Halloysite Clay Nanotubes for Corrosion Protection Coating

摘要

The common methods for anticorrosion protection of metals include use of chromate based pigments; however, their use is limited because of high toxicity [1]. We have introduced naturally abundant halloysite clay nanotubes to encapsulate triazole-based corrosion inhibitors and doped these nanotubes into acrylic coating for enhanced steel corrosion protection. Once paint coating is damaged organic corrosion inhibitors interact with released metal ions and form protective barrier on the surface [2, 3]. Materials. Halloysite clay nanotubes were obtained from Applied Minerals Co. BTA, 2-MBT and 2-MBI were purchased from Sigma-Aldrich, USA. Acrylic paint (PDS-33 country blue) was purchased from Krylon Co. Instrumentation. Halloysite clay nanotubes were characterized using a Scanning Electron Microscope (Hitachi S4800 FE-SEM) to analyze external surface morphologies. A Transmission Electron Microscope (TEM, Zeiss EM 912) was used at 120 kV for the imaging of internal hollow lumens. Concentration of corrosion inhibitors BTA, 2-MBT and 2-MBI was measured with UV-Vis spectrophotometer (Agilent 8453) at absorption peaks at 265nm, 320nm and at 300nm. A light microscope (Olympus, Japan) with a video camera (Sony SSC DC 80) was used for the analysis of corrosion spots on a scratched metal surface and on the surface of paint.