version_ | 1867613749012070400 |
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| access_status_str | Open Access |
| author | Harmzen-Pretorius, Elrika |
| author2 | Klumperman, Bert |
| author_browse | Harmzen-Pretorius, Elrika Klumperman, Bert |
| author_facet | Klumperman, Bert Harmzen-Pretorius, Elrika |
| author_sort | Harmzen-Pretorius, Elrika |
| collection | Thesis |
| dc_rights_str_mv | Stellenbosch University |
| description | Thesis (PhD)--Stellenbosch University, 2018. |
| format | Thesis |
| id | oai:scholar.sun.ac.za:10019.1/103257 |
| institution | Stellenbosch University (South Africa) |
| language | en_ZA |
| last_indexed | 2026-06-10T12:41:04.390Z |
| license_str | Other — see source repository |
| provenance_str_mv | Harvested via OAI-PMH from SUNScholar — Stellenbosch University Repository |
| publishDate | 2018 |
| publishDateRange | 2018 |
| publishDateSort | 2018 |
| publisher | Stellenbosch : Stellenbosch University |
| publisherStr | Stellenbosch : Stellenbosch University |
| record_format | dspace |
| source_str | SUNScholar — Stellenbosch University Repository |
| spelling | oai:scholar.sun.ac.za:10019.1/103257 Preparation of novel functional polymeric nanoparticles and various applications Harmzen-Pretorius, Elrika Klumperman, Bert Stellenbosch University. Faculty of Science. Dept. of Chemistry and Polymer Science. Janus Particles Nanoparticles Polymers -- Synthesis Confocal fluorescence microscopy Encapsulation, Particle Thesis (PhD)--Stellenbosch University, 2018. ENGLISH ABSTRACT: Polymeric nanoparticles (PNPs) with accessible reactive and functional groups on the surface of the particles, commonly known as functional polymeric nanoparticles (FPNPs), provide additional physical and chemical characteristics for a wide range of fields, including biomedical, optical, electronic and environmental technologies. The main aim of this study was to investigate the synthesis of FPNPs and various applications using further modified FPNPs. A facile technique, i.e. surfactant-free dispersion polymerization, was used to prepare FPNPs, of controlled and tunable size and morphology, based on the highly-crosslinked terpolymer of styrene, maleic anhydride and divinylbenzene (poly(St-co-MAnh-co-DVB) also called MAnh- FPNPs). The particle size, varying from 70 nm to 1300 nm, and surface morphology, smooth to popcorn-shaped, were obtained by simply varying the experimental parameters, such as RAFT, monomer and crosslinker (DVB) concentrations, feed rate and reaction time. The highly reactive maleic anhydride and the pendant vinyl groups on the surface of the particles allow for easy modification if additional functionalization is needed for a specific application. The obtained FPNPs interestingly showed auto-fluorescent properties which allowed visualization using confocal fluorescence microscopy. Cytotoxicity assays and cellular uptake studies showed that these particles are benign to cells and are rapidly taken up in the cells. The surface of these particles was modified with different functional groups including, N,N-dimethyl-3-aminopropyl-1-amine (DMAPA), boronic acid (BA) and a tetraphenylborate derivative respectively, producing DMAPA-FPNPs and BA-FPNPs respectively that were further used to fabricate Janus nanoparticles (JNPs) and permeable micro-sized capsules, as well as an adsorbent for the extraction of biomolecules. Inverse Pickering emulsions were utilized as template for (a) the synthesis of JNPs and (b) the formation of permeable capsules combined with the encapsulation of viable live bacteria. Rotating DMAPA-FPNPs captured at the interface of an inverse Pickering emulsion droplet, and Au-ions in the aqueous phase, allowed the complementary reaction between the tertiary amine on