Modifikacija brončanih površina dugolančanim fosfonskim kiselinama

master's thesis

• Title (english): Modification of bronze surfaces by long-chain phosphonic acids
• Author: Evelina Mustapić
• Mentor: Helena Otmačić Ćurković (mentor)
• Committee member: Helena Otmačić Ćurković (predsjednik povjerenstva)
• Committee member: Marijana Kraljić Roković (član povjerenstva)
• Committee member: Mirela Leskovac (član povjerenstva)
• Granter: University of Zagreb; Faculty of Chemical Engineering and Technology; Zagreb
• Defense date and country: 2017-07-14, Croatia
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Chemistry; Applied Chemistry

Abstract

Metalne materijale od kojih su građena brojna umjetnička djela nužno je zaštiti od posljedica djelovanja korozijskih procesa. Ako materijali nisu adekvatno zaštićeni može doći do kroničnog propadanja materijala što uzrokuje materijalne troškove popravka ili zamjene te do onečišćenja okoliša što može imati značajne posljedice na čovjeka i okoliš. Onečišćenje zraka (plinovi SO2, O3, NOX) i meteorološki uvjeti (temperature, relativna vlažnost zraka, kisele kiše) igraju ključnu ulogu u atmosferskoj koroziji materijala, a najviše brončanih materijala koji se nalaze na spomenicima kulture uzrokujući neprocjenjivu štetu zbog gubitka izvorne građe. Jedna od mogućnosti zaštite brončanih površina je modifikacija površine tankim filmom organskih molekula takozvanim samoorganizirajućim monoslojem. Cilj ovog rada bio je ispitati mogućnost zaštite bronce, od korozije uzrokovane kiselim kišama, primjenom samoorganizirajućih monoslojeva dugolančnih fosfonskih kiselina. U tu svrhu ispitivana je u ovisnosti postignute zaštite o parametrima koji utječu na formiranje samoorganizirajućeg monosloja i o načinu nanošenja zaštite. Ispitivanja zaštitnih svojstva provedena su u otopini koja simulira kiselu kišu čiji pH iznosi 5. Zaštitno djelovanje dobivenih tankih filmova potvrđeno je elektrokemijskim ispitivanjima, metodama Tafelove ekstrapolacije, linearne polarizacije te elektrokemijske impedancijske spektroskopije. Osim elektrokemijskih ispitivanja, uzorci su podvrgnuti analizama pretražnom elektronskom mikroskopijom i Fourier transformacijskom infracrvenom spektroskopijom kako bi se dobile kvalitativne i kvantitativne informacije o dobivenom zaštitnom sloju. Potvrđeno je postojanje i djelotvornost zaštitnog filma je 16 – fosfonoheksadekanoične kiseline na primjenjivanim materijalima što ukazuje na poboljšanju korozijsku otpornost pri čemu se viši stupanj zaštite postiže kod postupka uranjanja.

Abstract (english)

Metallic materials, from which numerous works of art are built, should be protected from the effects of corrosion processes. If materials are not adequately protected it may cause their continuous deterioration which results in significant material costs of repair or replacement and environmental pollution which may have significant consequences on human and the environment. Air pollution (emissions of SO2, O2, NOX) and meteorological conditions (temperature, relative humidity, acid rain) play a key role in the atmospheric corrosion of materials, especially of bronze monuments causing invaluable damage due to the loss of original material. One of the possibilities of protecting the bronze is the modification of the surface with a thin film of organic molecules so-called self – assembled monolayers. The aim of this study was to examine the possibility of protecting bronze from corrosion caused by acid rain, by using self – assembled monolayers of long-chain phosphonic acids. With this aim, dependence of protection on the parameters influencing the formation of the self- assembled monolayers and the manner of protection application is examined. Testing of protective properties was carried out in a solution that simulates acid rain with a pH of 5. Protective action of the obtained thin films was determined by electrochemical methods: Tafel extrapolation method, linear polarization and electrochemical impedance spectroscopy. Apart from electrochemical testing, samples were subjected to scanning electron microscopy and Fourier transformational infrared spectroscopy to gain qualitative and quantitative information on the obtained protective layer. The existence and effectiveness of the protective film of 16 - phosphonohexadecanoic acid on the applied materials was confirmed indicating the improvement of corrosive resistance, where by a higher level of protection is achieved with the immersion process.

• Keywords: brončani spomenici; kisela kiša; samoorganizirajući monoslojevi; fosfonske kiseline
• Keywords (english): bronze monuments; acid rain; self – assembled monolayers; phosphonic acid
• Language: croatian
• URN:NBN: urn:nbn:hr:149:277464
• 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: 2020-04-22 08:48:03