Uljni nanofluidi s kemijski modificiranim ugljikovim nanocijevima

master's thesis

• Title (english): Oil based nanofluids with chemically modified carbon nanotubes
• Author: Damjan Gracin
• Mentor: Ante Jukić (mentor)
• Mentor: Fabio Faraguna (komentor)
• Committee member: Ante Jukić (predsjednik povjerenstva)
• Committee member: Fabio Faraguna (član povjerenstva)
• Committee member: Juraj Šipušić (član povjerenstva)
• Granter: University of Zagreb; Faculty of Chemical Engineering and Technology; Zagreb
• Defense date and country: 2019-09-24, Croatia

Abstract

Cilj ovog rada je priprava i karakterizacija uljnih nanofluida s oksidiranim i neoksidiranim ugljikovim nanocijevima. Pratila se stabilnost nanofluida kroz određeni vremenski period te odredila toplinska vodljivost i reološka svojstva nanofluida. U tu svrhu pripremljene su suspenzije višestjenčanih ugljikovih nanocijevi (MWCNT) u sintetskom polialfaolefinskom (PAO) baznom ulju uz dodatak polimernih površinski aktivnih tvari (PAT). U prvoj fazi pripreme koristile su se neoksidirane višestjenčane ugljikove nanocijevi, a u drugoj oksidirane višestjenčane ugljikove nanocijevi. Stabilnost pripravljenih nanofluida određivana je vizualno i pomoću UV-VIS spektrofotometrije. Karakterizacija nanofluida provedena je određivanjem reoloških svojstava, toplinske vodljivosti i površinski aktivnih tvari kromatografijom isključenja po veličini. Pripravljeni nanofluidi pokazuju stabilnost kroz ramjerno dug vremenski period, više od jednog mjeseca. Reološka svojstva nanofluida se ne mijenjaju značajno s povećanjem udjela nanocijevi. Toplinska vodljivost se neznatno smanjuje s povećanjem udjela nanočestica. U nastavku istraživanja istražit će se maziva svojstva pripravljenih nanofluida.

Abstract (english)

The aim of this work is preparation and characterization of oil nanofluids with oxidized and unoxidized carbon nanotubes. The stability of the nanofluid was monitored over a period of time and thermal conductivity and also rheological properties of nanofluids. For this purpose, suspensions of multi-wall carbon nanotubes (MWCNTs) were prepared in a synthetic polyalphaolefin (PAO) base oil with the addition of polymeric surfactants (PATs). In the first phase of preparation, unoxidized multi-wall carbon nanotubes were used and in the second oxidized multi-wall carbon nanotubes. The stability of the prepared nanofluids was determined visually and by using UV-VIS spectrophotometry. The characterization of nanofluids was performed by determining rheological properties, thermal conductivity and surfactants using exclusion chromatography by size. The prepared nanofluids show stability over a relatively long time period, more than one month. The rheological properties of nanofluids do not change significantly with increasing nanotube fraction. Thermal conductivity decreases slightly with increasing nanoparticle fraction. In the continuation of the research the lubricating properties of the prepared nanofluids will be investigated.

• Keywords: nanofluidi; bazno PAO ulje; ugljikove nanocijevi; stabilnost; reologija; toplinska vodljivost
• Keywords (english): nanofluids; PAO base oil; carbon nanotubes; stability; rheology; thermal conductivity
• Language: croatian
• URN:NBN: urn:nbn:hr:149:489747
• Study programme: Title: Environmental Engineering - Graduate study; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra inženjer/inženjerka ekoinženjerstva (magistar/magistra inženjer/inženjerka ekoinženjerstva)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2022-02-21 11:39:14