Polimerni filmovi na bazi biopolimera kitozana

undergraduate thesis

• Title (english): Polymer films based on biopolymer chitosan
• Author: Duje Kusanović
• Mentor: Zlata Hrnjak-Murgić (mentor)
• Committee member: Zlata Hrnjak-Murgić (predsjednik povjerenstva)
• Committee member: Zvonimir Katančić (član povjerenstva)
• Committee member: Ana Vrsalović Presečki (član povjerenstva)
• Granter: University of Zagreb; Faculty of Chemical Engineering and Technology; Zagreb
• Defense date and country: 2021-09-22, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Chemical Engineering

Abstract

Biopolimeri se u svakodnevnom životu sve češće koriste kao zamjena za sintetske polimere zbog svoje sposobnosti biorazgradnje i tako značajno utječu na smanjenje onečišćenja okoliša i emisije CO2. Jedan od široko primjenjivanih biopolimera je kitozan. Kitozan se zbog svojih iznimno dobrih svojstava poput biorazgradljivosti, biokompatibilnosti i antimikrobnog djelovanja koristi u prehrambenoj industriji, biomedicini te industriji premaza. U ovom radu provedeno je ispitivanje filmova čistog kitozana (Cs) te kitozana uz dodatak titanijevog dioksida (Cs-TiO2) s ciljem povećanog učinka antimikrobnog djelovanja te smanjenja adsorpcije organskih tvari. Uzorci kitozanskih filmova pripremljeni su otapanjem kitozana velikih molekulskih masa (100.000 - 300.000 Da) u 1%-tnoj otopini octene kiseline, a nanokompozitni filmovi su pripremljeni uz dodatak 5 mas. % nanočestica titanijevog dioksida (TiO2) u otopinu kitozana. Karakterizacija kitozanskih filmova provedena je određivanjem antimikrobnog djelovanja na tri bakterijske kulture: Escherichia coli (3001), Pseudomonas aeruginosa (3011) i Bacillus subtilis (3020), određivanjem kontaktnog kuta pomoću goniometra te određivanjem mehaničkih svojstava na kidalici testom naprezanje - istezanje. Morfologija kitozanskih filmova karakterizirana je pretražnim elektronskim mikroskopom (SEM) u svrhu određivanja dispergiranja nanočestica u kitozanskoj matrici. Analiza rezultata karakterizacije pokazuje da uzorci kitozana te nanokompozita kitozana ne posjeduju antimikrobno djelovanje ni za jednu od tri ispitivane bakterijske kulture. Dodatkom nanočestica TiO2 u kitozan došlo je do promjene mehaničkih svojstava te do smanjenja hidrofobnosti.

Abstract (english)

Biopolymers are increasingly used in everyday life as a substitute for synthetic polymers due to their biodegradability as they have a significant impact on reduction of environment pollution and CO2 emissions. One of the widely used biopolymers is chitosan. Due to its extremely good properties such as biodegradability, biocompatibility and antimicrobial activity, chitosan is used in the food industry, biomedicine, and the coating industry. In this work, the films of pure chitosan (Cs) and chitosan with the addition of titanium dioxide (Cs-TiO2) were studied with the aim of increasing the effect of antimicrobial activity and reducing the adsorption of organic matter. Samples of chitosan films were prepared by dissolving high molecular weight chitosan (100.000 - 300.000 Da) in 1% acetic acid solution, and nanocomposite films were prepared with the addition of 5 wt. % titanium dioxide (TiO2) nanoparticles in chitosan solution. Characterization of chitosan films was performed by determining the antimicrobial activity on three bacterial cultures: Escherichia coli (3001), Pseudomonas aeruginosa (3011) and Bacillus subtilis (3020). Then, the contact angle was determined using a goniometer and the mechanical properties were determined by testing machine performing a stress - strain measurements. The morphology of chitosan films was characterized by scanning electron microscope (SEM) to determine the dispersion of nanoparticles in the chitosan matrix. Analysis of the results shows that the samples of chitosan and nanocomposites of chitosan do not have antimicrobial activity for any of the three tested bacterial cultures. The addition of TiO2 nanoparticles to chitosan resulted in a change in mechanical properties and a decrease in hydrophobicity.

• Keywords: biopolimeri; biorazgradljivost; kitozan; nankompoziti; antimikrobno djelovanje
• Keywords (english): biopolymers; biodegradability; chitosan; nanocomposites; antimicrobial activity
• Language: croatian
• URN:NBN: urn:nbn:hr:149:209746
• Study programme: Title: Materials Science and Engineering - Undergraduate study; Study programme type: university; Study level: undergraduate; Academic / professional title: sveučilišni/a prvostupnik/ prvostupnica (baccalaureus/baccalaurea) inženjer/inženjerka kemijskog inženjerstva (sveučilišni/a prvostupnik/ prvostupnica (baccalaureus/baccalaurea) inženjer/inženjerka kemijskog inženjerstva)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2023-04-06 12:12:18