title: Anomalous spreading with Marangoni flow on agar gel surfaces.
abstract: We have experimentally observed anomalous spreading of aqueous alcohol solutions on flat and rough fractal agar gel surfaces. On flat agar gel surfaces, extremely fast spreading [θ(D)(t) ∝ t(-0.92)] that differs from Tanner's law [θ(D)(t) ∝ t(-0.3)] was observed when the liquid contained over 9 wt % of 1-propanol in which strong Marangoni flow was observed as a fluctuation on the liquid surface. However, on fractal gel surfaces, different spreading dynamics [θ(D)(t) ∝ t(-0.58)] were observed, although Marangoni flow still occurred. We found the surface-dependent spreading can be discussed in terms of competition between Marangoni flow and the pinning effect due to surface roughness.
authors.affiliation: Department of Biochemical Engineering, Graduate School of Science and Engineering, Yamagata University, 4-3-16 Jonan, Yonezawa 992-8510, Japan. nonoy@yz.yamagata-u.ac.jp
authors.forename: Yoshimune
authors.initials: Y
authors.lastname: Nonomura
authors.forename: Shigeki
authors.initials: S
authors.lastname: Chida
authors.forename: Eri
authors.initials: E
authors.lastname: Seino
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Mayama
mesh_terms: D000362:Agar / Q000737:chemistry*; D005782:Gels / Q000737:chemistry*; D013499:Surface Properties
chemical_list: D005782:Gels; D000362:Agar