Experimental and computational conductivity study of multilayer graphene in polypropylene nanocomposites
Por:
del Castillo, Roxana M., del Castillo, Luis F., Calles, Alipio G., Vicente, Compan
Publicada:
21 jul 2018
Resumen:
We study the electric conductivity of compounds formed by multilayer
graphene in polypropylene. Our study makes a comparative analysis
between the experimental and computational results. To obtain an
experimental measurement of the electronic properties, we deposited
multilayer graphene (MLG) nanoparticles over a polypropylene matrix. The
deposition was made over several stages, in which we added to the
polymer matrix different percentages of MLG nanoparticles using the melt
compounding technique, and we studied the conductivities of the
nanocomposites by means of electrochemical impedance spectroscopy (EIS).
The second part consists of computational calculations, in which we
studied the electronic properties of a graphene sheet under a
polypropylene molecule with different slabs in the monomer. In both
analyses, there is a strong percolation phenomenon with a percolation
threshold of around 18% of the MLG nanoparticles. Before the
percolation threshold, the charge carriers are constrained in the
polypropylene molecule, making the system an insulating material and
creating p-type doping. After the percolation threshold, the charge
carriers are constrained in the graphene, making the system a conductor
material and creating n-type doping with conductivity values of around
20 S m(-1). This phenomenon is a consequence of a change in the
mechanism of charge transfer in the interface between the polypropylene
molecule and graphene sheet. To describe the charge transfer mechanism,
it is necessary to consider the quantum effect. The incorporation of the
quantum effects and the percolation phenomenon make it possible for the
theoretical conductivity to be close to the conductivity measured
experimentally.
Filiaciones:
del Castillo, Roxana M.:
Univ Nacl Autonoma Mexico, Dept Fis, Fac Ciencias, Mexico City 04510, DF, Mexico
del Castillo, Luis F.:
Univ Nacl Autonoma Mexico, Dept Polimeros, Inst Invest Mat, Apdo Postal 70-360, Mexico City 04510, DF, Mexico
Calles, Alipio G.:
Univ Nacl Autonoma Mexico, Dept Fis, Fac Ciencias, Mexico City 04510, DF, Mexico
Vicente, Compan:
Univ Politecn Valencia, ETSII, Dept Termodinam Aplicada, Campus Vera S-N, E-46022 Valencia, Spain
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