MECHANISM OF FORMATION OF SILVER NANOPARTICLES IN MAGDMAEMA COPOLYMER AQUEOUS SOLUTIONS.
Journal of Nanoparticle Research
Dmitry O. Shvedchenkoa, Tatiana N. Nekrasovab, Olga V. Nazarovab, Philippe A. Buffatc,
Elena I. Suvorovaa,c*.
a
A.V. Shubnikov Institute of Crystallography of Russian Academy of Sciences, Leninsky pr., 59,
119333 Moscow, Russia
b
Institute of Macromolecular Compounds of Russian Academy of Sciences, Bolshoy pr., 31,
199004 Saint-Petersburg, Russia
c
Ecole Polytechnique Fédérale de Lausanne, Centre Interdisciplinaire de Microscopie
Electronique, Station 12, CH-1015 Switzerland
*Corresponding author. E-mail address: elena.suvorova@epfl.ch, suvorova@ns.crys.ras.ru
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SUPPLEMENTARY MATERIALS
1. Some particles, mainly the large ones, are twinned:
Mainly the large particles are twinned, most often several times, that may result from
agglomeration of smaller ones and sintering enhanced by size effect:
Figure SM-1 TEM image of twinned and multiply twinned Ag nanoparticles about 20 nm in
diameter (a), HRTEM of micro-twins in Ag nanoparticle (b).
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2. The incorporation of DMAEMA units into copolymers produces more rigid and compact chain
configuration what is reflected by longer relaxation times.
Obviously higher local density of units and optimized spatial distribution of reducing groups in
poly[MAG-DMAEMA] configuration can lead to shortening latent periods and higher rate of
reactions.
The relaxation time (nanoseconds) characterizes the intramolecular mobility of chain fragments in
DMAEMA–MAG copolymers solutions. Table SM-1 summarizes data obtained by Andreeva et al (2014)
for copolymers in water and in 0.1M HCl. Accuracy of measurements is about 10 %. It shows that the
incorporation of nonionized (in pure water) DMAEMA units into a copolymer increases relaxation times
and decreases the intramolecular mobility of fragments of copolymer chains.
Table SM-1 Relaxation times depending on structure of copolymers MAG/DMAEMA (adapted from
Table 4 in Andreeva et al, Polymer Science Series A56 (2014) p 410)
DMAEMA molar ratio,
%
, ns
water
0.1M HCl
.
100
66
32
75
47
32
47
54
35
20
37
28
0
22-19
22-19
3. Comparison of size distributions for copolymers and mixture of homopolymers
Table SM-2 summarizes the mode diameters, mean diameters and volume fractions of small (d<
10 nm) and large (d≥10nm) Ag particles for copolymers MAG/DMAEMA with different molar ratio and
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for physical mixtures of homopolymers with the ratio 50% MAG: 50% DMAEMA and 80% MAG: 20%
DMAEMA.
Table SM-2 Diameter (mode and average) of Ag particles and volume fractions of small and
large Ag particles in MAG/DMAEMA copolymers solutions and solutions with MAG + DMAEMA
mixture of homopolymers
Mode
diameter
Average
particle
diameter
Standard
deviation
Volume
fraction of
NP with
diameter
d< 10 nm
(%)
(nm)
(nm)
(nm)
(%)
(%)
DMAEMA
100.0
3.4
2.34
0.89
100
0
MAG
0
4.0
5.99
5.81
6
94
MAG/DMAEMA
75.0
8.4
8.62
2.48
42
1
MAG/DMAEMA
70.7
8.4
7.04
3.33
48
33
MAG/DMAEMA
47.0
13.4
13.27
3.68
2
29
Polymer
DMAEMA
molar ratio
α
Volume
fraction of
Ag NPs from
tail d≥ 10nm
Bimodal
distribution
MAG/DMAEMA
15.0
5 and 15
7.57
4.88
8
4*
MAG +
DMAEMA
50
4.0
7.19
7.55
4
95
MAG +
DMAEMA
20
8.0
11.25
8.69
5
94
* 4%-volume fraction of Ag NP from the tail after the second peak in the bimodal size distribution
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The Figures SM-2 and SM-3 show the presence of very small but also large particles formed in a
solution containing homopolymers mixtures. The size/volume distributions of Ag particles produced in
solutions with polymer mixtures of 50% MAG+50% DMAEMA and 80% MAG+20% DMAEMA are
shown in Figures SM-4 and SM-5.
Figure SM-2 Low magnification (a) and high magnification (b) bright field STEM image of Ag
particles formed in the solution with the mixture of homopolymers 50% DMAEMA: 50% MAG
Figure SM-3 Low magnification (a) and high magnification (b) bright field STEM image of Ag
particles formed in the solution with the mixture of homopolymers 20% DMAEMA: 80% MAG.
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Figure SM-4 Particle/volume diameter
Figure SM-5 Particle/volume diameter
distribution of Ag particles formed in the
distribution of Ag particles formed in the
solution with the mixture of homopolymers
solution with the mixture of homopolymers
50 DMAEMA: 50 MAG.
20% DMAEMA: 80% MAG.
The comparison of size distributions obtained in solutions with pure homopolymer DMAEMA, pure
homopolymer MAG, physical mixtures of 50 DMAEMA: 50 MAG and 20% DMAEMA: 80% MAG
homopolymers and the copolymers 47% DMAEMA: 53% MAG and 82% MAG: 18% DMAEMA is
shown in Figures SM-6 and SM-7.
(a)
(b)
Figure SM-6 Comparison diameter (a) and volume (b) distribution between pure homopolymers
(DMAEMA –  brown, MAG - green), a physical mixture of homopolymers 50% DMAEMA: 50%
MAG ( red) and the copolymer 47% MAG: 53% DMAEMA ( blue). The secondary axis in (a)
shows frequency multiplied by factor 5 to highlight the contribution of the coarser particles.
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(a)
(b)
Figure SM-7 Comparison diameter (a) and volume (b) distribution between pure homopolymers
(DMAEMA –  brown, MAG - green), a physical mixture of homopolymers 80% MAG: 20%
DMAEMA ( red) and the copolymer 82% MAG: 18% DMAEMA ( blue). The secondary axis
in (a) shows frequency multiplied by factor 5 to show the part of the coarser particles.
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