Premium
Chitosan Microspheres as Carriers for pH‐Indicating Species in Corrosion Sensing
Author(s) -
Sousa Isabel,
Quevedo Marcela C.,
Sushkova Alesia,
Ferreira Mário G. S.,
Tedim João
Publication year - 2020
Publication title -
macromolecular materials and engineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.913
H-Index - 96
eISSN - 1439-2054
pISSN - 1438-7492
DOI - 10.1002/mame.201900662
Subject(s) - corrosion , materials science , chitosan , phenolphthalein , aluminium , electrochemistry , bromocresol purple , cathodic protection , fourier transform infrared spectroscopy , nuclear chemistry , chemical engineering , metallurgy , electrode , chemistry , organic chemistry , engineering
Chitosan microspheres containing bromocresol green, cresol red, and phenolphthalein for corrosion detection, through pH change, are synthesized in order to be used in protective coatings for aluminium alloys. Microspheres containing corrosion detection species are characterized morphologically (SEM) and physico‐chemically (FTIR, TGA). Release studies (UV–vis) are performed in corrosion‐promoting conditions (pH, NaCl), and detection studies by immersion in media associated with corrosion activity while microspheres' sensing activity is evaluated visually. Electrochemical characterization of AA2024 substrates in the presence of chitosan spheres is performed to understand material performance, and a color change is observed as a result of local pH increase in cathodic areas when corrosion takes place. These findings can be correlated with the results from release studies and seem a promising approach for corrosion sensing purposes, not only because pH increase is possible to detect due to corrosion, but also because chitosan is considered an environmentally friendly material.