Pridobivanje bakterijskih celuloznih tekstilij iz odpadkov živilskopredelovalne industrije

Ogrizek, Linda (author), Gorjanc, Marija (mentor), Čuš, Franc (comentor)

Celuloza, ki jo proizvajajo bakterije (BC), je v tekstilni industriji obetaven material za razvoj inovativnih materialov. Težava pri pridobivanju BC so visoki stroški klasičnega gojišča, saj ti zajemajo 30 % celotnega proizvodnega stroška, in okužbe gojišč z mikroorganizmi (npr. s plesnimi). Poleg tega so membrane BC krhke in lomljive, kar omejuje njihovo širšo uporabnost. To lahko rešujemo z in situ gojenjem BC na nosilni tkanini, vendar med njima ni dobre adhezije. V sklopu doktorskega dela smo raziskali uporabnost odpadkov živilskopredelovalne industrije za pridobivanje BC in lastnosti take BC ter modifikacija nosilne tkanine s plinsko plazmo, da se izboljšata adsorpcija in adhezija BC. Kot delno ali popolno zamenjavo klasičnega gojišča (HS) smo uporabili tropine belega in rdečega grozdja, zmanjšanje okužbe z mikroorganizmi pa smo proučili z dodajanjem naravnega sredstva v gojišče, npr. avokadove koščice in tropin belega grozdja. Nosilno tkanino smo obdelali v nizkotlačni induktivno sklopljeni plazmi kisika v porazelektritvi, E- in H-načinu. Tropine belega grozdja (BT) so se izkazale za odličen nadomestek za gojišče HS, s trikrat večjim donosom membran BC, ki so imele do petkrat večjo sposobnost zadrževanja vode in povečano prožnost v primerjavi s klasično pridobljenimi. Membrane BC, pridobljene v gojišču BT, so imele tudi malce višjo kristaliničnost, nižjo stopnjo polimerizacije, večjo vsebnost vlage in nižjo intenziteto vodikovih vezi kot membrane BC, pridobljene v gojišču HS. Dodatek avokadove koščice v gojišče HS je pozitivno vplival na zaviranje okužbe s plesnijo, vendar je negativno vplival na donos membran BC. V gojiščih BT se plesen ni razvila zaradi velikega deleža polifenolov in močne antioksidativne aktivnosti. Modifikacija bombažne tkanine s plazmo kisika v porazelektritvi je povzročila kemijske, v E- in H-načinu tudi morfološke spremembe bombažnih vlaken, kar je izboljšalo donos BC, zmožnost zadrževanja vode, predvsem pa adhezijo med BC in tkanino. Modifikacija tkanine dlje časa v E-načinu ni priporočljiva, saj povzroči močno jedkanje, posledično pa luščenje bombažnih vlaken in odstopanje posamičnih fibrilov.

• Language: Slovenian
• Keywords: grozdne tropine, plinska plazma, donos, trajnostne tekstilije, adhezija
• Work type: Doctoral dissertation
• Organization: NTF - Faculty of Natural Sciences and Engineering
• Year: 2024
• PID: 20.500.12556/RUL-158592
• Publication date in RUL: 16.06.2024

Secondary language

• Language: English
• Title: Production of bacterial cellulose textiles from food processing industry waste

Abstract

Cellulose produced by bacteria (BC), is recognized as a promising material for the textile industry. However, its production faces challenges, including the high cost of traditional culture media, which constitutes 30% of the total production cost, and contamination by microorganisms such as molds. Additionally, the fragile and delicate nature of BC membranes limits their broader applicability. This issue may be addressed by cultivating BC in situ on a support fabric, though adhesion poses a significant challenge. The doctoral thesis investigated the applicability of waste from the food processing industry to produce BC and their properties as well as the modification of the support fabric with gaseous plasma to increase the adsorption and adhesion of BC. The white (BT) and red (RT) bagasse was used as a partial or complete replacement for the classical culture medium (HS), and the reduction of microbial contamination was investigated by adding a natural substance, e.g. avocado pit and white grape bagasse, to the medium. The support fabric was treated in an inductively coupled low-pressure oxygen plasma in afterglow, E and H mode. BT medium proved to be an excellent substitute for the HS medium, with a threefold higher yield of BC membranes that exhibited up to five times higher water retention capacity and higher flexibility than membranes prepared in HS medium. The BC membranes obtained in BT medium also exhibited slightly higher crystallinity, lower degree of polymerization, higher moisture content and lower hydrogen bonding intensity than the BC membranes obtained in HS medium. The addition of avocado pits to HS medium had a positive effect on the inhibition of mold infection but a negative effect on the yield of BC membranes. Due to the high content of polyphenols and the high antioxidant activity, mold did not develop in BT media. The modification of the cotton fabric with oxygen plasma in the afterglow led to chemical, and in the E and H mode also to morphological changes of the cotton fibers, which improved the BC yield, the water retention capacity and above all the adhesion between BC and fabric. Modification of the fabric over a longer period in E-mode is not recommended, as it causes strong etching, which leads to peeling of cotton fibers, and detachment of individual fibrils.

• Keywords: grape bagasse, gas plasma, yield, sustainable textiles, adhesion