Priprava i karakterizacija nanofluida na osnovi transformatorskog ulja i čestica magnetita

master's thesis

• Title (english): Preparation and characterization of nanofluids of transformer oil and magnetite particles
• Author: Aleksandra Putnik
• Mentor: Ante Jukić (mentor)
• Committee member: Ante Jukić (predsjednik povjerenstva)
• Committee member: Fabio Faraguna (član povjerenstva)
• Committee member: Mirela Leskovac (član povjerenstva)
• Granter: University of Zagreb; Faculty of Chemical Engineering and Technology; Zagreb
• Defense date and country: 2018-09-26, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Chemical Engineering; Chemical Engineering in Material Development

Abstract

Cilj ovog rada je priprava i karakterizacija nanofluida od kojeg se očekuje dugotrajna stabilnost i visoka toplinska vodljivost. U odnosu na mineralno transformatorsko ulje koje se upotrebljava kao izolacijski materijal u transformatorima, nanofluid se pokazao kao puno bolji izolacijski materijal. U istraživanju koje se provodilo, nanofluid je smjesa transformatorskog ulja u kojemu se nalaze različiti molarni omjeri površinski aktivnih tvari te nanočesice magnetita. Eksperimentalni dio se može podijeliti u dva dijela. U prvom dijelu su se sintetizirale površinski aktivne tvari različitog sastava, pripravljali su se nanofluidi iste koncentracije nanočestica i ispitivalo se koji maseni udio površinski aktivnih tvari rezultira najboljom stabilnosti nanofluida. U drugom dijelu se provodilo ispitivanje utjecaja koncentracije, odnosno masenog udjela nanočestica na stabilnost nanofluida za prethodno odabranu najbolju površinski aktivnu tvar. U ovom radu kao površinski aktivna tvar koristio se polimer koji je dobiven od dva različita monomera: dodecil-metakrilata i N,N-dimetilaminoetil-metakrilata. Ispitivanje se provodilo s uzorcima koji imaju različit međusobni molarni udio ova dva monomera te kao najstabilniji i najekonomičniji uzorak se pokazao DD97,5 s 0,1 mas. % PAT i 0,01 mas. % Fe3O4.

Abstract (english)

The aim of this work is preparation and characterisation of nanofluids from which is expected long lasting stability and high thermal conductivity. In comparison with mineral transfarmator oil, nanofluids resulted as a much better isolation material. In the experimet nanofluid is mixture of transformator oil consisted of different mass fractions of surfactants and magnetite nanoparticles. Experimental part is divided into two parts. The first part is about synthesis of surfactants, preparation of nanofluids and testing mass fractions that has the best effect on nanofluid's stability. In the second part the focus is on testing of mass fraction that has the best effect on stability of nanofluid for previously selected fraction of sufractants. In this work as sufractant is used polymer made of two different monomers: Dodecyl methacrylate and 2-(Dimethylamino)ethyl methacrylate. The experiment was performed with samples that have different mass fraction of this two monomers. Sample DD97.5 with 0.1 mas. % PAT and 0.01 mas. % Fe3O4 has shown as the most stable and most economic.

• Keywords: nanofluidi; magnetit; stabilnost; površinski aktivne tvari; toplinska vodljivost
• Keywords (english): nanofluids; magnetit; stability; surfactants; thermal conductivity
• Language: croatian
• URN:NBN: urn:nbn:hr:149:259027
• Study programme: Title: Chemical Engineering - Graduate study; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra inženjer/inženjerka kemijskog inženjerstva (magistar/magistra inženjer/inženjerka kemijskog inženjerstva)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2020-10-29 11:11:54