AC Conductivity of Selectively Located Carbon Nanotubes in Poly(ε-caprolactone)/Polylactide Blend Nanocomposites.
writer：Estrella Laredo, Mario Grimau, Alfredo Bello, Defeng Wu, Yisheng Zhang, Dongpo Lin.
keywords：Conductivity; Polylactide; Poly(ε-caprolactone); Blend; Nanocomposites
source：期刊
Issue time：2010年
Biomacromolecules, 2010, 11(5), 1339-1347.
ABSTRACT:
DC and AC electrical conductivity of bionanocomposites based on the immiscible polymer blend poly(e-caprolactone)/polylactide, (PCL/PLA, w/w 70/30), loaded with multi-wall carbon nanotubes (CNT) were studied in a wide frequency range, 10-3 £ f £107 Hz from 143 to 313 K. The nanofiller concentration ranged from 0 to 4 wt % and it was shown to be selectively located in the PCL phase. The PCL crystallinity degree was not affected by the presence of CNT. The variation of the DC conductivity allowed the determination of the percolation threshold, pc = 0.98 wt %, and the critical exponent t = 2.3 of the scaling law. The linear dependence of showed the existence of tunneling conduction among CNT not yet in physical contact. The temperature independent results indicated a conventional tunnel effect. The AC conductivity of the nanocomposites followed the predictions of the universal dynamic response and the s exponents were determined at low concentrations. Master curves are presented showing the length and temperature-time superpositions.
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http://pubs.acs.org/doi/abs/10.1021/bm100135n