Elsa V. Pereira

Organic–inorganic hybrid sol–gel coatings for metal corrosion protection: a review of recent progress

Abstract This paper is a review of the most recent and relevant achievements (from 2001 to 2013) on the development of organic–inorganic hybrid (OIH) coatings produced by sol–gel-derived methods to improve resistance to oxidation/corrosion of different metallic substrates and their alloys. This review is focused on the research of OIH coatings based on siloxanes using the sol–gel process conducted at an academic level and aims to summarize the materials developed and identify perspectives for further research. The fundamentals of sol–gel are described, including OIH classification, the interaction with the substrate, their advantages, and limitations. The main precursors used in the synthesis of OIH sol–gel coatings for corrosion protection are also discussed, according to the metallic substrate used. Finally, a multilayer system to improve the resistance to corrosion is proposed, based on OIH coatings produced by the sol–gel process, and the future research challenges are debated.

Long-Term Efficiency of Two Organic Corrosion Inhibitors for Reinforced Concrete

In this paper the efficiency of two organic corrosion inhibitors, a migratory and an admixture inhibitor, was evaluated by electrochemical techniques in solutions simulating the interstitial electrolyte of concrete and on concrete slabs exposed to natural environmental conditions over a five-year period. From obtained results, the usefulness of the two products is discussed aiming its application in new structures to prevent chlorides induced corrosion and as a curative method for repairing reinforced concrete structures contaminated with chlorides and affected by reinforcement corrosion.

Embedded Sensors for Corrosion Monitoring of Existing Reinforced Concrete Structures

In this work the performance of two surface treatments and the efficiency of a corrosion inhibitor were evaluated, in the control of steel corrosion in concrete induced by chlorides, through measurements of galvanic current and polarization resistance applied to embedded sensors fixed in existing concrete using different methodologies. From the results obtained the use of the different embedded sensors in the measurement of corrosion rate is discussed aiming the development of new systems for permanent evaluation of the on site performance of products for repairing reinforced concrete structures affected by reinforcement corrosion.