Page 110 - Book Hosokawa Nanoparticle Technology Handbook

FUNDAMENTALS CH. 2 STRUCTURAL CONTROL OF NANOPARTICLES

20

15

25 Rv=0.3
(%) 10 d = 53.7
20
5
15
(%)
10 Nanocoating 0 4 7 12 22 42 77 143 265 491
Diameter (nm)
5 20

0
2 3 7 13 26 50 59 193 378 15
Diameter (nm)

(%) 10 Rv=1.0
SiO
2 d = 59.3nm
d 48.5nm
5
Dynamic light scattering spectrophotometer
ELS-800Y (Otsuka Electronics) 0
2 7 13 24 47 91 177 341 680
Diameter (nm)
Figure 2.4.15
Particle size distribution for VO –SiO hybrid nanoparticles.
2
2
alkoxide to suppress the following polycondensation Site 1
of the metal alkoxide, even for the case of the metal
alkoxide with rapid hydrolysis and condensation rate, CH 3
to form the hydroxide precipitates. The deduced CH 3
molecular structure of the vanadium alkoxide precur- C O
sor prepared by the chemical modification in the O C
vanadium precursor solution was shown in O O O
Fig. 2.4.16. The nanometer-level uniform coating
could be successfully attained by the preferential con-
densation on the silica nanosphere of the partially V V
hydrolyzed alkoxide precursor due to steric hindrance Site3
and introduction of the preferential active side chain O O O
group in an alkoxide molecule. O C O O C O
Thermochromic property of the resultant smart
film is shown in Fig. 2.4.17. In this figure, infra-red CH 3 O C O C CH 3
(IR) spectra of the smart film at a room temperature
and a temperature higher than the phase transition CH 3 CH 3
temperature were shown to investigate the perform-
ance of the resultant smart film, together with the
same IR spectra for the film composed of the com- Site2
mercial VO particles and PLA. As a result, the trans-
2
mittance change of the film consisting of the Figure 2.4.16
commercial VO particles and PLA between the Schematic illustration of VO –SiO precursor.
2
2
2
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