Izboljšava homogenosti nanosov filma na steklene površine

Zlatnar, Klemen (author), Ručigaj, Aleš (mentor)

V tem magistrskem delu sem se ukvarjal z izboljšavo homogenosti filma na steklenih površinah. Raziskovalno delo te magistrske naloge sloni na funkcionalizaciji steklene površine z ustreznimi funkcionalnimi skupinami, preko katerih bo mogoče vršiti Diels-Alder reakcijo. Osnovni reakcijski mehanizem predvideva zamreženje furanskih in maleimidnih skupin polimera, produkt katerih je stabilen šestčlenski obroč. Največjo težavo mi je predstavljalo doseganje homogenosti nanosa filma, čeprav v literaturi posebnega poudarka na tem ni bilo zaslediti. V literaturi je bilo mogoče zaslediti predpostavko o homogenem nanosu, medtem ko je eksperimentalno to slabše predstavljeno. Za tehniko nanosa sem izbral potapljanje v raztopino (angl. dip-coating). Stekla sem predhodno očistil s segrevanjem v peči, kjer sem se znebil vseh organskih onesnaževal, ki so bila predhodno prisotna na steklu. Po določenem času je sledilo namakanje stekel v raztopini klorovodikove kisline, segrete na temperaturo vrelišča, s katero sem tvoril novo oksidno plast z veliko silanolnimi skupinami. V prvi stopnji nanosa filma sem se ukvarjal z aminsko funkcionalizacijo krovnega stekla, kjer poteka reakcija med hidroksilnimi skupinami substrata in reaktivnimi skupinami silana. Kot posledica takih reakcij nastane vez Si-O-Si. Odločil sem se, da bom uporabljal dva različna aminosilana. Prvi aminosilan je bil 3-aminopropiltrietoksisilan (APTES), drugi pa 3-aminopropiltrimetoksisilan (APTMS). V tem magistrskem delu sem se osredotočil na primerjavo različnih koncentracij APTMS in APTES. Glavni cilj je bil doseči homogen nanos filma in to eksperimentalno ovrednotiti. Po doseženem homogenem nanosu filma oziroma aminski funkcionalizaciji sem izvedel še maleimidno funkcionalizacijo in Diels-Alder reakcijo s furanom. Za topilo pri aminski funkcionalizaciji sem se odločil uporabljati raztopino etanola in vode. Uspešnost kemijsko vezanega organosilana na objektnih steklih sem preveril s fluorescenčno spektroskopijo, saj se z metodo infrardeče spektroskopije s Fourierjevo transformacijo ni dalo zagotovo potrditi uspešnosti funkcionalizacije. To je verjetno posledica debelosti stekla in zelo tankega premaza. Skladno s tem sem se odločil, da objektna stekla zamenjam za krovna, ki so tanjša, in jih potem uspešno analiziral s FTIR. Po nanosih sem površino analiziral tudi z vrstičnim elektronskim mikroskopom (SEM).

• Language: Slovenian
• Keywords: APTMS, APTES, steklo, homogen nanos, Diels-Alder
• Work type: Master's thesis/paper
• Typology: 2.09 - Master's Thesis
• Organization: FKKT - Faculty of Chemistry and Chemical Technology
• Year: 2020
• PID: 20.500.12556/RUL-114116
• COBISS.SI-ID: 1538539715
• Publication date in RUL: 17.02.2020

Secondary language

• Language: English
• Title: The improvement of film homogeneity on the glass surface

Abstract

In this master's thesis, the focus was on improving the homogeneity of the film on glass surfaces. The research work was based on the functionalization of the glass surface with appropriate functional groups through which it shall be possible to perform the Diels-Alder reaction. The basic reaction mechanism involves the crosslinking of furan and maleimide functional groups in a stable six-membered ring. The biggest problem was in achieving the homogeneity of the film since there was no specific emphasis in the literature regarding this aspect. In the contrary, the assumption of a homogeneous coating was found, while experimentally the homogeneity was not sufficiently presented. The glass was cleaned by heating it in a furnace in which case all originally presented organic pollutants were removed. After a while, the glass was soaked in a hydrochloric acid solution heated to the boiling point, which formed a new oxide layer with many silanol groups. In the first stage of the film application, amine functionalization of glass, where the reaction takes place between the hydroxyl groups of the substrate and the reactive groups of the silane, was performed. As a result, a Si-O-Si bond was formed. Two different aminosilanes were chosen. The first aminosilane was 3-aminopropyltriethoxysilane (APTES) and the second was 3-aminopropyltrimethoxysilane (APTMS). The comparison of different concentrations of APTMS and APTES on the glass functionalization was studied. The main objective was to achieve and experimentally evaluate a homogeneous film deposition. After the homogeneous application of the film, maleimide functionalization and Diels-Alder reaction with furan was carried out. The solution of ethanol and water was used for the amine functionalization solvent. Successfulness of the chemically bound organosilane on the slides was verified by fluorescence spectroscopy, as the Fourier transform method could not confirm successful functionalization. This is probably due to the thickness of the glass and the very thin coating. That is why the swap for thinner slides was made which were then successfully analyzed with FTIR. After application, the surface was also analyzed by scanning electron microscope (SEM).

• Keywords: APTMS, APTES, glass, homogeneous coating, Diels-Alder