Utjecaj polimera na radiolitičku sintezu magnetskih nanočestica željezovih oksida

doctoral thesis

• Title (english): The effect of polymers on the radiolytic synthesis of magnetic iron oxide nanoparticles
• Author: Ivan Marić
• Mentor: Tanja Jurkin (mentor)
• Committee member: Sanda Rončević (predsjednik povjerenstva)
• Committee member: Dubravka Matković-Čalogović (član povjerenstva)
• Committee member: Željka Petrović (član povjerenstva)
• Granter: University of Zagreb; Faculty of Science; (Department of Chemistry); Zagreb
• Defense date and country: 2022-05-13, Croatia
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Chemistry
• Universal decimal classification (UDC): 54 - Chemistry. Crystallography. Mineralogy

Abstract

U ovom doktorskom radu istražen je utjecaj različitih polimera i drugih eksperimentalnih čimbenika na γ-radiolitičku sintezu magnetskih nanočestica željezovih oksida. Redukcija Fe3+ do koje dolazi γ-ozračivanjem prekursorske suspenzije praćena je spektrofotometrijski metodom s 1,10-fenantrolinom. Uz dekstran, dietilaminoetil-dekstran i dekstran sulfat moguće je postići 100 %-tnu redukciju te nastaju stabilne suspenzije magnetskih nanočestica. Uz dietilaminoetil-dekstran pri dozama 10 – 36 kGy nastaju superparamagnetske nanočestice magnetita, dok pri dozama 50 – 130 kGy nastaju magnetski nanodiskovi feroksihita. Uz dekstran sulfat nastaju getit i željezov(III) sulfat hidroksid. Uz poli(etilen-oksid) (PEO) i poli(vinil-pirolidon) nastaju magnetski polimerni gelovi ili magnetske suspenzije, a znatno slabija redukcija (~55 %) rezultira nastankom magnetita i getita, čak i pri visokim dozama (300
kGy). Stupanj umreženja i čvrstoća PEO gela rastu s dozom i koncentracijom prekursora, a do umrežavanja dolazi i preko nanočestica. Osim polimera i doze zračenja, važan utjecaj na stupanj redukcije i fazni sastav produkta imaju i koncentracija 2-propanola i Fe3+ prekursora, pH te koncentracija i molekulska masa polimera.

Abstract (english)

In this thesis, the effect of different polymers and other experimental factors on the γ-radiolytic synthesis of magnetic iron oxides nanoparticles (NPs) was investigated. γ-irradiation-induced Fe3+ reduction was monitored spectrophotometrically with the 1,10-phenanthroline method. With dextran, diethylaminoethyl-dextran, and dextran sulfate colloids, it is possible to achieve
a 100 % reduction and formation of stable suspensions of magnetic NPs. With DEAE-dextran, superparamagnetic magnetite NPs form in the dose range of 10 – 36 kGy, while magnetic feroxyhyte nanodiscs form in the 50 – 130 kGy dose range. With dextran sulfate, goethite and iron(III) sulfate hydroxide form. Synthesis with poly(ethylene oxide) (PEO) and poly(vinylpyrrolidone) resulted in the formation of magnetic polymer hydrogels or magnetic suspensions. Significantly lower reduction (~55 %) results in the formation of magnetite and goethite, even at high doses (300 kGy). Degree of crosslinking and strength of PEO gels improve with dose and precursor concentration, while NPs act as additional crosslinkers. Besides the polymer and dose absorbed, 2-propanol and precursor concentrations, pH, polymer concentration and molar mass also affect the reduction and phase composition of the products.

• Keywords: 1; 10-fenantrolin; feroksihit; gama-zračenje; magnetit; magnetske nanočestice; Mössbauerova spektroskopija; polimeri
• Keywords (english): 1; 10-phenanthroline; feroxyhyte; gamma-irradiation; magnetic nanoparticles; magnetite; Mössbauer spectroscopy; polymers
• Language: croatian
• URN:NBN: urn:nbn:hr:217:512027
• Promotion: 2022
• Project: Number: UIP-2017-05-7337; Title: Utjecaj polimera na radiolitičku sintezu magnetskih nanočestica; Acronym: POLRADNANOP; Leader: Tanja Jurkin; Jurisdiction: Croatia; Funder: HRZZ; Funding stream: UIP
• Study programme: Title: Doctoral study in chemistry; Study programme type: university; Study level: postgraduate; Academic / professional title: doktor/doktorica znanosti, područje prirodnih znanosti, polje kemija (doktor/doktorica znanosti, područje prirodnih znanosti, polje kemija)
• Type of resource: Text
• Extent: 229 str. ; 30 cm
• File origin: Born digital
• Access conditions: Open access; Embargo expiration date: 2024-05-13
• Created on: 2022-05-18 12:48:25