1995 Fiscal Year Final Research Report Summary
Basic study on the development of high performance gas-sensing system based on the holographic method.
| Project/Area Number |
06650940
|
|---|
| Research Category |
Grant-in-Aid for General Scientific Research (C)
|
| Allocation Type | Single-year Grants |
|---|
| Research Field |
工業物理化学
|
|---|
| Research Institution | University of Tokyo |
|---|
Principal Investigator |
BABA Ryo Univ.of Tokyo, Faculty of Eng. ; Research Associate, 大学院・工学系研究科, 助手 (70198951)
|
|---|
| Project Period (FY) |
1994 – 1995
|
| Keywords | Hologram / Gas sensor / Metal oxide semiconductor / Surface reaction / LB film / Optical sensing / Photochromism / Photocatalysis |
|---|
| Research Abstract |
The present research has aimed, by both theoretical and experimental approaches, at the development of a high performance gas-sensing system using a holographic grating method. Those major issues studied are as follows :
1.Preparation of holograms and their characterization
Holograms were prepared on vacuum-evaporated Au thin films, SnO2 and ITO coated glass substrates by exposing the overcoated photoresist to the interfering two UV-laser beams. Exposure, rinsing, optical geometry and other conditions were optimized to give holograms of higher diffraction and higher exposure of the bare substrate as sensing material.
2.In situ monitoring of thiol self-asembly (SA) on Au-based holograms
Preliminary results on the electrode reaction of methylene bule using Au- and ITO-based holograms showed that the change in dielectric properties of the substrate surface are possibly monitored by the present method. Thus, the method was applied to study SA process of thiol on Au-hologram which is expected to proceed with no color change to be monitored. The kinetic parameters of SA crystalization was experimentally obtained for the first time.
3.Holographic response to flammable gas by metal-oxide semiconductors
SnO2-based hologram was tested as sensor to H2 and CO.The response to the model gas was observed but found to be somewhat temperature dependent. Factors affecting the time response and the gas selectivity were also studied. Hybrid substrate was suggested to be useful as hologram base material for the selective detection of the gas of interest.
4.In situ monitoring of the photocatalytic reaction on a TiO2 hologram
Since the present method was shown to be highly sensitive to the small change in the surface optical constant it was also applied to the study of a photoinduced surface reaction of photocatalysis using TiO2-based hologram. The experimental proof of monitoring submonolayr adsorbed intermediates was obtained in situ during the photocatalysis.
|
