Extended Data Fig. 9: Characteristics of SCLs prepared from cholesterol analogs.
From: Entropic repulsion of cholesterol-containing layers counteracts bioadhesion
(a) Layer thickness, (b) surface roughness, and (c) morphology of cholesterol analog SCLs as determined by ellipsometry and atomic force microscopy. The contact mode atomic force microscopy images in (c) were used to determine the surface roughness. While all SCLs have a relatively uniform thickness of 150 – 200 nm, their morphology and roughness vary. However, a significant influence of the morphological surface properties on the bioadhesion properties is excluded, as e.g. cholesterol and dehydrocholesterol SCLs show a strongly diverging surface roughness but very similar bioadhesion properties (see Extended Data Fig. 10). (d) Dynamic contact angle measurements of the cholesterol analog SCLs. For SCLs of non-amphiphilic cholesterol analogs, only a surface roughness-dependent contact angle hysteresis (i.e. the rougher the surface, the higher the hysteresis due to pinning effects at elevations of the surface) but no resting time-dependent decrease of the receding contact angle (i.e. a dynamic interfacial polarity adaptation in response to changes in the polarity of the environment) is observed. Only for cholesterol and dehydrocholesterol SCLs a contact time-dependent decrease of the receding contact angle could be detected. In all graphs, the mean and + standard deviation are shown. The number of observations (n) is indicated.
