AVS 51st International Symposium
    Surface Science Monday Sessions
       Session SS-MoP

Paper SS-MoP11
Chemical Functionalisation of High Porosity, Nanostructured Thin Films

Monday, November 15, 2004, 5:00 pm, Room Exhibit Hall B

Session: Poster Session
Presenter: S. Tsoi, University of Alberta, Canada
Authors: S. Tsoi, University of Alberta, Canada
E. Fok, University of Alberta, Canada
J.G.C. Veinot, University of Alberta, Canada
J.C. Sit, University of Alberta, Canada
Correspondent: Click to Email
In sensing and catalysis applications, controlled interaction of nanostructured materials with the outside environment is essential. Control over both the structure and the surface properties of these nano-materials allows optimisation for a wide range of applications. Using an advanced technique known as glancing angle deposition (GLAD)@footnote 1@, we can grow porous thin films with controlled nanostructure and a high surface area easily accessible from the surrounding environment. These structural properties make GLAD films highly suitable for sensing and catalysis; the surface properties can then be controlled through chemical functionalisation. Siloxane-based self-assembly@footnote 2@ has been demonstrated as an effective means for functionalisation of a wide variety of simple flat and freestanding structures. Our work is the first application of this technique to the complex, porous, three-dimensional nanostructures grown using GLAD. Goniometer measurements on as-deposited films (hydrophilic, 0° advancing aqueous contact angle) and films treated with various trichlorosilanes (R-SiCl@sub 3@) (hydrophobic, ~120° contact angle) support a substantial modification of the hydrophilicity of the GLAD film surfaces. X-ray photoelectron spectroscopy and standard electrochemistry measurements confirm that the siloxane-based self-assembly process effectively penetrates the GLAD film surface, allowing complete functionalisation of the 3D structures and underlying substrate. Of particular importance, varying degrees of hydrophilicity of the GLAD structures can be achieved by further functionalising the tail groups of the assembled molecule. Such flexibility in the self-assembly process allows the surface chemistry of GLAD films to be extensively tailored for specific requirements of a wide range of applications. @FootnoteText@ @footnote 1@ K. Robbie and M.J. Brett, J. Vac. Sci. Technol. A 15 (1997).@footnote 2@ J.E. Malinsky, J.G.C. Veinot, et al., Chem. Mat. 14 (2001).