As shown in Fig. 4b and d, the ln [1 − P(tp)/P(∞)] versus tp plots exhibit a good linearity for CNT/EVA10 and CNT/EVA25 system. From the intercept and the slope of the lines, the values of P(0)/P(∞) and c/η are also calculated and listed in Table 1. The solid curves between Φ and 1/tp in Fig. 4a and c suggest Eq. (3) can fit the experimental results well. It is found that Φ∗ is about 0.19 vol.% for CNT/EVA10 system in Table 1, while Φ∗ of CNT/EVA25 system rises to 0.27 vol.%. The results indicate that, theoretically, the conductive network can be more easily built in polymer matrix with a lower polarity.
The reorganization velocity (V(t)) of the CNTs for the conductive network formation can be obtained by V(t) = dP(t)/dt. According to Eq. (4), V(t) is expressed as