| | SLO | ENG | Cookies and privacy

Bigger font | Smaller font

Show document Help

Title:VPLIV TEMPERATURE NA KRITIČNO MICELJNO KONCENTRACIJO SURFAKTANTOV
Authors:ID Novak, Renata (Author)
ID Fuchs-Godec, Regina (Mentor) More about this mentor... New window
ID Petek, Aljana (Comentor)
Files:.pdf VS_Novak_Renata_2014.pdf (1,60 MB)
MD5: 1A6F2451A382104BFF0189DA878D7D8E
 
Language:Slovenian
Work type:Undergraduate thesis
Typology:2.11 - Undergraduate Thesis
Organization:FKKT - Faculty of Chemistry and Chemical Engineering
Abstract:Namen diplomskega dela je bil določiti kritično micelarno koncentracijo (CMC) anionskega surfaktanta natrijev dodecil sulfat (SDS) in kationskega surfaktanta cetildimetilbenzilamonijev klorid (CDBACl) pri standardnih pogojih in proučiti vpliv temperature na vrednost CMC. Kot topilo smo uporabili Milli-Q vodo. Izbrano temperaturno območje je bilo med 283 K in 323 K. Meritve smo izvedli pri sedmih različnih temperaturah v prej omenjenem temperaturnem območju. Pri tem smo uporabili klasično konduktometrično metodo. Na osnovi grafične predstavitve, CMC v odvisnosti od temperature, smo v skladu z literaturo dobili krivuljo v obliki črke U, kar pomeni, da obstaja minimalna vrednost CMC za posamezni surfaktant pri določeni temperaturi. Na koncu smo izračunali še standardne termodinamske količine: stopnjo disociacije proti-iona (β), spremembo standardne entalpije micelizacije (〖ΔH〗_mic^°), spremembo standardne entropije micelizacije (〖ΔS〗_mic^°) in spremembo standardne proste Gibbsove energije (〖ΔG〗_mic^°). To smo naredili v skladu z dvema enačbama, ki se razlikujeta po tem, da ena vpliv temperature na stopnjo disociacije proti-iona β upošteva v celoti, druga pa ta vpliv na β zanemari. Stopnja disociacije proti-iona s temperaturo narašča. Ta ugotovitev velja za izbrano temperaturno območje in za oba izbrana surfaktanta. Standardna prosta Gibbsova energija micelizacijeje negativna (in glede na izbrano temperaturno območje skoraj konstantna), kar pove, da je proces micelizacije spontan proces.
Keywords:surfaktant, kritična micelarna koncentracija, natrijev dodecil sulfat, standardna prosta Gibbsova energija, standardna entalpija micelizacije, standardna entropija micelizacije, stopnja disociacije proti-iona
Place of publishing:Maribor
Publisher:[R. Novak]
Year of publishing:2013
PID:20.500.12556/DKUM-43218 New window
UDC:544.31:544.6.018.4(043.2)
COBISS.SI-ID:17695510 New window
NUK URN:URN:SI:UM:DK:3ELGTDSC
Publication date in DKUM:20.03.2014
Views:2160
Downloads:232
Metadata:XML DC-XML DC-RDF
Categories:KTFMB - FKKT
:
Copy citation
  
Average score:(0 votes)
Your score:Voting is allowed only for logged in users.
Share:Bookmark and Share



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

Secondary language

Language:English
Title:INFLUENCE OF THE TEMPERATURE ON THE CRITICAL MICELLE CONCENTRATION OF THE SURFACTANTS
Abstract:Purpose of this study was to determine the critical micelle concentration (CMC) of the anion surfactant named sodium dodecyl sulphate (SDS) and cationic surfactant cetyldimethylbenzilammonium chloride (CDBACl) under standard conditions. Moreover, the effect of the temperature on the CMC value was also investigated. The Milli-Q water was used as a solvent. Measurements were performed at different temperatures within the temperature range of 283 - 323 K. As measurement method the classical conductivity measurements were used. Using graphs CMC as a function of temperature are consistent with the literature given curve U-shaped, which means that there is a minimum value of the CMC for each surfactant at a given temperature. In the end the standard thermodynamic quantity: degree of counterion dissociation (β), standard enthalpy of micellization (〖ΔH〗_mic^°), standard entropy of micellization (〖ΔS〗_mic^°) and the standard Gibbs free energy (〖ΔG〗_mic^°) were calculated. This was done in accordance with the equations, which differ in that one the effect of temperature on the degree of counterion dissociation β takes into consideration as whole the other this effect ignores. It was found that degree of counterion dissociation increased with increasing temperature (within chosen temperature range) for both SDS and CDBACl. The values for standard Gibbs free energy are negative and almost constant within chosen temperature range, which indicates that the micellization process is spontaneous process for presented system.
Keywords:surfactant, critical micelle concentration, sodium dodecyl sulphate, standard Gibbs free energy, standard enthalpy of micellization, standard entropy of micellization, the degree of counterion dissociation


Comments

Leave comment

You must log in to leave a comment.

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

Back
Logos of partners University of Maribor University of Ljubljana University of Primorska University of Nova Gorica