20.500.12556/RUL-164885 Izdelava plasti nanovlaken iz titanovega oksinitrida in vrednotenje njihovega protibakterijskega delovanja ter elektrokatalitičnih lastnosti Formulation of titanium oxynitride nanofiber mats and evaluation of their antibacterial activity and electrocatalytic properties Nanovlakna predstavljajo edinstveno podskupino nanomaterialov, ki v zadnjih letih predstavlja pomembno področje raziskav in potencialno rešitev problemov na številnih področjih. Vedno večjo pozornost privabljajo nanovlakna na osnovi titana, predvsem titanovega dioksida (TiO2) in titanovega oksinitrida (TiON). Ta so se do sedaj že izkazala kot potencialno uporabna v elektrokemičnih, biomedicinskih in farmacevtskih aplikacijah. Na podlagi tega smo se odločili tovrstna nanovlakna izdelati tudi v sklopu magistrske naloge, pri tem pa z različnimi analiznimi tehnikami ovrednotiti njihovo uporabnost na omenjenih področjih. Naše delo smo pričeli z optimizacijo polimernih raztopin in pogojev elektrostatskega sukanja za pridobivanje enoslojnih in dvoslojnih nanovlaken ter večplastnih vzorcev. Optimizacija raztopin je temeljila na variiranju masnih deležev polimera (polivinil pirolidona ali poliakrilonitrila (PAN)), prekurzorja TiO2 (titanovega(IV) izopropoksida (TIP)) in aditiva (ocetne kisline) v izbranem topilu (N,N – dimetilformamidu (DMF) ali etanolu). Za pripravo katalitično aktivnih vzorcev smo optimizirali tudi raztopine z dodatkom soli niklja. Izbrane vzorce smo nadalje izpostavili visokim temperaturam v atmosferi amonijaka, pri čemer smo dobili nanovlakna TiON, ali na zraku za izdelavo nanovlaken iz TiO2. Morfologijo in elementarno sestavo nanovlaken smo preučevali s pomočjo vrstične elektronske mikroskopije in elementarne disperzijske analize. V nadaljevanju smo se poslužili različnih elektrokemijskijh metod za analizo katalitičnih lastnosti termično obdelanih vzorcev ter metod za analizo protibakterijskih aktivnosti proti bakterijam Escherichia coli TOP10. Ugotovili smo, da je za uspešno pripravo nanovlaken TiON ali TiO2 potreben višji delež ocetne kisline v primerjavi s TIP ter da višji delež polimera rezultira v večjem premeru nanovlaken. Nanovlakna PAN pa smo uspeli izdelati le z uporabo DMF v vlogi topila. Nanovlakna TiON sama po sebi niso katalitično aktivna, vendar pa ta izkazujejo potencial v obliki večplastnih nanomaterialov z dodatno vključenimi katalizatorji. Rezultati testov analiz protibakterijske aktivnosti so bili prav tako obetavni, saj je bila zaznana zmanjšana metabolna aktivnost bakterij in zaviranje njihove rasti. Na podlagi naših dobljenih rezultatov smo potrdili potencial za uporabo tovrstnih nanovlaken tako na področju elektrokatalize kot tudi v namene zaviranja rasti bakterij. Among all nanostructured materials, nanofibers represent a unique subgroup, which represents an important area of research and a potential solution to the current problems in several fields. The variety of materials and production methods that can be used to form nanofibers and easily adjust their properties additionally increases their value. Titanium-based, especially titanium dioxide (TiO2) and titanium oxynitride (TiON), have so far been successfully applied in electrochemical, biomedical and pharmaceutical field. Therefore, the aim of this Master’s thesis was to produce titanium-based inorganic nanofibers and evaluate their properties and consequently their use in applied fields. Our first step was to optimize polymer solutions and the electrospinning method itself, with the goal of developing single-layer and double-layer nanofibers as well as multi-layer nanofiber mats. Optimization consisted of varying the content of polymer (polyvinylpyrrolidone (PVP) or polyacrylonitrile (PAN)), precursor of TiO2 (titanium (IV) isopropoxide (TIP)) and additives (acetic acid) in suitable solvent (N,N-dimethylformamide (DMF) and ethanol). In order to prepare catalytically active nanofibers, solutions with nickel salt were also prepared and optimized. Selected samples were further calcinated in an ammonia atmosphere to produce TiON nanofibers or in an inert atmosphere to produce TiO2 nanofibers. Morphology and elemental composition of prepared nanofibers were investigated by scanning electron microscopy and energy dispersive spectroscopy. Furthermore, we used various electrochemical methods to analyze the catalytic properties of selected nanofiber samples and different methods to analyze their antibacterial activity against Escherichia coli TOP10. We found that a successful development of nanofibers TiON or TiO2 requires a higher amount of acetic acid compared to TIP and that a higher amount of polymer results in a higher diameter of nanofibers. Preparation of PAN nanofibers is possible only from DMF. Although nanofibers TiON are not catalytically active on their own, we concluded a potential of their use in catalysis in the form of multi-layer nanomaterials with additionally included catalysts. Results of antibacterial activity analyzes were also promising, as a reduced metabolic activity of bacteria and an inhibition of their growth were detected. With this we have confirmed the potential for the use of this type of nanofibers both in the field of electrocatalysis and for the purpose of inhibiting the growth of bacteria. nanovlakna elektrostatsko sukanje TiON elektrokataliza protibakterijska aktivnost nanofibers electrospinning TiON electrocatalysis antibacterial activity true false false Slovenski jezik Angleški jezik Magistrsko delo/naloga 2024-11-15 08:45:27 2024-11-15 08:45:40 2024-11-22 14:56:31 0000-00-00 00:00:00 2024 0 0 0000-00-00 NiDoloceno NiDoloceno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 2025-11-14 114326 26709.pdf 26709.pdf 1 83BA4EDA846991743D59742653BA8CA4 7d75fff748ae07f1e0badc2ef22aa9aa5707a554b6819daf0cb38a55eb8f91e2 3de1f002-a325-11ef-b232-0050569b8976 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=195706 Fakulteta za farmacijo 0 0 0