elena yunda undergraduate student, [email protected]@tpu.ru tomsk- 2014 scientific advisors:asst. prof....
TRANSCRIPT
Elena YundaUndergraduate Student, [email protected]
Tomsk- 2014
Scientific advisors: Asst. Prof. Anna Godymchuk (TPU)Dr. Gunilla Herting (KTH)Prof. Inger Odnevall Wallinder (KTH)
Tomsk Polytechnic University, TomskKTH Royal Institute of Technology, Stockholm
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Background
Goal/Aim
Materials and Methods
Results and Discussion
Conclusions
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Annual growth rate+ 29.8 %
[BBC Research]
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Increasing number and diversity of nanoparticles sources
Nanoparticles characteristics identify nanoparticles behavior in liquid environment
Growth of NPs production Articles published on toxicity of NPs
NMs
NMs toxicity
NMs ecotoxicity
[Kahru A., 2009]
Metal releaseAgglomeration
SedimentationChange of surface charge
Lack of data on physicochemical behavior of nanoparticles in environmental media
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100 nm 100 nmAl
S=15,5 m2/g
Evaluate the effect of particle loading on nanoparticle stability and metal release in artificial surface water.
Ni Zn
S=6,0 m2/g S=13,6 m2/g
Chemical composition (mg/L) and pH of OECD surface waterCaCl22H2O MgSO47H2O NaHCO3 KCl
29.38 12.33 6.48 0.58pH = 6.0
Buffering: 170 L 0.95% H2SO4
* OECD - Organisation for Economic Co-operation and Development* GF-AAS - Graphite furnace atomic absorption spectroscopy* PCCS – Photon Cross-correlation Spectroscopy
Exposure of NPs to solutionTime: 60 minutesTemperature: 21°CLoadings: 10 and 100 mg/L
Centrifugation of suspensions10 minutes, ~3000 r/min
Analysis of metal concentration in solution
GF-AAS
Evaluation of stability and average
diameter of NPsPCCS
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5
0
0,1
0,2
0,3
0,4
0,25 0,5 1Alu
min
um
rel
ease
d, %
Time, hours
10 mg/L 100 mg/L
0
0,02
0,04
0,06
0,08
0,1
0 0,5 1Ra
te o
f m
eta
l re
lea
se,
µg
/cm
2 /h
ou
r
Time, hours
10 mg/L 100 mg/L
The surface of particles was more active in suspensions with lower loading.
0
1
2
3
4
5
6
1 10 100 1000 10000
Den
sity
dis
trib
uti
on, %
Size of particles, nm
1 min
30 min
60 min
1 mindm = 950 nm
24 μg/L 115 μg/L
Loading: 100 mg/L
Metal released after15 minutes of exposure
10 …
30 mindm = 1230 nm
60 mindm = 2700 nm
An increase of particles agglomeration with time.
Low amounts of released aluminum in solution up to 1 h of exposure (<0.5% of the particle mass). Aluminum NPs
100 mg/L
6
0
2
4
6
8
0,25 0,5 1
Zin
c re
leas
ed, %
Time, hours
10 mg/L 100 mg/L
0
0,5
1
1,5
2
2,5
3
3,5
4
4,5
5
1 10 100 1000 10000
Den
sity
dis
trib
utio
n, %
Size of particles, nm
1 min
15 min
30 min
0
1
2
3
4
5
0 0,5 1R
ate
of m
etal
rel
ease
, µ
g/cm
2 /h
our
Time, hours
10 mg/L 100 mg/L
0
0,5
1
1,5
2
0,25 0,5 1
Nic
kel
rel
ease
d, %
Time, hours
10 mg/L 100 mg/L
0
0,1
0,2
0,3
0,4
0 0,5 1
Rat
e of
met
al r
elea
se,
µg/
cm2 /
hou
r
Time, hours
10 mg/L 100 mg/L
0
0,5
1
1,5
2
2,5
3
3,5
4
1 10 100 1000 10000
Den
sity
dis
trib
uti
on, %
Size of particles, nm
1 min
15 min
30 min
60 min
Metal released from Zn and Ni nanoparticles
Agglomeration of Zn and Ni nanoparticles
Decrease in concentration of particles in solution leads to an increase in solubility
60 min – all NPs settled
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05
101520253035404550
0 1 2 3 4 5Sca
tter
ed li
ght
inte
nsi
ty,
kcp
s
Time, min
0
50
100
150
200
250
300
350
400
450
0 20 40 60Sca
tter
ed li
ght
inte
nsi
ty,
kcp
s
Time, min
0
10
20
30
40
50
60
0 1 2 3 4 5Sca
tter
ed li
ght
inte
nsi
ty,
kcp
s
Time, min
0
400
800
1200
1600
2000
0 1 2 3 4 5 6 7 8Sca
tter
ed li
ght
inte
nsi
ty,
kcp
s
Time, min
0
20
40
60
80
100
120
140
160
180
200
0 20 40 60Sca
tter
ed li
ght
inte
nsi
ty,
kcp
s
Time, min
0
200
400
600
800
1000
1200
0 20 40 60Sca
tter
ed li
ght
inte
nsi
ty,
kcp
s
Time, min
Loading 10 mg/L was below the limits of the instrument under chosen experimental conditions
Zn and Ni NPs settled after 60 minutes of exposure. Al NPs were relatively stable for 1 hour.
Zn 10 mg/L
Zn 100 mg/L
Ni 10 mg/L
Ni 100 mg/L Al
100 mg/L
Al 10 mg/L
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Nanoparticles characteristics (size, amount of metal released, stability) changed significantly with time (agglomeration + gradual dissolution + sedimentation).
Reducing the loading of nanoparticles in solution in 10 times increased the dissolution rate of Al in 2.5 times, Zn – in 3.1 times, Ni – in 2.2 times.
The loading of particles did not affect the kinetics of dissolution.
The influence of particles loading on the agglomeration process was not investigated due to the limits of the technique under chosen experimental conditions.
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Prof. Inger Odnevall [email protected]
Ass. prof. Anna [email protected]
Dr. Gunilla [email protected]
PhD studentSara [email protected]
This work was supported by the scholarship of the President of the Russian Federation for studying abroad and performed at the Division of Surface and Corrosion Science at KTH Royal Institute of Technology, Stockholm, Sweden.