title: Universality and specificity in molecular orientation in anisotropic gels prepared by diffusion method.
abstract: Molecular orientation in anisotropic gels of chitosan, Curdlan and DNA obtained by dialysis of those aqueous solutions in gelation-inducing solutions was investigated. In this diffusion method (or dialysis method), the gel formation was induced by letting small molecules diffuse in or out of the polymer solutions through the surface. For the gels of DNA and chitosan, the polymer chains aligned perpendicular to the diffusion direction. The same direction of molecular orientation was observed for the Curdlan gel prepared in the dialysis cell. On the other hand, a peculiar nature was observed for the Curdlan gel prepared in the dialysis tube: the molecular orientation was perpendicular to the diffusion direction in the outermost layer of the gel, while the orientation was parallel to the diffusion direction in the inner translucent layer. The orientation parallel to the diffusion direction is attributed to a small deformation of the inner translucent layer caused by a slight shrinkage of the central region after the gel formation. At least near the surface of the gel, the molecular orientation perpendicular to the diffusion direction is a universal characteristic for the gels prepared by the diffusion method.
authors.affiliation: Department of Chemistry and Chemical Biology, Graduate School of Engineering, Gunma University, Kiryu 376-8515, Japan. Electronic address: maki@chem-bio.gunma-u.ac.jp.
authors.forename: Yasuyuki
authors.initials: Y
authors.lastname: Maki
authors.affiliation: Faculty of Advanced Life Science, Hokkaido University, Sapporo 060-0810, Japan.
authors.forename: Kazuya
authors.initials: K
authors.lastname: Furusawa
authors.affiliation: Department of Chemistry and Chemical Biology, Graduate School of Engineering, Gunma University, Kiryu 376-8515, Japan.
authors.forename: Sho
authors.initials: S
authors.lastname: Yasuraoka
authors.affiliation: Department of Chemistry and Chemical Biology, Graduate School of Engineering, Gunma University, Kiryu 376-8515, Japan.
authors.forename: Hideki
authors.initials: H
authors.lastname: Okamura
authors.affiliation: Department of Chemistry and Chemical Biology, Graduate School of Engineering, Gunma University, Kiryu 376-8515, Japan.
authors.forename: Natsuki
authors.initials: N
authors.lastname: Hosoya
authors.affiliation: Department of Chemistry and Chemical Biology, Graduate School of Engineering, Gunma University, Kiryu 376-8515, Japan.
authors.forename: Mari
authors.initials: M
authors.lastname: Sunaga
authors.affiliation: Department of Chemistry and Chemical Biology, Graduate School of Engineering, Gunma University, Kiryu 376-8515, Japan.
authors.forename: Toshiaki
authors.initials: T
authors.lastname: Dobashi
authors.affiliation: Division of Biophysical Engineering, Graduate School of Engineering Science, Osaka University, Toyonaka, Osaka 560-8531, Japan.
authors.forename: Yasunobu
authors.initials: Y
authors.lastname: Sugimoto
authors.affiliation: Division of Biophysical Engineering, Graduate School of Engineering Science, Osaka University, Toyonaka, Osaka 560-8531, Japan.
authors.forename: Katsuzo
authors.initials: K
authors.lastname: Wakabayashi
mesh_terms: D016880:Anisotropy; D048271:Chitosan / Q000737:chemistry; D004247:DNA / Q000737:chemistry; D005782:Gels / Q000737:chemistry*
chemical_list: D005782:Gels; D004247:DNA; D048271:Chitosan
keywords: Anisotropic; Birefringence; Chitosan; Curdlan; DNA; Gel