Modified halloysite nanotubes decorated with Ceria for synergistic corrosion inhibition of Polyolefin based smart composite coatings

Abstract

The deteriorating effect of corrosion can be controlled by applying suitable polymeric-based coatings. In this work, polyolefin based smart composite coatings containing modified halloysite nanotubes decorated with ceria particles were investigated to analyze their anti-corrosion behavior. For this purpose, halloysite nanotubes (Hals) were utilized as nanocarriers which were loaded with sodium dodecyl sulfate (SDS) as a corrosion inhibitor via overnight stirring and vacuum cycling method. The loaded Hals were then modified/decorated with cerium oxide (CeO2) particles by reacting cerium nitrate (Ce (NO3)3.6H2O) and sodium hydroxide (NaOH) which resulted in the formation of CeO2@HAL/SDS. The synthesized modified particles (CeO2@HAL/SDS) were characterized by energy-dispersive X-ray spectroscopy (EDX), Transmission electron microscopy (TEM), Fourier-Transform Infrared Spectrometer (FTIR), Thermogravimetric analysis (TGA), and differential thermal gravimetric analysis (DTA), X-ray diffraction analysis (XRD) and UV-vis spectroscopic analysis. TGA analysis results demonstrated that about 32% (w/w) of SDS has been loaded into Hal, and 47% (w/w) of CeO2 has been immobilized on the surface of Hal. UV-Vis analysis results demonstrated the pH-sensitive and time-dependent release behavior of synthesized particles. Furthermore, the modified CeO2@HAL/SDS particles (1 wt%) were reinforced into the polyolefin-based matrix, coated on a polished steel substrate and their electrochemical properties were investigated. The electrochemical impedance spectroscopy (EIS) analysis confirms the promising improvement in the corrosion inhibition performance of polyolefin coatings modified with CeO2@HAL/SDS particles when compared to the polyolefin composite coatings modified with HAL/SDS due to the synergistic corrosion inhibition performance of Ce(OH)3 and Fe-SDS formation at the cathodic and anodic region of steel.