Thesis (PhD)--Stellenbosch University, 2008. / ENGLISH ABSTRACT: This study concerns the synthesis, properties and quantitative analysis of polydiallyldimethylammonium chloride (polyDADMAC), a water-soluble polymer used world-wide for potable water purification. The special interest in this polymer is the result of its widespread use and the current lack of adequate analytical methods for it. This is especially important for water treatment organisations. A novel gel permeation chromatography (GPC) method was developed and evaluated for polymer analysis. The scope was extended to determine the presence of unreacted monomer (DADMAC) as well as the percentage active polymer. polyDADMAC was first prepared using a known synthesis method. The product was purified and characterized by GPC and 13C-NMR spectroscopy. New and conclusive evidence of the existence of a five-member pyrrolidine ring system was obtained. A proposed mechanism of polymerization was determined. The activity of the synthesized polyDADMAC was evaluated and it was found to perform effectively as a coagulant. The physical and chemical properties of polyDADMAC were then studied under simulated water treatment conditions. The polymer reaction with chlorine revealed the formation of trihalogenated methane compounds (THMs). Gas chromatography–mass spectrometry (GC–MS) was used to conclusively identify the formation of chloroform. The polymer stability under different conditions of heat exposure, UV radiation and pH variations was studied. GPC results indicated that polyDADMAC is a very stable polymer and undergoes structural change only when subjected to extremes of pH, temperature and UV conditions. Results of a short study on microbial degradation indicated growth of the cultures, and subsequent polymer degradation. Reactions of polyDADMAC were concluded with a study of the impact of ozone on polyDADMAC. GPC results indicated a significant change in the ozonated polymer peak profile. Analytical methods to determine polyDADMAC residues in water were reviewed and critically evaluated. Methods based on complex formation/spectroscopy suffered from severe limitations and produced no meaningful results, contrary to claims made by previous researchers. Colloid titration based on an established method was promising but required extensive modification for quantitative analysis. Finally four novel methods were developed, including: solid phase extraction, membrane filtration-GPC, the HACH complexation method, and a GPC method with indirect UV detection. The study is concluded with a chemical risk assessment that indicated minimal human health risks associated with the production and use of polyDADMAC. / AFRIKAANSE OPSOMMING:Hierdie studie behels die sintese, eienskappe en kwantitatiewe analise van polidiallielmetielammoniumchloried (polyDADMAC), 'n wateroplosbare polimeer wat wêreldwyd vir drinkwatersuiwering gebruik word. Die belangstelling in hierdie spesifieke polimeer is as gevolg van die wydverspreide gebruik daarvan en die feit dat daar tans onvoldoende eenvoudige analitiese metodes daarvoor bestaan. Dit is veral belangrik vir waterbehandelingsorganisasies. 'n Nuwe gelpermeasiechromatografie (GPC) metode is ontwikkel en geevalueer vir die analise van hierdie polimeer. Die omvang van die studie is later uitgebrei om die teenwoordigheid van ongereageerde monomeer (DADMAC) asook die persentasie aktiewe polimeer te bepaal. polyDADMAC is eers volgens 'n bekende sintesemetode berei. Die produk is gesuiwer en gekarakteriseer m.b.v. GPC en 13C-KMR. Nuwe bewyse vir die bestaan van 'n vyflid pirollidoonringsisteem is verkry. 'n Meganisme vir hierdie polimerisasie metode is vasgestel. Die aktiwiteit van die bereide polyDADMAC is geevalueer en daar is bevind dat dit effektief as koaguleermiddel optree. Daarna is die chemiese en fisiese eienskappe van polyDADMAC onder gesimuleerde waterbehandelingskondisies bepaal. polyDADMAC het met chloor gerageer om trihalogeneerde metaanverbindings (THMs) te vorm. Gaschromatografie–massa-spektrometrie (GC–MS) is gebruik om die ontstaan van chloroform te bevestig. Daarna is die stabiliteit van die polimeer onder verskei reaksiekondisies bepaal: hitte, UV-bestraling, en pH. GPC-resultate het aangeduiui dat polyDADMAC baie stabiel is en ondergaan strukturele veranderings slegs onder uiterste kondisies van pH, temperatuur en UV. 'n Kort studie van die effek van mikro-organismes op polyDADMAC het egtermikrobiese kultuurgroei met die gevolglike afbreek van die polimeer getoon. Resultate van 'n studie van die impak van osoon op polyDADMAC het getoon dat daar 'n groot verandering in die GPC-profiel van die ge-osoneerde vorm van die polimeer was. Verdere analitiese metodes wat al gebruik is om polyDADMAC residue in water te bepaal, is uitgevoer en krities geevalueer. Metodes gebasseer op kompleksvorming/ spektroskopie het erge beperkings gehad en het nie betekenisvolle resultate gelewer nie. Dit was in teenstelling met wat voorheen deur ander navorsers bevind is. 'n Kolloiedtitrasie gebasseer op 'n bestaande metode het goeie resultate gelewer maar het omvattende veranderings benodig om kwantitatiewe resultate te lewer. Ten slotte is vier nuwe metodes ontwikkel: soliede fase-ekstraksie, membraanfiltrasie-GPC, die HACH-komplekseringsmetode, en 'n GPC-metode met indirekte UV-waarneming.. Die studie is afgesluit met 'n bepaling van die chemiese risiko wat poly DADMAC vir die gesondheid van die mens inhou. Daar is tot die gevolgtrekking gekom dat die produksie en gebruik van poly DADMAC slegs‘n minimum gesondheidsrisiko inhou.

