Modifikacija polimernog filma kitozanom

master's thesis

• Title (english): Modification of polymer film with chitosan
• Author: Benjamin Banožić
• Mentor: Zlata Hrnjak-Murgić (mentor)
• Committee member: Zlata Hrnjak-Murgić (predsjednik povjerenstva)
• Committee member: Zvonimir Katančić (član povjerenstva)
• Committee member: Mirela Leskovac (član povjerenstva)
• Granter: University of Zagreb; Faculty of Chemical Engineering and Technology; Zagreb
• Defense date and country: 2021-09-17, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Chemical Engineering

Abstract

Kitozan je biorazgradljiv i biokompatibilan biopolimer, koji se sve više istražuje u različitim ljudskim djelatnostima, primjerice kao ambalaža za pakiranje hrane, u medicini ili kao premazi na brodovima ili jahtama. U ovom radu pripremljeni su i karakterizirani nanokompozitni filmovi biopolimera kitozana s dodatkom aktivnih tvari, s ciljem razvoja antimikrobnog djelovanja. Za pripravu nanokompozitnih kitozanskih filmova upotrijebljene su nanočestice titanijeva (II) oksida (TiO2), cinkova oksida (ZnO) te nanočestice kitozana (NCs), koje su pripremljene iz kitozana niskih molekulskih masa (50.000–190.000 Da), otapanjem u 2%-tnoj octenoj kiselini te precipitacijom s natrijevim tripolifosfatom (Na5P3O10). Otapanjem kitozana (Cs) velikih molekulskih masa (100.000–300.000 Da) u 2%-tnoj octenoj kiselini i dodatkom nanočestica kitozana (Cs/NCs) te dodatkom nanočestica TiO2 (Cs/NCs/TiO2) i ZnO (Cs/NCs/ZnO) pripremljeni su nanokompozitni filmovi. Dobiveni nanokompozitni filmovi karakterizirani su skenirajućom elektronskom mikroskopijom (SEM), određivanjem mehaničkih svojstava (čvrstoća i istezanje), određivanjem kontaktnog kuta (Θ) i određivanjem antimikrobnog djelovanja za tri različite vrste bakterija (Escherichia coli, Pseudomonas aeruginosa i Bacillus subtilis). Analizom rezultata ustanovljeno je da nanokompozitni film s dodatkom ZnO pokazuje antibakterijsko djelovanje za sve tri vrste ispitivanih bakterija. Kod Cs/NCs/ZnO uzorka vidljiva je i homogenija morfologija u odnosu na preostale nanokompozitne filmove, a također pokazuje i najveću vrijednost prekidne čvrstoće što znači da ostala svojstva materijala nisu narušena već ojačana.

Abstract (english)

Chitosan is a biodegradable and biocompatible biopolymer, which applications are more and more studied for food packaging, medicine and coatings for boats and yachts. In this work, nanocomposite films of biopolymer chitosan with an addition of active compounds were prepared and characterized, with the aim to enhance the antimicrobial activity. For the preparation of chitosan nanocomposite films, nanoparticles of TiO2, ZnO and chitosan (NCs) were used. Nanoparticles of chitosan were prepared from chitosan of low molecular weights (50.000-190.000 Da), by dissolving chitosan in 2% acetic acid solution and precipitating with sodium tripolyphosphate (Na5P3O10). By dissolving chitosan of high molecular weights in 2% acetic acid, with the addition of ZnO, TiO2 and nanoparticles Cs, nanocomposite films were prepared. The newly prepared films were characterized by scanning electron microscopy (SEM) and contact angle measurement, mechanical properties (strength and strain) and the antimicrobical activity for three different types of bacteria (Escherichia coli, Pseudomonas aeruginosa and Bacillus subtilis) were determined. The results indicate that the nanocomposite film with ZnO nanoparticles shows antimicrobical activity towards all three types of bacteria. Sample of Cs/NCs/ZnO shows the homogenous morphology relative to the other nanocomposite films. Also, the same sample show the highest tensile strength, which implies that the other properties of nanocomposites are not deteriorated rather opposite, they are enhanced.

• Keywords: kitozan; titanijev (II) oksid; cinkov oksid (ZnO); SEM; kontaktni kut; antimikrobno djelovanje; mehanička svojstva
• Keywords (english): chitosan; titanium (II) oxide (TiO2); zinc oxide (ZnO); SEM; contact angle; animicrobical activity; mechanical properties
• Language: croatian
• URN:NBN: urn:nbn:hr:149:657238
• Study programme: Title: Chemical Engineering - Graduate study; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra inženjer/inženjerka kemijskog inženjerstva (magistar/magistra inženjer/inženjerka kemijskog inženjerstva)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Access restricted to students and staff of home institution
• Created on: 2023-04-13 13:49:40