Određivanje optimalne atmosfere zračenja za umrežavanje prevlaka masnih kiselina

master's thesis

• Title (english): Investigation of optimal radiation atmosphere for crosslinking of fatty acid coatings
• Author: Helena Mijić
• Mentor: Marijana Kraljić Roković (mentor)
• Mentor: Katarina Marušić (komentor)
• Committee member: Katarina Marušić (predsjednik povjerenstva)
• Committee member: Marijana Kraljić Roković (član povjerenstva)
• Committee member: Helena Otmačić Ćurković (član povjerenstva)
• Granter: University of Zagreb; Faculty of Chemical Engineering and Technology; Zagreb
• Defense date and country: 2021-07-16, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Chemical Engineering

Abstract

Cilj ovog rada bio je ispitati primjenu ionizirajućeg zračenja u svrhu poboljšanja zaštitnih svojstva prevlake samoorganizirajućeg monosloja (SAM) elaidinske kiseline kao inhibitora korozije na uzorcima bakra. SAM-ovi se često koriste kao korozijski inhibitori, zbog jednostavne adsorpcije na površinu metala. U radu je prevlaka nanesena metodom uranjanja u otopinu elaidinske kiseline. Gama zračenje je primijenjeno s ciljem umrežavanja nanesenih prevlaka, čime se očekuje poboljšanje njihovih zaštitnih svojstava. Uzorci su ozračeni u tri različita medija: vodi, etanolu i na zraku. Utjecaj gama zračenja na svojstva prevlaka proučavan je elekrokemijskim metodama (metoda Tafelove ekstrapolacije i elektrokemijska impedancijska spektroskopija), metodom mjerenja kontaktnog kuta i FTIR analizom. U vodi kao mediju za ozračivanje, uspoređen je utjecaj propuhivanja otopine plinovima dušikom i dušikovim(I)oksidom, koji oba služe za uklanjanje kisika iz sustava, dok N2O dodatno formira radikale čime pospješuje umrežavanje prevlake. Uzorci su u vodi, prethodno propuhanoj sa dušikom, ozračeni u rasponu apsorbiranih doza od 5-60 kGy. Prema dobivenim rezultatima, u rasponu od 20-60 kGy umreženi SAM elaidinske kiseline pruža određeno poboljšanje učinkovitosti zaštite, no najveću učinkovitost zaštite pokazuje uzorak ozračen sa 40 kGy (41,6%). Uzorak ozračen sa 40 kGy u vodi prethodno propuhanoj sa N2O pokazuje još veću učinkovitost, zbog većeg utjecaja na umrežavanje nanesenog SAM-a (58,7%). Najveću učinkovitost zaštite i stupanj umrežavanja pokazuje uzorak ozračen sa 110 kGy na zraku (63,5%). Uzorci u etanolu su ozračeni u rasponu od 0,5-110 kGy no niti jedna doza nije pokazala povećanje učinkovitosti zaštitinih svojstava u odnosu na neozračeni uzorak sa nanesenim samoorganizirajućim monoslojem elaidinske kiseline.

Abstract (english)

The aim of this study was to examine the application of ionizing radiation in order to improve the protective properties of a self-organizing monolayer of elaidic acid as a corrosion inhibitor on copper samples. SAMs are often used as corrosion inhibitors, due to their simple adsorption on the metal surface. In this work, the coating was applied by immersion in a solution of elaidic acid. Gamma radiation was applied to achieve crosslinking of the coatings and to improve their protective properties. The samples were irradiated in three different media: water, ethanol and air. The influence of gamma radiation was studied by electrochemical methods (Tafel extrapolation and electrochemical impedance spectroscopy), contact angle measurements and FTIR analysis. In water as an irradiation medium the effect of purging the solution with nitrogen and nitric(I)oxide gases, both of which serve to remove oxygen from the system, was compared, while N2O additionally formed radicals which promote crosslinking of the coating. In water previously purged with nitrogen, the samples were irradiated in a apsorbed dose range of 5-60 kGy. According to the obtained results, in the range of 20-60 kGy the crosslinked SAM of elaidic acid provides a certain improvement of efficiency compared to the nonirradiated SAM, but the highest improvement is shown on the samples irradiated with 40 kGy (41.6%). The samples irradiated with 40 kGy in water previously purged with N2O show even greater improvement of efficiency, due to the greater effect on the crosslinking of the applied SAM (58.7%). The highest improvement of protection efficiency and degree of crosslinking is shown by the sample irradiated with 110 kGy in air (63.5%). Samples in ethanol were irradiated in the range of 0.5–110 kGy, but an increase in the effectiveness of the protective properties was not achieved in comparation with the non-irradiated samples.

• Keywords: korozija; korozijski inhibitori; bakar; samoorganizirajući monoslojevi; elaidinska kiselina; gama zračenje; metoda Tafelove ekstrapolacije; elektrokemijska impedancijska spektroskopija; metoda mjerenja kontaktnog kuta; FTIR analiza
• Keywords (english): corrosion; corrosion inhibitors; copper; self-organizing monolayers; elaidic acid; gamma radiation; Tafel extrapolation method; electrochemical impedance spectroscopy; contact angle measurements; FTIR analysis
• Language: croatian
• URN:NBN: urn:nbn:hr:149:769958
• Project: Number: IP-2020-02-4344; Title: Primjena ionizirajućeg zračenja za dobivanje polimernih nano prevlaka na metalima; Title: Irradiated Polymer Nano-Coatings for Metal Protection; Acronym: RadMeNano; Leader: Katarina Marušić; Jurisdiction: Croatia; Funder: HRZZ; Funding stream: IP
• Study programme: Title: Applied Chemistry - Graduate study; specializations in: Environmental chemistry and green technologies, Advanced materials and technologies, Applied organic chemistry; Course: Applied organic chemistry; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra primijenjene kemije (magistar/magistra primijenjene kemije)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2023-04-11 09:20:57