Thesis (PhD)--Stellenbosch University, 2012. / ENGLISH ABSTRACT: Hierarchical information transfer is investigated as a tool to prepare well‐defined nanostructures with high aspect ratios, via the self‐assembly of helically folding poly(paraaryltriazole) (P(p‐AT)) foldamers. A novel ‘helicity codon’ based on the 1,4‐linkage geometry in 1,4‐aryl‐disubstituted‐1,2,3‐ triazoles is developed. Helical folding is induced exclusively by directing all triazole moieties into a cisoid configuration. By linking the triazole rings in a para fashion about the aryl moiety, this helicity codon codes for a helix with a large internal cavity of ~ 3 nm. One turn of the putative helical conformation requires 14 repeat units and the helical pitch is ~ 0.38 nm. The aryltriazole backbone is appended with amphiphilic oligo(ethylene glycol) (oEG) units which have the dual roles of imparting solubility as well as instigating a solvophobic helical folding in solvents which poorly solvate the hydrophobic arytriazole backbone but, solvate the side chains fully. The helix interior is hydrophobic and the exterior is amphiphilic. A true polymer synthesis approach to the foldamer synthesis, based on the copper catalysed azide‐alkyne cycloaddition (CuAAC) AB step growth polymerization system, is developed. This is preceded by a facile synthetic protocol for the AB monomers. The subsequent P(p‐ AT)s have high molecular weights ensuring several turns in the helical foldamer. A DMF/H2O good solvent/bad solvent system is established. Twist sense bias in the helical foldamers is successfully imparted by installing enantiopure chiral oEG side chains. Spectroscopic signatures for the solvent dependent coil to helix transition are established enabling the tracking of the conformational transitions from primary to secondary and finally tertiary structure. Conclusive evidence for the formation of stable, long stacked helical columns, in the solution state, is provided via cryo‐TEM. The helical stacks are several microns long, but of random lengths and do not intertwine but rather run parallel to each other. The helical stacks, however, have indeterminate lengths. Control over the length and chirality of the self‐assembled helical stacks is successfully imparted by using a template which mimics the role of ribonucleic acid (RNA) in tobacco mosaic virus (TMV). The template used is the hydrophobic α‐helical polypeptide poly(γ‐ benzyl‐L‐glutamate) (PBLG). Self‐assembly is driven by solvophobicity in a DMF/H2O system, the PBLG template being encapsulated inside the hydrophobic cavities of the stacked/selfassembled helical foldamers. Information from the template, i.e. length and chirality, is used to control the length and the chirality of the stacked/self‐assembled construct. The templated self‐assembly process is solvent dependent. When carried out in the solvent regime at the coil to helix transition mid‐point of the foldamer host, system operates under a dynamic equilibrium. Under these conditions, the self‐assembly process is shown to take place between two distinct states, the foldamer helices and the helical template, the template threading through the foldamer helices. The resulting self‐assembled construct has a pseudo‐rotaxane architecture. Under dynamic equilibrium conditions, temperature induced dis‐assembly of the templated assembled construct, is shown to be a cooperative process, whilst re‐assembly is characterized by a large hysteresis. By increasing the volume fraction of water, the solvophobic character of the system is increased and template assembled construct is better stabilised. The assembly system, however, loses its dynamic equilibrium character and falls into kinetic traps. Temperature induced de‐threading, of the foldamer helices, becomes less favourable and loses its cooperative character although the hysteresis loop is reduced. / AFRIKAANSE OPSOMMING: Hiërargiese inligtingsoordrag is bestudeer as ‘n hulpmiddel om goed gedefinieerde nanostrukture met ‘n goeie beeldverhouding voor te berei. Die nanostrukture word voorberei deur middel van self‐samestelling van heliese vouing van poli(para‐arieltriasool) (P(p‐AT)) ‘foldamers’. ‘n Nuwe heliese‐kodon gebaseer op die 1,4 koppelingsgeometrie in 1,4 arieldigesubstitueerde‐ 1,2,3‐triasool is ontwikkel. Heliese vouing word uitsluitlik geïnduseer as al die triasole in die sis konfigurasie is. Deur die triasole in ‘n para konfigurasie te bind, kodeer die heliese kodon vir ‘n heliks met ‘n groot interne kanaal van ~ 3 nm. Een draai van die heliks benodig 14 herhalende eenhede en die heliese gradiënt ~ 0.38 nm. Amfifiliese oligo(etileen glikol) (oEG) eenhede is aan die arieltriasoolruggraat aangeheg. Hierdie aanhegting van oEG eenhede bevorder oplosbaarheid en dit induseer ‘n solvofobiese heliese vouing in oplosmiddels wat nie die hidrofobiese arieltriasoolruggraat oplos nie, maar wel die sy‐kettings volledig oplos. Die binnekant van die heliks is hidrofobies en die buitekant is amfifilies. ‘n Polimeersintese benadering tot die ‘foldamer’ sintese (gebaseer op die koper gekataliseerde siklo‐addisie reaksie tussen ‘n asied en ‘n alkyn) AB stapsgewyse groei polimerisasiestelsel, is ontwikkel. Dit is voorafgegaan deur ‘n geskikte sintetiese protokol vir die AB monomere. Die daaropvolgende P(p‐AT) het ‘n hoë molekulêre massa wat verseker dat daar ‘n hele paar draaie in die heliese ‘foldamer’ is. ‘n DMF/H2O goeie oplosmiddel/ swak oplosmiddel sisteem is vasgestel. Draaiing van die heliks na ‘n spesifieke kant alleenlik is suksesvol geïnduseer deur die toevoeging van suiwer enantiomere van die chirale oEG sykettings. Spektroskopiese handtekeninge van die oplosmiddel‐afhanklike ketting tot heliks transformasie word vasgestel sodat die oorgangstoestande gevolg kan word vanaf primêre tot sekondêre en uiteindelik tesiêre struktuur. Beslissende bewyse vir die formasie van stabiele, lang gestapelde heliese kolomme in die opgeloste toestand is bewys met cryo‐TEM. Die heliese stapels is verskeie mikron lank, maar het verskillende lengtes. Die heliese stapels is parallel aan mekaar en oorvleuel nie. Die lengte van die heliese stapels is egter onbepaalbaar. Beheer oor die lengte en chiraliteit van die self‐samestellende heliese stapels is verkry deur gebruik te maak van ‘n templaat wat die rol van ribonukleïensuur (RNS) in die tabakmosaïekvirus (TMV) naboots. Hidrofobiese α‐heliese polipeptied poli(γ‐bensiel‐Lglutamaat) (PBLG) is gebruik as die templaat. Self‐samestelling word gedryf deur solvofobisiteit in ‘n DMF/H2O stelsel, met die PBLG templaat wat dan geënkapsuleer word binne die hidrofobiese holtes van die gestapelde/ self‐saamgestelde heliese ‘foldamers’. Die lengte en die chiraliteit van die templaat word gebruik om die lengte en chiraliteit van die gestapelde helikse te beheer. Die templaatbemiddelde self‐samestellende proses is afhanklik van die oplosmiddel. Die stelsel is by ‘n dinamiese ewewig wanneer, uitgevoer in ‘n oplosmiddel, die ketting na heliks oorgang die middelpunt van die ‘foldamer’ gasheer bereik het. By hierdie omstandighede vind die self‐samestellende proses plaas tussen twee afsonderlike toestande nl. die ‘foldamer’ helikse en die heliese templaat, en die templaat wat vleg deur die ‘foldamer’ helikse vleg. Die gevolglike struktuur het ‘n pseudo‐rotaxane argitektuur. By dinamiese ewewigstoestande veroorsaak temperatuur dat die self‐samestellende templaatstrukture weer disintegreer. Hierdie is ‘n koöperatiewe proses terwyl die hersamestelling gekarakteriseer word deur ‘n sloerende proses. Deur die waterfraksie te vermeerder, word die solvofobiese karakter van die sisteem verhoog en die templaat selfsamestellende struktuur beter gestabiliseer. Die samestellingsproses verloor egter sy dinamiese ewewigkarakter en val in kinetiese slaggate. Temperatuur geïnduseerde disintegrasie van die foldamer helikse word minder gunstig en dit verloor die koöperatiewe karakter alhoewel die sloering verminder is.

