CMC kationskih površinsko aktivnih snovi v vodni raztopini kohumulona : magistrsko delo

Galun, Tamara

| | SLO | ENG | Cookies and privacy

Bigger font | Smaller font

First page > Show document

Show document

Title:	CMC kationskih površinsko aktivnih snovi v vodni raztopini kohumulona : magistrsko delo
Authors:	ID Galun, Tamara (Author) ID Hostnik, Gregor (Mentor) More about this mentor... ID Bren, Urban (Comentor)
Files:	MAG_Galun_Tamara_2025.pdf (4,09 MB) MD5: 83B29C73DF4892AE3FD9CEB0A1ABE94B
Language:	Slovenian
Work type:	Master's thesis/paper
Typology:	2.09 - Master's Thesis
Organization:	FKKT - Faculty of Chemistry and Chemical Engineering
Abstract:	Kohumulon je ena izmed α-kislin v hmelju, ki se uporablja na različnih področjih od pivovarstva do farmacije. Kohumulon deluje protibakterijsko, med drugim zaradi sposobnosti poškodovanja celične membrane, zato je raziskovanje njegovih interakcij s površinsko aktivnimi snovmi (PAS) ključnega pomena. V raziskavi smo določali kritično micelno koncentracijo (CMC) treh kationskih površinsko aktivnih snovi: DTAB, TTAB in HTAB ter spremljali vpliv kohumulona na te vrednosti. Raziskavo smo začeli z opazovanjem emisijskega in absorpcijskega spektra kohumulona v območju UV in vidne svetlobe. Nato pa določali CMC površinsko aktivnih snovi s fluorescenčno spektroskopijo in opazovali vpliv dodatka kohumulona na CMC PAS. Uspešno smo določili CMC PAS s pirenom, vendar določitev CMC s pirenom v prisotnosti kohumulona ni bila mogoča, saj je bila absorbanca kohumulona previsoka. Zato smo uporabili alternativo – fluorescein – s katerim smo uspešno določili CMC. Ugotovili smo, da kohumulon pri DTAB in TTAB zniža CMC, pri HTAB pa jo nekoliko poveča. Prisotnost 1 % etanola, ki je bil potreben za raztapljanje kohumulona, ni imela pomembnega vpliva na CMC. Zaznali smo tudi pojav bele oborine ob dodatku PAS v raztopino kohumulona, ki je izginila tik pred dosegom CMC, kar dodatno potrjuje mehanizem micelizacije.
Keywords:	kohumulon, CMC, UV–VIS spektroskopija, fluorescenčna spektroskopija, piren, fluorescein
Place of publishing:	Maribor
Place of performance:	Maribor
Publisher:	[T. Galun]
Year of publishing:	2025
Number of pages:	1 spletni vir (1 datoteka PDF (XI, 48 f.))
PID:	20.500.12556/DKUM-93612
UDC:	543.42:544.77.051.62(043.2)
COBISS.SI-ID:	243889411
Publication date in DKUM:	16.07.2025
Views:	141
Downloads:	61
Metadata:
Categories:	KTFMB - FKKT
:	Copy citation

Average score:	(0 votes)
Your score:	Voting is allowed only for logged in users.
Share:

Hover the mouse pointer over a document title to show the abstract or click on the title to get all document metadata.

Licences

License:	CC BY-SA 4.0, Creative Commons Attribution-ShareAlike 4.0 International

Link:	http://creativecommons.org/licenses/by-sa/4.0/
Description:	This Creative Commons license is very similar to the regular Attribution license, but requires the release of all derivative works under this same license.
Licensing start date:	06.07.2025

Secondary language

Language:	English
Title:	CMC of cationic surfactants in aqueous cohumulone solutions
Abstract:	Cohumulone is one of the α-acids in hops, used in various fields ranging from brewing to pharmaceuticals. Cohumulone exhibits antibacterial activity, likely due to its ability to damage the cell membrane, which makes studying its interactions with surfactants essential. In this thesis, we determined the critical micelle concentration (CMC) of three cationic surfactants: DTAB, TTAB, and HTAB, and monitored the influence of cohumulone on these values. Initially, we determined the effect of solvent polarity on cohumulone using UV–VIS and fluorescence spectra. Then we determined the CMC of the surfactants using fluorescence spectroscopy and observed how the addition of cohumulone affected their CMC values. The CMC of the surfactants was successfully determined using pyrene, but determining the CMC with pyrene in the presence of cohumulone was not possible due to the high absorbance of cohumulone. Therefore, we used an alternative – fluorescein – with which we successfully determined the CMC. We found that cohumulone lowers the CMC of DTAB and TTAB, while slightly increasing the CMC of HTAB. The presence of 1% ethanol required to dissolve cohumulone had no significant effect on the CMC. We also observed the appearance of a white precipitate upon adding surfactants to the cohumulone solution, which disappeared just before reaching the CMC, further confirming the micellization mechanism.
Keywords:	cohumulone, CMC, UV–VIS spectroscopy, fluorescence spectroscopy, pyrene, fluorescein

Comments

Leave comment

You must log in to leave a comment.

Comments (0)

0 - 0 / 0

There are no comments!

Back