Browsing by Author "Stenholm, Mikko"

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Intercalation of organic molecules into layered ceramic oxides
(2017-01-09) Stenholm, Mikko
Kemian tekniikan korkeakoulu | Master's thesis
Intercalation is a relatively simple method for preparing inorganic-organic hybrids. The intercalation is based on layered materials that have inorganic blocks separated by interlayer cations. In the intercalation guest specie is inserted into the interlayer region of the host material. This master’s thesis goes through the basics behind the intercalation of simple organic molecules into layered ceramic oxides. The literature review consists of explaining the intercalation specially for layered ceramic oxides including Dion-Jacobson phases, Ruddlesden-Popper phases and titanoniobate. In addition to the intercalation reaction and the structures of the interlayer regions of inorganic-organic hybrids, possible ways to utilize them especially as photocatalysts are discussed. In the experimental part the intercalation of molecules with functional hydroxyl group/s such as diols, phenol, hydroquinone and glycolic acid into titanoniobate were experimented. The purpose was to investigate if the intercalation of these molecules is possible through multistep intercalation. After the intercalation, the structure of the interlayer region of these derivatives and the amount of intercalated molecules were investigated. The intercalation of organic molecules into layered ceramic oxides could combine the properties of inorganic and organic materials. Because layered ceramic oxides have many different properties including photocatalytic, dielectric and optoelectronic properties they provide possibly new interesting applications especially for inorganic-organic hybrids. The intercalation of simple organic molecules like amines and alcohols is relatively simple. The host material is protonated with ion-exchange reaction in which the interlayer cations are exchanged with protons from acid. The protonated form acts as Brønsted acid thus making the intercalation of bases possible. In addition, more complex molecules can be intercalated via multistep intercalation where shorter molecule is first intercalated into the lattice to expand the interlayer distance after that the intercalation of more complex or longer molecules is possible via exchange reaction. In the experimental part of the thesis diols and possibly phenol and hydroquinone were successfully intercalated into titanoniobate, whereas glycolic acid was not clearly intercalating. The biggest problem in the intercalation was the remaining butylammonium from the multistep intercalation in the interlayer region. This did the analysis of the interlayer distance, FTIR spectra and TGA really complicated. However, it was clear that diols affected the interlayer distance of the host material by increasing it. According to the results, longer diols formed a monolayer in the interlayer region and the rest of the intercalated molecules formed a bilayer.
Termosähköiset klatraattimateriaalit
(2014-08-26) Stenholm, Mikko
Kemiantekniikan korkeakoulu | Bachelor's thesis