izpis_h1_title_alt

Identifikacija kristaliničnih snovi v kremah za sončenje z rentgensko praškovno difrakcijo
Terkaj, Eva (Author), Meden, Anton (Mentor) More about this mentor... This link opens in a new window

.pdfPDF - Presentation file, Download (1,61 MB)
MD5: B7836FB8EFFB7A325DF92E827EE5DBF1

Abstract
Povzetek: brez kreme za sončenje si ne moremo predstavljati oddiha na morju ali pa preživljanja prostega časa zunaj v sončnih mesecih. Krema za sončenje nas varuje pred nevarnimi UV žarki. Katere sestavine krem za sončenje nas varujejo pred prej omenjenimi nevarnimi UV žarki? Prav to je bil namen mojega diplomskega dela, določiti katere kristalinične snovi vsebujejo kreme za sončenje in katere od njih so aktivne. Kristalinične snovi v kremah sem identificirala s pomočjo rentgenske praškovne difrakcije. Princip delovanja rentgenske praškovne difrakcije je uporaba rentgenske svetlobe določene valovne dolžine, s katero obsevamo vzorec. Na kristaliničnih snoveh pride do različnih uklonov, katere beleži detektor. Rezultat rentgenske praškovne difrakcije je difraktogram, s katerim si pomagamo identificirati snov. Difraktograme sem prebrala s pomočjo programa X'Pert HighScore Plus, v katerem sem posamezne vzorce primerjala med seboj in na podlagi skupnih vrhov te vrhove primerjala s standardi v podatkovni zbirki PDF, ki jo uporablja drugi program Crystallographica Search-Match. V primerih nepojasnjenih vrhov sem si pomagala s posameznimi deklaracijami sestavin vzorcev in na podlagi skupnih sestavin določila nekatere organske kristalinične sestavine s pomočjo programov ConQuest in Mercury. Pri prebiranju literature sem ugotovila, da obstajata dve vrsti UV filtrov; organski in anorganski. Glavna predstavnika pri slednjih sta titanov dioksid in cinkov oksid. Identifikacija teh ni delala preglavic v primerjavi z organskimi. S pomočjo primerjav deklaracij in uporabo programov ConQuest in Mercury mi je uspelo določiti organski filter metilen bis-benzotriazolil tetrametilbutilfenol, ki ga poznamo pod drugim imenom bizoktrizol. Poleg omenjenih UV filtrov sem identificirala še preostale neaktivne kristalinične snovi, katere dodajajo kremam za sončenje za izboljšanje stabilnosti, absorbcije v kožo in izboljšanje videza.

Language:Slovenian
Keywords:krema za sončenje, rentgenska praškovna difrakcija, UV filtri, difraktogram
Work type:Bachelor thesis/paper (mb11)
Tipology:2.11 - Undergraduate Thesis
Organization:FKKT - Faculty of Chemistry and Chemical Technology
Year:2020
COBISS.SI-ID:26665987 This link opens in a new window
Views:360
Downloads:261
Metadata:XML RDF-CHPDL DC-XML DC-RDF
 
Average score:(0 votes)
Your score:Voting is allowed only to logged in users.
:
Share:AddThis
AddThis uses cookies that require your consent. Edit consent...

Secondary language

Language:English
Title:Identification of crystalline solids in sunscreen using x-ray powder diffraction
Abstract:
Identification of crystalline solids in sunscreen using x-ray powder diffraction Abstract:We cannot imagine spending our time on a seaside and outside during sunny summer months without any sunscreen. Sunscreens protect us from harmful UV rays. But which sunscreen ingredients protect us from those so-called harmful UV rays? This was the main purpose of my thesis, to determine crystalline phases and the active ones among them in sunscreens using X-ray powder diffraction. The principle of X-ray powder diffraction is the usage of X-ray waves with a specific wavelength to irradiate a sample. This results in various reflections from a crystalline solid, recorded by the detector. X-ray powder diffraction results in a diffraction pattern to help identify a substance. I opened and read the diffraction patterns using the X'Pert HighScore Plus program, in which I compared individual samples with each other and, based on common peaks, compared those peaks with the standards in another program Crystallographica Search-Match, containing a database. In cases of unexplained peaks, I looked at individual ingredients list of samples and, based on common ingredients, identified possible organic crystalline ingredients using the ConQuest and Mercury programs. When going through the literature I found out that there are two types of UV filters: organic and inorganic. The main representatives of inorganic filters are titanium dioxide and zinc oxide. Identification of those two UV filters did not cause any problems unlike the organic ones. Through the comparisons of declarations and usage of the ConQuest and Mercury programs, I was able to identify the organic filter of methylene bis-benzotriazolyl tetramethylbutylphenol, known by the other name bizoktrizol. In addition to the UV filters mentioned, I also identified the remaining inactive crystalline substances that are added to the sunscreens to improve stability, skin absorption and appearance.

Keywords:sunscreen, x-ray powder diffraction, UV filters, diffraction pattern

Similar documents

Similar works from RUL:
Similar works from other Slovenian collections:

Comments

Leave comment

You have to log in to leave a comment.

Comments (0)
0 - 0 / 0
 
There are no comments!

Back