Self-Assembled Monolayers of Long-Chain Hydroxamic Acids on the Native Oxides of Metals

摘要: Departments of Materials Science and Engineering Chemistry, Uniuersity lllinois,Urbana-Champaign, (Irbana, Illinois 61801Receiued September 79, 1994eLong-chain alkanehydroxamic acids adsorb on the native oxides metals formed oriented self-assembled monolayers (SAMs). This study examined SAMs hydroxamic ofcopper, silver, titanium, aluminum, zirconium, iron. These were characterized usingwettability,X-ray photoelectron spectroscopy (XPS), polarized infrared external reflectance (PIERS).Alkanehydroxamic give better than corresponding alkanecarboxylic certainbasic metal (especially copper(Il) oxide). On oxide copper (which has an isoelectricpoint greater pK" acid), ligand is bound to surface predominantly asthe hydroxamate. The strength interaction between hydroxamate allowsincorporation polar tail groups into monolayer. acidic or neutral (e.g., TiO2), thepredominant species acid. Alkanehvdroxamic titaniumdioxide bind relatively weakly but. nonetheless. form SAlts that are more stable those from carboxylicacids (although not as alkanephosphonic r.