An investigation of electrochemical behavior of nanofluids containing MWCNT on the corrosion rate of carbon steel

In this research, the corrosion rate of carbon steel in nanosuspensions containing multi-walled carbon nanotubes (MWCNT) is investigated by using potentiodynamic polarization measurements. It was observed that functionalized MWCNTs prevent carbon steel corrosion to some extent in comparison with the distillated water, but by adding MWCNTs to the SDS and SDBS water solution, the corrosion current increased. On the other hand, after adding acid-based commercial inhibitor to the functionalized sample, in the range of 12–100 ppm, polarization measurements indicated an increase in the corrosion rate of carbon steel from 0.538 to 4.26 mpy. This increase is believed to be due to the enhanced mass transfer of species to and from the metal, as well as the partial destruction of functional groups on CNTs by the protective layer adsorbed (such as SDS) on the carbon steel surface. Also by using a basic CSI inhibitor (nitrite based), corrosion rate decreased to 0.499 mpy.