Stabilnost nanosuspenzija pripravljenih iz niskotemperaturnih eutektičkih otapala

undergraduate thesis

• Title (english): Stability of nanosuspension prepared from deep eutectic solvents
• Author: Tea Barbaro
• Mentor: Jasna Prlić Kardum (mentor)
• Committee member: Jasna Prlić Kardum (predsjednik povjerenstva)
• Committee member: Aleksandra Sander (član povjerenstva)
• Committee member: Sanja Lučić Blagojević (član povjerenstva)
• Granter: University of Zagreb; Faculty of Chemical Engineering and Technology; Zagreb
• Defense date and country: 2018-09-07, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Chemical Engineering; Mechanical, Thermal and Separation Processes

Abstract

Razvoj novih tehnologija i materijala doveo je do mogućnosti uspješnog raspršivanja nanočestica u otapalima koja tako čine nanosuspenzije kao odličan medij za prijenos topline ili tvari sa znatno boljim svojstvima od čistih otapala. Sposobnost nanosuspenzija da poboljšaju transportna svojstva u procesima prijenosa topline i tvari mogla bi doprinijeti energetskoj učinkovitosti različitih industrijskih procesa. Primarni uvjet za ostvarenje spomenutih poboljšanja je priprema stabilnih nanofluida. U ovom radu ispitana je mogućnost primjene niskotemperaturnih eutektičkih otapala (eng. Deep eutectic solvent, DES) koja u posljednje vrijeme zamjenjuju klasična otapala, kao bazni fluidi u pripremi stabilnih nanosuspenzija. Stabilnost nanofluida podrazumijeva sposobnost suspenzije da ostane homogena duže vremensko razdoblje odnosno, da ne dođe do aglomeracije i sedimentacije nanočestica. Cilj ovog rada bio je istražiti stabilnost nanosuspenzija pripremljenih raspršivanjem nanočestica Al2O3 u tri različita eutektička otapala. Stabilnost je određena vizualnom metodom, sedimentacijom primjenom centrifuge, metodom mikroskopiranja te mjerenjem raspodjele veličina nanočestica. Kao bitno svojstvo nanosuspenzija, izmjerena je i njihova toplinska vodljivost. Iako se rezultati za sva ispitivanja nisu slagala sa očekivanim ishodom, oni su pokazali kako je odabir eutektičkog otapala za pripremu nanosuspenzija ključan, te je metodama za određivanje stabilnosti eutektičko otapalo Ma-Fru-Gly-30 određeno kao najpogodnije otapalo za dobivanje stabilnih nanosuspenzija.

Abstract (english)

The development of new technologies and materials have enabled the possibility of a successful dispersion of nanoparticles in solvents thus forming nanosuspensions as an excellent media for heat or matter transfer with better properties than pure solvents. The ability of nanosuspensions to improve the transport properties in processes of heat and matter transfer could contribute to the energy efficiency of industrial processes. The primary requirement for accomplishing this kind of improvements is the preparation of stabile nanofluids. In this study, the possibility of applying deep eutectic solvents – DES, which are lately very often used as a replacement to conventional solvents, as base fluids for preparing stabile nanosuspensions was being tested. The stability of nanofluids is consisted of the ability of the suspension to stay homogeneous for a long period of time apropos, that there is no agglomeration and sedimentation of nanoparticles. The aim of this study was to research the stability of nanosuspensions prepared by dispersing Al2O3 nanoparticles in three different eutectic solvents. The stability has been evaluated using the visual method, sedimentation method applied in the centrifuge, microscope and by measuring the size distribution of the nanoparticles. As an important property of nanosuspensions, the heat transfer has also been measured. Even though the results did not match the expected outcome, they have shown that the selection of the suitable eutectic solvent is crucial in preparing nanosuspensions and that considering the results of stability determination methods, Ma-Fru-Gly-30 is the most suitable eutectic solvent for getting the most stabile nanosuspensions.

• Keywords: niskotemperaturna eutektička otapala; nanočestice; nanofluidi; stabilnost
• Keywords (english): deep eutectic solvents; nanoparticles; nanofluids; stability
• Language: croatian
• URN:NBN: urn:nbn:hr:149:469478
• 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: 2021-06-24 12:05:46