title: SEM observation of hydrous superabsorbent polymer pretreated with room-temperature ionic liquids.
abstract: Room-temperature ionic liquid (RTIL), which is a liquid salt at or below room temperature, shows peculiar physicochemical properties such as negligible vapor pressure and relatively-high ionic conductivity. In this investigation, we used six types of RTILs as a liquid material in the pretreatment process for scanning electron microscope (SEM) observation of hydrous superabsorbent polymer (SAP) particles. Very clear SEM images of the hydrous SAP particles were obtained if the neat RTILs were used for the pretreatment process. Of them, tri-n-butylmethylphosphonium dimethylphosphate ([P(4, 4, 4, 1)][DMP]) provided the best result. On the other hand, the surface morphology of the hydrous SAP particles pretreated with 1-ethyl-3-methylimidazolium tetrafluoroborate ([C2mim][BF4]) and 1-butyl-3-methylimidazolium tetrafluoroborate ([C4mim][BF4]) was damaged. The results of SEM observation and thermogravimetry analysis of the hydrous SAP pretreated with the RTILs strongly suggested that most water in the SAP particles are replaced with RTIL during the pretreatment process.
authors.affiliation: Department of Applied Chemistry, Graduate School of Engineering, Osaka University, Suita, Osaka, Japan.
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Tsuda
authors.affiliation: Department of Applied Chemistry, Graduate School of Engineering, Osaka University, Suita, Osaka, Japan.
authors.forename: Eiko
authors.initials: E
authors.lastname: Mochizuki
authors.affiliation: Department of Applied Chemistry, Graduate School of Engineering, Osaka University, Suita, Osaka, Japan.
authors.forename: Shoko
authors.initials: S
authors.lastname: Kishida
authors.affiliation: Department of Applied Chemistry, Graduate School of Engineering, Osaka University, Suita, Osaka, Japan.
authors.forename: Kazuki
authors.initials: K
authors.lastname: Iwasaki
authors.affiliation: Department of Material Science, Wakayama National College of Technology, Gobo, Wakayama, Japan.
authors.forename: Katsuhiko
authors.initials: K
authors.lastname: Tsunashima
authors.affiliation: Department of Applied Chemistry, Graduate School of Engineering, Osaka University, Suita, Osaka, Japan.
authors.forename: Susumu
authors.initials: S
authors.lastname: Kuwabata
mesh_terms: D065966:Absorption, Physicochemical; D052578:Ionic Liquids / Q000737:chemistry*; D008855:Microscopy, Electron, Scanning / Q000379:methods*; D011108:Polymers / Q000737:chemistry*; D013696:Temperature; D014618:Vacuum; D014867:Water / Q000737:chemistry*
chemical_list: D052578:Ionic Liquids; D011108:Polymers; D014867:Water