20.500.12556/RUL-177281 Matematično modeliranje Youngovega modula in natezne trdnosti alginatnih hidrogelov s TEMPO oksidirano celulozo Mathematical modeling of the Young’s modulus and tensile strength of alginate hydrogels with TEMPO oxidized cellulose Magistrsko delo obravnava mehanske lastnosti hidrogelov na osnovi alginata in TEMPO-oksidirane nanoceluloze (TONCF) ter njihov matematični opis. Namen raziskave je bil eksperimentalno ovrednotiti vpliv sestave na elastičnost, natezno trdnost in mrežno arhitekturo kompozitov ter razviti modele za napoved mehanskega odziva glede na razmerje sestavin. Pripravljeni so bili vzorci z različno koncentracijo alginata (5–10 ut%) in deleži TONCF (0–100 %), pri konstantni koncentraciji CaCl₂ in TONCF (3 %). Mehanske lastnosti so bile določene z nateznimi preizkusi. Rezultati so pokazali, da imajo kompoziti ojačevalen učinek na mehanske lastnosti: tako Youngov modul kot natezna trdnost presegata vrednosti posameznih komponent. Youngov modul doseže maksimum pri 75 % TONCF, medtem ko natezna trdnost doseže vrh pri 25 % TONCF, kar potrjuje nelinearno in lastnostim specifično vedenje mešanic. Za napoved mehanskih lastnosti so bili razviti trije pristopi. Random Forest model je izkazal najvišjo natančnost z R² = 0,9838 (Youngov modul) in R² = 0,9888 (natezna trdnost), vendar brez možnosti interpretacije in ekstrapolacije. Ekstrapolacijski model omogoča napoved tudi za sestave izven eksperimentalnega območja (za alginat), z nekoliko nižjo natančnostjo (R² ≈ 0,91–0,94). Tretji, semiempirični model, kateri temelji na perkolacijski teoriji, omogoča fizikalno utemeljeno interpretacijo opaženih pojavov ter razlago sprememb v gostoti mreže in medverižnih interakcijah. Delo dokazuje, da je s kombinacijo eksperimenta in modeliranja mogoče učinkovito opisati in napovedati mehanske lastnosti alginatno-celuloznih hidrogelov ter razumeti mehanizme ojačanja, kar predstavlja pomembno izhodišče za nadaljnji razvoj funkcionalnih mehkih materialov. This master's thesis investigates the mechanical properties of hydrogels based on alginate and TEMPO-oxidized nanocellulose (TONCF), along with their mathematical modeling. The aim of the research was to experimentally evaluate the effect of composition on elasticity, tensile strength, and network architecture of the composites, and to develop predictive models for mechanical response based on component ratios. Samples were prepared with varying alginate concentrations (5–10 wt%) and TONCF fractions (0–100%) at a constant CaCl₂ and TONCF concentration (3%). Mechanical properties were assessed through tensile testing. The results demonstrated that the composites exhibit reinforcing effects on mechanical properties: both Young’s modulus and tensile strength surpassed the values of the individual components. Young’s modulus peaked at 75% TONCF, while tensile strength reached a maximum at 25% TONCF, confirming non-linear and property-specific behavior of the mixtures. Three modeling approaches were developed to predict mechanical properties. The Random Forest model showed the highest accuracy, with R² = 0.9838 (Young’s modulus) and R² = 0.9888 (tensile strength), though it lacks interpretability and extrapolation capability. The extrapolation model enables prediction beyond the experimental composition range (for alginate), with slightly lower accuracy (R² ≈ 0.91–0.94). The third, semi-empirical model, based on percolation theory, offers a physically grounded interpretation of observed phenomena and explains changes in network density and interchain interactions. The study demonstrates that combining experimental data with modeling enables effective prediction and explanation of the mechanical behavior of alginate–cellulose hydrogels, providing a solid foundation for further development of functional soft materials. hidrogel alginat TEMPO-oksidirana celuloza mehanske lastnosti modeliranje hydrogel alginate TEMPO-oxidized cellulose mechanical properties modeling true false false Slovenski jezik Angleški jezik Magistrsko delo/naloga 2025-12-19 11:10:03 2025-12-19 11:10:12 2026-01-29 09:41:21 0000-00-00 00:00:00 2025 0 0 0000-00-00 NiDoloceno NiDoloceno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 25513 266594563 Vidergar_Jan_-_Matematicno_modeliranje_Youngovega_modula_in_natezne_trdnosti_alginatnih_hidrogel.pdf Vidergar_Jan_-_Matematicno_modeliranje_Youngovega_modula_in_natezne_trdnosti_alginatnih_hidrogel.pdf 1 082D74C46C099116ED03D1CD1C3A89DA f9ff44d659ddf71cd5a83e23c4a4ba1caa061c82d3cb774dec12a5eddf083951 7a1f1a1d-dcc2-11f0-9328-0050569b8976 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=224225 Fakulteta za kemijo in kemijsko tehnologijo 0 0 0