Priprava tankih prevlaka CaMnO3

undergraduate thesis

• Title (english): Preparation of thin CaMnO3 films
• Author: Suzana Kralj
• Mentor: Jelena Macan (mentor)
• Committee member: Jelena Macan (predsjednik povjerenstva)
• Committee member: Anamarija Rogina (član povjerenstva)
• Committee member: Vilko Mandić (član povjerenstva)
• Granter: University of Zagreb; Faculty of Chemical Engineering and Technology; Zagreb
• Defense date and country: 2019-09-03, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Chemical Engineering

Abstract

Cilj ovog rada je priprava sitnih čestica kalcijevog manganita (CaMnO3) metodom koprecipitacije. U tu svrhu ispitan je utjecaj temperature, koncentracije, vremena starenja otopine i redoslijeda miješanja na veličinu koprecipitiranih čestica. Dobiveni talozi su žareni pri temperaturi 900 °C u trajanju od 2 sata pri čemu dolazi do kristalizacije kalcijevog manganita. Koprecipitirani i žareni uzorci analizirani su rendgenskom difrakcijskom analizom, infracrvenom spektroskopskom analizom i pretražnom elektronskom mikroskopijom. Drugi dio ovog rada obuhvaća pripravu tankih i homogenih prevlaka iz sintetiziranog praha. Praškasti CaMnO3 homogeniziran je u tarioniku s 3 %-tnom otopinom poli(viniliden-fluorida) u
1-metil-2-pirolidinonu. Prevlake su nanošene na staklenu podlogu tehnikom rakel-noža
(engl. „Doctor blade“) u debljinama od 20 μm i 40 μm. Proučavana je kvaliteta i pokrivenost podloge tako nanošenih prevlaka, a karakterizirane su pretražnom elektronskom mikroskopijom. Eksperimentalni podaci ukazuju na činjenicu da ispitivani faktori imaju minimalan utjecaj na veličinu čestica, a značajniji utjecaj na stupanj aglomeracije i na oblik koprecipitiranih čestica. Kvalitetnije i pravilnije prevlake nanošene su iz smjesa većeg udjela krute faze te u većoj debljini.

Abstract (english)

The aim of this study is to prepare small particles of calcium manganite (CaMnO3) by coprecipitation. For this purpose, the influence of temperature, concentration, aging time of the solution and the order of mixing on the size of coprecipitated particles was studied. The precipitate was calcined at 900 °C for 2 hours, resulting in crystallization of calcium manganite. Coprecipitated and calcined samples were analyzed by X-ray diffraction analysis, infrared spectroscopic analysis and scanning electron microscopy. The second part of this study covers the preparation of thin and homogeneous coatings of synthesized powder. Samples were homogenised with 3 % solution of poly (vinylidene fluoride) in
1-methyl-2-pyrrolidinone in a mortar. Coatings were applied on a glass substrate using a doctor blade with 20 μm and 40 μm deposition thickness. The quality and coverage of the surface of the coatings was studied and characterized by scanning electron microscopy. Experimental data point to the fact that the investigated factors have minimal effect on the particle size, and a more significant effect on the degree of agglomeration and on the form of coprecipitated particles. Coatings of better quality and homogeneity were deposited from mixtures of a higher solids content using the greater deposition thickness.

• Keywords: kalcijev manganit (CaMnO3); koprecipitacija; prevlake; rakel-nož
• Keywords (english): calcium manganite (CaMnO3); coprecipitation; coatings; doctor blade
• Language: croatian
• URN:NBN: urn:nbn:hr:149:562456
• Project: Number: IP-2018-01-5246; Title: Nanokompoziti s perovskitima za fotovoltaike, fotokatalizu i senzoriku; Acronym: NanoPeroPhotoSens; Leader: Andreja Gajović; Jurisdiction: Croatia; Funder: HRZZ; Funding stream: IP
• 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: 2023-05-24 10:58:14