magistrsko delo
Barbara Kaker (Author), Matjaž Kristl (Mentor), Uroš Maver (Co-mentor), Janja Stergar (Co-mentor)

Abstract

Magistrsko delo predstavlja sintezo superparamagnetnih nanodelcev sestave Ni67,5Cu32,5, s sol-gel metodo, v različnih funkcionalnih oblogah iz silike. Namen magistrskega dela je bila modifikacija površine oz. prevleke nanodelcev s funkcionalnimi skupinami preko in situ uporabe prekurzorja tetraetil ortosilikata (TEOS) oz. kombinacije tega s prekurzorji (3-aminopropil) trietoksisilan (APTES), feniltrietoksisilan (FTES), viniltrietoksisilan (VTES) in bis-1,2-(trietoksisilil) etan (BTSE). Za nastanek končnih magnetnih nanodelcev smo vzorce homogenizirali v peči Bosio in reducirali nastale okside v cevni peči pri 850 °C in času 6 h v inertni atmosferi Ar/H2. Želeli smo oceniti vpliv uporabe različnih funkcionalnih prekurzorjev na osnovne lastnosti nanodelcev in proučiti razlike v površini oz. funkcionalnosti prevlek. Ni67,5Cu32,5 nanodelce smo okarakterizirali z različnimi analiznimi tehnikami. Kemijsko sestavo nanodelcev smo določili z rentgensko praškovno difrakcijo (RTG) in FTIR spektroskopijo. Potrdili smo odsotnost nemagnetnih oksidov v vzorcih in prisotnost obloge iz silike. S termogravimetrično analizo (TGA) smo določili Curiejeve temperature (Tc) in opazovali termični razkroj nanodelcev. Različno oblečeni nanodelci izkazujejo odstopanja v Tc, ki so z dodatno optimizacijo primerne za namene magnetne hipertermije. S transmisijsko elektronsko mikroskopijo (TEM) smo ugotovili, da so nanodelci sferični in monodisperzni v matrici silike. Nanodelci so veliki med 5 nm in 20 nm. Z magnetnimi meritvami smo določili pričakovano magnetizacijo delcev, ki je odvisna od njihove velikosti ter vrste in debeline uporabljene prevleke. Z BET analizo smo proučevali specifično površino in poroznost, ki se je prav tako spreminjala glede na razlike v funkcionalnih prekurzorjih. Meritve stičnih kotov na vzorcih nanodelcev, pripravljenih v obliki tankega filma, nakazujejo prisotnost funkcionalnih skupin na površini delcev, ki vplivajo na spremembe v hidrofilnosti oz. hidrofobnosti prevleke. Sintetizirani Ni67,5Cu32,5 nanodelci so potencialno uporabni pri terapevtski hipertermiji in razvoju nanozdravil. Ugotovili smo, da lahko s pripravo funkcionalnih oblog do določene mere spreminjamo karakteristike NiCu nanodelcev.

Keywords

nanodelci;sol-gel;Curierjeva temperatura;magnetna hipertemija;silika prekurzor;funkcionalna prevleka;magistrske naloge;

Data

Language: Slovenian
Year of publishing:
Typology: 2.09 - Master's Thesis
Organization: UM FKKT - Faculty of Chemistry and Chemical Engineering
Publisher: [B. Kaker]
UDC: 54.3:620.3(043.2)
COBISS: 20566038 Link will open in a new window
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Other data

Secondary language: English
Secondary title: Development of NiCu nanoparticles with different functional coatings
Secondary abstract: The master’s thesis presents the synthesis of superparamagnetic nanoparticles with the composition Ni67,5Cu32,5, using the sol-gel method, in various functional silica coatings. The purpose of this master’s thesis was to modify the surface or coating on nanoparticles with functional groups, via in situ application of the precursor tetraethyl orthosilicate (TEOS) or its combination with other silica precursors, e.g. (3-aminopropyl)triethoxysilane (APTES), phenyltriethoxysilane (FTES), vinyltriethoxysilane (VTES) and bis-1,2-(triethoxysilyl)ethane (BTSE). The final magnetic nanoparticles were formed after initial sample homogenization in a Bosio furnace, followed by the reduction of the resulting oxides in a tube furnace at 850 °C for 6 h and an Ar/H2 inert atmosphere. Our aim was to assess the impact of the different used functional precursors on the fundamental characteristics of the nanoparticles by studying their structural, morphological and chemical properties, and the surface or coating functionality. Ni67,5Cu32,5 nanoparticles were characterized by various analytical techniques. The chemical composition of nanoparticles was determined with the X-ray powder diffraction (XRD) and FTIR spectroscopy. We confirmed the absence of nonmagnetic oxides in samples and the presence of the silica coating formed from respective precursors. Using the thermogravimetric analysis (TGA), we determined the Curie temperatures (Tc) and observed the thermal decomposition of the nanoparticles. Variously coated nanoparticles exhibit a deviation in Tc, which have, with further optimization, a high potential to be used in magnetic hyperthermia. Transmission electron microscopy (TEM) has shown that the formed nanoparticles are spherical in shape, monodisperse and homogenously distributed in the silica matrix. The nanoparticles exhibit sizes between 5 nm and 20 nm. Magnetization measurements confirmed an expected magnetization, which was dependent on the particle size and the type, as well as the thickness of the respective coatings. The specific surface area and porosity were studied with the BET analysis, which showed that both parameters varied among the different used precursors. Measurements of contact angles on nanoparticle coating thin film samples indicate the presence of surface functional groups, which lead to changes in hydrophilicity or hydrophobicity of the coating. Synthesized Ni67,5Cu32,5 nanoparticles are potentially useful for therapeutic hyperthermia and nanomedicines development. Based on all mentioned, we concluded that the basic characteristics of NiCu nanoparticles can be varied to a certain extent with the preparation of such functional coatings.
Secondary keywords: nanoparticles;sol-gel;Curie temperature;magnetic hypertermia;silica precursor;functional coating;
URN: URN:SI:UM:
Type (COBISS): Master's thesis/paper
Thesis comment: Univ. v Mariboru, Fak. za kemijo in kemijsko tehnologijo
Pages: XI, 59 str.
ID: 9595462