Electronic Supplementary Materials
Effects of nm-size Laponite discs on thermal conductivity and specific heat of water and ice, and the gelation time
Junchun Yu1, Ove Andersson1*, and G. P. Johari2
1
Department of Physics, Umeå University, 901 87 Umeå, Sweden
2
Department of Materials Science and Engineering, McMaster University, Hamilton, Ontario, L8S 4L7, Canada
* E-mail: ove.andersson@physics.umu.se
Telephone: +46-90-7865034
Fax: +46-90-7866673
Figure S1 shows the temperature effect on the macroscopic flow of the gel. The solution of 3.2 wt% sample
obtained higher viscosity in shorter time than 2.8 wt% sample at the same temperature, e.g. at 310 or 336 K. This
indicated the 3.2 wt% sample gels faster than 2.8 wt% sample. Moreover, the 2.8 wt% and 3.2 wt% sample gels
faster at elevated temperature than at room temperature.
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Figure S1: Images of studies of temperature effect on the macroscopic flow of the gel. (a) initial state of 2.8 wt%
and 3.2 wt% sample, (b) the 2.8 wt% and 3.2 wt% samples aged at 336 K for 3.5 h. These samples aged at 310 K for
7.5 h (c) and 336 K for 7.5 h (d).
Figure S2 shows the plots of κ, ρCp and temperature against time of 3.2 wt % (a, b, c) Laponite dispersion at 349
K. The plots show the κ and ρCp are almost constant at high temperature with fluctuation by ± 1 K. This indicates
that if there is thermal effect on gel formation, it is too small to be observable within ± 0.1 K.
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-1 -1
 (W.m .K )
-3 -1
Cp (MJ.m .K )
Temperature (K)
(a)
3.2 wt% Laponite/water dispersion
at 349 K
0.680
0.677
(b)
3.69
3.66
3.63
349.0
(c)
348.5
348.0
0
5
10
15
Time (Hours)
20
25
Figure S2: The (a) κ, (b) ρCp and (c) the temperature of 3.2 wt % Laponite dispersion in water measured at 1 bar
pressure at 349 K are plotted against time during the course of their homogenization to thixotropic states.
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