Vpliv dolžine alkilne verige 1-metil-3-alkilimidazolijevega klorida na viskoznostni B-koeficient v vodnih raztopinah

Kuhar, Jure (author), Bešter Rogač, Marija (mentor)

Ionske tekočine so eden od stebrov principov zelene, do okolja prijazne kemije, saj s svojimi lastnostmi predstavljajo odlično alternativo strupenim in nevarnim organskim topilom. Poleg tega njihova vloga narašča in postaja vse pomembnejša tudi pri sintezi novih spojin in materialov, kjer jih uporabljamo kot prekurzorje ali katalizatorje. Njihova zgradba z možnostjo veliko kombinacij različnih kationov in anionov ponuja široko paleto željenih lastnosti ionskih tekočin, zato je pomembno poznavanje njihovih fizikalnokemijskih lastnosti. 1-metil-3-alkilimidazolijeve ionske tekočine so ene najbolj uporabljenih. S podaljševanjem alkilne verige se njihove lastnosti spreminjajo. Ob tem raste njihova površinska aktivnost in težnja po micelizaciji. Meritve viskoznosti in gostote njihovih razredčenih vodnih raztopin nam omogočajo izračun in določitev A- in B-koeficienta Jones-Doleove enačbe viskoznosti, te vrednosti pa nam dajejo informacije o meddelčnih interakcijah ion-ion in ion-topilo. Da lahko potrdimo ustreznost dobljenih rezultatov, je potrebna kritična primerjava in potrditev dobljenih vrednosti. Za preučevane sisteme se izkaže, da so interakcije med ioni in topilom močnejše kot med samimi ioni, vse uporabljene ionske tekočine pa so v vodnih raztopinah kozmotropi.

• Language: Slovenian
• Keywords: imidazolijeve ionske tekočine, Jones-Doleova enačba, viskoznostni B-koeficient, urejanje strukture vode, kozmotropi
• Work type: Master's thesis/paper
• Typology: 2.09 - Master's Thesis
• Organization: FKKT - Faculty of Chemistry and Chemical Technology
• Year: 2020
• PID: 20.500.12556/RUL-120551
• COBISS.SI-ID: 34310403
• Publication date in RUL: 22.09.2020

Secondary language

• Language: English
• Title: Impact of alkyl chain length at 1-methyl-3-alkylimidazolium chloride on viscosity B-coefficient in aqueous solutions

Abstract

Ionic liquids are one of the most important chemical compounds in the green environmental friendly chemistry. They offer us an excellent alternative for poisonous and dangerous organic solvents. Their role is becoming more and more important also at synthesis of new compounds and materials as precursors or catalysts. The numerous possibilities of their structure and combinations of different cation-anion pairs is giving us a wide range of preferable properties for desired applications. Therefore it is important to know their physicochemical properties. One of the most used ionic liquids have 1-methyl-3-alkylimidazolium cation. By prolonging the alkyl chain their properties are also changing. Their surface activity and tendance to micellization is becoming more important. By measurements of viscosity and density of their diluted aqueous solutions we can calculate and determine A- and B-coefficients from Jones-Dole viscosity equation. These data is giving us an insight on ion-ion and ion-solvent interactions. To confirm the adequacy of the results their critical evaluation is needed. At investigated systems is evident that ion-solvent interactions are more important than ion-ion interactions in solutions. All studied ionic liquids show water structure making effect and are kosmotropes.

• Keywords: imidazolium based ionic liquids, Jones-Dole equation, viscosity B-coefficient, structure making effect, kosmotrope