Ränioksiid vahul baseeruv
termoisolatsioonmaterjal ning nanotraatide
dispersioonid "targa klaasi" rakendusteks
Martin Timusk, Jörgen Metsik,
Andris Šutka, Martin Järvekülg
martin.timusk@ut.ee
07.09.2016 Tallinn
Ränioksiid vaht
2
o Suure poorsusega SiO
2
materjali valmistamismeetodi
väljatöötamine, millel on aerogeelile sarnased omadused,
kuid mis ei vaja valmistamiseks geelide superkriitilist
kuivatamist.
o Odav ja lihtne valmistamise protsess
Ränioksiid vaht
3
M. Timusk, A. Kuus, K. Utt, T. Kangur, A. Šutka, M. Järvekülg, M. Knite, Thick silica foam films through combined catalytic
decomposition of H
2
O
2
and sol–gel processes, Materials & Design, 111 (2016) 80−87
The H
2
O
2
-loaded sols were sprayed on MnO2-coated substrates, resulting
in heterogeneous catalytic decomposition of H2O2 and effective foaming
and simultaneous gel formation due to oxygen gas and water formation
Acid-catalysed hydrolysis of
tetramethoxysilane + H
2
O
2
.
Ränioksiid vaht
4
M. Timusk, A. Kuus, K. Utt, T. Kangur, A. Šutka, M. Järvekülg, M. Knite, Thick silica foam films through combined catalytic
decomposition of H2O2 and sol–gel processes, Materials & Design, 111 (2016) 80−87
• Thickness up to 530 µm
(2 mm)
• Macropore sizes in the range of 29–47 µm
• Macropore wall thicknesses 16–50 nm
• Bulk density 64 - 143 kg/m
3
• Thermal conductivity 0.018 - 0.022 (±0.001)
W/(m*K)
• Both bulk density and thermal conductivity
comparable to the aerogels
• In the future – peparation
in bulk
Nanotraatide dispersioonid "targa klaasi"
rakendusteks
7
o Nanotraatide
dispersioonide
elektroforeetiline
manipuleerimine – valguse hajumise ja neeldumise
ristlõike muutmine.
o Dopeerimata
ZnO
nanotraatide
dispersioonid
–
elektriliselt muudetav valguse hajumine
o Dopeeritud ZnO nanotraatide dispersioonid – valguse
hajumine ja neeldumine
o MnO
2
nanotraatide dispersioon – valguse neeldumine
Dopeerimata ZnO nanotraatide dispersioon
8
Electro-optical performance of a 150 µm thick sample
with 0.05 vol% of ZnO NWs in PDMS during several “on-
off” cycles in AC electric field (1 V/µm).
Schematic representation of the electrophoretic ZnO NW
alignment (top). Fixed focus photographs presenting the
visual appearance of a sample containing 0.05 vol% of ZnO
NWs before (left photo) and after (right photo) applying the
electric field (bottom).
A. Šutka, M. Timusk, M. Järvekülg, A. Loot, U. Joost, R. Lõhmusa , K. Saal, Counterintuitive increase in optical scattering
efficiency during negentropic orientational transition in dilute ZnO nanowire suspensions. RSC Advances, 5 (2015),
104149−104154
Dopeerimata ZnO nanotraatide dispersioon
9
A. Šutka, M. Timusk, M. Järvekülg, A. Loot, U. Joost, R. Lõhmusa , K. Saal, Counterintuitive increase in optical scattering
efficiency during negentropic orientational transition in dilute ZnO nanowire suspensions. RSC Advances, 5 (2015),
104149−104154
Change of transmittance of 150 µm thick sample cells filled with 0.02 vol % (a) the kinetics of
alignment under an applied AC field (1 V/µm), represented as change in transmittance of
different suspensions B
Dopeeritud ZnO nanotraatide dispersioon
10
(a) Response of nanowire dispersion to charged surfaces (b)
Schematic illustration of electrostatic charge detecting and a
photograph of a glass vial filled with Zn
0.95
Ni
0.05
O nanowire
colloid in amino-PDMS (0.1 vol.%) before and after
contacting with rubber gloves.
Change in the transmittance spectrum of the
Zn
0.95
Ni
0.05
O NW suspension (0.1 vol% in PDMS) during
applying a uniform electric field.
0.1 V/µm, 100 Hz
A. Šutka, M. Timusk, A. Loot, U. Joost, T. Käämbre, Polarizable nanowire colloids for power free naked eye optical
detection of electrostatic surface charges, Adv. Mater. Technol. (2016) accepted
Dopeeritud ZnO nanotraatide dispersioon
11
Simulated electric field (left) and gradient of electric field strength (right) resulting from the electrostatic charge
on the surface of the glass vial by using finite element method (FEM) simulation. Charge density on the surface
of the glass - 10
-5
C/m2.
Electric field strength of up to 2.06*10
5
V/m is induced in the vicinity of the glass surface inside the dispersion
and electric field gradients of up to 5.2*10
7
V/m
2
.
A. Šutka, M. Timusk, A. Loot, U. Joost, T. Käämbre, Polarizable nanowire colloids for power free naked eye optical
detection of electrostatic surface charges, Adv. Mater. Technol. (2016) accepted
MnO
2
nanowires
Chaotic (C)
Aligned (A)
Time (s)
Tr
ans
mit
tance
Algined state
Chaotic state
Electro-optical response of 0.1 wt% MnO
2
in PDMS
12
MnO
2
nanotraatide dispersioon
Thank you for listening!
13
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