11.3. NANOCRYSTALS
289
Table 11.1. Nanocrystals prepared by recrystallization of four n-conjugated compounds
listed in Fig. 11.4, and by recrystallization of four diacetylene polymers with the side
chains listed in Fig. 11.7
Material
Type
Crystallite size
Anthracene CI4Hl0
PIC
Perylene C20HL2
Fullerene CG0
DCHD
DCHD
4-BCMU
14-8ADA
n-Conjugated compound
n-Conjugated compound
n-Conjugated compound
n-Conjugated compound
Polydiacety lene
Polydiacetylene
Polydiacetylene
Polydiacety lene
150 m-1 pm
200-300 nrn
50-200 nm
200 nm
200 nm- 1 pm
15 nm-1 prn
1 -pm-long, 60-nm-diameter
microfiber
1 5-200 nm
Source: Data were obtained from H. Kasai et al., in Nalwa (2000), Vol. 5, Chapter 8, p. 441.
11.3.2. Polydiacetylene Types
The nanocrystals listed toward the bottom of Table 11.1 were prepared by
recrystallization from a polydiacetylene polymer with a backbone formed from
the diacetylene molecule, which has the structure sketched at the lower part of
Fig. 1 1.1. The starting compound is RCEC-C-CR',
where examples of the R and
800
I
I
I
I
I
-70
"C
-60
"C
b
5
0 "C
Figure 11
---P-40 "C
-35 "C
6oo b r K - -30
-25
"C "C
=? 400
-.?
1
I
12
Timelh
.5. Growth of the scattered light intensity /Jt)/h from perylene particles dispersed in
water at various temperatures during the reprecipitation process for the formation -of nan0crystals, where lo is the incident light intensity [From H. Kasai et al., in Nalwa (2000), Vol. 5,
Chapter 8, p. 450.1