Electronic Supplementary Material (ESI) for Green Chemistry
This journal is © The Royal Society of Chemistry 2012
Supplementary information
Preparation of electrochromic Prussian blue nanoparticles
dispersible into various solvents for realisation of printed
electronics
Manabu Ishizaki,a Katsuhiko Kanaizuka, a Makiko Abe,a Yuji Hoshi,a Masatomi
Sakamoto,a,b Tohru Kawamoto,b Hisashi Tanaka,b and Masato Kurihara*a,b
An insoluble solid of historic Prussian blue (PB) has been transformed into dispersible PB nanoparticles
in water and various hydrophilic and hydrophobic organic solvents. Via hybrid surface modification using
Na4[FeII(CN)6] and short-chain alkylamines, the insoluble PB was successfully dispersed in
hydrophilic-and-hydrophobic boundary alcohols, such as n-butanol. The n-butanol-dispersible PB
nanoparticles afforded homogeneous spin-coated thin films on various substrates. The chemisorbed
shorter-chain alkylamines, n-propylamines, of the PB nanoparticles were thermally released at 100 ○C
from their surfaces to present stubborn electrochromic PB thin films adhering to the substrate via mutual
(2 0 0)
coordination-bonding networks.
(6 2 0)
(4 4 0)
(6 0 0)
(a)
(4 2 2)
(4 2 0)
(4 0 0)
Intensity / a.u.
(2 2 0)
Scherrer’s particle size : (a)10.5 nm
(b)10.2 nm
(b)
10
20
30
40
2θ / degree
50
60
Fig. S1. XRD patterns of the original PB (insoluble PB NP solid) (a), the water-dispersible
PB NP solid using Na4[Fe(CN)6] (b).
Electronic Supplementary Material (ESI) for Green Chemistry
This journal is © The Royal Society of Chemistry 2012
H2O
(a)
(b)
H2O
H2O
NH2
NH3
NH2
+
NH3
N
C
OH－
N
C
NC
OH－
+
Fe NH
NC3 FeII CN FeIII
N
－
N N OH C
C N N
III
NH2
+
C
FeII CN
N
C
FeIII NC
FeII CN
C
C
N
N
C
C
C
N
Fig. S2. Two types of surface modification using Fe(III)-OH2 sites with alkylamines
(R-NH2).
absorbanc
(a)
(b)
1.5
1.0
0.5
0
350
550
750
950
1150
Wavelength / nm
Fig S3. (a) UV-Vis-near IR absorption spectrum of the n-dodecylamine (C12-amine)-modified PB
NPs almost independently dispersed in n-butanol (78 μg / mL), and (b) a photograph of the blue
dispersion solution with high transparency.
(a)
(b)
200 nm
200 nm
Fig. S4. AFM images of the spin-coated thin film using dilute (a) and dense (b)
n-dodecylamine (C12-amine)-modified PB NP inks.
Electronic Supplementary Material (ESI) for Green Chemistry
This journal is © The Royal Society of Chemistry 2012
Alkylamine-modified PB NPs
Scherrer’s particle size; 10.2 nm
(i)
(h)
9.6 nm
(g)
9.3 nm
10.6 nm
(f)
(e)
9.9 nm
(d)
11.1 nm
(c)
10.5 nm
(b)
10.0 nm
(a)
10.5 nm
10
20
30
40
50
60
2θ / degree
Fig. S5. Powder X-ray diffraction (XRD) patterns of (a) the original PB (insoluble PB NP solid), (b)
n-propylamine-modified,
(c)
n-butylamine-modified,
(d)
n-hexylamine-modified,
(e)
n-octylamine-modified,
(f)
n-dodecylamine-modified,
(g)
n-hexadecylamine-modified,
(h)
n-octadecylamine-modified, (i) oleylamine-modified PB NP solids. The XRD patterns were recorded on
Rigaku MiniFlex II desktop X-ray diffractometer (Cu Kα1 radiation (1.540562 Å)). The single-crystalline
particle diameter (D) was calculated by the Scherrer’s equation: D = Kλ/βcosθ, where K = 0.9 (Scherrer’s
constant), λ = wavelength of X-ray, β = half band width, and θ = peak angle.
