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

Area of Science:

• Materials Science
• Surface Chemistry
• Nanotechnology

Background:

• Titanium tungsten (TiW) films are utilized in various electronic and biomedical applications.
• Surface functionalization is crucial for tailoring the properties and performance of TiW films.
• Understanding the stability of different organolayers on TiW is essential for practical applications.

Purpose of the Study:

• To functionalize oxidized titanium tungsten (TiW) surfaces with three different organomolecules: 3-aminopropylphosphonic acid (APPA), 3-ethoxydimethylsilylpropylamine (APDMES), and dopamine (DA).
• To characterize the resulting organolayers using advanced surface analysis techniques.
• To investigate and compare the stability of the APPA, APDMES, and DA organolayers on TiW.

Main Methods:

• Oxygen plasma cleaning of 200 nm thick TiW films.
• Surface functionalization using APPA, APDMES, and DA.
• Characterization via X-ray photoelectron spectroscopy (XPS), time-of-flight secondary ion mass spectrometry (ToF-SIMS), and Fourier transform infrared spectroscopy (FTIR).

Main Results:

• The organolayers formed by APDMES exhibited labile Si-O-Ti or Si-O-W bonds on the oxidized TiW surface.
• The dopamine (catechol) layer showed improved stability compared to the APDMES layer.
• The 3-aminopropylphosphonic acid (APPA) layer demonstrated the highest stability among all tested surface modifications.

Conclusions:

• APPA provides a highly stable organolayer on oxidized TiW surfaces.
• The stability of functionalized TiW surfaces varies significantly depending on the chosen molecule.
• APPA functionalization is a promising strategy for creating durable modified TiW surfaces.