MARGARIT-MATTOS, I. C. P.; BENDINELLI, E. V.; SOUSA, F. V. V. (2024).
Resumo: Smart materials are of interest to several industrial sectors, for example, pharmacy, food, and corrosion protection, the focus of this work. Particle doping for intelligent action when added to corrosion-protective paints has been very studied in the literature. Electrochemical techniques have been undeniably important tools for the R&D of organic coatings, mainly when the interest is to evaluate protection mechanisms. On the other hand, the results of electrochemical measurements do not in themselves encompass all aspects that determine the performance of coatings. For example, it is common to find statements in the scientific literature such as coating X is better than coating Y because it has a higher impedance. However, higher impedance is not enough to assure good performance of a paint. Our objective is not to make negative criticisms, nor to belittle the vast literature that has been dedicated to the application of electrochemical techniques to the evaluation of organic coatings, but rather to reflect/warn about the overvaluation that has been given to this type of approach. Specifically, in the area of smart particles and coatings, bibliographical research proves that long-term corrosion tests, recognized by large users of coatings, are hardly considered in experimental procedures. These tests and performance evaluations using standardized criteria allow not only to identify the best environmental conditions for using the smart materials but also to increase credibility and stimulate product development. In this context, we summarize the results obtained by our group with the doping of double hydroxide layers (DHL) by corrosion inhibitors, as well as with the formulation of epoxy paints pigmented with these particles. The behaviour of these materials was characterized using electrochemical techniques and classical corrosion tests. The analysis of the results emphasizes the advantages and limitations of each of the methods used, from particle synthesis to paint formulation criteria. Supporting this analysis with the scientific production of the last twenty years related to intelligent anticorrosive particles and coatings is an invitation to reflect on the steps that still need to be taken so that this so-called "promising" technology can be promoted to the category of "advanced and applied”.
