| Project/Area Number |
10555219
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (B).
|
| Allocation Type | Single-year Grants |
|---|
| Section | 展開研究 |
|---|
| Research Field |
Inorganic materials/Physical properties
|
|---|
| Research Institution | Nagasaki University |
|---|
Principal Investigator |
EGASHIRA Makoto Nagasaki University, Faculty of Engineering, Professor, 工学部, 教授 (60037934)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
HIROTSURU Hideki Denki Kagaku Kogyo, Senior Researcher, 総合研究所, 専任研究員
HYODO Takeo Nagasaki University, Faculty of Engineering, Research Associate, 工学部, 助手 (70295096)
SIMUZU Yasuhiro Nagasaki University, Faculty of Engineering, Associate Professor, 工学部, 助教授 (20150518)
|
|---|
| Project Period (FY) |
1998 – 2000
|
| Keywords | surface chemical modification / metal nitride / dicarboxylic acid / ceramic monolayer / mesoporous tin dioxide / surfactant / semiconductor gas sensor / diethoxydimethylsilane |
|---|
| Research Abstract |
Preparation of various new functional meterials and improvement of its properties were attempted as below.
1.Chemical stability of metal nitride powders against water was improved by surface chemical modification with sebacic acid, while maintaining a hydrophilic surface. Treatment of the sebacic acid-modified powder with yttrium acetate resulted in strong immobilization of Y^<3+> ions, as a sintering aid, at a highly dispersive level on the metal nitride powder surface through ion exchange. By selecting slip compositions for better deflocculation and firing conditions, a thermal conductivity of ca.250 W m^<-1>K^<-1> was attained by the pressureless sintering of AIN at 1900℃ for 5h.
2.Closely packed monolayer of spherical oxide perticles of sub-micron size was fabricated on a silicon or glass substrate by employing a Langmuir-Blodgett film of 1, 12-dodecanedicaboxylic acid, followed by dehydration-condensation reatcion between carboxyl groups of the dicarboxylic acid and the surface hydroxyl groups of both the substrate and the ceramic spheres.
3.Ordered mesoporous SnO_2 powders with high thermal stability and a high surface area 305 m^2g^<-1> were prepared from sodium stannate by utilizing the self-assembly of n-cetylpyridinium chloride, followed by treatment with phosphoric acid and calcinations at 600℃ for 5h.
4.SnO_2 powder was subjected to surface chemical modification with diethyoxydimethylsilane and the gas sensing properties were evaluated. The SiO_2 introduced by the surface modificaton was found to exist as a grain-boundary phase from TEM observation. The limitation of neck growth between SnO_2 particles by the SiO_2 thin film coating is anticipated to be responsible for increasing the potential barrier height and improving the sensing properties to inflammable gases such as H_2, CH_4 and C_3H_8.
|
