title: Wetting dynamics of colloidal dispersions on agar gel surfaces.
abstract: The effects of silica particle addition on the wetting velocity on flat and fractal agar gel surfaces were analyzed along with the applicability of such particles for controlling the wetting dynamics of water. The contact angles (θD) of the colloidal dispersions obeyed the power law, i.e., θD∝t(-x), where t is time and x is a constant. Wetting was inhibited by the addition of a suitable amount of 20-nm-diameter silica particles. Specifically, the exponent x reached a minimum value for a silica composition of 0.1wt%. However, such inhibition effects were not observed upon the addition of silica particles with diameters of 100, 550, and, 1000nm. The mechanism of the inhibition of the liquid wetting on gel surfaces may be attributed to a slight increase in local viscosity around the contact line during wetting.
authors.affiliation: Department of Biochemical Engineering, Graduate School of Science and Engineering Yamagata University, 4-3-16 Jonan, Yonezawa 992-8510, Japan.
authors.forename: Eri
authors.initials: E
authors.lastname: Seino
authors.affiliation: Department of Biochemical Engineering, Graduate School of Science and Engineering Yamagata University, 4-3-16 Jonan, Yonezawa 992-8510, Japan.
authors.forename: Shigeki
authors.initials: S
authors.lastname: Chida
authors.affiliation: Research Institute for Electronic Science, Hokkaido University, CRIS Building, N21W10, Sapporo 001-0021, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Mayama
authors.affiliation: Department of Bio-systems Engineering, Graduate School of Science and Engineering Yamagata University, 4-3-16 Jonan, Yonezawa 992-8510, Japan.
authors.forename: Jun-Ichi
authors.initials: JI
authors.lastname: Hotta
authors.affiliation: Department of Biochemical Engineering, Graduate School of Science and Engineering Yamagata University, 4-3-16 Jonan, Yonezawa 992-8510, Japan. Electronic address: nonoy@yz.yamagata-u.ac.jp.
authors.forename: Yoshimune
authors.initials: Y
authors.lastname: Nonomura
mesh_terms: D000362:Agar / Q000737:chemistry*; D003102:Colloids; D005782:Gels; D013499:Surface Properties; D017155:Wettability
chemical_list: D003102:Colloids; D005782:Gels; D000362:Agar
keywords: Agar gel; Colloidal dispersion; Fractal structure; Wetting phenomena