SEM observation of hydrous superabsorbent polymer pretreated with room-temperature ionic liquids

Tetsuya Tsuda; Eiko Mochizuki; Shoko Kishida; Kazuki Iwasaki; Katsuhiko Tsunashima; Susumu Kuwabata

doi:10.1371/journal.pone.0091193

SEM observation of hydrous superabsorbent polymer pretreated with room-temperature ionic liquids

PLoS One. 2014 Mar 12;9(3):e91193. doi: 10.1371/journal.pone.0091193. eCollection 2014.

Authors

Tetsuya Tsuda¹, Eiko Mochizuki¹, Shoko Kishida¹, Kazuki Iwasaki¹, Katsuhiko Tsunashima², Susumu Kuwabata¹

Affiliations

¹ Department of Applied Chemistry, Graduate School of Engineering, Osaka University, Suita, Osaka, Japan.
² Department of Material Science, Wakayama National College of Technology, Gobo, Wakayama, Japan.

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.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Absorption, Physicochemical*
Ionic Liquids / chemistry*
Microscopy, Electron, Scanning / methods*
Polymers / chemistry*
Temperature*
Vacuum
Water / chemistry*

Substances

Ionic Liquids
Polymers
Water

Grants and funding

Part of this research was supported by Grant-in-Aid for Scientific Research B, Grant No. 24350071, from Japanese Ministry of Education, Culture, Sports, Science and Technology (MEXT), from Advanced Low Carbon Technology Research and Development Program (ALCA), Japan Science and Technology Agency (JST), and from Japanese Ministry of Economy, Trade and Industry (METI). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.