Thesis (PhD)--University of Stellenbosch, 2005. / ENGLISH ABSTRACT: Density functional theory (DFT) has been used to investigate the effect of the surrounding molecules on the structure of selected boron-nitrogen compounds. It was found that a very limited number of molecules, orientated according to the experimental crystal structure, are needed to successfully reproduce the large changes in structure witnessed when HCN–BF3 and CH3CN–BF3 crystallises. Specifically, the addition of seven molecules shortens the B–N distance by 0.735 °A in (HCN–BF3)8 and 0.654A° in (CH3CN– BF3)8. Accompanying the large changes in B–N bond length are equally large changes in the N–B–F angle. Investigation of the structure of these complexes in terms of localised electron pairs shows that the availability of lone pairs, in close proximity to the B–N bond axis, plays an important role in the bond change. Through delocalisation of the fluorine lone pairs the antibonding σ ∗(B–N) orbital becomes increasingly occupied as the N–B–F angle lessens and vice versa. Further, an investigation of the specific effects of dipole-dipole interactions was performed by applying uniform electric fields of varying strength along the donor-acceptor bond axis of a series of compounds of the form X–Y; X=H3N, HCN, CH3CN; Y = BF3, BH3, SO3. All complexes investigated show sensitivity to the external electric field, however, only the compounds having nitrile donors and acceptors with fluorine atoms produce large changes, which in turn are dominated by a very sudden large change in B–N bond length occurring in a very narrow range of changing field strength. Analysis of the changes in bond character reveals that HCN–BF3 and CH3CN–BF3 have long bonds in the gas phase, formed primarily through electrostatic interaction between the donor and acceptor. In the short bond in the condensed phase the bond character changes considerably through the introduction of strong electron sharing interactions, i.e. covalent or orbital interactions. Fundamental changes in the nature of the bond, catalysed by surrounding molecules, thus lie at the heart of the large phase-dependent changes in these species. / AFRIKAANSE OPSOMMING: ’n Kohn-Sham elektrondigtheidsteorie (DFT) studie is gedoen op die effek van die omliggende molekules in die kristalstruktuur van sekere molekules wat boor-stikstof bindings bevat. Daar is gevind dat ’n klein aantal molekules, georienteer soos in die eksperimentele kristalstruktuur, benodig word om die groot veranderinge in stuktuur te veroorsaak wat eksperimenteel waargeneem word wanneer HCN–BF3 en CH3CN–BF3 kristaliseer. Spesifiek, die byvoeging van sewe molekules verminder die B–N bindingslengte met 0.735 °A in (HCN–BF3)8 en 0.654 A° in (CH3CN–BF3)8. Die groot veranderinge in B–N bindingslengte gaan saam met ewe groot veranderinge in die N–B–F hoek. ’n Ondersoek van die struktuur van die molekules in terme van gelokaliseerde elektronpare wys dat die beskikbaarheid van alleenpare, wat naby die B–N bindingsas lˆe, ’n belangrike rol speel in the verandering in bindingslengte. Deur delokalisasie van die fluoor alleenpare word die antibindende σ ∗(B–N) orbitaal toenemend beset soos die N–B–F hoek afneem en omgekeerd. Verder is die spesifieke effek van dipool-dipool interaksies ondersoek deur uniforme elektriese velde aan te lˆe langs the donor-akseptor bindingsas van ’n reeks komplekse van die vorm X–Y; X = H3N, HCN, CH3CN; Y = BF3, BH3, SO3. Al die komplekse toon sensitiwiteit teenoor die eksterne elektriese veld, maar net die verbindings wat nitriel akseptore en fluoor atome aan the donor fragmente het, toon groot veranderinge, wat op hulle beurt weer oorskadu word deur ’n skielike verandering in the B–N bindingslengte in ’n nou band van veranderende veldsterkte. Analise van die veranderinge in bindingskarakter toon dat HCN–BF3 en CH3CN–BF3 lang bindings in die gasfase het, wat hoofsaaklik gevorm word deur elektrostatiese interaksies tussen die donor en akseptor fragmente. In die kort binding in die kristalfase is daar ’n aansienlike verandering in the karakter as gevolg van die intrede van sterk elektrondelingsinteraksies, m.a.w. kovalente of orbitaalinteraksies. Fundamentele veranderinge in the manier wat die binding saamgestel word, wat gekataliseer word deur omliggende molekules, is dus die oorsaak van die groot faseafhanklike veranderinge.

Thesis (PhD)--Stellenbosch University, 2004. / ENGLISH ABSTRACT: To comply with the ever growing demands for materials with better properties and complex architectures, polymer chemistry has resorted to the use of living free radical polymerization techniques. Despite the structural control some of these techniques offer, major disadvantages do exist. For example, most require ultra-pure reagents, hence only a small fraction of the monomers used in industry can be polymerized in this way. This rendered these new living techniques less advantageous from a commercial point of view. Recently, a revolutionary new living free radical process, namely the reversible addition-fragmentation chain transfer process, or RAFT process, was developed that combines the control over the polymer produced with the robustness and versatility of a free radical process. However, the RAFT process is not without its problems. In some dithioester mediated polymerizations, significant inhibition and rate retardation effects have been observed. Two main opposing opinions have been proposed in recent literature to explain these phenomena observed. The main point of difference between these two groups is the fate of the formed intermediate RAFT radicals, i.e., slow fragmentation of the formed intermediate radicals together with possible reversible intermediate RAFT radical termination, or fast fragmentation of the formed intermediate radicals together with possible irreversible intermediate RAFT radical termination. Between these opposing two groups, there is a difference of six orders of magnitude for the rate of fragmentation of the formed intermediate RAFT radicals. The work presented in this thesis is an attempt to clarify some of the mysteries, i.e., inhibition and rate retardation observed in some RAFT polymerizations. Experimental evidence to support or contradict the theories of the above mentioned two opposing groups was investigated. The concentration-time evolution of the intermediate radical concentration (cy), for styrene and butyl acrylate polymerizations mediated by cumyl dithiobenzoate (COB) at 70°C and 90 °C, was followed via in situ electron spin resonance spectroscopy (ESR). The concentration-time evolution profiles observed were ascribed to the formation of very short chains during the early stages of the reaction. It was also found that the RAFT process is not particularly sensitive to oxygen. The intermediate and propagating radical (cp) concentrations (and their ratio) for the cumyl dithiobenzoate mediated styrene polymerizations were examined by ESR spectroscopy and kinetics. The system showed strong chain length effects in kinetics, assuming all chains were of similar number average molar mass (Mn). However, unusual behavior with respect to existing mechanistic knowledge was observed in other aspects of the system. The central equilibrium "constant" (Keq) was found to be dependent on both temperature and initial reactant concentrations. The observed intermediate radical concentrations were not consistent with predictions based on existing literature models. It was also found that the time dependence of the intermediate radical concentration varies significantly with the type of RAFT agent used. Unexpectedly, intermediate radicals were detected at very long reaction times in the virtual absence of initiator, enhancing the belief of possible reversible termination reactions involving the intermediate radicals. An extra radical (nonpropagating or intermediate) species was