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Orientador(es)
Resumo(s)
The thesis consists of two major research topic i.e. Porphyrin and Nano crystalline
cellulose.
The porphyrin project started with the production of porphyrin chromophores for dye
sensitized solar cells. These derivatives were required as references for an ongoing project of the research group that hosted me. In addition, some porphyrin-porphyrin tweezers were prepared using a one pot synthetic methodology developed in our lab, based on the use of trichloro triazine as a linker. These derivatives were necessary for collaboration with Professor Nina Berova at Columbia University that studies their use for the determination of the absolute configuration of chiral molecules by circular dichroism. After this training period, the thesis project continued with an original research based on the use of clickchemistry for porphyrin functionalization.
The nanocellulose project started with the production of nanocrystalline cellulose from
microcrystalline cellulose by acid hydrolysis. The nanocellulose has chemically modifiable OH groups on the surface. This allows the use of a wide range of chemical reactions for its functionalization. The linking of a pH sensitive dye on the surface of NCC was studied. In addition, several strategies were being employed for the functionalization of NCC with other groups such as cationic substituents (using (2,3-epoxypropyl)trimethylammonium chloride), amino (using epichlorohydrin and 3-aminopropyltrimethoxysilane), carboxy (using ammonium persulfate and TEMPO). Out of various chemical modifications carried out on NCC, the TEMPO mediated carboxylation for introduction of carboxyl group on NCC was proved to be easy, convenient and even resulted in high degree of functionalization. Using these material and typical carbodiimide chemistry, functional groups such as porphyrins (that acts as a sensitizer for singlet oxygen production) and a nitro-derivative (capable of producing NO upon irradiation) were prepared. These features are under study to verify their potential in various therapeutic applications.
Descrição
Tese arquivada ao abrigo da Portaria nº 227/2017 de 25 de Julho.
