Ispitivanje dugotrajnosti zaštite polimernih nanoprevlaka umreženih primjenom gama zračenja

master's thesis

• Title (english): Investigation of the long-time behaviour of nanocoatings crosslinked by using gamma radiation
• Author: Ena Pezić
• Mentor: Helena Otmačić Ćurković (mentor)
• Mentor: Katarina Marušić (komentor)
• Committee member: Helena Otmačić Ćurković (predsjednik povjerenstva)
• Committee member: Katarina Marušić (član povjerenstva)
• Committee member: Marijana Kraljić Roković (član povjerenstva)
• Granter: University of Zagreb; Faculty of Chemical Engineering and Technology; Zagreb
• Defense date and country: 2021-09-30, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Chemical Engineering

Abstract

Cilj ovog rada bio je odrediti optimalnu proceduru za formiranje polimernih nanoprevlaka na bakru iz samoorganiziranih (SAM) masnih kiselina umreženih primjenom ionizirajućeg zračenja te ispitati dugotrajnost njihove zaštite u simuliranoj urbanoj atmosferi. Spoj koji je korišten za samoorganizaciju je elaidinska kiselina, EA, C18H34O2, nezasićena masna kiselina sa jednom dvostrukom vezom u trans položaju. EA se spontano samoorganizira na bakru u slojeve visokog stupnja uređenosti. U radu je korištena metoda uranjanja. Jednom posložene molekule na površini bakra umrežavaju se preko dvostruke veze primjenom gama zračenja te nastaju umrežene 3D strukture nanometarske debljine. Polimerizacijom masnih kiselina se poboljšavaju elektrokemijska i mehanička svojstva samoorganiziranih prevlaka. U ovome radu je ispitivan optimalni postupak za nanošenje EA na površinu bakra koji nakon zračenja tvori polimerne prevlake najvećeg stupnja zaštite. Pomoću elektrokemijskih metoda sa istosmjernom i izmjeničnom strujom su provedena ispitivanja zaštitnih svojstava razvijenih prevlaka. Korištene su metoda Tafelove ekstrapolacije, metoda linearne polarizacije te elektrokemijska impedancijska spektroskopija (EIS). Goniometrija i infracrvena spektrometrija s Fourierovom transformacijom signala (FTIR) su korištene za karakterizaciju razvijenih prevlaka. Dobiveni rezultati su pokazali kako je optimalna procedura za formiranje SAM-ova EA na površini bakra sa oksidacijom i adsorpcijom od 24h te bez sušenja, uz koncentraciju etanolne otopine EA od 10 mM. Prisutnost EA na površini bakra čini površinu hidrofobnom, bez obzira da li su molekule umrežene ili nisu. Ispitivanja dugotrajnosti zaštite prevlaka su pokazala da neumreženi sloj ima bolja zaštitna svojstva od samog bakra, ali pruža značajno manju zaštitu od umreženog sloja te da gubi svoja zaštitna svojstva već nakon 9 dana. Umrežena polimerna nanoprevlaka pruža bakru 30 puta veću zaštitu od neumrežene prevlake te zadržava svoja zaštitna svojstva i nakon 20 dana uranjanja u otopinu simulirane kiše.

Abstract (english)

The aim of this study was to determine the optimal procedure for the formation of polymer nanocoatings on copper from self - assembled (SAM) fatty acids crosslinked using ionizing radiation and to examine the longevity of their protection in a simulated urban atmosphere. The compound used for self - assembling on copper is elaidic acid, EA, C18H34O2, an unsaturated fatty acid with one double bond in a trans position. EA spontaneously self - assembles on copper into layers of nanometer thickness with a high degree of arrangement. The immersion method was used in the work. Once the molecules are arranged on the surface of copper, they are crosslinked using gamma radiation via the double bond into 3D structures of nanometer thickness formed on the surface of the metal. Polymerization of fatty acids improves the electrochemical and mechanical properties of self - organized coatings. This paper examines the optimal procedure for applying EA to the surface, which after radiation forms polymer coatings of the highest degree of protection. With the help of electrochemical methods with direct and alternating current, the protective properties of the coatings were investigated. Tafel extrapolation method, linear polarization method and electrochemical impedance spectroscopy (EIS) were used. Goniometry and Infrared spectrometry with Fourier Signal Transformation (FTIR) were used to characterize the formed coatings. The obtained results showed that the optimal procedure for the formation of EA SAM on the copper surface is with oxidation and adsorption of 24 h and without drying, with a 10 mM concentration of ethanolic solution of EA. The presence of EA on copper surface makes it hydrophobic, regardless of whether the molecules are crosslinked or not. Tests of long-term protection of coatings have shown that the non-crosslinked layer has better protective properties than copper itself, but provides significantly less protection than the cross-linked coatings and that it loses its protective properties after only nine days. The crosslinked polymer nanocoating provides copper with 30 times greater protection than the non-crosslinked coating and retains its protective properties even after 20 days of immersion in a simulated rain solution.

• Keywords: polimerne nanoprevlake; gama zračenje; SAM; elektrokemijske metode; bakar; elaidinska kiselina
• Keywords (english): polymer nanocoatings; gamma radiation; SAM; electrochemical methods; copper; elaidic acid
• Language: croatian
• URN:NBN: urn:nbn:hr:149:254387
• 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: 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: Open access
• Created on: 2023-04-21 12:37:38