particles and Au-ions producing JNPs with tunable Au-covered surfaces. Correlative SEM imaging was used to confirm the synthesis of JNPs with varying fractions of surface areas modified through utilizing the rotation of the particles at the interface of the droplets. The BA-FPNPs were also used to synthesize permeable micro-capsules (MCs) via inverse Pickering emulsions, that were stabilized by boronic ester-FPNPs (BE-FPNPs), and the capsule wall fabricated through crosslinking individual FPNPs on the interface using a polydiol, starch, with capsule diameters between 20 μm and 100 μm. Successful fabrication of MCs was proven by LM and SEM analyses. The hollow hybrid starch-FPNP microcapsules (MC) were used to encapsulate constructed Escherichia coli. The E. coli strain allowed the release of amylase using an inducible GAL10 promotor to express AmyA amylase upon exposure to galactose. The degradation was visualized by confocal fluorescence microscopy (CFM). Furthermore, the FPNPs were utilized in the extraction of biomolecules from dilute solutions after post-modification of the PNPs. The particle’s surface was modified via two different routes, i.e. direct surface modification using the reactive maleic anhydride and chain extending from the surface of the particles, to obtain particles able to extract specific biomolecules. One of the more intriguing and challenging aspects in current material science is the synthesis of functional and anisotropic particles, as theoretical work has shown that such particles could be very useful for controlling molecular recognition, self-assembly processes and various other applications. AFRIKAANSE OPSOMMING: Polimeriese nanopartikels (PNPs) met toeganklike reaktiewe en funksionele groepe op die oppervlakte van die partikel, algemeen bekend as funksionele polimeriese nanopartikels (FPNPs). Die FPNPs het addisionele fisiese en chemiese eienskappe wat aanwending in `n wye verskeidenheid van velde, insluitend dié van biomedisyne, optiese, elektroniese en omgewingstegnologie moontlik maak. Hierdie studie se hoofoogmerk is om ondersoek in te stel na die sintese van FPNPs en verskeie toepassingsmoontlikhede van verder gemodifiseerde FPNPs. Die FPNPs was voorberei by wyse van `n inskiklike tegniek i.e. benatter vrye verspreidings polimerisasie met n beheerde en manipuleerbare grootte en morfologie, gebaseer op die hoogs kruisverbinde terpolimeer of stireen, maleïensanhidried en diviniel benseen (poli(St-co-MAnh-co-DVB) ook MAnh-FPNPs). Die partikels se grootte, wat wissel van 70nm tot 1300 nm, en oppervlak morfologie (glad tot springmielie-vormig) is verkry deur om die eksperimentele beperkings, onder andere die RAFT-, monomeer- and kruisverbinder konsentrasies, te verander. Weens die hoogs reaktiewe maleïensanhidried en die vryhangende viniel groepe aanwesig op die oppervlakte van die partikels, is dit maklik om veranderinge aan te bring indien addisionele funksionaliteit vereis word vir `n spesifieke aanwending. Die verkrygde FPNPs het interessant genoeg ook auto- fluoresseerende eienskappe getoon wat visualisering by wyse van konfokale fluoresseerende mikroskopie (KFM) moontlik maak. Sitotoksiese toetse en selulêre opname studies dui daarop dat hierdie partikels goedaardig vir die selle is en vinnig in die selle opgeneem word. Die oppervlakte van die partikels was aangepas met verskeie funksionele groepe, naamlik N,N- dimetiel-3-aminopropiel-1-amien (DMAPA), boronsuur (BA) and n tetrafenielboraat afgeleide. Hierdie aangepaste DMAPA-FPNPs en BA-FPNPs was toe gebruik om Janus nanopartikels (JNPs), deurlaatbare mikro-grootte kapsules, sowel as `n funksionele partikel, vir die onttrekking van biomolekules, te vervaardig. Omgekeerde Pickering emulsies was aangewend as templaat vir (a) die sintese