In situ GISAXS Investigation of Gold Sputtering onto a Polymer Template

• Published in: Langmuir 2008-04, Vol.24 (8), p.4265-4272
• Main Authors: Metwalli, E, Couet, S, Schlage, K, Röhlsberger, R, Körstgens, V, Ruderer, M, Wang, W, Kaune, G, Roth, S. V, Müller-Buschbaum, P
• Format: Article
• Language: English
• Subjects: Chemistry; Colloidal state and disperse state; Exact sciences and technology; General and physical chemistry; Surface physical chemistry
• ISSN: 0743-7463; 1520-5827
• DOI: 10.1021/la7038587

Microphase-separation structures in mixed diblock-triblock copolymer thin films are used for the incorporation of gold atoms inside the polymer matrix via sputtering of gold. Polystyrene (PS) spheres are arranged in a liquidlike type with a well defined nearest neighbor distance inside a polyisoprene matrix acting as a template for directing the gold atoms. Sputtering conditions are selected with a very low sputtering rate to avoid clustering in the atmosphere so that gold reaches the polymer surface in its atomic state. Due to the mobility of the gold atoms and the selective interaction with the PS parts of the microphase separation structure, gold is accumulated inside the polymer film in the PS spheres, as probed in situ with grazing incidence small-angle X-ray scattering (GISAXS). Nominally 4.3 Å of gold is deposited, which by diffusion is spread out vertically over a thickness of 280 nm. UV−vis spectroscopy reveals a small blue shift for the gold sputtered polymer film. Atomic force microscopy proves the absence of gold clusters on the film surface. For low sputtering rate, GISAXS proves good sensitivity for gold migration inside the polymer film and opens new possibilities for studying polymer−metal interaction.