Electronic Supplementary Material (ESI) for Green Chemistry
This journal is © The Royal Society of Chemistry 2012
Alkylamine-modified PB NPs
CO2
CH stretching bands
CN stretching band
(h)
(g)
(f)
(e)
(d)
(c)
(b)
(a)
3000
3000
2800
2800
2600
2600
2400
2200
2400
2200
Wavenumber / cm-1
2000
2000
1800
1800
Fig. S6. FT-IR spectra of (a) n-propylamine-modified, (b) n-butylamine-modified, (c)
n-hexylamine-modified,
(d)
n-octylamine-modified,
(e)
n-dodecylamine-modified,
(f)
n-hexadecylamine-modified, (g) n-octadecylamine-modified, (h) oleylamine-modified PB NP solids.
Electronic Supplementary Material (ESI) for Green Chemistry
This journal is © The Royal Society of Chemistry 2012
Hybrid surface-modified PB NPs
Scherrer’s particle size; 10.8 nm
(i)
(h)
10.6 nm
(g)
10.3 nm
(f)
9.7 nm
(e)
10.4 nm
(d)
10.6 nm
10.7 nm
(c)
10.4 nm
(b)
10.5 nm
(a)
10
20
30
40
50
60
2θ / degree
Fig. S7. Powder X-ray diffraction (XRD) patterns of (a) the original PB (insoluble PB NP solid), (b)
n-propylamine-modified,
(c)
n-butylamine-modified,
(d)
n-hexylamine-modified,
(e)
n-octylamine-modified, (f) n-dodecylamine-modified, (g) n-hexadecylamine-modified, (h)
n-octadecylamine-modified, (i) oleylamine-modified PB NP solids. The XRD patterns were recorded
on Rigaku MiniFlex II desktop X-ray diffractometer (Cu Kα1 radiation (1.540562 Å)). The
single-crystalline particle diameter (D) was calculated by the Scherrer’s equation: D = Kλ/βcosθ,
where K = 0.9 (Scherrer’s constant), λ = wavelength of X-ray, β = half band width, and θ = peak angle.
Electronic Supplementary Material (ESI) for Green Chemistry
This journal is © The Royal Society of Chemistry 2012
Hybrid surface-modified PB NPs
CO2
CH stretching bands
CN stretching band
(h)
(g)
(f)
(e)
(d)
(c)
(b)
(a)
3000
3000
2800
2800
2600
2600
2400
2400
2200
2200
2000
2000
1800
1800
Wavenumber / cm-1
Fig. S8. FT-IR spectra of (a) n-propylamine-modified, (b) n-butylamine-modified, (c)
n-hexylamine-modified, (d) n-octylamine-modified, (e) n-dodecylamine-modified, (f)
n-hexadecylamine-modified, (g) n-octadecylamine-modified, (h) oleylamine-modified PB NP
solids.
Electronic Supplementary Material (ESI) for Green Chemistry
This journal is © The Royal Society of Chemistry 2012
Eluted
Apparently not eluted
Apparently not eluted
(a)
(c)
(b)
n-butanol
water
Propylene carbonate
Fig. S9. Photographs of the PB NP thin film after drying at room temperature in (a) water, (b)
n-butanol, and (c) propylene carbonate.
Eluted
Eluted
(a)
Eluted
(b)
water
Apparently not eluted
(c)
water
(d)
water
water
Fig. S10. Photographs of the PB NP thin film in water after heating (a) at 50℃ for 10 min, (b) at
80℃ for 10 min, (c) at 100℃ for 10 min, and (d) at 100℃ for 20 min.
Electronic Supplementary Material (ESI) for Green Chemistry
This journal is © The Royal Society of Chemistry 2012
0.4
(a)
Absorbance
0.3
0.2
0.1
0
400
400
450
500
500
550
600
600
650
700
700
750
800
800
Wavelength / nm
0.4
(b)
Absorbance
0.3
0.2
0.1
0
400
500
600
700
800
Wavelength / nm
Fig. S10. Time-course change in the UV-vis absorption spectra of the PB NP film at -0.8 V (a) and
0.5 V (b) vs. Ag/Ag+.