Karakterizacija kiselih prirodnih niskotemperaturnih eutektičkih otapala

undergraduate thesis

• Title (english): Characterization of acidic natural deep eutectic solvents
• Author: Antonia Ravlija
• Mentor: Jasna Prlić Kardum (mentor)
• Committee member: Jasna Prlić Kardum (predsjednik povjerenstva)
• Committee member: Aleksandra Sander (član povjerenstva)
• Committee member: Lidija Furač (član povjerenstva)
• Granter: University of Zagreb; Faculty of Chemical Engineering and Technology; Zagreb
• Defense date and country: 2020-09-25, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Chemical Engineering

Abstract

Posljednjih dvadesetak godina radi se na istraživanju i razvoju raznih metoda, u svrhu dobivanja okolišno prihvatljivijih kemijskih procesa. Niskotemperaturna eutektička otapala i prirodna niskotemperaturna eutektička otapala pokazala su se kao obećavajuća zamjena za razne primjene i privukla značajnu pažnju istraživača koji traže svestrana otapala. Kako bi navedena otapala na kraju i pronašla odgovarajuću primjenu, bitno je okarakterizirati njihova fizikalno-kemijskih svojstava. Ovaj rad obuhvaća teorijski pregled fizikalno-kemijskih svojstava eutektičkih otapala te njihovu klasifikaciju, pripremu i primjenu. U eksperimentalnom dijelu rada karakterizirana su fizikalno-kemijska svojstva dvaju prirodnih niskotemperaturnih eutektičkih otapala, sastavljenih od kolin-klorida i limunske kiseline (ChCl-Cit) te jabučne kiseline i glukoze (Ma-Glu). Praćena je viskoznost, električna vodljivost, indeks loma i pH kao funkcija različitih temperatura (15–55 °C) te različitih masenih udjela vode u smjesi. Iz dobivenih podataka izrađen je Waldenov dijagram koji prikazuje ovisnost molarne vodljivost i viskoznosti. Gustoća je određena pri temperaturi od 25 °C i ona se smanjuje kako se povećava udio vode. Sva ispitivana otapala su Newtonovi fluidi i pokazuju izrazitu kiselost. Poprilično su viskozni pri nižim temperaturama i niskom udjelu vode. Povišenjem temperature i povećanjem udjela vode viskoznost i indeks loma se smanjuju, dok električna vodljivost raste.

Abstract (english)

Over the last twenty years, new methods have been researched and developed in order to obtain more eco-friendly chemical processes. Deep eutectic solvents and natural deep eutectic solvents have been introduced as promising alternatives for many applications. They have attracted significant attention from researchers looking for versatile solvents. In order for these solvents to eventually find a suitable application, it is important to characterize their physicochemical properties. This paper includes a theoretical overview of the physicochemical properties of eutectic solvents, their classification, preparation and application. Two natural deep eutectic solvents, prepared of choline chloride and citric acid (ChCl-Cit) and malic acid and glucose (Ma-Glu), were characterized in the experimental part. Viscosity, electrical conductivity, refractive index and pH were measured as a function of different temperatures (15–55 °C) and also different water contents in the mixture. A Walden plot showing the dependence of molar conductivity and viscosity was made from the obtained data. The densities were determined at 25 °C. As the water content increased, the density of the solvents decreased. All investigated solvents are Newtonian fluids and they have shown extreme acidity. They are quite viscous at lower temperatures and low water content. Viscosity and the refractive index have decreased, while electrical conductivity increased with increasing temperature and water content.

• Keywords: električna vodljivost; gustoća; indeks loma; pH vrijednost; prirodna niskotemperaturna eutektička otapala; viskoznost
• Keywords (english): electrical conductivity; density; refractive indeks; pH value; natural deep eutectic solvents; viscosity
• Language: croatian
• URN:NBN: urn:nbn:hr:149:592634
• Study programme: Title: Chemical Engineering - Undergraduate study; Study programme type: university; Study level: undergraduate; Academic / professional title: sveučilišni/a prvostupnik/ prvostupnica (baccalaureus/baccalaurea) inženjer/inženjerka kemijskog inženjerstva (sveučilišni/a prvostupnik/ prvostupnica (baccalaureus/baccalaurea) inženjer/inženjerka kemijskog inženjerstva)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2023-05-08 14:14:24