Biomedical Engineering Reference
In-Depth Information
Table 9.2
Superconducting characteristics of nanocomposites based on
Y
1
Ba
2
Cu
3
O
6.97
ceramic (t
press
= 1308C, τ
press
= 4min)
Antioxidant
(5% by
weight of
binder)
Difference in
parameters of
the elementary
cell (
˚
)
Content
of binder
(wt%)
Index
of
oxygen
Binder
T
c
(K) ΔT
c
(K)
HDPE
10
15
92.1
91.8
7.0
7.0
0.0732
0.0719
6.98
6.97
SHMPE
10
15
20
15
15
91.2
91.5
91.8
91.7
91.2
7.0
~
0.0660
0.0703
0.0719
0.0719
0.0708
6.93
6.96
6.97
6.97
6.96
5.0
6.0
6.0
6.0
Irganox 1010
NG-2246
PMMA
10
15
20
15
92.3
93.7
91.7
93.2
8.0
7.0
7.0
6.0
0.0707
0.0710
0.0689
0.0747
6.96
6.96
6.95
6.98
NG-2246
PS
10
15
20
15
92.0
93.1
92.3
93.0
6.0
7.0
8.0
7.0
0.0719
0.0752
0.0703
0.0751
6.97
6.99
6.96
6.99
NG-2246
SPL
Styrene-MMA
(60:40
mole%)
10
15
20
15
91.7
92.3
92.1
92.0
7.0
7.0
7.0
7.0
0.0689
0.0659
0.0666
0.0659
6.95
6.93
6.93
6.93
NG-2246
SPL
styrene-MMA
(80:20
mole%)
10
15
20
15
92.1
91.9
92.6
93.4
8.0
7.0
8.0
~9.0
0.0689
0.0707
0.0739
0.0767
6.95
6.96
6.98
6.998
NG-2246
the initial ceramic, whilst for the acryl and vinyl homo- and copolymers, the
initial temperature of transition to the SC properties is 1-2K higher (Table
9.2). There is no distinct relationship between the amount of ceramic in the
composite, the values of T
c
and
T
c
for the interval of concern, and the
degree of filling of the SC polymer-ceramic materials (80-90 wt%). An
increase of the press load of the composites, up to 200MPa, does not change
the T
c
and
Δ
T
c
values. Furthermore, the addition of antioxidants (5% of the
mass of binder) at the given pressing temperature of the composite does not
notably affect either the ceramic's crystalline lattice structure or the critical
temperatures of transition to the SC state.
As previously indicated, in pressing the polymer-ceramic composites at
200
Δ
C for 30min, the SC properties of the materials are lost. Cutting the
pressing duration down to 4min at the same temperature for composites
based on SHMPE (content of ceramic is 85% by weight) retains the same
8
