P1.0.7 Preparation of Porous In2O3 Powders by Ultrasonic-spray Pyrolysis Employing PMMA Microspheres Synthesized by Emulsion Polymerization and Their Gas-sensing Properties
- Event
- 14th International Meeting on Chemical Sensors - IMCS 2012
2012-05-20 - 2012-05-23
Nürnberg/Nuremberg, Germany - Chapter
- P1.0 Metal Oxide-based Sensors
- Author(s)
- T. Hyodo, M. Katsuhide, S. Motokucho, K. Kojio, Y. Shimizu - Graduate School of Engineering, S. Furuno, E. Fujii - Faculty of Engineering, Nagasaki University (Japan)
- Pages
- 768 - 771
- DOI
- 10.5162/IMCS2012/P1.0.7
- ISBN
- 978-3-9813484-2-2
- Price
- free
Abstract
The suspension containing polymethylmethacrylate (PMMA) microspheres was synthesized by the emulsion polymerization employing methyl methacrylate monomer, sodium lauryl sulfate as a surfactant and ammonium persulfate as an initiator, and porous In2O3powders(pr-In2O3(M), M: n2O3 source (N: In(NO3)3, Cl: InCl3))were prepared by ultrasonic-spray pyrolysis of In(NO3)3 or InCl3 aqueous solution containing the synthesized PMMA microspheres as a template. The average diameter of the PMMA microspheres, which was measured by dynamic light scattering, was ca. 60.2 nm. The pr- In2O3(N) powder consisted of large microspheres with well-developed spherical mesopores (≤ ca. 30 nm in diameter) and a small number of macropores (ca. 100 nm in diameter) on the spherical surface, while the pr- In2O3(Cl) powder was composed of meso-sized particles (ca. 30 nm in diameter), respectively. On the other hand, the morphology of conventional In2O3 powder (c- In2O3(N)) prepared by ultrasonicspray pyrolysis of PMMA-free In(NO3)3 aqueous solution as a reference was roughlyspherical with a diameter of ca. 100~700nm and the bulk was relatively dense. The NO2 response of pr- In2O3(M) sensors was much larger than that of a c- In2O3(N) sensor. In addition, the response and recovery speeds of the pr- In2O3(M) sensors were faster than those of the c- In2O3(N) sensor.