Electronic Supplementary Material (ESI) for Physical Chemistry Chemical Physics.
This journal is © the Owner Societies 2016
Supporting Information for
Tunable thermal transport and mechanical
properties of graphyne heterojunctions
Shuaiwei Wang a,b, Yubing Si a,b, Jinyun Yuan a,b, Baocheng Yang a,b, Houyang
Chenc*
a Henan
provincial key laboratory of nano-composite and applications, Huanghe
Science and Technology College, Zhengzhou, Henan 450006, China
bInstitute
of Nanostructured Functional Materials, Huanghe Science and Technology
College, Zhengzhou, Henan 450006, China
cDepartment
of Chemical and Biological Engineering, State University of New York
at Buffalo, Buffalo, New York 14260-4200, USA
________________
* To whom correspondence should be addressed. Email: [email protected]
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1. Model of GY sheets
l1
l3
l2
l2
l1
l3
l2
l1
y
x
(a)
l2
l3
(b)
l1
l4
l2
l4
(d)
l1
l3
(e)
(c)
l3
l1
l2
(f)
Figure S1 . The geometric structures of the 2D graphyne allotropes: (a) -, (b) -, (c)
-, (d) δ-, (e) 6,6,12- and (f) 14-graphyne sheets. l1, l2, l3 and l4 are the bond length.
The x and y axis along the zigzag and armchair directions, respectively.
2. Thermal conductivity of GY sheets
The structures of δ-GY is shown in Fig. S2(a). The outmost atoms highlighted
with blue are defined as “cold slab”, and the middle atoms highlighted with red are
defined as “hot slab”. Fig. S2(b) shows the temperature profile of δ-GY. The
temperature profile is symmetrical, while the nonlinear temperature profile occur near
cold and hot regions. The linear portion (solid red line in Fig. S2b) is selected to
calculate the temperature gradient. The thermal conductivity for -GY with 20 nm ×
20 nm is 18.7 W/mk in the armchair direction and 18.6 W/mk in the zigzag direction,
which are consistent with the previous MD results1 using Airebo potential (17.66
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W/mk in both armchair and zigzag directions). Fig. S2(c-d) shows the curve of
inverse of thermal conductivity versus the inverse of length.
(c)
1/ (mK/W)
(a)
0.14 Armchair
-GY
6,6,12-GY
0.12
-GY
-GY
14-GY
0.10
-GY
1/=0.59243*1/lx+0.06377
1/=0.499333*1/lx+0.06103
1/=0.78374*1/lx+0.05255
0.08
0.06
1/=0.4495*1/lx+0.03048
1/=0.48289*1/lx+0.05774
1/=0.78857*1/lx+0.04212
0.04
0.00
0.02
0.04
0.06
0.08
0.10
0.12
-1
1/Lx (nm )
(b)
(d)
360
MD
Fitting
320
1/ (mK/W)
Temperature (K)
340
300
280
260
240
0.14 Zigzag
-GY
6,6,12-GY
0.12
-GY
-GY
0.10
14-GY
-GY
0.08
1/=0.60864*1/ly+0.06316
1/=0.31437*1/ly+0.01983
1/=0.68147*1/ly+0.05039
0.06
0.04
1/=0.43556*1/ly+0.03095
1/=0.43168*1/ly+0.04180
1/=0.62287*1/ly+0.04545
0.02
0
20
40
60
Position (nm)
80
100
0.00
0.02
0.04
0.06
0.08
0.10
0.12
-1
1/Ly (nm )
Figure S2. (a) Schematic diagram of the NEMD model for δ-graphyne at the
temperature T = 300 K. The atoms highlighted with blue and red represent the cold
and hot regions, respectively. (b) The corresponding temperature profile (the red line
indicated the temperature gradient). The inverse of thermal conductivity (1/κ) versus
the inverse of length (1/lb) for six graphynes in the armchair (c) and zigzag direction
(d). lx and ly indicated the heat flux direction along the x and y axis, respectively.
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Figure S3. Stress-strain curves of (a) γ-GY/14-GY/γ-GY, (b) α-GY/14-GY/α-GY and
(c) 6,6,12-GY/14-GY/6,6,12-GY sheets with uniaxial tension along the armchair and
zigzag directions at various temperatures from 1 K to 1200 K. The percentage of each
graphyne in the GYHJ is approximately 50%.
References
1.
Y. Zhang, Q. Pei and C. Wang, Comp. Mater. Sci., 2012, 65, 406-410.
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