diplomsko delo
Ines Saje (Avtor), Amalija Golobič (Mentor)

Povzetek

Rentgenska praškovna difrakcija je ena izmed osnovnih metod za karakterizacijo trdnih snovi. S to metodo sem analizirala 11 vzorcev tempera in 10 vzorcev vodenih barv dveh proizvajalcev. Kvalitativno analizo sem izvedla s pomočjo programa Crystallographica Search-Match (CSM) in zbirke praškovnih difraktogramov standardov (PDF-2). Na podlagi primerjave ujemanja uklonov na difraktogramu standarda in vzorca, sem določila prisotne kristalne faze v posameznem vzorcu. Sledila je še kvantitativna analiza v programu TOPAS, kjer sem določila masne deleže predhodno identificiranih faz. Ugotovila sem, da se kot polnilo v tempera in vodenih barvah znamk Aero in Fila najpogosteje uporabljajo kalcit, rutil in dolomit. Najbolj zastopana spojina v vseh analiziranih barvah je bila kalcit, saj ga je bilo povsod več kot 59 %. Dolomit oz. rutil pa sta v vzorcih zastopana s precej manjšim masnim deležem. Poleg polnila pa tempera in vodene barve vsebujejo še pigmente. Gre za organske ali anorganske snovi, ki imajo vlogo barvila v barvah. Masni deleži organskih pigmentov so vedno zelo majhni – večinoma manj kot 1 %. Anorganski pigmenti se nahajajo v večji količini, npr. več deset procentov. Večinoma so bili to različni železovi oksidi ali pa sodalitni tektosilikati. Na difraktogramu vzorcev, ki so kot pigment vsebovali različne železove minerale, smo opazili linearno povišanje ozadja z naraščanjem uklonskega kota, kot posledico pojava fluorescence. Pri nekaterih vzorcih nisem uspela identificirati prav vseh uklonskih vrhov. Predvidevam, da je to posledica tega, da v podatkovnih zbirkah ni bilo ustreznega standarda, ki bi uklone pojasnil. Čeprav na ovojnini tempera in vodenih barv ni bilo deklaracije, ki bi navajala njihovo sestavo in omogočila primerjavo, menim glede na obstoječo literaturo, da so rezultati mojih analiz smiselni.

Ključne besede

rentgenska praškovna difrakcija;kvalitativna fazna analiza;kvantitativna fazna analiza;tempera barvice;vodene barvice;diplomske naloge;

Podatki

Jezik: Slovenski jezik
Leto izida:
Tipologija: 2.11 - Diplomsko delo
Organizacija: UL FKKT - Fakulteta za kemijo in kemijsko tehnologijo
Založnik: [I. Saje]
UDK: 543.442.3(043.2)
COBISS: 135055619 Povezava se bo odprla v novem oknu
Št. ogledov: 61
Št. prenosov: 23
Ocena: 0 (0 glasov)
Metapodatki: JSON JSON-RDF JSON-LD TURTLE N-TRIPLES XML RDFA MICRODATA DC-XML DC-RDF RDF

Ostali podatki

Sekundarni jezik: Angleški jezik
Sekundarni naslov: Analysis of tempera and water paints by X-ray powder diffraction
Sekundarni povzetek: X-ray powder diffraction is one of the basic methods for characterising crystalline materials. Using this method, I analysed 11 samples of tempera and 10 samples of water-based paints from two different manufacturers. Qualitative analysis was carried out using Crystallographica Search-Match program (CSM) and Powder Diffraction File (PDF-2). By comparing the diffractogram of standard and sample, I determined the crystalline phases in each sample. This was followed by a quantitative analysis in TOPAS program to determine the mass fractions of previously identified phases. I have found out that calcite, rutile and dolomite are the most commonly used fillers in Aero and Fila tempera and water-based paints. The most represented compound in all analysed samples is calcite. There is more than 59 % calcite in each paint. Dolomite and rutile represent lower mass fractions. Tempera and water-based paints also contain pigments. These are organic or inorganic compounds that are used for colouring. The mass fractions of organic pigments are very low – mostly less than 1 %. Inorganic pigments are found in higher quantities, e. g. tens of percent. These were mostly various iron oxides or sodalite tectosilicates. On the diffractogram of samples containing different iron minerals as pigments, we observed a linear increase in the background with increasing diffraction angle, as a result of appearance of fluorescence. In some samples, I was not able to identify all diffractions peaks. I assume that this is because there was no appropriate standard in the database. Although the fact that there was no declaration on packaging of tempera and water-based paints about their composition which would enable comparison, I think the results of my analyses are reasonable based on the existing literature.
Sekundarne ključne besede: X-ray powder diffraction;qualitative phase analysis;quantitative phase analysis;tempera paints;water-based paints;Univerzitetna in visokošolska dela;
Vrsta dela (COBISS): Diplomsko delo/naloga
Študijski program: 1000374
Konec prepovedi (OpenAIRE): 1970-01-01
Komentar na gradivo: Univ. v Ljubljani, Fak. za kemijo in kemijsko tehnologijo, VSŠ Kemijska tehnologija
Strani: 66 str.
ID: 16901274