2 research outputs found
A study of synergistic effect on oxygen reduction activity and capacitive performance of NiCo2O4/rGO hybrid catalyst for rechargeable metal-air batteries and supercapacitor applications
Hybrid sol–gel coatings for corrosion protection of galvanized steel in simulated concrete pore solution
The aim of this experimental research was to study the electrochemical behavior of organic–
inorganic hybrid (OIH) coatings for corrosion protection of hot-dip galvanized steel (HDGS) in the first
instants of immersion in simulated concrete pore solution (SCPS) (pH > 12.5). The electrochemical
performance of the OIH coatings was assessed by electrochemical impedance spectroscopy, potentiodynamic
polarization curves, macrocell current density, and polarization resistance. The OIH coatings were
prepared via the sol–gel method and were deposited on HDGS surfaces by dip-coating using one or three dip
steps. The electrochemical results obtained for HDGS samples coated with OIH matrices in SCPS showed
higher corrosion resistance than bare HDGS; as the molecular weight (MW) of Jeffamine increased the
barrier protection of the coating decreased. The lowest protection efficiency was found for HDGS samples
synthesized with oligopolymers with an MW of 2000.
Coatings produced with an oligopolymer of 230 MW
conferred the highest protection. The surface morphology
of the OIH coatings deposited on HDGS
surfaces was studied by atomic force microscopy. The
results show that the roughness of the OIH films
depends on the MW of Jeffamine and on the number
of dip-coating steps used. Thermogravimetry results
show that the Jeffamine MW affected the thermal
properties of the prepared OIH samples. The prepared
OIH materials are thermally stable within the range of
20–80 C.The authors would like to gratefully acknowledge the financial support from Fundacao para a Ciencia e Tecnologia (FCT) for the PhD grant SFRH/BD/62601/2009 and EU COST action MP1202: HINT-"Rational design of hybrid organic-inorganic interfaces: the next step towards functional materials.''info:eu-repo/semantics/publishedVersio