observed (via ESR spectroscopy) to form during some reactions. Its concentration increased with time. The combination of data from several analytical techniques provided evidence for the formation of dead chains by the termination of intermediate radicals in the free radical polymerization of styrene, mediated by a cumyl dithiobenzoate RAFT agent, at 84°C. Experiments done focused on the early stages of the reactions, targeting very low final number average molar mass values, with high initiator concentrations. The formation of these terminated chains did not occur to a significant extent until a large fraction of the chains reached a degree of polymerization greater than unity. This corresponded to the occurrence of a maximum in intermediate radical concentration. In situ 1H nuclear magnetic resonance (NMR) and electron spin resonance spectroscopy was used to directly investigate the processes that occur during the early stages (typically the first few monomer addition steps) of an AIBN-initiated reversible addition fragmentation chain transfer polymerization of styrene, in the presence of a cyanoisopropyl dithiobenzoate and cumyl dithiobenzoate RAFT agent, at 70°C and 84 °C respectively. 1H NMR spectroscopy allowed the investigation of the change in concentration of important dithiobenzoate species as a function of time. Identification and concentrations of the radicals present in the system could be inferred from corresponding ESR spectroscopy data. An apparent "inhibition" effect was observed in both the cyanoisopropyl and cumyl dithiobenzoate mediated polymerizations. This effect could be reduced by increasing the reaction temperature to 84 °C. However, the use of cumyl dithiobenzoate as RAFT agent prolonged this effect. This apparent "inhibition" effect was attributed to selective fragmentation of the formed intermediate radicals during the early stages of the reaction, and to different propagation rate coefficients (kp) of the resulting (different) radicals. A change in the equilibrium coefficient for the systems investigated was ascribed to possible progressively decreasing addition and fragmentation rate coefficients of propagating and intermediate radicals formed during the reaction. The increase in intermediate radical concentration, and thus possible intermediate radical termination, was shown to also be a probable cause of the rate retardation observed in the RAFT mediated systems investigated. To conclude, probable causes of the observed inhibition and rate retardation in some dithiobenzoate mediated systems were investigated. It was found that intermediate RAFT radical termination does occurs, albeit reversibly or irreversibly. A maximum in the intermediate radical concentration, and thus possible intermediate radical termination, was seen to occur during the observed rate retardation. An apparent inhibition effect observed was ascribed to a possible change in termination kinetics, the formation of terminated intermediate radical products and a rapidly changing kp of the propagating radicals. / AFRIKAANSE OPSOMMING: Om te voldoen aan die ewig groeiende aanvraag vir materiale met beter eienskappe en komplekse samestellings, is in die polimeerchemie lewende vry-radikaal polimerisasietegnieke ontwikkel. Ten spyte van die feit dat party van die polimerisasie tegnieke die strukuur van die gevormende polimere kan beheer, bestaan daar tog nadele. Die meeste polimerisasie tegnieke benodig ultra suiwer reagense, dus kan net 'n klein fraksie van die monomere wat deur die industrie gebruik word op so 'n manier gepolimeriseer word. Dus, vanuit 'n komersieële oogpunt, is die nuwe lewende polimerisasietegnieke minder voordelig. Onlangs is 'n revolusionere nuwe lewende vry-radikaal polimerisasieproses, naamlike die RAFT-(eng. reversible addition-fragmentation chain transfer process) proses ontwikkel, wat die beheer oor die geproduseerde polimere, kombineer met die robuustheid en veelsydigheid van 'n vry-radikaalproses. Die RAFT proses is egter nie sonder probleme nie. Beduidende inhibisie en vertraging van die polimerisasie tempo is in sommige dithioester-bemiddelde polimerisasies opgemerk. Daar is hoofsaaklik twee opponerende opinies oor die redes vir die inhibisie en vertragings effekte. Die grootste verskil tussen die twee groepe lê in die lot van die gevormde intermediêre radikaal, m.a.w. stadige fragmentasie van die gevormende intermediêre radikale tesame met moontlike onveranderlike intermediêre radikaalterminasie, of vinnige fragmentasie tesame met moontlike omkeerbare intermediêre radikaalterminasie. Tussen die twee groepe, is daar 'n verskil van ses ordegrotes vir die groote van die tempo van fragmentasie van die gevormende intermediêre radikaal. Die werk wat in die tesis weergee word, is 'n poging om sommige van die geheime van die RAFT proses, m.a.w. inhibisie en vertraging van die polimerisasietempo, op te los. Die ondersoek was gerig op eksperimetele bewyse om die teorieë van die twee opponerede groepe of te bevestig of teen te spreek. Die konsentrasie tyd-verandering van die intermediêre radikaal konsentrasie vir stireen- en butielakrilaatpolimerisasie, bemiddeled deur CDB (eng cumyl dithiobenzoate) by 70 oe and 90 oe, is gevolg deur middel van in situ (lat. vir in die oorspronklike plek, m.a.w. binne-in die ESR masjien) elektronspin-resonans (ESR) spektroskopie. Die vorm van die konsentrasie tyd-profiele is toegeskryf aan die vorming van baie kort polimeerkettings gedurende die vroeë reaksietye. Dit is ook bepaal dat die RAFT-proses nie besonder sensitief was vir suurstof nie. Die intermediêre en die propagerende radikaalkonsentrasie (en hulle verhouding) vir die CDB bemiddelde stireen polimerisasies, is bepaal deur middel van elektronspin-resonans spektroskopie en die kinetika van die sisteem. Die kinetika van die sisteem toon 'n sterk afhanklikheid teenoor die lengte van die polimeerkettings, as aanvaar word dat al die kettings dieselfde numeriese gemiddelde molêre massa het. Des nieteenstaande, is egter onverwagte gedrag in ander aspekte van die sisteem opgemerk. Dit was ook gevind dat die sentrale ewewigs-"konstante" (Keq) afhanklik was van die temperatuur en die oorspronklike reaktant konsentrasie. Die bepaalde intermediêre radikaalkonsentrasie het verskil van voorspelde waardes gebaseer op literatuur modelle. Dit is ook gevind dat die intermediêre radikaalkonsentrasie afhanklik is van die tipe RAFT agent wat in die polimerisasie reaksies gebruik word. Intermediêre radikale is onverwags gevind na baie lang reaksietye, wanner verwag is dat die konsentrasie van die afsetter, en dus ook die intermediêre radikale, baie klein sou wees. Dit het die verwagting dat omkeerbare intermediêre radikaalterminasie kan plaasving, versterk. 'n Ekstra radikale spesie, wat gedurende die reaksie vorm en waarvan die konsentrasie groter word met tyd, is ook deur ESR-spektroskopie geidentifiseer. 'n Kombinasie van verskillende skeikundige tegnieke is gebruik om bewyse te kry vir die vorming van dooie kettings wat ontstaan deur middel van intermediêre radikale terminasiereaksies, in die vry-radikaalpolimerisasie van stireen, wat deur 'n CDB RAFT-agent bemiddeled word by 84°C. Eksperimente is gedoen om die reaksie tydens vroeë reaksietye te ondersoek. Baie hoë afsetter konsentrasies is ook gebruik, wat tot uiters lae numeriese gemiddelde molêre massas van die polimeerkettings gelei het. Beduidende konsentrasies van die dooie kettings is eers gevind nadat 'n graad van polimerisasie van groter as een bereik is. Dit het ooreengestem met 'n maksimum in die konsentrasie van die intermediêre radikale. In situ 1H kern magnetiese-resonans (KMR) en electronspin-resonans spektroskopie was gebruik om 'n RAFT proses, wat gedurende die vroeë reaksie tye (tipies gedurende die eerste paar monomeer toevoegingstappe) te bestudeer, wat deur AIBN (eng azo bis(isobutyronitrile)) afgeset word en bestaan uit stireen en CIDB (eng cyanoisopropyl dithiobenzoate) en CDB RAFT agente onderskeidelik, en by 70°C and 84 °C reageer. 