Nanolayer Coatings

Abstract

Langmuir–Blodgett and self assembled molecular layers of hydroxamic and phosphonic acids deposited onto metal surfaces were studied in corrosive aqueous solution with and without corrosion relevant microorganisms. The role of intermolecular interaction, molecular layer thickness, self assembled molecular layer (SAM) formation time as well as the alkyl chain length in the anticorrosion processes and in the microbiological adhesion was in the focus of our experiments. Langmuir films characterized by isotherms and Brewster angle microscopy (BAM) were deposited as Langmuir–Blodgett (LB) layers onto copper and iron surfaces. The SAM layer formation was followed by sum frequency vibration (SFG) and infrared (IRRAS) spectroscopy, the morphology of the LB and SAM films was visualized by atomic force microscopy (AFM), and the change in the wettability was characterized by contact angle values measured in pure water on metals (with and without nanocoatings). The anticorrosion efficiency of the nanofilms was confirmed by electrochemical as well as by AFM measurements. The decrease in the microbial adhesion caused by the nanolayers was visualized by epifluorescence microscopy and enumerated by microbiological technique. Correlation was found between the metal surface energy and the number of adhered corrosion relevant microorganisms.