AVS 51st International Symposium
    Advanced Surface Engineering Tuesday Sessions
       Session SE-TuP

Paper SE-TuP3
Chemisorption to the Oxide Surface of Aluminium Metal: The Competing Roles of Hydroxide Formation and Adventitious Contamination

Tuesday, November 16, 2004, 4:00 pm, Room Exhibit Hall B

Session: Poster Session
Presenter: M.R. Alexander, The University of Nottingham, UK
Authors: M.R. Alexander, The University of Nottingham, UK
G.E. Thompson, UMIST, UK
Correspondent: Click to Email
An understanding of the interaction of organic functionalities with the surface of aluminium is required for development of a range of application areas including environmentally friendly adhesion promoters, superhydrophobic architecture, MEMS and NEMS. Formation of numerous types of organic monolayer on aluminium has been reported in the literature, the first of which predates that of alkane thiols on gold.@footnote 1@,@footnote 2@,@footnote 3@ Whilst the instability of the aluminium oxide surface in ambient conditions is widely recognised, quantification of the changes in surface hydroxyl group concentration and carbonaceous contaminant from the ambient atmosphere have only recently been achieved using X-ray photoelectron spectroscopy (XPS).@footnote 4@,@footnote 5@ Previous work has identified the significant influence of an ambient laboratory atmosphere on assembly of alkyl carboxylic and phosphonic acid monolayer.@footnote 6@,@footnote 7@ Here, we investigate the influence on chemisorption from dilute solutions of such molecules using controlled atmospheric exposure prior to assembly. The order of the resultant SAMs is used as a relative measure of the reactivity of the surface to the headgroups. Water contact angle, IRRAS and XPS are used to provide information on the chemistry of the oxide surface and the order the monolayer assembled onto this surface. Differences are rationalised using the competitive processes of hydroxyl adsorption site formation and adventitious contamination blocking of such sites developed in the earlier work. @FootnoteText@ @footnote 1@ Bigelow, W et al. Colloid Sci 1946; 1: 513.@footnote 2@ Timmons, C, Zisman, W. JPhysChem 1965; 69: 984.@footnote 3@ Allara, DL, Nuzzo, RG. Langmuir 1985; 1: 45.@footnote 4@ Alexander et al. SIA 2000; 29: 468.@footnote 5@ Alexander et al. SIA 2003; 35: 649.@footnote 6@ Alexander, MR et al. ASST:ATB Metallurgie, Brussels, 2004; 60.@footnote 7@ Pertays, K et al. SIA In Press.