Anticorrosive properties of a superhydrophobic coating based on an ORMOSIL enhanced with MCM-41-HDTMS nanoparticles for metals protection

Abstract

The anticorrosive properties of hexadecyltrimethoxysilane (HDTMS) functionalized MCM-41 silica particles (MCM-41-HDTMS) incorporated into a methyltriethoxysilane (MTES) sol-gel matrix coatings were studied. The MCM-41 particles were synthesized and functionalized with HDTMS, and added to a sol composed of MTES:methanol:NH₄OH 7M to create a coating. The materials synthesized with and without MCM-41-HDTMS were deposited, by dip coating, on Cu and Fe sheets, and were physically characterized by scanning electron microscopy (SEM), atomic force microscopy (AFM), contact angle, surface energy using the Owens, Wendt, Rabel, and Kaelble (OWRK) method, and by electrochemical impedance spectroscopy (EIS). The addition of the MCM-41-HDTMS to the MTES matrix induced an increase of the contact angle by about 10 degrees with an augment in its dispersive component, caused by a lofty deposition of long carbon chains from HDTMS over the high surface area of the MCM-41 particles, changing from hydrophobic to superhydrophobic materials with a contact angle of 155° for the Cu-MTES-HDTMS sample. EIS results show that the addition of MCM-41-HDTMS increases the charge transfer resistance providing better protection to metals. The results show that with the addition of MCM-41-HDTMS to an MTES matrix it is possible to synthesize superhydrophobic coatings capable of limiting the corrosion degradation process.

Graphical abstract