The structure of films formed by γ-aminopropyltriethoxysilane adsorbed onto copper

• Published in: Journal of colloid and interface science Vol. 91; no. 2; pp. 485 - 495
• Main Authors: Boerio, F.J, Williams, J.W, Burkstrand, J.M
• Format: Journal Article
• Language: English
• Published: Elsevier Inc 01.01.1983
• ISSN: 0021-9797; 1095-7103
• DOI: 10.1016/0021-9797(83)90362-4

The structure of thin films formed by γ-aminopropyltriethoxysilane (γ-APS) adsorbed onto copper mirrors from aqueous solutions was determined using reflection-absorption infrared (RAIR) and X-ray photoelectron spectroscopy (XPS). Films formed at pH 10.4 were composed of siloxane polymers containing absorbed carbon dioxide and Cu(I) ions that formed coordination complexes with the amino groups. These films were stable in a dry atmosphere but a transition was observed during exposure to a humid atmosphere. During such exposure the extent of polymerization in the siloxane polymers increased, some carbon dioxide was desorbed, and the Cu(I) ions were oxidized to form Cu(II)/amine complexes with γ-APS. Films formed by adsorption of γ-APS onto copper from aqueous solutions acidified by addition of HCl were also composed of siloxane polymers. Most of the amino groups in these films were coordinated to copper ions but the films formed at low pH values contained little absorbed carbon dioxide.