Page 103 - Book Hosokawa Nanoparticle Technology Handbook

2.4 COMPOSITE STRUCTURE FUNDAMENTALS
generated particles N exponentially increases with [5] T. Nomura, H. Arima, T. Mori and Y. Konishi: Trans.
increasing chromate ion concentration regardless of Mater. Res. Soc. Jpn., 29, 2387 (2004).
the barium ion concentration. Since the total vol-
ume of generated particles V is also constant from
the stoichiometry, the aspect ratio of the generated 2.4 Composite structure
particle decreases with an increase in the chromate
ion concentration.
Figure 2.3.11 shows TEM photographs of the prod- 2.4.1 Gas-phase method
uct material obtained when a poor solvent (ethanol)
was added in the standard condition. When the There are specific functional requirements for making
amount of additional poor solvent increases, the fine particles as ceramics materials. Figure 2.4.1 shows
supersaturation ratio S increases with a decrease in these applications and material names. Ceramic pow-
the solubility product of BaCrO . Thus the number ders are not always in nanosizes. However, in the
4
concentration of the generated particle N increases practical applications and the development of new
exponentially, and the aspect ratio of the generated materials, the properties of nanoparticles, such as
particle is decreased. As mentioned above, it is possi- chemical, mechanical, optical, thermal, electric, and
ble to control the shape and size of nanoparticles by magnetic characteristics, are investigated. Depending
controlling the supersaturation ratio, which depends on applications, the specifications of nanoparticles
on the raw material concentration and the amount of can be their particle diameters, shapes, surface prop-
poor solvent, etc., and by suppressing the growth of erties, purities, and manufacturing histories.
specific crystal faces with a selectively adsorbing sur- Recently, in addition to single metal oxide, the
factant. nanoparticles with complex metal oxides become
popular. The near-term potential industrial applica-
tions of nanoparticles are in the fields of electronic
device, energy, environment, polymer, film, and bio-
References medical. In these areas, research and development
are geared to explore the functional effects of vari-
[1] Y. Li, J. Wan and Z. Gu: Mat. Sci. Eng. A, 286, 106
ous nanomaterials. On the other hand, the production
(2000).
method for producing nanoparticles with highly
[2] X. Peng, L. Manna, W. Yang: Nature, 404, 59 (2000). advanced characteristics in commercial quantity has
[3] S. Yu, M. Yoshimura: Adv. Mater., 14, 296 (2002). been studied. This section describes a plasma
[4] M. Li, H. Schnablegger and S. Mann: Nature, 402, 393 enhanced gas-phase method to produce nanoparti-
(1999). cles with complex compounds and structures.

, La
,
V
ZrO
Catalysts : : ZrO 2 , CeO 2 , ZnO, SnO 2 , Al 2 O 3 , MnO 2 , La 2 O 3 , V 2 O 5 , MgO, CuO
Catalysts
, ZnO
, SnO
, Al
, MnO
, MgO
, CuO
, CeO
y electrodes
LiCoO
, MnO
Battery electrodes : : LiCoO , MnO 2
Batter
2
Chemical Photocatalyst : : TiO 2
TiO
Photocatalyst

Chemical
KNO
Explosives
:
Explosiv es : KNO 3
Fire retardants : : ZrO , Sb O
ZrO
Fire retardants
, Sb
2 5
2
Solid lubr icants : : BN, MoS 2
Solid lubricants
BN, MoS
Mechanical
Mechanical Mold : : CaSO · 1/2H O
CaSO
1/2H
Mold
2
4
MgO
Fillers
, ZrO
, F
e
Fillers : : MgO, Fe O , ZrO 2
2 3
, Cr
, CeO
ZrO
asiv
, SiC
, Al
es
Abr
, SnO
Abrasives : : ZrO , Al O , CeO , SnO , SiC, Cr O
2
2
2 2
2 3
2
Cosmetics
, ZnO

Cosmetics : : TiO , ZnO, SiO , CaCO 3
, SiO
, CaCO
TiO
2
2
Optical
Ceramics Optical P aints , Pr inting in : : TiO , Fe O , Fe O , ZnO, SiO , Cr O , BaSO , PbCrO , MnO 2
, F
e
, Cr
, PbCrO
, BaSO
, SiO
, MnO
Cer
, F
TiO

e
, ZnO
amics
Paints, Printing in
3 4
2 3
2
4
2 3
2
4
UV stabiliz ers : TiO , ZnO, CeO 2
TiO

:
, CeO
UV stabilizers
, ZnO
2
Fluorescents : Y O :Eu, BaMgAl O :Eu, Zn SiO :Mn, ZnS (Ag)
:Mn, ZnS (Ag)
:Eu, Zn

:
Fluorescents
:Eu, BaMgAl
SiO
Y
2 3
14
14 23
2
23
4
ts
Catalytic suppor
Ther mal Catalytic supports : Al O , SiO 2
, SiO
Al
:
Thermal
2 3
Fillers : Al O , SiO , SiC, AlN
, SiC
Al
, SiO
Fillers
, AlN
:
2 3
2
, SnO
Semiconductors
IT
, LaTiO
ic
Electr
Electric Semiconductors : : ITO, SnO , LaTiO 3
O
2
F
Magnetic
Magnetic Magnets , Disks : Ferrite, 3CoFe O · Fe O , YIG
:
Magnets, Disks
,
YIG
e
F
err
ite
e
, 3CoF
3 4
2 4
Figure 2.4.1
Ceramic powders used for various purposes.
79