FIGURE 4 Pseudocolor thermal images of the front view of the
MMT-PI subjected to the alcohol lamp flame at different times (0
s~90 s). Time dependence of the center of the cotton
ball temperature (last one).
The cotton ball was selected as the observation object, where
C1 is the periphery and P1 is the center
of the cotton ball, respectively. The maximum temperature of
C1 was detected to be close to 70 oC
when the alcohol lamp was once lit. This may be due to the small
thickness of MMT-PI and the short longitudinal distance of heat
transfer, which makes it easier to reach the high temperature of the
MMT-PI mentioned above. Later, the temperature gradually decreased,
probably due to the increased heat conduction along the plane direction.
Therefore, the temperature of C1 dropped to about 45oC, subsequently kept at a constant value of no more
than 50 °C. During the recorded 90 s, the cotton ball was not ignited.
On the contrary, both C1 and P1 reached
the maximum temperature after contact with the flame for 33 s for DABPPI
(Fig. S4 in Supporting Information), and the cotton ball
ignited immediately upon exposure to the flame and burned off in 9 s.