Študij površinskih pojavov, katalize in ločbe v pretočnem sistemu emulzijsko vtisnjenih polimerov

Mravljak, Rok (author), Podgornik, Aleš (mentor)

To delo govori o sintezi in razvoju zanesljivega poroznega pretočnega materiala, ki se lahko uporablja kot orodje za preučevanje pretočnih reakcij. Material temelji na emulzijsko vtisnjenem polimeru iz emulzije z visokim deležem notranjo fazno. Za preučevanje učinkov poroznosti na padec tlaka so bili uporabljeni polimeri z različnimi poroznostmi, vendar podobno velikimi porami. Lastnosti toka, povezane s homogenostjo toka, so bile preučene vnaprej, da bi preprečili njihov vpliv na rezultate. Tehnike karakterizacije glavnega toka so bile kombinirane, da bi prvič tako podrobno testirali lastnosti proučevanega materiala. Ker so se tokovne lastnosti izkazale za ustrezne, smo nadaljevali z uporabo pripravljenega materiala za različne aplikacije. V ta namen je bilo najprej koristno poiskat zanesljive načine za spreminjanje kemije površin. To je bilo narejeno v vodnih raztopinah in običajno je bila sprememba pH zadostna, da omogoči dobro pretvorbo za vse proučevane molekule. Modificirani polimeri so bili pripravljeni tako, da imajo določeno stopnjo pretvorjene polimerne površine za preučevanje metode, imenovane metoda pH prehoda, ki omogoča določanje površinsko vezanih ionskih skupin. Raznolikost prisotnih kemikalij je bila razširjena z dodajanjem kelatnih sredstev z več ionskimi funkcionalnimi skupinami. Poleg tega je bila ista metoda uporabljena za veliko biomolekulo, in sicer protein A. Rezultati so potrdili, da se lahko metoda pretočnega pH prehoda uporablja za različne elektrolite, vezane na nosilec. Ker so bili rezultati obetavni, smo raziskali tudi možnost uporabe polimera kot katalitskega reaktorja na osnovi srebra. V ta namen smo izbrali dva pristopa, in sicer in situ rast kristalov in tehniko imobilizacije. Rast in situ je omogočila izdelavo reaktorjev z zelo visokim deležem srebra in skoraj popolno pokritostjo površine polimera. Po drugi strani je tehnika imobilizacije veliko bolj splošna in jo je teoretično mogoče uporabiti za vse nanokristale, če so dobro dispergirani in veliko manjši od por materiala. Oba reaktorja sta bila preizkušena za katalitsko pretvorbo 4-nitrofenola. Nazadnje je bila testirana študija o ločevanju na podlagi slalom kromatografije, ki je bila izvedena na dolgih polimernih kolonah in dolgih kapilarnih kolonah. Aplikacije, prikazane v disertaciji, prikazujejo koristne lastnosti proučevanega polimera in so zato koristen dodatek zakladnici znanja

• Language: Slovenian
• Keywords: -
• Work type: Doctoral dissertation
• Typology: 2.08 - Doctoral Dissertation
• Organization: FKKT - Faculty of Chemistry and Chemical Technology
• Year: 2023
• PID: 20.500.12556/RUL-152301
• COBISS.SI-ID: 177142787
• Publication date in RUL: 17.11.2023

Secondary language

• Language: English
• Title: Study of surface phenomena, catalysis and separation in the flow system of emulsion-templated polymers

Abstract

This work is about the synthesis and development of a reliable porous flow material that can be used as a tool for studying reactions in flow. The material is based on a polymer templated by a high internal phase emulsion. Polymers with different porosities but similar sized pores were used to study the effects of porosity on pressure drop. Flow properties related to flow homogeneity were studied in advance to prevent their influence on the reported results. The main flow characterization techniques were combined to test the properties of the studied material for the first time in such detail. Since the flow properties were shown to be adequate, we proceeded with the use of the prepared material in various applications. To this end, it was first useful to find reliable ways to change the chemistry of the surfaces. This was done in aqueous solutions and usually a change in pH was sufficient to allow good conversion for all the chemicals studied. The modified polymers were prepared to have some degree of converted polymer surface area to study a method called the pH transition method, which allows the determination of surface-bound ionic groups. The variety of chemicals present was expanded by adding chelating agents with multiple ionic functional groups. In addition, the same method was applied to a large biomolecule, namely protein A. The results confirmed that the flow-through pH transition method can be used for a variety of electrolytes bound to a support. Since the results were promising, we also investigated the possibility of using the polymer as a silver-based catalytic reactor. For this purpose, we chose two approaches, namely in situ growth of crystals and immobilization technique. The in-situ growth allowed the fabrication of reactors with very high silver loading and almost complete coverage of the polymer surface. The immobilization technique, on the other hand, is much more general and can theoretically be used for all nanocrystals as long as they are well dispersed and much smaller than the pores of the material. Both reactors were tested for their performance in the catalytic conversion of 4-nitrophenol. Finally, a study on the separation based on slalom chromatography performed on long polymer columns and long capillary columns was tested. The applications shown in the dissertation all demonstrate the beneficial properties of the polymer studied and are therefore a valuable addition to the scientific community.

• Keywords: -