Novel Corrosion Protective Nanostructured Composite Coatings

Abstract

Jay Mondali doktoritoos uuriti grafeenoksiidi ja redutseeritud grafeenoksiidi nanoliistakute valmistamise tehnoloogiat ja valmistati nende ainete baasil lihtkatted, hubriidkatted koos elektrit juhtiva polumeeri polupurrooliga ning komposiitkatted koos metalloksiidide Al2O3 ja TiO2 nanokiledega. Katted kanti roostevaba terase voi Ti-sulamist valmistatud katseobjektide pindadele, kasutades vurrkatmise, elektrokeemilise sadestamise ja aatomkihtsadestamise meetodeid. Katete omaduste uurimiseks kasutades laia hulka tahkisobjektide karakteriseerimise vahendeid, mis on saadaval TU Fuusika ja Keemia instituutides. Samuti maarati elektrokeemiliste mootmiste ja standarttestidega nende katete voime kaitsta alusmaterjale korrosiooni eest. Too tulemusena naidati ara, et kuigi nii valmistatud liht- kui hubriidkatted aitavad teatud maaral pidurdada korrosiooniprotsesse metallalustel, ei suuda need katted tohusalt pidurdada punktkorrosiooni nimetatud aluste pikaajalisel hoidmisel tugevasti korrodeeruvates soolalahustes. Seevastu uudsed, submikromeetrilise paksusega grafeeni baasil loodud komposiitkatted naitasid ules vaga head korrosioonikaitset molema sulami pinnal, uletades paljude tanapaeva toostuses kasutatavate kumneid kuni sadu kordi paksemate kaitsekatete naitajaid. Too tulemused on avaldatud eriala juhtivates ajakirjades ja tutvustatud rahvusvahelistel konverentsidel. Antud doktoritoo valmis prof. Vaino Sammelselja juhendamisel. Tood oponeerima on kutsutud prof. M. Ferreira Aveiro Ulikoolist ja dr. M. Krunks TTU-st.; In this thesis corrosion inhibition performance of graphene and graphene oxide based composite/hybrid coatings was studied. Graphene is a two-dimensional one-atom-thick sheet of carbon having hexagonal lattice, and it is a basic structural unit of graphite. Graphene has proven to be one of the most popular advanced materials in recent developments. This carbon material is widely studied for advanced applications starting from energy harvesting to nanoelectronics and finishing with drug delivery because of many extraordinary properties of it. Among all of the properties the atom/ion barrier property was one of the most interesting for this work. Some studies to use graphene or graphene-based materials as a barrier sheet were published before starting this work and some appeared during the run of this investigation. Lately, the development of graphene and graphene oxide based functionalized biocompatible barrier coatings attracts a great attention among scientists and probably industrialists as well. But the use of graphene oxide/reduced graphene oxide nanoplatelets for corrosion protection of metal alloys was practically not studied before this work, despite the facts that the ideas of preparation the materials were known already decades, and as row material relatively cheap powder of natural graphite can be used. In this thesis the barrier properties of graphene/graphene oxide based nanostructured coatings, including composite and hybrid coatings were investigated towards corrosion protection. Investigations…