TY - JOUR
T1 - Rheological and conductivity percolations of syndiotactic polystyrene composites filled with graphene nanosheets and carbon nanotubes
T2 - A comparative study
AU - Chiu, Yen Chang
AU - Huang, Chien Lin
AU - Wang, Chi
N1 - Funding Information:
The authors are grateful to the Ministry of Science and Technology of Taiwan (ROC) for the research grant ( NSC-101-2221-E-006-069-MY2 ) to support this work.
Publisher Copyright:
© 2016 Elsevier Ltd
Copyright:
Copyright 2017 Elsevier B.V., All rights reserved.
PY - 2016/10/6
Y1 - 2016/10/6
N2 - Two-dimensional graphene nanosheets (GNSs) and one-dimensional carbon nanotubes (CNTs) possess large aspect ratios but different geometries. In this study, syndiotactic polystyrene (sPS) composites reinforced with different contents of GNSs were prepared via a solution coagulation method. The dispersion and microstructure of GNSs in sPS were confirmed via transmission electron microscopy and atomic force microscopy. Rheological and electrical properties of sPS/GNS composites were investigated to reveal the effect of filler concentration, and the results were compared with those of sPS/CNT composites. Percolation scaling laws were applied to the magnitudes of storage modulus and electrical conductivity to determine the threshold concentration and corresponding exponent. The sPS/GNS and sPS/CNT composites possess a similar percolation threshold for melt elasticity and solid conductivity. However, the rheological threshold (∼0.1 vol%) is distinctly lower than the conductivity threshold (∼0.5 vol%) because of the formation of polymer–nanofiller hybrid network. The exponents for rheological and electrical percolations of sPS/GNS composites are determined as 4.12 and 4.71, respectively, which are higher than the corresponding values of 2.64 and 2.87 for sPS/CNT composites. The derived exponents indicate that the 2D GNS-related network is more effective than the 1D CNT-related network for enhancing the melt elasticity and solid conductivity of sPS matrix.
AB - Two-dimensional graphene nanosheets (GNSs) and one-dimensional carbon nanotubes (CNTs) possess large aspect ratios but different geometries. In this study, syndiotactic polystyrene (sPS) composites reinforced with different contents of GNSs were prepared via a solution coagulation method. The dispersion and microstructure of GNSs in sPS were confirmed via transmission electron microscopy and atomic force microscopy. Rheological and electrical properties of sPS/GNS composites were investigated to reveal the effect of filler concentration, and the results were compared with those of sPS/CNT composites. Percolation scaling laws were applied to the magnitudes of storage modulus and electrical conductivity to determine the threshold concentration and corresponding exponent. The sPS/GNS and sPS/CNT composites possess a similar percolation threshold for melt elasticity and solid conductivity. However, the rheological threshold (∼0.1 vol%) is distinctly lower than the conductivity threshold (∼0.5 vol%) because of the formation of polymer–nanofiller hybrid network. The exponents for rheological and electrical percolations of sPS/GNS composites are determined as 4.12 and 4.71, respectively, which are higher than the corresponding values of 2.64 and 2.87 for sPS/CNT composites. The derived exponents indicate that the 2D GNS-related network is more effective than the 1D CNT-related network for enhancing the melt elasticity and solid conductivity of sPS matrix.
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U2 - 10.1016/j.compscitech.2016.08.016
DO - 10.1016/j.compscitech.2016.08.016
M3 - Article
AN - SCOPUS:84983738578
SN - 0266-3538
VL - 134
SP - 153
EP - 160
JO - Composites Science and Technology
JF - Composites Science and Technology
ER -