van JNPs en (b) die vorming van deurlaatbare mikrokapsules (MKs) gekombineer met die inkapsulering van lewendige bakterië Roterende DMAPA-FPNPs, vasgevang op die skeidingsvlak van `n omgekeerde Pickering emulsie druppel, en Au-ione in die waterige fase, het die komplementêre reaksie tussen die tersiêre amien op partikels en die Au-ione, wat JNPs met manipuleerbare Au-bedekte oppervlaktes produseer, moontlik gemaak. Korrelatiewe skandeer elektron mikroskoop (SEM) beelding was gebruik om die sintese van die JNPs met wisselende fraksies op die oppervlak areas, gemodifiseer deur die aanwending van die rotering van die partikels op die skeidingsvlak van die druppels, vas te stel. Die FPNPs was ook aangewend om deurlaatbare MKs via omgekeerde Pickering emulsies, wat gestabliseer was deur boron ester-FPNP’s (BE-FPNPs), te sintetiseer. Die kapsule-wand was vervaardig deur `n kruisbinding van individuele FPNPs op die skeidingsvlak deur n polidiol, stysel, te gebruik. Kapsules met `n deursnee van tussen 20 μm en 100 μm was vervaardig. Lig mikroskopie en SEM analises was gebruik om suksesvolle vervaardiging van die MKs te bewys. Die hol hibriede stysel-FPNP MKs was gebruik om geneties gemodifiseerde Escherichia coli te enkapsuleer. Die tipe E Coli het die vrystelling van amilase moontlik gemaak deur die gebruik van `n induseerbare GAL10 promotor om die uitdrukking van AmyA amilase te verkry wanneer dit blootgestel word aan galaktose. Die afbreking was uitgebeeld by wyse van KFM. Die FPNPs was verder ook aangewend in die onttrekking van biomolekules vanuit verdunde oplossings na die modifisering van die PNPs. Die oppervlakte van die partikels was aangepas by wyse van twee verskillende metodes, i.e. direkte oppervlak aanpassing deur reaktiewe maleïensanhidried en ketting verlenging van die oppervlakte van die partikels, om sodoende partikels te kry wat spesifieke biomolekules kan onttrek. Een van die meer belangwekkende en uitdagende aspekte in die huidige materiële wetenskappe is die sintese van funksionele en anisotrope partikels aangesien teoretiese werk daarop dui dat hierdie partikels baie bruikbaar kan wees in onder andere die beheer van molekulêre herkenning, die selfvervaardigingsproses en verskeie ander aanwendings. Die sintese en vervaardiging van FPNPs is `n voortudrende navorsingsveld wat ontelbare addisionele funksionaliteite kan bied en dien as intelligente instrumente in verskeie aanwendings. Doctoral 2018-01-23T11:50:52Z 2018-04-09T06:50:59Z 2021-03-22T03:00:07Z 2018-03 Thesis http://hdl.handle.net/10019.1/103257 en_ZA Stellenbosch University 174 pages application/pdf Stellenbosch : Stellenbosch University |
| spellingShingle | Janus Particles Nanoparticles Polymers -- Synthesis Confocal fluorescence microscopy Encapsulation, Particle Harmzen-Pretorius, Elrika Preparation of novel functional polymeric nanoparticles and various applications |
| title | Preparation of novel functional polymeric nanoparticles and various applications |
| title_full | Preparation of novel functional polymeric nanoparticles and various applications |
| title_fullStr | Preparation of novel functional polymeric nanoparticles and various applications |
| title_full_unstemmed | Preparation of novel functional polymeric nanoparticles and various applications |
| title_short | Preparation of novel functional polymeric nanoparticles and various applications |
| title_sort | preparation of novel functional polymeric nanoparticles and various applications |
| topic | Janus Particles Nanoparticles Polymers -- Synthesis Confocal fluorescence microscopy Encapsulation, Particle |
| url | http://hdl.handle.net/10019.1/103257 |
| work_keys_str_mv | AT harmzenpretoriuselrika preparationofnovelfunctionalpolymericnanoparticlesandvariousapplications |