Superfícies seletivas absorvedoras com base em Cr03: avaliação dos tratamentos dos substratos e influência nas propriedades ópticas dos filmes

Abstract

Whereas that energy consumption has been showing continuous growth, the increasing search for sustainable human development practices is present in the generation and use of different energy sources. In this context, it justifies the expansion of research and studies related to the improvement of new materials used in the exploration of renewable energy sources, such as termosolar. Therefore, the present research deals with the making of selective absorbing surfaces (SSAs) based on CrO3 through electroplating in 304 stainless steel and the evaluation of the influence of the substrates treatment on the films optical properties. To this end, three main steps constituted the methodology applied: substrates treatment, coatings (films) deposition and physical-chemical characterizations after deposition of the coatings. The first step was performed by three methods: cleaning by detergent (DC), acid treatment (AT) and electropolishing (EP) of the substrates. Hereafter, coatings electroplating was carried out, where an electrolytic bath containing CrO3 was prepared for the deposition of chromium on the substrates with deposition times of 1 min, 2 min, 5 min and 10 min. Then, the films were characterized by: Profilometry, Spectroscopy in the UV-Vis-NIR regions, Scanning Electron Microscopy (SEM) and Spectroscopy in the IR (infrared) region. Finally, the results obtained indicated that SSAs were obtained and the electropolished coatings (EP) presented better optical performance than other samples (DC and AT), with solar absorptivity values around 98% and thermal emissivity of approximately 7%.