Ternary hydrogel blends of water-soluble polymers: A fundamental study

Date
2021-03
Journal Title
Journal ISSN
Volume Title
Publisher
Stellenbosch : Stellenbosch University
Abstract
ENGLISH ABSTRACT: Poly(vinyl alcohol) (PVA) is a water-soluble polymer. The use of PVA in the preparation of hydrogels has been well reported. However, PVA is not inherently antimicrobial, thus if this polymer is to be used in the medical industry in the form of a hydrogel, binary or ternary hydrogel blends with polymers and fillers offering antimicrobial and wound healing properties could impart these advantageous properties to the end product.In this study primary and binary hydrogel blends of PVA, chitosan, and a chitosan derivative, namely N,O- carboxymethyl chitosan, were produced. Upon successful production and finding the optimum blending ratio, ternary hydrogel blends were produced by the addition of chitin nanowhiskers and cellulose nanowhiskers, individually, to the binary matrices. The distribution of these fillers within the respective matrices was then evaluated by using confocal fluorescence microscopy after labeling the chitin nanowhiskers and cellulose nanowhiskers with a fluorescent marker, fluorescein 5(6)-isothiocyanate. The effect of blending PVA with chitosan, N,O- carboxymethyl chitosan, and the respective fillers was evaluated by using various characterization techniques. Scanning electron microscopy was employed to visualize the effects that blending had on the morphology of the hydrogel blends. Thermogravimetric methods and differential scanning calorimetry were used to investigate the thermal properties and the effects that blending had on these properties. The viscoelastic properties of these hydrogel blends were investigated by exploiting rheological analysis methods. Lastly, the antimicrobial properties of the primary, binary, and ternary hydrogel blends were evaluated by employing a variation of the disk diffusion method.
AFRIKAANSE OPSOMMING: Poli(vinielalkohol) (PVA) is 'n wateroplosbare polimeer. Die gebruik van PVA tydens die voorbereiding van hidrogelle is wyd bespreek. P VA is egter nie inherent antimikrobies nie, dus as hierdie polimeer in die mediese industrie gebruik gaan word in die vorm van 'n hidrogel, sal binêre of tersiêre hidrogel mengsels met polimere en vullers wat antimikrobiese en wondgenesen de eienskappe bied, gemeng word om sodoende hierdie voordelige eienskappe tot die eindproduk by te voeg. In hierdie studie is primêre en binêre hidrogelmengsels van PVA, kitosaan en ‘n kitosaan afgeleide, naamlik N,O-karboksimetiel kitosaan, vervaardig. Na afloop van suksesvolle produksie en nadat die optimale mengverhouding gevind is, is tersiêre hidrogelmengsels geproduseer deur die byvoeging van kitien nanovesels en sellulose nanovesels tot die binêre matrikse. Die verspreiding van hierdie vullers binne die onderskeie matrikse is vervolgens met behulp van konfokale fluoressensie mikroskopie geëvalueer na afloop van etikettering van die kitien - en sellulose nanovesels met 'n fluoreserende merker, fluoresien 5(6)-isothiosianaat. Die effek van die vermenging van PVA met kitosa an, N,O- karboksimetiel kitosaan, en die onderskeie vullers is met behulp van verskillende karakteriseringstegnieke geëvalueer. Skandeer elektron mikroskopie is gebruik om die effek wat vermenging op die morfologie van die hidrogelmengsels het, te visualiseer. Termogravimetriese metodes en differensiële skanderingskalorimetrie is gebruik om die termiese eienskappe en die effek wat vermenging op hierdie eienskappe gehad het, te ondersoek. Die viskoë lastiese eienskappe van hierdie hidrogelmengsels is ondersoek deur gebruik te maak van reologie. Laastens is dieantimikrobiese eienskappe van die primêre, binêre en tersiêre hidrogelmengsels geëvalueer deur gebruik te maak van 'n aangepaste skyfdiffusiemetode.
Description
Thesis (MSc)--Stellenbosch University, 2021.
Keywords
Chitosan, Hydrogels, Poly(vinyl alcohol), N,O - carboxymethyl chitosan, Cellulose, Chitin, Polysaccharide nanofillers
Citation