1H KMRspektroskopie was gebruik om die veranderinge in die konsentrasie van die belangrike spesies te bepaal. Die identifikasie en konsentrasie van die radikale kon bepaal word deur middel van ESR data. 'n Skynbare 'inhibisie-effek' is waargeneem in die reaksies wat bemiddeled word deur CIDB en CDB. Die effek is verminder toe die reaksietemperatuur verhoog is na 84°C. Die gebruik van CDB as RAFT agent het egter die effek vergroot. Die skynbare 'inhibisie effek' was toegeskryf aan die selektiewe fragmentasie van die intermediêre radikale gedurende die vroeë reaksietye, en aan verskillende propagasie tempokoëffisiënte (kp) van die verskillende radikale. Die veranderlike sentrale ewewigskoëffisiënte is toegeskryf aan die toevoegings en fragmentasie tempokoëffisiënte van die propagerende en intermediêre radikale wat toenemend afneem. Die is ook getoon dat die toename in die konsentrasie van die intermediêre radikale en dus moontlike intermediêre radikale terminasie, 'n oorsaak kan wees van die vertraging van die polimerisasietempo in die RAFT-bemiddelde reaksies. Ter samevatting, die waarskynlike oorsake vir inhibisie en die polimerisasietempo vertraging opgemerk in sekere dithiobenzoaat-bemiddelde sisteme, is ondersoek. Dit was gevind dat intermediêre radikaalterminasie wel kan gebeur, of dit nou omkeerbaar of onveranderlik gebeur. 'n Maksimum in die konsentrasie van die intermediêre radikale, en dus moontlike intermediêre radikaalterminasie, het voorgekom tesame met 'n vertraging in die polimerisasietempo. Die skynbare inhibisie-effek wat opgemerk was kan toegeskryf word aan 'n moontlike verandering in die terminasie kinetika, die formasie van getermineerde intermediêre radikale en 'n vinnig veranderende propagasie tempokoëffisiënt.

Thesis (PhD)--Stellenbosch University, 2005. / ENGLISH ABSTRACT: See fulltext for abstract / AFRIKAANSE OPSOMMING: Sien volteks vir opsomming

Thesis (PhD)--Stellenbosch University, 2001. / ENGLISH ABSTRACT: Please refer to fulltext for abstract. / AFRIKAANSE OPSOMMING: Sien volteks vir opsomming.

Thesis (PhD)--Stellenbosch University, 2003. / ENGLISH ABSTRACT: The general objective of this research was to develop a new approach to direct templating, where the organised phases of polyelectrolyte-surfactant complexes are used as hosts for organic polymerisation reactions. The lamellar polyelectrolyte-surfmer complex of the tail-functionalised di (undecenyl) phosphate (roC11) and polydiallyldimethylammonium chloride (pDADMAC) was identified as a host for organic polymerisation reactions. The complex showed higher stability (than the one found in the case of roC11 alone) when used as a template, owing to the presence of the polyelectrolyte backbone. The mobility of the reactive groups (positioned in the tails of the surfmer) was not sufficient for homopolymerisation reactions to take place. Direct, 1:1 templating was only achieved on the incorporation of an unbound co-monomer (a dithiol) in the complex. Furthermore the thiol-ene polyaddition reaction used offered the advantage over conventional free radical polymerisation that volume shrinkage was largely avoided and possibilities for phase disruption minimised. The pDADMA I roC11 complex was able to withstand swelling with -35 wt % of thiol co-monomer (constituting a 1:1 ratio of thiol to vinyl groups) without signs of phase disruption. The obtained polymer symplexes were cured copies of the template proving that no phase disruption or disordering occurred during the polyaddition. These results were confirmed using X-ray scattering and microscopy. This is the first case of successful polyaddition within the organised phases of polyelectrolyte-surfactant complexes to be reported. The addition of a second co-monomer (a diene) to the reaction system provided a possibility by which to vary the composition of the novel composite materials obtained through the ternary thiol-ene polyaddition within the complex. it therefore allowed for the investigation of the effect of increasing the amount of guest polymer on the structure of the host polyelectrolyte-surfactant complex. The increased d-spacing of the host structure with the increase in guest polymer content gave the possibility to tune the material properties of those highly anisotropic networks. Onset of phase disruption was only observed with 72 wt% copolymer included within the host. This unusually high degree of swelling under preservation of nanoscale order could be attributed to the flexible, linear structure of the co-monomers used, since the addition of rigid comonomers was reported to cause phase disruption at only - 17 wt% of swelling of the host polyelectrolyte-surfactant complex.' The high loading capability of the pDADMA I roC11 allowed for a large amount of otherwise unstructured material to be organised within the template. / AFRIKAANSE OPSOMMING: Die doel van hierdie navorsing was om 'n nuwe benadering tot direkte afdrukvorming (Eng: templating) te ontwikkel, waar die georganiseerde fases van polielektroliet-seepkomplekse as gashere vir organiese polimerisasiereaksies gebruik is. Die lamellêre (Eng: lamellar) polielektroliet-seepkompleks van die eindfunksionele verbinding di(undekiel)fosfaat (coC11) en polidiallieldimetielammoniumcloried (pDADMAC) is as gasheer vir die organiese polimerisasiereaksies geïdentifiseer. Tydens gebruik van laasgenoemde vir afdrukvorming was die stabiliteit van die gevormde kompleks hoër as wanneer coC11 alleen gebruik is. Dit word toegeskryf aan die teenwoordigheid van die polielektrolietskelet. Die mobiliteit van die reaktiewe groepe (aan die punte van die seep/surfmer) was nie voldoende om homopolimerisasiereaksies te laat plaasvind nie. Direkte1:1 afdrukvorming is slegs bereik met die byvoeging van 'n ongebonde komonomeer ('n ditiol) tot die kompleks. Gebruik van die tiol-een addisiepolimerisasiereaksie was meer voordelig as konvensionele vryeradikaalpolimerisasie, aangesien volume-inkrimping grootendeels vermy is en die kanse vir fase-ontwrigting tot 'n mimimum beperk is. Die pDADMA / coC11 kompleks het swelling met -35 massa % tiol-komonomeer (bestaande uit 'n 1:1 verhouding van tiol tot viniel groepe) sonder enige tekens van faseversteuring weerstaan. Die polimeersimplekse wat verkry is, was gesette kopieë van die patroonvorm. Dit het bewys dat daar geen faseversteuring of ontordening gedurende die polimeeraddisie plaasgevind het nie. Hierdie bevindinge is d.m.v. X-straalverstrooiing en mikroskopie bevestig. Hierdie was die eerste keer dat meervoudige aanhegting binne-in die georganiseerde fases van polielektroliet-seepkomplekse suksesvol uitgevoer is. Die byvoeging van 'n tweede komonomeer ('n dieen) het die moontlikheid geskep om die samestelling van die nuwe saamgestelde materiale, wat d.m.v. ternêre ticl-een poliaddissie binne-in die kompleks verkry is, te varieer. Dit was gevolglik moontlik om die invloed van 'n toename in die hoeveelheid gaspolimeer op die struktuur van die gasheerpolielektroliet-seepkompleks te bepaal. Die toename in die d-spasiëring van die gas-struktuur, met die toename in gaspolimeerinhoud, het tot gevolg gehad dat die materiaaleienskappe verander kon word. Die aanvang van faseversteuring is opgemerk by 72 massa % kopolimeer in die gasheer. Die ongewone hoë swelling met behoud van die nano-skaalorde, is toegeskryf aan die buigbare, liniêre struktuur van die komonomere wat gebruik is. Volgens die literatuur het die byvoeging van starre komonomere alreeds faseversteuring by slegs - 17 massa % swelling van die gasheer polielektroliet-seepkompleks veroorsaak. Die hoë ladingskapasiteit van die pDADMA I coC11 het daartoe aanleiding gegee dat 'n groot hoeveelheid andersins ongestruktureerde materiaal binne-in die templaat gestruktureer kon word.

