Primjena samoorganizirajućih monoslojeva organskih kiselina u zaštiti metala od korozije u morskoj vodi

doctoral thesis

• Title (english): Self-assembled monolayers of organic acids in seawater metal corrosion protection
• Author: Zana Hajdari
• Mentor: Helena Otmačić Ćurković (mentor)
• Committee member: Mirela Leskovac (predsjednik povjerenstva)
• Committee member: Sanja Martinez (član povjerenstva)
• Committee member: Željka Petrović (član povjerenstva)
• Granter: University of Zagreb; Faculty of Chemical Engineering and Technology; Zagreb
• Defense date and country: 2015-11-20, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Basic Technical Sciences; Materials
• Universal decimal classification (UDC): 66 - Chemical technology. Chemical and related industries ; 620 - Materials testing. Power stations. Economics of energy

Abstract

Morska voda je korozivan medij koji agresivno djeluje na izložene površine brojnih metalnih konstrukcija. Zbog toga se one štite različitim tehnikama zaštite od korozije. Pri tome je važno da postupci i tvari koje se koriste ne djeluju štetno na morski ekosustav. Jedna od mogućnosti je modifikacija metalne površine tankim filmom organskih molekula takozvanim samoorganizirajućim monoslojem. Cilj ovog rada bio je ispitati mogućnost zaštite legure bakra i nikla samoorganizirajućim monoslojevima dugolančanih organskih kiselina. Ispitane su dvije zasićene karboksilne kiseline – stearinska i palmitinska, dvije nezasićene karboksilne kiseline – oleinska i linoleinska te tri fosfonske kiseline – oktadecil, heksadecil i (1H, 1H, 2H, 2H – heptadekafluorodec-1-il) fosfonska kiselina. Ovisnost uređenosti i zaštitnog djelovanja monosloja o duljini alkilnog lanca te vrsti adhezijske i završne funkcionalne skupine organske kiseline određena je elektrokemijskim metodama (polarizacijskim metodama u uskom i širokom području potencijala te metodom elektrokemijske impedancijske spektroskopije) i različitim metodama analize površine, mikroskopskim i spektroskopskim tehnikama (Fourier transformacijskom infracrvenom spektroskopijom, mikroskopijom atomskih sila, goniometrijom i pretražnom elektronskom mikroskopijom). Istražena je i ovisnost svojstava filma stearinske kiseline o parametrima postupka priprema. Nakon odabira optimalnog postupka, ispitane su ostale kiseline, a stabilnost monoslojeva koji su pokazali najbolja svojstva u umjetnoj morskoj vodi ispitana je i u prirodnoj morskoj vodi. Dobiveni rezultati pokazuju da se efikasnija zaštita od korozije postiže ukoliko nastaju uređene višeslojne strukture te da između ispitivanih kiselina oktadecil fosfonska kiselina daje površinski film najboljih zaštitnih svojstava.

Abstract (english)

Seawater is very corrosive towards metallic structures exposed to it. Therefore, corrosion protection is often necessary. However, it is important that techniques and compounds used in corrosion protection are not harmful to marine ecosystem. One of the environmentally friendly techniques is modification of metallic surface by thin film of organic compounds so called self-assembled monolayer. The aim of this work was to examine possibility of protection of copper-nickel alloy with selfassembled monolayers of long chain organic acids, two saturated carboxylic acids – stearic and palmitic, two unsaturated carboxylic acids – oleic and linoleic and three phosphonic acids – octadecylphosphonic acid, hexadecylphosphonic acid and (1H, 1H, 2H, 2H – heptadecafluorodec-1-yl) phosphonic acid. To study dependence of structure and protective efficiency of monolayer on organic acid alkyl chain length, head group and end group properties, various electrochemical techniques – polarization techniques in wide and narrow potential range and electrochemical impedance spectroscopy, and surface analisys techniques – Fourier transform infrared spectroscopy, atomic force microscopy, scanning electron microscopy and goniometry were used. The influence of monolayer preparation technique on its properties was examined for stearic acid films. After optimization of preparation method, protective films of other organic acids were formed. Performance of the most protective organic monolayer was also followed in time in natural and sterilized seawater. The results obtained, show that the moste efficient and durable corrosion protection is exhibited by films of octadecylphosphonic acid.

• Keywords: morska voda; bakar nikal legura; samoorganizirajući monoslojevi; korozija u morskoj vodi
• Keywords (english): seawater; copper nickel alloy; self-assembled monolayers; seawater corrosion
• Language: croatian
• URN:NBN: urn:nbn:hr:149:211767
• Promotion: 2015
• Project: Number: 09.01/253; Title: Ekološki prihvatljiva zaštita metalnih konstrukcija izloženih agresivnom djelovanju mora; Leader: Helena Otmačić Ćurković; Jurisdiction: Croatia; Funder: HRZZ; Funding stream: IS
• Study programme: Title: Engineering Chemistry - Doctoral Course; Study programme type: university; Study level: postgraduate; Academic / professional title: doktor/doktorica znanosti, područje prirodnih znanosti, polje kemija (doktor/doktorica znanosti, područje prirodnih znanosti, polje kemija)
• Type of resource: Text
• Extent: 171 str. ; 30 cm
• File origin: Born digital
• Access conditions: Open access
• Created on: 2023-12-11 13:15:40