Elektrokemijsko određivanje pK vrijednosti molekula stabilizatora adsorbiranih na površini nanočestica srebra

master's thesis

• Title (english): Electrochemical determination of the ionisation constant of capping agents adsorbed on the surface of silver nanoparticles
• Author: Vanja Rukavina
• Mentor: Stjepan Milardović (mentor)
• Committee member: Stjepan Milardović (predsjednik povjerenstva)
• Committee member: Zoran Mandić (član povjerenstva)
• Committee member: Lidija Furač (član povjerenstva)
• Granter: University of Zagreb; Faculty of Chemical Engineering and Technology; Zagreb
• Defense date and country: 2018-09-27, Croatia
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Chemistry; Inorganic Chemistry

Abstract

Predmet ovog rada bila je sinteza nanočestica srebra te njihova stabilizacija u otopini. Kao molekule stabilizatori homogene suspenzije korištena su dva polimera: poli(akrilna kiselina) (PAA) i poli(metakrilna kiselina) (PMA). Dobivene nanočestice su zatim taložene slabim organskim kiselinama: limunskom, octenom, jantarnom i askorbinskom kiselinom. Dobiveni praškasti produkt korišten je kao baza za pripravu vodljive tinte. Utjecaj taložnog sredstva na stabilnost dobivene formulacije, te interakcije između nanočestica, ispitane su metodama cikličke voltametrije (engl. cyclic voltammetry, CV), te elektrokemijskom impedancijskom spektroskopijom (engl. electrochemical impedance spectroscopy, EIS). Načinjen je niz eksperimenata u Britton-Robinsonovim puferima različitih pH vrijednosti. Sva su elektrokemijska mjerenja provodena u troelektrodnom sustavu koji se sastojao od radne elektrode (disk elektroda od staklastog ugljika), referentne elektrode (Ag|AgCl||3M KCl) i pomoćne elektrode (štapićasta platinska elektroda). Iz dobivenih rezultata određena je pKa vrijednost polikiselina adsorbiranih na površinu nanočestica.

Abstract (english)

The subject of this diploma work was the synthesis of silver nanoparticles and their stabilization in solution. As a homogeneous suspension stabilizer molecules, two polymers were used: poly(acrylic acid) (PAA) and poly(methacrylic acid) (PMA). Obtained nanoparticles were then precipitated using weak organic acids: citric, acetic, succinic, oxalic and ascorbic acid. The resulting powder product was used as a basis for the conductive ink preparation. The influence of the precipitation agent on the stability of the formulation as well as the interaction between the nanoparticles were studied by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). A series of experiments were performed in Britton-Robinson's buffers of different pH values. All electrochemical measurements were carried out in a three-electrode system consisting of a work electrode (glassy carbon disc electrode), a reference electrode (Ag|AgCl||3M KCl) and a platinum rod as a counter electrode. From the gained results, the pKa value of the polyacid adsorbed on the nanoparticle surface was determined.

• Keywords: ciklička voltametrija; elektrokemijska impedancijska spektroskopija; nanočestice srebra; polielektroliti; slabe organske kiseline
• Keywords (english): cyclic voltammetry; electrochemical impedance spectroscopy; silver nanoparticles; polyelectrolytes; weak organic acids
• Language: croatian
• URN:NBN: urn:nbn:hr:149:431168
• 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: Open access
• Created on: 2020-10-29 12:16:54