Funkcionalni optički materijali temeljeni na novim derivatima iminokumarina

master's thesis

• Title (english): Functional optical materials based on novel iminocoumarine derivatives
• Author: Štefica Kamenić
• Mentor: Lidija Furač (mentor)
• Committee member: Lidija Furač (predsjednik povjerenstva)
• Committee member: Ivana Steinberg (član povjerenstva)
• Committee member: Marijana Hranjec (član povjerenstva)
• Granter: University of Zagreb; Faculty of Chemical Engineering and Technology; Zagreb
• Defense date and country: 2015-09-24, Croatia
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Chemistry; Applied Chemistry

Abstract

Svrha ovog rada je optička karakterizacija novih derivata imonokumarina imobiliziranih u različite polimerne matrice s ciljem razvoja novih funkcionalnih optičkih materijala, odnosno optičkih pH senzora. U radu su istraženi utjecaj prirode supstituenata, vrste matrica i vrijednosti pH na svojstva imobiliziranih spojeva te je procijenjena njihova primjenjivost u pH senzorima. Ispitivani spojevi 2-imino-3-(2-N-metilbenzimidazolil) kromen (IM1), 7-N,N-dietilamino-2-imino-3-(2-N-metilbenzimidazolil) kromen (IM2) i 7-N,N-dietilamino-2-imino-3-(2-N-1H-6-nitrobenzimidazolil) kromen (IM3) su lipofilne prirode, a razlikuju se u položaju dietilamino i nitro skupine.
Karakterizacija navedenih spojeva, imobiliziranih u PVC, silikatnu, pHEMA i PMMA matricu, provedena je UV-vidljivom apsorpcijskom i fluorescencijskom spektrofotometrijom te je ispitan utjecaj promjene vrijednosti pH u univerzalnom puferu u rasponu vrijednosti pH od 1,00 do 13,00. Određena kiselo-bazna svojstva važna su za određivanje potencijalne primjene dobivenih polimernih filmova za pH osjetljive senzorske sustave.
Spektralnom karakterizacijom imobiliziranih spojeva u PVC, silikatnoj i pHEMA matrici utvrđeno je da se dobiveni filmovi mogu koristiti kao potencijalni optički pH senzori uz daljnja ispitivanja i poboljšanja svojstava filmova. PMMA filmovi ne mogu se koristiti kao optički pH senzori, ali njihova izražena fluorescencija te homogenost i stabilnost omogućuju širok spektar njihove primjene u drugim područjima. Također je utvrđeno da dietilamino i nitro supstituenti imaju velik utjecaj na intenzitet fluorescencije.
Najpravilniji i najintenzivniji odziv kalibracijske krivulje uočen je u plastificiranoj PVC matrici. Vrijednost pKa uočena kod poli(HEMA) matrice za spoj IM2 je najbliža pH krvi (pH = 7,4), stoga je navedena polimerna matrica najpogodnija za uporabu u biološkim sustavima.

Abstract (english)

The aim of this work was optical characterisation of novel iminocoumarine derivatives immobilised in various polymer matrices in order to develope novel functional optical materials (optical pH sensors). Effect of the substituents, effect of polymer matrix and effect of pH on the examined compounds was determined. Compounds 2-imino-3-(2-N-methylbenzimidazolyl) chromene (IM1), 7-N,N-diethylamino-2-imino-3-(2-N-methylbenzimidazolyl) chromen (IM2) and 7-N,N-diethylamino-2-imino-3- (2-N-1H-6-nitrobenzimidazolyl) chromene (IM3) are lipophilic and distinguished by diethylamino and nitro substituent position.
Characterisation of the compounds mentioned, immobilised in PVC, silicate, pHEMA and PMMA matrix, was performed by UV-visible absorption and fluorescence spectrophotometry. Effect of pH was invastigated in the universal buffer solutions, in the pH range from 1,00 to 13,00. Acid-base properties determined through this work are important parameter for potential sensing applications.
Spectral characterization of immobilized compounds in thin polymer films showed that developed materials can be used as a potential optical pH sensors, along additional research. PMMA films can't be used as optical pH sensors, but their expressed fluorescence, stability and homogeneity enable a wide range of applications. It was also found that diethyl amino and nitro substituents have a major impact on the fluorescence intensity.
The difference between the pKa values of the compound IM2 immobilized in different polymer matrix is up to ΔpKa = 3. Most intense and precise response was observed in the plasticised PVC matrix. The value of the pKa observed at poly(HEMA) matrix is the closest to blood pH (pH = 7.4). Therefore, plasticised PVC matrix is most suitable for use in biological systems.

• Keywords: optički pH senzori; polimerne matrice; fluorescencija; derivati iminokumarina
• Keywords (english): optical pH sensors; polymer matrix; fluorescence; iminocoumarine derivatives
• Language: croatian
• URN:NBN: urn:nbn:hr:149:094864
• Study programme: Title: Chemical Engineering - Graduate study; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra inženjer/inženjerka kemijskog inženjerstva (magistar/magistra inženjer/inženjerka kemijskog inženjerstva)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Closed access
• Created on: 2016-12-16 11:35:34