Drastic Dependence of the pH Sensitivity of Fe₂O₃-Bi₂O₃-B₂O₃ Hydrophobic Glasses with Composition

Tadanori Hashimoto; Fumiya Murayama; Masashi Nakao; Hiroyuki Nasu; Atsushi Ishihara; Yuji Nishio

doi:10.3390/ma8125480

Drastic Dependence of the pH Sensitivity of Fe₂O₃-Bi₂O₃-B₂O₃ Hydrophobic Glasses with Composition

Materials (Basel). 2015 Dec 10;8(12):8624-8629. doi: 10.3390/ma8125480.

Authors

Tadanori Hashimoto¹, Fumiya Murayama², Masashi Nakao³, Hiroyuki Nasu⁴, Atsushi Ishihara⁵, Yuji Nishio⁶

Affiliations

¹ Division of Chemistry for Materials, Graduate School of Engineering, Mie University, 1577 Kurimamachiya-Cho, Tsu City, Mie Prefecture 514-8507, Japan. hasimoto@chem.mie-u.ac.jp.
² Division of Chemistry for Materials, Graduate School of Engineering, Mie University, 1577 Kurimamachiya-Cho, Tsu City, Mie Prefecture 514-8507, Japan. mieuniv@me.com.
³ Division of Chemistry for Materials, Graduate School of Engineering, Mie University, 1577 Kurimamachiya-Cho, Tsu City, Mie Prefecture 514-8507, Japan. 415M338@m.mie-u.ac.jp.
⁴ Division of Chemistry for Materials, Graduate School of Engineering, Mie University, 1577 Kurimamachiya-Cho, Tsu City, Mie Prefecture 514-8507, Japan. nasu@chem.mie-u.ac.jp.
⁵ Division of Chemistry for Materials, Graduate School of Engineering, Mie University, 1577 Kurimamachiya-Cho, Tsu City, Mie Prefecture 514-8507, Japan. ishihara@chem.mie-u.ac.jp.
⁶ HORIBA, Ltd., 2 Miyanohigasi, Kisshoin, Minami-Ku, Kyoto 601-8510, Japan. yuji.nishio@horiba.com.

Abstract

Fe₂O₃-Bi₂O₃-B₂O₃ (FeBiB) glasses were developed as novel pH responsive hydrophobic glasses. The influence of the glass composition on the pH sensitivity of FeBiB glasses was investigated. The pH sensitivity drastically decreased with decreasing B₂O₃ content. A moderate amount of Fe₂O₃ and a small amount of B₂O₃ respectively produces bulk electronic conduction and a pH response on glass surfaces. Because the remaining components of the glass can be selected freely, this discovery could prove very useful in developing novel pH glass electrodes that are self-cleaning and resist fouling.

Keywords: Fe2O3-Bi2O3-B2O3 glasses; hydrophobicity; pH electrodes.