Influence of gamma radiation on self-assembled molecular layers developed on different metals

Abstract

In this work, self-assembled molecular layers (SAMs), developed from special amphiphilic molecules (undecenyl phosphonic acid) on the top of two types of stainless steels (1.4571 and 1.4841) were in focus. The metal surface was modified by a self-assembled molecular layer with a double bond at the end of the carbon chain. The modification of the structure of the unsaturated hydrophobic chain was done by gamma irradiation to produce a more compact layer. We were interested in the influence of the metal composition on the layer formation. To give answers to these questions SAM layers were deposited on the top of the stainless steels and then the nanolayers were modified by post-treatment (gamma irradiation). The thickness of the surface films was characterized by ellipsometry and the composition of the amphiphilic SAM layers by infrared spectroscopy. Atomic Force Microscope (AFM) visualized the morphological changes due to the layer deposition and the post-treatment; the surfaces were numerically characterized by roughness parameters; contact angle values proved the change in the wettability caused by the metal surface and the gamma irradiation.