diplomsko delo
Alen Cvijanović (Author), Tilen Kopač (Mentor)

Abstract

Hidrogeli na osnovi nanokristalinične celuloze (CNC) se zaradi svoje biokompatibilnosti, biorazgradljivosti in primerljivih lastnosti z drugimi hidrogeli vedno več uporabljajo kot material za različne aplikacije na mnogih področjih. Informacije o viskoelastičnih lastnostih hidrogela, ki so odvisne od načina zamreževanja, so ključnega pomena za nadaljnji razvoj hidrogela za specifične aplikacije. V diplomski nalogi sem celulozne hidrogele zamreževal kemijsko, z epiklorohidrinom (ECH). Pripravil sem vzorce z različnimi koncentracijami CNC in ECH, pri čemer sem CNC raztapljal v raztopini NaOH/Urea/H2O. Vzorce sem karakteriziral s pomočjo reometra, na katerem sem izvedel frekvenčne teste in meritve viskoznosti vzorcev. Meritve so pokazale, da je kritična koncentracija za tvorbo hidrogela po uporabljenem postopku 3,9 ut% CNC. Strižni modul se z večanjem koncentracije ECH povečuje le do določene koncentracije, ko jo presežemo, se kljub naraščanju koncentracije zamreževala strižni modul zniža. Strižni modul se pripravljenim vzorcem z večanjem koncentracije CNC povečuje. Z večanjem koncentracije CNC se povečujejo tudi viskoznosti nezamreženih CNC vodnih raztopin. Dobljeni rezultati predstavljajo dobro podlago za nadaljnje raziskave na CNC hidrogelih, pri katerih so mehanske in tokovne lastnosti ključnega pomena.

Keywords

nanokristali;hidrogeli;strižni modul;zamreževanje;epiklorhidrin;viskoelastične lastnosti;diplomske naloge;

Data

Language: Slovenian
Year of publishing:
Typology: 2.11 - Undergraduate Thesis
Organization: UL FKKT - Faculty of Chemistry and Chemical Technology
Publisher: [A. Cvijanović]
UDC: 678.54:532.13(043.2)
COBISS: 205788419 Link will open in a new window
Views: 67
Downloads: 27
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Other data

Secondary language: English
Secondary title: Effect of epichlorohydrin concentration on mechanical and flow properties of hydrogels based on cellulose nanocrystals
Secondary abstract: Hydrogels based on cellulose nanocrystals (CNC) are increasingly being used due to their biocompatibility, biodegradability, and comparable properties to other hydrogels as a material for various applications in many fields. Information about the viscoelastic properties of a cross-linked hydrogels using a specific method is crucial for the further development of the hydrogel for specific applications. In this work, hydrogels were chemically cross-linked using epichlorohydrin (ECH). Samples were prepared with different concentrations of CNC and ECH, dissolving CNC in a solution of NaOH/Urea/H2O. The samples were characterized using a rheometer, performing frequency tests and viscosity measurements. The measurements showed that the critical concentration for hydrogel formation using the applied method is 3,9 ut% CNC. The shear modulus increases with the increasing concentration of ECH only up to a certain point, after which, despite the continued increase in the cross-linking agent concentration, the shear modulus decreases. The shear modulus of prepared samples increases with CNC concentration. Increasing the CNC concentration also increases the viscosity of non-crosslinked CNC water solutions. The obtained results provide a good foundation for further research on CNC hydrogels, where mechanical and flow properties are of crucial importance.
Secondary keywords: cellulose;nanocrystals;shear modulus;crosslinking;viscoelastic properties;Celuloza;Nanodelci;Univerzitetna in visokošolska dela;
Type (COBISS): Bachelor thesis/paper
Study programme: 1000374
Embargo end date (OpenAIRE): 1970-01-01
Thesis comment: Univ. v Ljubljani, Fak. za kemijo in kemijsko tehnologijo, VSŠ Kemijska tehnologija
Pages: 1 spletni vir (1 datoteka PDF (30 str.))
ID: 24791773