20.500.12556/DKUM-82742 Vpliv površinske funkcionalizacije anizotropnih magnetnih struktur z amini na njihovo aktivnost za aldolno kondenzacijo magistrsko delo Surface functionalization effect of anisotropic magnetic structures with amines on their activity for aldol condensation Aldolne reakcije uvrščamo med pomembne reakcije za tvorbo C-C vezi. Med zanimivimi spojinami, uporabljenimi v aldolni kondenzaciji, je hidroksimetilfurfural, ki je prekurzor za veliko uporabnih spojin. Z reakcijo aldolne kondenzacije hidroksimetilfurfurala se pridobijo uporabne molekule na področjih farmacije in zelene energije. Aldolne kondenzacije se najpogosteje izvajajo v prisotnosti močne baze, kisline ali kovinskega katalizatorja. Ti katalizatorji pa imajo slabosti. Močne kisline in baze zaradi visoke reaktivnosti niso primerne za vse reagenčne materiale. Prav tako so škodljive okolju in se ob industrijski uporabi le teh ustvari veliko odpadnega materiala. Kovinski katalizatorji teh pomanjkljivosti nimajo, imajo pa slabost visoke tržne cene. V zadnjih desetletjih se je uporaba magnetnih struktur v kemiji močno povečala. Zaradi magnetnih lastnosti se lahko magnetni katalizatorji enostavno regenerirajo po reakciji in znatno zmanjšajo stroške porabe katalizatorja. Magnetne strukture imajo velike aktivne površine, tako omogočajo vezavo velikega števila aminskih funkcionalnih skupin. Posledično povečajo aktivnost magnetnih katalizatorjev. Aminosilani se uvrščajo med šibke baze, zato se zniža škodljivost odpadnih materialov. Z uporabo magnetnih struktur, prevlečenih z aminosilani, bi lahko odpravili težave, ki se pojavljajo pri uporabi močnih baz in kislin ter kovinskih katalizatorjev v reakciji aldolne kondenzacije. V magistrskem delu sem pripravil hidrotermalno sintetizirane anizotropne magnetne nanodelce, prevlečene z alumino, in anizotropne magnetne nanodelce, prevlečene s siliko. Magnetne nanodelce sem dodatno prevlekel z aminosilani (3-aminopropil)trietoksisilan, 3-(2-aminoetilamino)propilmetildimetoksisilan in 1-(3-(trietiloksilil)propil)imidazol, nato pa sem se osredotočil na vpliv magnetnih struktur, prevlečenih z aminosilani, v katalizi aldolnih kondenzacij. Proučeval sem vpliv spreminjanja pogojev pri vezavi (3-aminopropil)trietoksisilana na ζ-potencial hidrotermalno sintetiziranih magnetnih nanodelcev, prevlečenih s plastjo (3-aminopropil)trietoksisilana, in vpliv pripravljenih magnetnih struktur s prevlekami na aldolno kondenzacijo hidroksimetilfurfurala. Vezave aminosilanov sem preveril z meritvami ζ-potenciala, analiza vsebnosti reakcijske zmesi v aldolni kondenzaciji pa se je opravila s plinsko kromatografijo-masno spektrometrijo. Na osnovi dobljenih rezultatov sem potrdil uspešnost prevlečenja magnetnih struktur z aminosilani in uspešnost katalize aldolne kondenzacije hidroksimetilfurfurala z magnetnimi strukturami, prevlečenimi z aminosilani. Aldol reactions are classified into important C-C bond formation reactions. Among interesting compounds used in aldol condensation is hydroxymethylfurfural, a precursor for many useful compounds. With aldol condensation reaction of hydroxymethylfurfural useful molecules are acquired on pharmaceutical and green energy fields. Aldol condensations are most commonly carried out in the presence of strong acids, bases or metal catalysts. But these catalysts have drawbacks. Strong acids and bases are not appropriate for all reagent materials because of their high reactivity. In industry they also produce waste materials in great quantities and are environmentally very damaging. Metal catalysts don't have these drawbacks, but they have high market costs. In the last ten years the use of magnetic structures in chemistry has risen. Magnetic catalysts are easily regenerated after reactions because of their magnetic properties. This lowers the cost of catalyst considerably. Magnetic structures have characteristic of large active surface. That is why large number of amine functional groups can be bonded to the surface, followed up by the increase in catalyst activity. Aminosilanes belong in the category of weak bases, which damage the environment less. By using magnetic structures, coated with aminosilanes, we could avoid problems, that arise with use of strong bases, strong acids and metal catalysts in reaction of aldol condensation. In my masters thesis I prepared hydrothermally synthetized anisotropic magnetic nanoparticles, coated in alumina, and anisotropic magnetic nanoparticles, coated in silica. I additionally coated magnetic particles with aminosilanes (3-aminopropyl)triethoxysilane, 3-(2-aminoethylamino)propylmethyldimethoxysilane and 1-(3-(triethyloxysilyl)propyl)imidazole. Afterwards I focused on the effect of magnetic nanoparticles, coated with aminosilanes in catalysis of aldol condensation. I studied the effect of parameter changes in (3-aminopropyl)triethoxysilane coating synthesis on ζ-potential of hydrothermally synthetized anisotropic magnetic nanoparticles, coated with a layer of (3-aminopropyl)triethoxysilane. I studied the effect of different magnetic structures on aldol condensation of hydroxymethylfurfural. Succesfulness of aminosilane coating was checked with ζ-potencial measurements. Analysis of reaction mixture content after aldol condensation was carried out with GC-MS. Based on results I have confirmed succesfulness of magnetic nanoparticles coating with aminosilanes and succesfulness of aldol condensation catalysis of hydroxymethylfurfural with nanoparticles coated in aminosilanes. hidroksimetilfurfural silika alumina aminosilani aldolna kondenzacija anizotropni magnetni nanodelci koloidna suspenzija hydroxymethylfurfural silica alumina aminosilanes aldol condensation anisotropic magnetic nanoparticles colloidal suspension true true false [J. Opara] Slovenski jezik Angleški jezik Magistrsko delo/naloga 2022-08-31 12:42:05 2022-09-26 13:46:22 2022-12-07 03:06:56 0000-00-00 00:00:00 2022 0 Maribor 0 Maribor 1 spletni vir (1 datoteka PDF (XI, 52 f.)) 0000-00-00 NiDoloceno NiDoloceno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 544.77:621.318.1(043.2) 132430339 MAG_Opara_Jan_2022.pdf MAG_Opara_Jan_2022.pdf 1 FDE7AE9D1759F16207651094852C99D6 27b016b667626fe00b18c8af4a9391bad755c88024392743d1cf1c46d1075b5c 01ee0587-3d88-11ed-9af8-00155d000105 https://dk.um.si/Dokument.php?lang=slv&id=163424 Fakulteta za kemijo in kemijsko tehnologijo 0 0 0