Improving the functionality and performance of AA2024 corrosion sensing coatings with nanocontainers

The compatibility between nanocontainers and coating formulations is perhaps the last frontier in the quest for functional coatings. Sensing coatings for early metallic corrosion detection is an urgently needed technology by aeronautical companies to mitigate the costs of corrosion through continuous monitoring. In this work, we revisit phenolphthalein encapsulated silica nanocapsules, which were incorporated into a water-based lacquer, resulting in a novel corrosion sensing coating for aluminum alloy 2024 with improved functionality and standard performance. The ability of the coatings to detect corrosion by color change was investigated by immersion and salt-spray tests. During these tests, it was clearly demonstrated that encapsulation of the active compound is essential to obtain a functional coating, since the shell of the silica nanocapsules minimizes the detrimental interaction of the active compound with the coating formulation. The compatibility between nanostructured additives and coatings is almost never taken into consideration in the literature. Herein this aspect evidences the positive effects of active agent encapsulation, which is explored in terms of reactivity, viscoelastic properties, curing, thermal stability, release and leaching studies, hardness, mechanical properties and corrosion resistance. Computer simulations based on the density functional theory and periodic structural models were performed to unveil the interaction mode of phenolphthalein with the metallic surface.This work was developed in the scope of the project CICECO – Aveiro Institute of Materials, POCI-01-0145-FEDER-007679 (Ref. FCT UID/CTM/50011/2013), financed by national funds through the FCT/ MEC and when applicable co-financed by FEDER under the PT2020 Partnership Agreement. This work has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreements No 645662. It was also financed in the framework of the project reference PTDC/QEQQFI/ 4719/2014, Project 3599 – Promover a Produção Científica e Desenvolvimento Tecnológico e a Constituição de Redes Temáticas (3599-PPCDT) and FEDER funds through COMPETE 2020, Programa Operacional Competitividade e Internacionalização (POCI). The authors also thank financial support from FCT and COMPETE (Programa Investigador FCT). JT thanks FCT for the research grant IF/00347/ 2013.publishe

Influence of surface treatment of pPigments particles with conducting polymers on corrosive-inhibitive properties of anticorrosive coatings

Tato diplomová práce se zabývá studiem antikorozní účinnosti nátěrových hmot, které obsahují částice plniv a pigmentů povrchově upravené vrstvou polyanilinu (PANI) nebo polypyrrolu (PPy). Modifikace částic pigmentů a plniv byla provedena tzv. oxidační polymerační reakcí. Byly připraveny epoxidové vodou ředitelné nátěrové hmoty (OKP = 10%) s obsahem pigmentů na bázi oxidů železa, směsných oxidů kovů, plniv na bázi křemičitanů a grafitu v upravené i neupravené formě. Nátěrové hmoty byly aplikovány na skleněné a ocelové panely. Antikorozní účinnost nátěrů byla hodnocena na základě fyzikálně-mechanických a urychlených korozních zkoušek.This thesis deals with study of anticorrosive efficiency of organic coatings, which contain particles of fillers and pigments surface-treated with layer of polyaniline (PANI) or polypyrrole (PPy). The modification of fillers and pigments particles was carried out by so-called chemical oxidative polymerization. Water-borne epoxy coatings (PVC = 10%) containing pigments based on iron oxides, mixed metal oxides, fillers based on silicates and graphite in modified and unmodified form were prepared. The organic coatings were applied on glass and steel panels. Anticorrosive efficiency of coatings was evaluated by means of physico-mechanical and accelerated laboratory corrosion tests.Ústav polymerních materiálůDokončená práce s úspěšnou obhajobo

Preparation and Colour Properties Evaluation of (Bi2O3)1-x(CeO2)x Compounds

Práce se zabývá možností přípravy nových pigmentů na bázi oxidu bismutitého, který je dopován cerem. Příprava pigmentů je založena na středněteplotní kalcinaci výchozí směsi obsahující příslušné oxidy. Připravené pigmenty pokrývají svojí barevností žádaný sortiment odstínů od jasně žluté po žluto-oranžovou.Katedra anorganické technologieDokončená práce s úspěšnou obhajobo