Ispitivanje dielektričnih svojstava polimernih folija elektrokemijskom impedancijskom spektroskopijom

master's thesis

• Title (english): Testing the dielectric properties of polymer foils by electrochemical impedance spectroscopy
• Author: Lorena Kostelac
• Mentor: Sanja Martinez (mentor)
• Committee member: Sanja Martinez (predsjednik povjerenstva)
• Committee member: Helena Otmačić Ćurković (član povjerenstva)
• Committee member: Mirela Leskovac (član povjerenstva)
• Granter: University of Zagreb; Faculty of Chemical Engineering and Technology; Zagreb
• Defense date and country: 2021-09-28, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Basic Technical Sciences

Abstract

Organski premazi vrlo su učinkoviti alat pri zaštiti metalnih konstrukcija od vanjskih utjecaja i pojave korozije. Kako bi se ispitao stupanj degradacije premaza često se koristi elektrokemijska impedancijska spektroskopija (EIS), zbog velike brzine dobivanja rezultata i mogućnosti uočavanja degradacije premaza prije nego je to vidljivo golim okom promatrača. Za kalibraciju EIS uređaja, kada se upotrebljavaju za ispitivanje premaza, koriste se slijepe ćelije s poznatim vrijednostima otpornika i kondenzatora. Međutim, slijepe ćelije ne mogu tako dobro imitirati premaze različitih vrsta kemijskoga sastava, debljine i dodanih aditiva. Stoga je predložena nova metoda kalibracije sa samim polimernim filmovima, koji bi imali točno definirana svojstva. U ovome radu ispitivala su se svojstva poliesterskih folija, različitih debljina koje bi se zatim mogle koristiti kao kalibracijske folije. Ispitivana su dielektrična svojstva i postotak upijanja vode u folije, ponovljivost, obnovljivost i linearnost EIS mjerenja, kao i utjecaj elektromagnetskih smetnji.

Abstract (english)

Organic coatings are very effective tools for protecting metal structures from external influences and corrosion. Electrochemical impedance spectroscopy (EIS) is often used to examine the degree of coating degradation, due to the short period of time required to obtain results and the ability to detect coating degradation before it is visible to the eyes of the observer. Dummy cells, with known values of resistors and capacitors, are used to calibrate the EIS devices, when devices are used for coating testing. However, dummy cells can´t so well mimic coatings with different types of chemical composition, thickness, and added additives. Therefore, a new calibration method was proposed with the polymer films, which have precisely defined properties. In this paper, the properties of polyester foils, of different thicknesses, which could then be used as calibration foils, were investigated. Dielectric properties and percentage of water absorption in foils, repeatability, reproducibility and linearity of EIS measurements, as well as the influence of electromagnetic interference were investigated.

• Keywords: elektrokemijska impedancijska spektroskopija (EIS); poliester; polimerne folije; organski premazi; kalibracija metode; dielektrični odgovor
• Keywords (english): electrochemical impedance spectroscopy (EIS); polyester; polymer foils; organic coatings; calibration; dielectric response
• Language: croatian
• URN:NBN: urn:nbn:hr:149:340331
• Study programme: Title: Materials Science and 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: Access restricted to students and staff of home institution
• Created on: 2023-04-19 14:31:05