title: Liquid chromatography and differential scanning calorimetry studies on the states of water in polystyrene-divinylbenzene copolymer gels.
abstract: The thermal phase transition behavior of water incorporated in crosslinked polystyrene-divinylbenzene copolymer (PS-DVB) gel packings for liquid chromatography was investigated by differential scanning calorimetry. Free or bulk water, freezable bound or intermediate water, and nonfreezing water were observed for TSKgel Styrene-250 samples, while only free water and nonfreezing water were observed for TSKgel Styrene-60 samples. Freezable bound water and nonfreezing water in these gel samples were considered to be water confined in pores of the polymer gels. A liquid chromatographic method for determination of the amounts of stationary phase water was applied to the characterization of water in the PS-DVB beads in the columns and it was found out that any water in the PS-DVB gels did not function as the stationary phase contrary to the water sorbed in hydrophilic polymer gels; not only freezable bound water but also nonfreezing water in hydrophobic PS-DVB gels are similar to bulk water with respect to the affinity to the solute compounds.
authors.affiliation: Department of Materials Technology, Faculty of Engineering, Chiba University, 1-33, Yayoi-cho, Inage, Chiba, 263-8522, Japan.
authors.forename: Takayuki
authors.initials: T
authors.lastname: Baba
authors.forename: Masami
authors.initials: M
authors.lastname: Shibukawa
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Heya
authors.forename: Shin-ichiro
authors.initials: S
authors.lastname: Abe
authors.forename: Koichi
authors.initials: K
authors.lastname: Oguma
mesh_terms: D002152:Calorimetry, Differential Scanning; D002853:Chromatography, Liquid / Q000379:methods*; D011137:Polystyrenes / Q000737:chemistry*; D014753:Vinyl Compounds / Q000737:chemistry*; D014867:Water / Q000737:chemistry*
chemical_list: D011137:Polystyrenes; D014753:Vinyl Compounds; D014867:Water; C004985:divinyl benzene