20.500.12556/RUL-183767 Kislinska hidroliza fibroina med razgradnjo svile Acid hydrolysis of fibroin during silk degradation Svila je naravni proteinski polimer, ki se zaradi svojih izrednih mehanskih lastnosti že tisočletja uporablja predvsem v tekstilni industriji in predstavlja dragocen element kulturne dediščine. Sestavlja jo pretežno protein fibroin, katerega vlakni tvorita jedro svilnega vlakna, objema pa ju protein sericin, ki deluje kot lepilo in zaščitni sloj. V okviru diplomskega dela sem v nasičeni raztopini litijevega bromida raztopil kisle ter nevtralne vzorce neobtežene svile, jim v kapilarnem viskozimetru določil pretočne čase in preko Mark-Houwinkove enačbe izračunal molsko maso, s čimer sem poskušal dokazati večjo stopnjo razgradnje fibroina in svile v kislem okolju. Pripravil sem tudi ekstrakte običajnih vzorcev neobtežene svile ter vzorcev, ki so bili izpostavljeni pospešeni razgradnji, in jih analiziral z ionskim kromatografom, da preverim nastanek morebitnih kislih anionskih zvrsti med procesom staranja. Za potrebe nadaljnjih raziskav sem skušal optimizirati metodo raztapljanja svile, ki je bila predhodno obtežena s kositrovim(IV) kloridom, saj se po standardnem postopku v nasičeni raztopini litijevega bromida ne raztaplja. Preizkusil sem uspešnost predobdelave svile z 0,5 M raztopino amonijaka, degumiranjem z alkalno raztopino natrijevega karbonata in obema metodama hkrati. Silk is a natural protein polymer that, due to its exceptional mechanical properties, has been used for millennia primarily in textile industry, thereby representing a valuable element of cultural heritage. It is mainly composed of the protein fibroin, whose two filaments form a core of a silk fiber, while being surrounded by the protein sericin, which acts as an adhesive and protective layer. As a part of my thesis, I dissolved acidic and neutral samples of non-weighted silk in saturated solution of lithium bromide, measured their flow times using capillary viscometer and calculated their molar mass using Mark-Houwink equation to demonstrate larger degree of fibroin and silk degradation in an acidic environment. I also prepared extracts of standard unweighted silk samples and samples subjected to accelerated degradation and analyzed them using an ion chromatograph to examine the formation of potential acidic anionic species during the aging process. For further research, I attempted to optimize the method of dissolving silk, which had been previously weighted with tin(IV) chloride, as it does not dissolve in a saturated lithium bromide solution under standard procedure. I tested the effectiveness of pretreating the silk with the 0,5 M ammonia solution, degumming with an alkaline sodium carbonate solution and a combination of both methods. fibroin viskozimetrija raztapljanje IC kisline fibroin viscometry dissolution IC acids true false false Slovenski jezik Angleški jezik Diplomsko delo/naloga 2026-06-18 10:30:02 2026-06-18 10:30:14 2026-07-08 11:12:54 0000-00-00 00:00:00 2026 0 0 0000-00-00 NiDoloceno NiDoloceno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 25557 284033539 Macek_Matevz_-_Kislinska_hidroliza_fibroina_med_razgradnjo_svile.pdf Macek_Matevz_-_Kislinska_hidroliza_fibroina_med_razgradnjo_svile.pdf 1 D07C6487ED17A81B8691E609D9CFAB8C 3cd2232f122fa13a1eacc10e198b652ec698d2861365039bd313b5b5d1998b15 dd796379-6aef-11f1-9b0d-0050569b8976 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=235930 Fakulteta za kemijo in kemijsko tehnologijo 0 0 0