Oxidized Titanium Tungsten Surface Functionalization by Silane-, Phosphonic Acid-, or Ortho-dihydroxyaryl-Based Organolayers

Langmuir. 2019 Jul 23;35(29):9554-9563. doi: 10.1021/acs.langmuir.8b04150. Epub 2019 Jul 10.

Abstract

Titanium tungsten (TiW) films (200 nm thick) were cleaned by oxygen plasma, and the resulting oxidized surfaces were functionalized by 3-aminopropylphosphonic acid (APPA), 3-ethoxydimethylsilylpropylamine (APDMES), or dopamine (DA) to form three different organolayers. The three resulting organolayers were characterized by X-ray photoelectron spectroscopy, time-of-flight secondary ion mass spectrometry, and Fourier transform infrared spectroscopy analyses. The stability of each organolayer was investigated. Our results suggested that the Si-O-Ti or Si-O-W bonds formed by the reactions of APDMES with surface-oxidized TiW were rather labile, whereas the catechol layer was less labile. The APPA layer was the most stable of all tested surface modifications.