magistrsko delo
Kaja Zadravec (Author), Mojca Škerget (Mentor), Lidija Fras Zemljič (Co-mentor), Simona Strnad (Co-mentor)

Abstract

Odpadna materiala, kot sta volna in piščančje perje, spadata v zelo obremenjujoče industrijske odpadke, vsakodnevno nastajata v ogromnih količinah in bremenita okolje. Odpadno piščančje perje, ki vsebuje 91 % keratina, je tako uporabno za razvoj naravnih vlaken. Danes vedno bolj narašča zanimanje za naravna vlakna, ki uporabljajo za razvoj okolju prijazne tehnologije. Namen tega dela je predstaviti enega izmed načinov, kako odpadno piščančje perje uporabiti za razvoj nanovlaken iz keratina. Za izvedbo tega smo najprej pridobili keratin iz odpadnega piščančjega perja s hidrotermično razgradnjo perja v reaktorju. Postopek hidrotermične razgradnje perja s subkritično vodo predstavlja okolju prijazno in zeleno tehniko, kar jo loči od preostalih tehnik, ki se uporabljajo za ekstrakcijo keratina iz perja. Prisotnost keratina v suspenziji smo potrdili z analizo ATR-IR in nato z elektroforezo SDS-PAGE določili molekulske mase. Suspenziji keratina smo določili protonirane in deprotonirane skupine s potenciometrično titracijo, izmerili zeta potencial v odvisnosti od pH-raztopine in določili velikost delcev z DLS-metodo. Koncentracijo keratina v suspenziji pa smo določili z Bradfordovo metodo. Za pripravo nanovlaken smo suspenzijo keratina pomešali s polietilenoksidom (PEO) v različnih razmerjih in s postopkom elektropredenja spredli nanovlakna ter jih preučili pod optičnim mikroskopom. Prav tako smo spredli nanovlakna iz mešanic PEO/keratin/alginat in PEO/keratin/hitozan v različnih razmerjih. Mešanicam PEO/keratin/alginat in PEO/keratin/hitozan smo določili prevodnost, viskoznost in stopnjo antioksidativnosti z ABTS-metodo. Spredenim vlaknatim strukturam smo posneli spekter ATR-IR, določili stopnjo antioksidativnosti in izmerili stični kot. Molsko maso suspenzije keratina smo določili v območju med 1 kDa in 14 kDa. Določena optimalna vsebnost PEO-ja, ko je nastalo nanovlakno, je 70 %. Ugotovili smo, da so se nanovlakna lepše oblikovala v primeru mešanic PEO/keratin/alginat in PEO/keratin/hitozan v razmerju 70/21/9, torej, ko je mešanica vsebovala več keratina. Vzorci PEO/keratin/alginat in PEO/keratin/hitozan imajo hidrofilno naravo s kontaktnimi koti med 33,16° in 39,58°. Tako mešanice iz katere smo spredli optimalna vlakna kot tudi spredena vlakna so pokazala antioksidativne lastnosti. Taka vlakna imajo tudi uporabno vrednost, kar pa je še posebej pomembno pri medicinskih tekstilijah.

Keywords

subkritična voda;keratin;elektropredenje;nanovlakna;hitozan;alginat;magistrske naloge;

Data

Language: Slovenian
Year of publishing:
Typology: 2.09 - Master's Thesis
Organization: UM FKKT - Faculty of Chemistry and Chemical Engineering
Publisher: [K. Zadravec]
UDC: 620.3:675.84(043.2)
COBISS: 99304707 Link will open in a new window
Views: 92
Downloads: 11
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Other data

Secondary language: English
Secondary title: Use of keratin-rich poultry feathers waste for keratin production and further development of nanofibers
Secondary abstract: Waste materials such as wool and chicken feathers are one of the most burdensome industrial wastes, which are generated in huge quantities on a daily basis and burden the environment. Waste chicken feathers containing 91% keratin are thus useful for the development of natural fibers. Today, there is a growing interest in natural fibers, which are used to develop environmentally friendly technology. The purpose of this paper is to present one of the ways to use waste chicken feathers to develop keratin nanofibers. To do this, we first obtained keratin from waste chicken feathers by hydrothermal decomposition of feathers in the reactor. The process of hydrothermal decomposition of feathers with subcritical water represents an environmentally friendly and green technique, which distinguishes it from other techniques used for the extraction of keratin from feathers. The presence of keratin in the suspension was confirmed by ATR-IR analysis and then molecular weights were determined by SDS-PAGE electrophoresis. The protonated and deprotonated groups of the keratin suspension were determined by potentiometric titration, the zeta potential was measured as a function of the pH of the solution, and the particle size was determined by the DLS method. The keratin concentration in the suspension was determined by the Bradford method. To prepare the nanofibers, the keratin suspension was mixed with polyethylene oxide (PEO) in various proportions and the nanofibers were spun by electrospinning and examined under an optical microscope. We also spun nanofibers from PEO/keratin/alginate and PEO/keratin/chitosan blends in different ratios. Mixtures of PEO/keratin/alginate and PEO/keratin/chitosan were determined for conductivity, viscosity, and antioxidant level by the ABTS method. The ATR-IR spectrum was recorded for the spun fiber structures, the degree of antioxidant was determined, and the contact angle was measured. The molar mass of the keratin suspension was determined in the range between 1 kDa and 14 kDa. The determined optimal content of PEO when the nanofibre is formed is 70 %. We found that nanofibers formed better in the case of PEO/keratin/alginate and PEO/keratin/chitosan mixtures in the ratio 70/21/9, ie when the mixture contained more keratin. The PEO/keratin/alginate and PEO/keratin/chitosan samples are hydrophilic with contact angles between 33,16° and 39,58°. Both the blends from which we spun the optimal fibers, as well as the spun fibers, showed antioxidant properties. Such fibers also have a useful value, which is especially important in medical textiles.
Secondary keywords: Subcritical water;keratin;electrospinning;nanofibers;chitosan;alginate;
Type (COBISS): Master's thesis/paper
Thesis comment: Univ. v Mariboru, Fak. za kemijo in kemijsko tehnologijo
Pages: 1 spletni vir (1 datoteka PDF (X, 61 f.))
ID: 14480164