Thesis (PhD)--Stellenbosch University, 2003. / ENGLISH ABSTRACT: Alkali-soluble rheology modifiers are commercially synthesised via conventional freeradical polymerisation processes. This results in the end product having certain limitations; there is poor control over the molar mass, molar mass distribution and chain architecture of the polymer chains. These limitations can be overcome by using a controlled/living free radical polymerisation process, for example the RAFT process. This alternate method of synthesis was used here to prepare model alkali-soluble rheology modifiers. The structure/property relationships of model alkali-soluble rheology modifiers synthesised via the RAFT process were studied. Model alkali-soluble rheology modifiers of different molar masses and chain architectures (block, co- and ter-polymers) were successfully synthesised by the RAFT polymerisation of methyl methacrylate, methacrylic acid and various hydrophobic macromonomers. The different types of alkali-soluble rheology modifiers were synthesised in solution and in miniemulsion. Each of the two systems had certain advantages and disadvantages. The conversion limit of reactions in solution was about 60 % and reaction times were much slower than those of the miniemulsion reactions. Higher final conversions were recorded for miniemulsion reactions, reactions were faster and no solvent removal was required. Unfortunately it was not possible to synthesise all the different types of associative rheology modifiers investigated here in a miniemulsion system. The latex solutions thickened with conventional rheology modifiers (co-polymers) show very contrasting behaviour (rheology profile and dynamic properties) to that of the latex solutions thickened with the associative rheology modifiers (ter-polymers). The AB block copolymers gave the latex solutions rheology results between those obtained with conventional rheology modifiers and those with the associative rheology modifiers. Varying the number of ethylene oxide spacer units in the hydrophobic macromonomers of the associative rheology modifiers had a significant influence on the rheology properties of the latex and alkali solutions. As the number of ethylene oxide spacer units was increased from 20 to 100 there was a significant increase in the zero-shear viscosity of the latex solutions thickened with the associative rheology modifiers. Contrasting results were obtained for the polymer solutions (no latex present), where the use of the associative rheology modifiers containing the highest number (EO = 100) of ethylene oxide spacer units resulted in solutions with the lowest viscosity, but the rheology modifiers containing the 50 ethylene oxide spacer units gave the highest steady shear viscosity. / AFRIKAANSE OPSOMMING: Alkali-oplosbare reologie-modifiseerders word kommersieël gesintetiseer d.m.v. konvensionele vrye-radikaal polimerisasieprosesse. Hierdie prosesse lewer gewoonlik 'n eindproduk met sekere tekortkominge, a.g.v. swak beheer oor molekulêre massa, molekulêre massa-verspreiding, en polimeerkettingstruktuur (Eng. chain architecture). Hierdie tekortkominge kan oorbrug word deur gebruik te maak van 'n beheerde/lewende vrye-radikaal polimerisasieproses, soos byvoorbeeld die RAFT-proses (Eng. RAFT: reversible addition-fragmentation chain transfer polymerisation). Hierdie alternatiewe metode is in die studie gebruik om model alkali-oplosbare reologiemodifiseerders te sintetiseer. Die struktuur-eienskapverhoudings van die model alkali-oplosbare reologie modifiseerders wat d.m.v. die RAFT-proses gesintetiseer is, is bestudeer. Model alkali-oplosbare reologiemodifiseerders van verskillende molekulêre massas en kettingstrukture (blok, ko- en ter-polimere) is suksesvol gesintetiseer d.m.v. RAFT-polimerisasie van metielakrilaat, metakrielsuur en hidrofobiese makromonomere. Die verskillende alkali-oplosbare reologiemodifiseerders is in organiese oplosmiddel sowel as in mini-emulsie gesintetiseer. Elkeen van die sisteme het sekere voordele en nadele getoon. In die reaksies wat in organiese oplosmiddels gedoen is, is slegs 60 % van die monomere ingebou in die polimeerkettings en die tydsduur van hierdie reaksie was heelwat langer as by die wat uitgevoer is in mini-emulsie. Meer as 60 % van die monomere is omgeskakel na polimeer tydens die reaksies wat in mini-emulsie uitgevoer is, die reaksietempo was vinniger en dit was nie nodig om die organiese oplosmiddel te verwyder nie. Ongelukkig was dit nie moontlik om al die verskillende tipes assosiatiewe-reologiemodifiseerders (Eng: associative rheology modifiers) in miniemulsie te sintetiseer nie. Die lateks wat met konvensionele reologiemodifiseerders (ko-polimere) verdik is, het kontrasterende eienskappe (reologie-profiel en dinamiese eienskappe) getoon teenoor die van die lateks-oplossings wat met assosiatiewe-reologiemodifiseerders (ter-polimere) verdik is. Die AB-tipe blok ko-polimere gee reologieresultate vir die lateks-oplossings wat lê tussen die wat bepaal is vir konvensionele reologieodifiseerders en assosiatiewe reologiemodifiseerders. Variasie in die aantal etileenoksiedeenhede in die hidrofobiese makromonomere van die assosiatiewe reologiemodifiseerders het 'n betekenisvolle invloed op die reologie-eienskappe van die lateks, sowel as die alkali-oplossings gehad. Namate die aantal etileenoksiedeenhede van 20 tot 100 vermeerder is, het 'n betekenisvolle verhoging in die "zero-shear " viskositeit van die lateks oplossings wat met die assosiatiewe reologiemodifiseerders verdik is voorgekom. Teenstrydige resultate is verkry vir die polimeeroplossings met geen lateks teenwoordig nie: die assosiatiewe reologiemodifiseerders met die hoogste aantal etieleenoksiedeenhede (EO = 100) het die laagste viskositeitsresultate opgelewer en die reologiemodifiseerders met slegs 50 etieleenoksiedeenhede het die hoogste viskositeitsresultate gelewer.

