Korozijska zaštita bakra karboksilnim kiselinama

undergraduate thesis

• Title (english): Corrosion protection of copper by carboxylic acids
• Author: Ena Pezić
• Mentor: Helena Otmačić Ćurković (mentor)
• Committee member: Helena Otmačić Ćurković (predsjednik povjerenstva)
• Committee member: Marijana Kraljić Roković (član povjerenstva)
• Committee member: Domagoj Vrsaljko (član povjerenstva)
• Granter: University of Zagreb; Faculty of Chemical Engineering and Technology; Zagreb
• Defense date and country: 2019-09-13, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Chemical Engineering

Abstract

Cilj ovog rada je istražiti korozijsku zaštitu bakra pomoću samoorganizirajućih monoslojeva stearinske kiseline u 3%-tnoj otopini NaCl-a kroz 24 dana mjerenja. Ispitivani uzorci su bili tretirani stearinskom kiselinom, pri čemu je dio uzoraka prethodno oksidiran u otopini NaOH ili u vreloj vodi. Mjerenja su se provodila elektrokemijskim tehnikama s izmjeničnom (AC) i istosmjernom (DC) strujom. Od DC tehnika su se provodila metoda Tafelove ekstrapolacije i metoda linearne polarizacije, dok se od AC tehnika koristila elektrokemijska impedancijska spektroskopija. Za ispitivanje površinskih karakteristika uzorka koristila se goniometrija i infracrvena spektrometrija s Fourierovom transformacijom signala (FTIR). Dobiveni rezultati mjerenja su pokazali da najlošiju zaštitu bakra pokazuje uzorak tretiran stearinskom kiselinom, c(SK)=10^-3M te uzorak oksidiran u vreloj vodi jer je polarizacijski otpor pao već nakon 2. dana mjerenja. Uzorci tretirani s c(SK)=10^-2 M sa ili bez dodatne oksidacije u u hidroksidu su pokazali bolju zaštitu. Najdugotrajnija zaštita postignuta je kod uzorka koji tretiran stearinskom kiselinom veće koncentracije, bez prethodne oksidacije u otopini NaOH ili vreloj vodi.

Abstract (english)

The aim of this work is to investigate the corrosion protection of copper using self-assembled monolayers of stearic acid in 3% NaCl solution over 24 days of measurement. The test specimens were treated with stearic acid, with some of the specimens being pre-oxidized in NaOH solution or in hot water. The measurements were taken by alternating current (AC) and direct current (DC) electrochemical methods. From the DC techniques, the Tafel extrapolation method and the linear polarization method were applied, while the AC technique used was electrochemical impedance spectroscopy. Goniometry and Fourier Transform Infrared spectrometry (FTIR) were used to test the surface characteristics of the sample. The results of the measurements showed that the sample treated with stearic acid, c(SK)=10^-3 M showed the lowest protection of copper, followed by the sample oxidized in hot water, since the polarization resistance of these samples decreased after the second day of the measurement. Samples treated with c(SK)=10^-2 M with or without additional oxidation in u hydroxide showed better protection. The longest lasting protection was obtained for a sample treated with the solution with higher concentration of stearic acid, without prior oxidation in NaOH solution or hot water.

• Keywords: korozijska zaštita; bakar; elektrokemijske metode; stearinska kiselina
• Keywords (english): corrosion protection; copper; electrochemical methods; stearic acid
• Language: croatian
• URN:NBN: urn:nbn:hr:149:373497
• Study programme: Title: Materials Science and 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: 2023-05-26 13:32:17