Priprava i karakterizacija polimernih filmova s kitozanom

undergraduate thesis

• Title (english): Preparation and characterisation of polymer films with chitosan
• Author: Magdalena Šimić
• Mentor: Zlata Hrnjak-Murgić (mentor)
• Committee member: Zlata Hrnjak-Murgić (predsjednik povjerenstva)
• Committee member: Zvonimir Katančić (član povjerenstva)
• Committee member: Elvira Vidović (član povjerenstva)
• Granter: University of Zagreb; Faculty of Chemical Engineering and Technology; Zagreb
• Defense date and country: 2021-09-08, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Chemical Engineering

Abstract

Biorazgradljivi polimeri sve više se istražuju u svrhu zamjene za sintetske polimere jer se njihovom upotrebom smanjuje emisija CO2 i onečišćenje okoliša. Kitozan, kao jedan od biorazgradljivih polimera, svoju primjenu nalazi u prehrambenoj i farmaceutskoj industriji, te kod proizvodnje i razvoja premaza novih funkcionalnih svojstava. U ovom radu ispitivani su filmovi kitozana (Cs), te nanokompozitni filmovi kitozana s cinkovim oksidom (Cs-ZnO), kako bi se istražilo funkcionalno svojstvo antimikrobnog djelovanja. Kitozanski filmovi su pripremljeni otapanjem kitozana velikih molekulskih masa (100.000 -300.000 Da) u 1%-tnoj otopini octene kiseline, a nanokompozitni filmovi pripremljeni su također otapanjem kitozana u octenoj kiselini uz dodatak nanočestica cinkovog oksida (ZnO) (5 mas.%). Karakterizacija uzoraka kitozanskih filmova provedena je određivanjem kontaktnog kuta goniometrom, mehaničkih svojstva; prekidna čvrstoća i prekidno istezanje određeni su na kidalici metodom naprezanje-istezanje. Skenirajućim elektronskim mikroskopom (SEM) karakterizirana je morfologija uzoraka, kako bi se utvrdilo dispergiranje nanočestica u kitozanu. Također, ispitano je antimikrobno djelovanje kitozanskih filmova (Cs i Cs-ZnO) na tri bakterijske kulture: Escherichia coli (3001), Pseudomonas aeruginosa (3011) i Bacillus subtilis (3020). Rezultati su pokazali da nanokompozitni film (Cs-ZnO) ima poboljšana svojstva u odnosu na čisti kitozanski film (Cs). Mehanička svojstava nanokompzitnog filma (Cs-ZnO) bolja su jer prekidna čvrstoća i prekidno istezanje imaju više vrijednosti, također isti uzorci pokazali su veće antimikrobno djelovanje.

Abstract (english)

Biodegradable polymers are increasingly being researched for the purpose of substitution of synthetic polymers because their use reduces CO2 emissions and environmental pollution. Chitosan, as one of the biodegradable polymers, finds its application in the food and pharmaceutical industry, and in the production and development of coatings with new, functional properties. In this work, chitosan (Cs) films and chitosan nanocomposites with zinc oxide (Cs-ZnO) were studied in order to investigate the functional property of antimicrobial activity. Chitosan films were prepared by dissolving high molecular weight chitosan (100.000 -300.000 Da) in 1 % acetic acid solution, and nanocomposite films were also prepared by dissolving chitosan in acetic acid with the addition of zinc oxide (ZnO) nanoparticles
(5 mass.%). Characterization of chitosan film samples was performed by determining the contact angle with a goniometer, mechanical properties; tensile strength and tensile elongation were determined by the stress-strain method. By scanning electron microscope (SEM) morphology has been characterized, in order to determine the dispersion of nanoparticles in chitosan. Also, the antimicrobial activity of chitosan films (Cs and Cs-ZnO) was examined on three type bacterial cultures: Escherichia coli (3001), Pseudomonas aeruginosa (3011) and Bacillus subtilis (3020). The results showed that nanocomposite film (Cs-ZnO) has improved properties compared to pure chitosan film (Cs). The mechanical properties of nanocomposite film (Cs-ZnO) are increased because the tensile strength and tensile elongation have higher values, also the same samples showed higher antimicrobial activity.

• Keywords: biorazgradljivi polimeri; kitozan; filmovi; nanokompoziti; antimikrobno djelovanje
• Keywords (english): biodegradable polymers; chitosan; films; nanocomposites; antimicrobial activity
• Language: croatian
• URN:NBN: urn:nbn:hr:149:078824
• 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: Closed access
• Created on: 2023-04-27 12:46:42