Karakterizacija međupovršina metalni oksid/vodena otopina polielektrolita

master's thesis

• Title (english): Characterization of metal oxide/polyelectrolyte aqueous solution interfaces
• Author: Anja Sadžak
• Mentor: Davor Kovačević (mentor)
• Committee member: Davor Kovačević (predsjednik povjerenstva)
• Committee member: Biserka Prugovečki (član povjerenstva)
• Committee member: Iva Juranović Cindrić (član povjerenstva)
• Committee member: Tajana Preočanin (član povjerenstva)
• Granter: University of Zagreb; Faculty of Science; (Department of Chemistry); Zagreb
• Defense date and country: 2018-02-02, Croatia
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Chemistry

Abstract

Čestice metalnih oksida u dodiru s vodenom otopinom elektrolita poprimaju naboj na
površini, te dolazi stvaranja električnog međupovršinskog sloja. U sklopu diplomskog rada
sintetizirane su i karakterizirane čestice cerijevog oksida, te su ispitana međupovršinska
svojstva sustava cerijev oksid/vodena otopina elektrolita. Mjerenjem elektrokinetičkog
potencijala i površinske gustoće naboja u ovisnosti o pH vrijednosti određene su izoelektrična
točka i točka nul-naboja, dok je ovisnost površinskog potencijala o pH vrijednosti sustava
ispitana korištenjem monokristalne elektrode. Također je istražena agregacija čestica
mjerenjem hidrodinamičkog radijusa metodom dinamičkog raspršenja svjetlosti. S obzirom da
je površina čestica, ovisno o pH vrijednosti sustava pozitivno ili negativno nabijena, na
čestice je adsorbiran negativno nabijeni polielektrolit, natrijev poli(stirensulfonat), te su
navedena svojstva ispitana i nakon adsorpcije polielektrolita. Uz to, korištenjem UV-VIS
spektrofotometrije provedena su adsorpcijska mjerenja, te je određena maksimalna površinska
koncentracija adsorbiranog polielektrolita.

Abstract (english)

Metal oxide particles in aqueous solutions of electrolytes acquire surface charge, which leads
to the formation of the electrical interfacial layer. In this thesis, cerium oxide nanoparticles
were synthesized and characterized, and interfacial properties in electrolyte aqueous solution
were studied. By measuring pH dependence of electrokinetic potential and surface charge
density, isoelectric point and point of zero charge were determined. Furthermore, pH
dependence of surface potential was estimated using single-crystal electrode. Aggregation of
cerium oxide particles was examined by measuring the hydrodynamic radius. Since the
surface of the particle can be positively or negatively charged, depending on the pH value, it
was possible to adsorb the negatively charged polyelectrolyte, sodium poly(styrene sulfonate).
Interfacial properties were examined after the adsorption. Finally, adsorption measurements
were carried out using UV-VIS spectrophotometry which enabled determination of the
maximum surface concentration of the adsorbed polyelectrolyte.

• Keywords: adsorpcija; cerijev oksid; električni međupovršinski sloj; polielektrolit
• Keywords (english): adsorption; cerium oxide; electrical interfacial layer; polyelectrolyte
• Language: croatian
• URN:NBN: urn:nbn:hr:217:246663
• Study programme: Title: Graduate university studies in chemistry; specializations in: Research programme; Course: Research programme; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra kemije (magistar/magistra kemije)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access; Embargo expiration date: 2019-02-02
• Created on: 2018-02-22 10:25:06