AVS 51st International Symposium
    Surface Science Thursday Sessions
       Session SS2-ThM

Paper SS2-ThM10
Nanotribological Effects of Substrate Surface Order and Partial Fluorination for Alkanephosphonic Acid Self-Assembled Monolayers on Alumina

Thursday, November 18, 2004, 11:20 am, Room 210C

Session: Tribology, Adhesion, and Friction
Presenter: M.J. Brukman, University of Wisconsin-Madison
Authors: M.J. Brukman, University of Wisconsin-Madison
T.D. Dunbar, 3M Company
R.W. Carpick, University of Wisconsin-Madison
Correspondent: Click to Email
SAMs are of considerable interest for applications such as lubrication, corrosion protection, and water repellency, particularly at the nano-scale. Here, we compare the wettability and nano-scale friction and adhesion of two phosphonic acid self-assembled monolayers (SAMs): CF@sub 3@(CF@sub 2@)@sub 7@(CH@sub 2@)@sub 11@-PO@sub 3@H@sub 2@ (F8H11 PA) and CH@sub 3@(CH@sub 2@)@sub 17@-PO@sub 3@H@sub 2@ (H18 PA) deposited on a series of three Al@sub 2@O@sub 3@ surfaces: C- and R- plane single crystal sapphire, and an amorphous alumina layer on Si. Contact angle measurements were performed to compare the wetting of fluorinated and hydrogenated SAMs by water and hexadecane. Atomic force microscopy was then used to characterize the nano-scale dependences of adhesion and friction on SAM composition and substrate surface order. We observe differences that depend on the substrate, indicating that substrate-imposed variations in packing density and ordering have measurable nanotribological effects.