Excellent corrosion protection performance of epoxy composite coatings filled with amino-silane functionalized graphene oxide

Epoxy coatings containing graphene oxide (GO) and amino-silane modified GO (A-GO) with various weight fractions (0.05, 0.1, 0.3, and 0.5 wt%) are prepared to investigate the effect of silane modified GO on performance of nanocomposite coatings. (3-Aminopropyl) triethoxysilane (APTES) is used as organosilane for A-GO synthesis. A-GO is characterized by FTIR, XRD, FE-SEM, and EDS. The dispersion quality of nanosheets in epoxy coating is examined by FE-SEM, revealing the interfacial interaction of GO in coating has improved via silane modification. Besides, the pull-off adhesion strength of epoxy coating to substrate increases by about two times via adding A-GO. The results of electrochemical impedance spectroscopy show that epoxy/A-GO coatings can provide superior corrosion protection performance and maximum corrosion resistance is achieved via adding 0.1 wt% A-GO. By increasing the loading of A-GO, the barrier properties decrease due to agglomeration of nanosheets in polymer matrix.