Thesis (PhD)--Stellenbosch University, 2003. / ENGLISH ABSTRACT: The synthesis of structured nanoparticles, in particular core/shells, IS of great technological and economical importance to modem materials science. One of the advantages of structured particles is that they can be synthesized with either a solid core (albeit soft or hard) or a liquid core (of varying viscosity). This adds to the versatility of structured particles and their relevance to a majority of industrial and commercial endapplications. The synthesis of core/shell particles with liquid cores was investigated for the effective impact modification of glassy amorphous polymers. Polybutyl acrylate was chosen as the shell due to its rubbery nature. Hexadecane functioned as the core oil and facilitated osmotic stability by being a suitable hydrophobe for the miniemulsion synthesis. Polymer synthesis was preceded by the prediction of particle morphology by using thermodynamic prediction models. Core/shell particles with liquid cores were synthesized via miniemulsion polymerization. This resulted in the direct introduction of core-oil and monomer into the miniemulsion droplets. Polymerization was achieved in situ, resulting in the formation of particles with the desired morphology. For additional strength, stability and matrix mixing capabilities, methyl methacrylate (MMA) was grafted onto the initial core/shell particles. The obtained morphology was in contradiction with the predicted morphology, thus pointing to strong kinetic influences during the polymerization process. These influences could be attributed to surface anchoring of polymer chains due to the initiator (KPS) used, the establishment of the polymerization locus as well as the increase in viscosity at the polymerization locus. To test these influences a surface-inactive initiating species (AIBN) and an interfacial redox initiating species (cumyl hydroperoxide/Fe/") were used. Use of the former resulted in the formation of solid polymer particles due to homogeneous polymerization throughout the droplet, thus leading to an inverse core/shell morphology as a result of thermodynamic considerations. The redox initiator promoted kinetic influences as a result of fast polymerization kinetics at the droplet/water interface. This, as well as the increase in viscosity, facilitated the production of core/shell particles. To obtain core/shell particles with the desired size, the influence of surfactant concentration was investigated. Capillary hydrodynamic fractionation (CHDF) was used to determine the particle size of the initial core/shell particles as well as the size of the MMA-grafted core/shell particles. The area stabilized per surfactant molecule was calculated stoichiometrically and compared to "classical" miniemulsion results, i.e. data generated from the synthesis of polymeric latexes in the presence of a hydrophobe, but at a much lower hydrophobe:monomer ratio than was used here. The influence of methanol as well as the possibility of scaling-up the process was also investigated. The study was further expanded to the investigation of living miniemulsion polymerization techniques to control the molecular architecture of synthesized core/shell latexes. The influence of different RAFT agents, initiators and monomers were investigated on the core/shell formation properties of the investigated systems. The combined effects of establishing the polymerization locus as well as increased polymerization kinetics, thus increasing the viscosity at the polymerization locus, lead to the successful formation of liquid- filled core/shell particles. To conclude, the ability of the synthesized core/shell particles to induce impact modification in glassy amorphous polymers was investigated. Results showed that incorporation of these particles could effectively modify the intrinsic properties of the investigated polymers, resulting in a brittle-to-ductile transition. Improved impact results of the investigated glassy matrix were obtained. Keywords: core/shell, liquid-filled, RAFT, miniemulsion, impact modification / AFRIKAANSE OPSOMMING: Die sintese van gestruktureerde nano-partikels, meer spesifiek kern/skil partikels, is van onskatbare tegnologiese en ekonomiese belang vir moderne materiaalkunde. Een van die voordele van hierdie tipe partikels is dat sintese kan geskied met 'n soliede kern (hard of sag) of vloeistofkern (met wisselende viskositeit). Dit dra by tot die veelsydigheid van gestruktureerde partikels en dus tot grootskaalse aanwending in industriële en kommersiële toepassings. Die sintese van kern/skiI partikels met vloeistofkerne is ondersoek met die oog op effektiewe slagsterkte modifikasie van glasagtige amorfe polimere. Polibutielakrilaat is gekies as skil-polimeer op grond van sy rubberige voorkoms. Heksadekaan moes funksioneer as die kern-olie, maar het ook bykomende osmotiese stabiliteit verleen tydens die miniemulsie-polimerisasie proses. Dit is as gevolg van die gepaste hidrofobiese eienskappe van heksadekaan. Polimeer sintese is voorafgegaan deur die voorspelling van partikel morfologie met behulp van termodinamies gebaseerde voorspellingsmodelle. Kern/skil partikels is gesintetiseer deur middel van 'n miniemulsie-polimerisasie reaksie wat die direkte inkorporering van kern-olie en monomeer in die miniemulsiedruppel teweeg bring. Polimerisasie vind in situ (lat. vir in die oorspronklike plek, m.a.w. binne-in die druppel) plaas en lei tot die vorming van partikels met die gewenste morfologie. Metielmetakrilaat is ge-ent op die oorspronklike kern/skil partikels om addisionele sterkte, stabiliteit en vermenging met die matriks polimeer te bewerkstellig. Die verkrygde morfologie is teenstrydig met die voorspelde morfologie, wat dus die teenwoordigheid van sterk kinetiese invloede aandui. Hierdie invloede kan toegeskryf word aan die oppervlak-aktiewe afsetter (KPS, kaliumpersulfaat) wat gebruik is, die daarstelling van die polimerisasie lokus asook die toename in viskositeit by die lokus van polimerisasie. Om hierdie invloede te toets is 'n oppervlak-onaktiewe afsetter (AIBN, asobisisobutironitriel) en intervlak redoks-afsetter (kumielhidroperoksied/Pe'") gebruik. Gebruik van eersgenoemde het die vorming van soliede partikels teweeg gebring. Dit is as gevolg van homogene polimerisasie in die druppel en dus die ontstaan van omgekeerde kern/skiI partikels weens termodinamiese oorwegings. Die redoks-afsetter het egter die kinetiese oorwegings bevoordeel as gevolg van vinnige polimerisasiekinetika by die druppel/water intervlak. Dit, tesame met die toename in viskositeit, maak die produksie van kern/skil partikels moontlik. Vir die verkryging van kern/skiI partikels met die gewenste partikelgrootte is die invloed van die seep konsentrasie ondersoek. CHDF (eng. capillary hydrodynamic fractionation) is gebruik om die partikelgrootte van die oorspronklike kern/skiI partikels, sowel as dié ge-ent met metielmetakrilaat, te bepaal. Die area gestabiliseer per seepmolekule is bereken d.m.v. stoichiometrie en vergelyk met "klassieke" miniemuisie data, d.i. data verkry deur die sintese van latekse in die teenwoordigheid van 'n hidrofoob, maar teen 'n baie laer hidrofoob:monomeer-verhouding as wat hier gebruik is. Die invloed van metanol, asook die moontlikheid om die reaksie op te skaal, is ondersoek. Die studie is verder uitgebrei om die invloed van lewende miniemulsie-polimerisasie tegnieke in te sluit, om sodoende beheer uit te oefen oor die molekulêre argitektuur van die gesintetiseerde latekse. Die invloed van verskeie RAFT (eng. reversible additionfragmentation chain transfer) agente, afsetters en monomere op die kern/skiI vormingsmoontlikhede van die bestudeerde stelsels, is ondersoek. Die gesamentlike effek van die daarstelling van die polimerisasie lokus en dus die verhoging van die viskositeit by die lokus, lei tot die suksesvolle vorming van vloeistof-gevulde kern/skiI partikels. Laastens is die invloed van die gesintetiseerde kern/skil partikels op die slagsterkte van glasagtige amorfe polimere ondersoek. Resultate dui daarop dat die insluiting van hierdie partikels kan lei tot die effektiewe verandering van die intrinsieke eienskappe van die bestudeerde polimere, en dus 'n oorgang van bros na rekbaar kan veroorsaak. 'n Verbetering in die slagsterkte resultate van die bestudeerde glasagtigte matriks is ook waargeneem.

