Partially Wetting Thin Liquid Films: Structure and Dynamics Studied with Coherent X Rays

Abstract

We studied the surface structure of thin liquid films vapor deposited on solid substrates in a partial wetting situation by means of coherent x-ray scattering. No dynamics has been observed showing the absence of capillary waves on liquid films partially wetting a substrate. Instead an exponential form of the height-height correlation function has been found pointing toward a solidlike behavior of the thin liquid films at large length scales. The exact surface structure and degree of replication with the substrate depend on the deposition rate of the molecules.

X-ray photon correlation spectroscopy

“…XPCS has been applied to a number of condensed matter systems, including soft materials such as colloids (Dierker et al, 1995;Narayanan et al, 2007;Thurn-Albrecht et al, 1996;Lu et al, 2008;Mochrie et al, 1997;Gao & Kilfoil, 2007;Fluerasu et al, 2007;Lal et al, 2001;Robert et al, 2008;Spannuth et al, 2011;Trappe et al, 2007;Zhang et al, 2011;Guo et al, 2007;Chung et al, 2006;Bandyopadhyay et al, 2004), liquid crystals (Madsen et al, 2003;Sikharulidze et al, 2002Sikharulidze et al, , 2003; Relaix et al, 2011), polymers (Falus et al, 2005(Falus et al, , 2006aGuo et al, 2009Guo et al, , 2012Hernandez et al, 2014;Hongyu et al, 2012;Mochrie et al, 1997;Narayanan et al, 2007;Orsi et al, 2011;Patel et al, 2010), capillary fluctuations (Gutt et al, 2003(Gutt et al, , 2007Jiang et al, 2007;Kim et al, 2003;Madsen et al, 2004;Alvine et al, 2012;Frieberg et al, 2013;Liu et al, 2013) as well as metals and alloys (Brauer et al, 1995;Brock & Sutton, 2008;Fluerasu et al, 2005;…”

X‐ray Photon Correlation Spectroscopy Studies of Surfaces and Thin Films

“…Gutt et al have studied the XPCS from partially wetting liquid films on relatively smooth substrates such as silicon and glass. The liquids were n‐hexane and cyclohexane introduced at vapor pressures well below saturation onto slightly cooled substrates.…”

Effects of partial coherence on correlation functions measured by x-ray photon correlation spectroscopy

“…[1][2][3][4][5][6][7][8][9][10][11] At third-generation synchrotrons it is nowadays possible to produce intense x-ray beam with a high degree of coherence. The scattered intensity distribution of such an x-ray beam coming from a rough surface provides a speckle pattern due to destructive and constructive interference.…”