Surface Modification Of Metal By Ultrafine Particles Self-assembling And Its Anti-Fouling Features

Ultrafine polytetrafluoroethylene (PTFE) particles and carbon nanotubes (CNTs) were activated successfully and then were self-assembled on the metal surface. Both the anti-wetting and anti-fouling capability of modified material surface were characterized.First, the raw CNTs were purified by diluted nitric acid solution. Then, the purified CNTs had been activated by seething dense nitric acid solution for 4 hours. Transmission electron microscopy (TEM) and x-ray photoelectron spectroscopy (XPS) were employed to characterize the purified and activated CNTs. The results indicate:the seething dense nitric acid solution could effectively break CNT particles and activate their surface. The carbonyl and carboxyl groups were formed on the CNT particles'surface after activated in the seething dense nitric acid solution.The 11-Aminoundecanoic acid [NH2(CH2)10COOH] molecules were grafted on the polished and activated metal surface in the cetane. Scanning electron microscopy (SEM) and XPS were employed to characterize the grafted metal surface. The most active metal surface was chosen for particles-grafting experiments.CNTs and PTFE particles were self-assembled on the copper surface which was characterized by SEM and XPS. The results indicate:CNTs and PTFE particles could combine with copper atom by the carboxyl groups and then adsorb on the copper surface intensively.In the end, the contact-angle measurement was employed to characterize the difference of wetting between the raw copper surface and the treated one; SEM was used to detect the change of anti-fouling capability before and after self-assembling treatment. The mechanism was then analyzed. The results indicate:After having been self-assembled, the anti-wetting and anti-fouling capabilities of copper surface were improved greatly. The self-assembled process could improve the contact-angle of the surface effectively, and debase the tendency of being fouling.Modified material surface can be used in many fields such as anti-fouling, anti-contamination and heat transfer enhancement.