diplomsko delo
Mojca Bartol (Author), Marta Kasunič (Mentor)

Abstract

Rentgenska praškovna difrakcija je metoda, ki temelji na sipanju rentgenske svetlobe na elektronih v atomih ter na interferenci tako sipane svetlobe. Uporablja se za identifikacijo trdnih, kristaliničnih snovi in faz v vzorcu, določanje mikrostrukturnih lastnosti vzorca ter kristalnih struktur. Vsaka kristalinična snov ima karakterističen praškovni diagram, kar nam omogoča kvalitativno analizo. Glavni namen diplomske naloge je bila določiti prisotnost različnih kristaliničnih faz, in sicer na osnovi primerjave praškovnih posnetkov vzorca ter standardov iz zbirke podatkov. V diplomskem delu sem analizirala deset vzorcev različnih dekorativnih kozmetičnih izdelkov. Zanimale so me razlike med izdelki različnih proizvajalcev in barvnih odtenkov, vsebnost kristaliničnih snovi v samem vzorcu ter prisotnost snovi, ki morda niso navedene na deklaraciji. Vzorce sem pred snemanjem ustrezno pripravila ter jih nato analizirala s pomočjo računalniških programov tako, da sem jih njihove difraktograme primerjala z difraktogrami standardov iz podatkovne zbirke PDF-2. Ugotovila sem, da so si difraktogrami nekaterih kozmetičnih izdelkov zelo podobni, kar nakazuje na podobno sestavo vzorcev. Pri nekaterih vzorcih mi vseh uklonskih vrhov ni uspelo identificirati. Eden od razlogov za to je, da so nekatere snovi v vzorcu prisotne v zelo majhnih količinah in posledično ne moremo z gotovostjo trditi, da vrhovi pripadajo točno določeni snovi. Možno je tudi, da so uklonski vrhovi pripadali snovi, katere difraktogram ni zastopan v podatkovni zbirki PDF-2.

Keywords

dekorativni kozmetični izdelki;rentgenska praškovna difrakcija;praškovni difraktogram;diplomske naloge;

Data

Language: Slovenian
Year of publishing:
Typology: 2.11 - Undergraduate Thesis
Organization: UL FKKT - Faculty of Chemistry and Chemical Technology
Publisher: [M. Bartol]
UDC: 543.442.3(043.2)
COBISS: 206033411 Link will open in a new window
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Downloads: 13
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Other data

Secondary language: English
Secondary title: Identification of crystalline phases in decorative cosmetic products by means of X-ray powder diffraction
Secondary abstract: X-ray powder diffraction is a method based on the scattering of electromagnetic waves by electrons in an atom. It is used to identify crystalline solids and phases in a sample, to determine the microstructural properties of the sample and crystal structures. Each crystalline substance gives a powder diagram that allows us to perform qualitative analysis. The main purpose of the tasks was to determine the presence of different crystalline phases, based on the comparison of powder images of the sample and the standards from the database. In my task, I analysed ten samples of various decorative cosmetic products. I was interested in the differences between products from different manufacturers and shades of colour, the content of crystalline substances in the sample itself, and the presence of substances that may not be listed on the declaration. I prepared the samples properly before recording and then analysed them using computer programs by comparing their diffractograms with the diffractograms of the standards in the database. I found that the diffraction grams of some cosmetics are very similar, suggesting a similar composition of the samples. In some samples, I have not been able to identify all the deflection peaks, as some substances are present in the sample in very small amounts and consequently, we cannot say with certainty that the peaks belong to a specific substance.
Secondary keywords: X-ray powder diffraction;decorative cosmetics;qualitative analysis;powder diffractogram;Kvalitativna analiza (kemija);Kristalna struktura;Univerzitetna in visokošolska dela;
Type (COBISS): Bachelor thesis/paper
Study programme: 1000374
Embargo end date (OpenAIRE): 1970-01-01
Thesis comment: Univ. v Ljubljani, Fak. za kemijo in kemijsko tehnologijo, VSŠ Kemijska tehnologija
Pages: 1 spletni vir (1 datoteka PDF (39 str.))
ID: 24798313