Thesis (PhD)--Stellenbosch University, 2013. / ENGLISH ABSTRACT: A new class of nanocolorants is described for the use as a colorant in hot-melt ink application for ink-jet printing technology. An inverse miniemulsion polymerization process was utilized successfully as a one-step encapsulation process to encapsulate the highly hydrophilic water-soluble fluorescent Rhodamine B dye (RhB) by the hydrophilic water-soluble poly(acrylamide) (PAAm). Three types of Rhodamine B-based nanocolorants, PAAm/RhB, crosslinked-PAAm/RhB and poly(AAm-co-Sty)/RhB, were synthesized using inverse miniemulsion polymerization. The PAAm/RhB nanocolorants exhibited solid dark nanoparticles morphology, while crosslinked-PAAm/RhB and poly(AAm-co-Sty)/RhB showed a core-shell type of morphology. The nanocolorants showed improved light and dye migration fastness as well as high thermal stability, especially, nanocolorants with core-shell morphology. The synthesis of polymerizable RhB-based nanocolorants is described. Poly(AAm-co-RhB) nanocolorants were successfully synthesized for the first time via inverse miniemulsion polymerization. RhB dye was first functionalized by esterification reaction to introduce an acrylate polymerizable group. The RhB-acrylate dye was copolymerized with AAm monomer in an inverse miniemulsion polymerization to produce nanocolorants with superior light and migration fastness. Crosslinked-poly(AAm-co-RhB) nanocolorants could be obtained based on the incorporation of a crosslinking agent. Poly(AAm-co-RhB) and crosslinked-poly(AAm-co-RhB) nanocolorants exhibited a morphology of dark solid and core-shell particles, respectively. In both nanocolorants, the RhB-acrylate dye was completely integrated by copolymerization into the polymer matrix, and by that, the dye migration was completely supressed. Both poly(AAm-co-RhB) and crosslinked-poly(AAm-co-RhB) nanocolorants showed high thermal stability as well as high Tg values. The syntheses of PAAm/RhB nanocolorants-based solid inks were carried out successfully via inverse miniemulsion polymerization. An in situ inverse miniemulsion polymerization, with the paraffin wax as the organic phase, was utilized in making a crosslinked-PAAm/RhB nanocolorants-based solid ink. A crosslinked-poly(AAm-co-RhB) nanocolorants-based solid ink was prepared by the direct mixing of the readymade crosslinked-PAAm/RhB nanocolorants (suspended in cyclohexane) with paraffin wax at temperature above the melting temperature of the wax until all the cyclohexane evaporated. The obtained solid inks appeared as a solid homogenous waxy material with a deep bright colour reflecting that the nanocolorants were well dispersed in the wax. DSC thermograms showed that the solid inks have one sharp melting transition indicating the applicability of our nanocolorants for hot-melt ink applications. / AFRIKAANSE OPSOMMING: ‘n Nuwe reeks nonokleursels word beskryf vir die gebruik in ink-smelt drukker tegnologie. Inverse minie-emulsie polymerisasie was suksesvol gebruik om die kleurstof Rhodamine B (RhB) in die water oplosbare poly(akrielamied) (PAAm) te enkapsuleer. Die roete is gebruik om drie tipes kleurstof te produseer. Elk van die kleurstowwe was gebaseer op Rhodamine B en ‘n PAAm, naamlik PAAm/RhB, kruisgebonde PAAm/RhB en poli(akrielamied-ko-stireen)/RhB. PAAm/RhB nanokleursel was in die vorm van soliede donker nanopartikels. Die kruisgebonde PAAm/RhB en poli(akrielamied-ko-stireen) het bestaan uit nanoparikels met ‘n kern en skil morfologie. Die nanokleursels het ‘n verbetering in terme van lig en hitte stabiliteit getoon. Die migrasie van kleursel uit die nanopartikels, veral die met kern en skil morfologie, was baie minder. Die sintese van ‘n polimeeriseerbare nanokleursel gebaseer op RhB word beskryf. Poly(AAm-ko-RhB) nanokleursels was vir die eerste keer suksesvol gesintetiseer met behulp van ‘n inverse minie-emulsie polimerisasie. RhB kleursel was eers gefunksionaliseer deur middel van ‘n esterifikasie reaksie om ‘n polimeeriseerbare akrilaat groep te verkry. Die RhB-akrilaat kleursel was gekopolimeeriseer met AAm monomeer in ‘n inverse minie-emulsie polimerisasie om nanokleursels met verbeterde lig en migrasie stabiliteit te verkry. Kruisgebonde poli(AAm-ko-RhB) nanokleursels was verkry deur ‘n geskikte verbinding in die reaksie mengsel by te voeg. Beide poli(AAm-ko-RhB) and kruisgebonde poly(AAm-ko-RhB) nanokleursels was verkry as donker partikels met ‘n kern en skil morfologie. In beide gevalle was die RhB-akrilaat kleursel deeglik geintegreer in die matriks en sodoende was die migrasie van die kleursel heeltemal onderdruk. In albei gevalle het poli(AAm-ko-RhB) en kruisgebonde poli(AAm-ko-RhB) nanokleursels hoë hitte stabiliteit en hoë Tg waardes getoon. Die sintese van nanokleursels gebaseer op PAAm/RhB was sukselvol uit gevoer via inverse minie-emulsie polimerisasie. ‘n In situ inverse minie-emulsie polimerisasie met paraffin waks as die organiese fase was gebruik om soliede ink te produseer wat opgemaak is uit kruisgebonde PAAm/RhB nanokleursel. Die kruisgebonde poli(AAm-ko-RhB) soliede ink was voorberei deur die kruisgebonde PAAm/RhB nanokleursels (in suspensie met sikloheksaan) direk met die paraffin waks te meng by ‘n temperatuur hoër as die smeltpunt van die waks todat al die sikloheksaan verdamp het. Die soliede ink was verkry as ‘n homogene waksagtige materiaal met ‘n diep en helder kleur wat ‘n aanduiding was dat die nanokleursels goed versprei was in die waks. DSC termogramme het bewys dat die ink slegs een skerp smelt punt oorgang het wat beteken dat die materiaal geskik is om te gebruik in ink-smelt drukkers.