The effect of nanotube surface oxidation in the electrical response of MWCNT / PVDF nanocomposites

Carbon nanotubes / poly(vinylidene fluoride) composites were prepared using CNT with different oxidation and thermal treatments. The oxidation procedure leads to CNT with the most acidic characteristics that lower the degree of crystallinity of the polymer and contribute to a large increase of the dielectric constant. The surface treatments, in general, increase percolation threshold and decrease conductivity, but, on the other hand, are able to promote the nucleation of the electroactive phase of the polymer, which is suitable for the use of PVDF in sensors, actuators and other smart materials applications. Finally, the surface treatments do not seem to affect CNT interaction among them, reaching similar degrees of dispersion in all cases, as shown by the SEM results. The maximum value of the dielectric constant is ~630. It is demonstrated that the composite conductivity can be attributed to a hopping mechanism that is strongly affected by the surface treatment of the CNT.

[1]  Robert B. Griffiths,et al.  Dependence of Critical Indices on a Parameter , 1970 .

[2]  Vinay Ambegaokar,et al.  Hopping Conductivity in Disordered Systems , 1971 .

[3]  S. Kirkpatrick.  Percolation and Conduction , 1973 .

[4]  K. Tashiro,et al.  Molecular Vibrations of Three Crystal Forms of Poly(vinylidene fluoride) , 1975 .

[5]  J. W. Essam,et al.  Percolation theory , 1980 .

[6]  S. Alexander,et al.  Density of states on fractals : « fractons » , 1982 .

[7]  E. Kong,et al.  Developments in crystalline polymers edited by D. C. Bassett , 1983 .

[8]  Isaac Balberg,et al.  Excluded volume and its relation to the onset of percolation , 1984 .

[9]  S. Redner,et al.  Introduction To Percolation Theory , 2018 .

[10]  S. Iijima.  Helical microtubules of graphitic carbon , 1991, Nature.

[11]  Saibal Roy,et al.  Broadband ac conductivity of conductor-polymer composites , 1998 .

[12]  J. Figueiredo,et al.  Modification of the surface chemistry of activated carbons , 1999 .

[13]  J. Mano,et al.  FTIR AND DSC STUDIES OF MECHANICALLY DEFORMED β-PVDF FILMS , 2001 .

[14]  M. Monthioux,et al.  Sensitivity of single-wall carbon nanotubes to chemical processing: an electron microscopy investigation , 2001 .

[15]  N. Baskaran.  Conductivity relaxation and ion transport processes in glassy electrolytes , 2002 .

[16]  Chang Seoul,et al.  Electrospinning of poly(vinylidene fluoride)/dimethylformamide solutions with carbon nanotubes , 2003 .

[17]  Ali Akbar Yousefi,et al.  Conformational changes and phase transformation mechanisms in PVDF solution-cast films , 2004 .

[18]  Sameet Sreenivasan,et al.  Effect of disorder strength on optimal paths in complex networks. , 2004, Physical review. E, Statistical, nonlinear, and soft matter physics.

[19]  Tunneling-percolation origin of nonuniversality: Theory and experiments , 2005, cond-mat/0503647.

[20]  Stanislaus S. Wong,et al.  Covalent Surface Chemistry of Single‐Walled Carbon Nanotubes , 2005 .

[21]  Z. Dang,et al.  Carbon nanotube composites with high dielectric constant at low percolation threshold , 2005 .

[22]  Tsu-Wei Chou,et al.  Nanocomposites in context , 2005 .

[23]  Jean-Christophe Charlier,et al.  Electronic and transport properties of nanotubes , 2007 .

[24]  Z. Dang,et al.  Influence of aspect ratio of carbon nanotube on percolation threshold in ferroelectric polymer nanocomposite , 2007 .

[25]  G. Kim,et al.  Structures and Physical Properties of Carbon Nanotube Reinforced PVDF Composites , 2007 .

[26]  Yi Yin,et al.  Giant Dielectric Permittivities in Functionalized Carbon-Nanotube/ Electroactive-Polymer Nanocomposites† , 2007 .

[27]  Yongjin Li,et al.  Ultrahigh-shear processing for the preparation of polymer/carbon nanotube composites , 2007 .

[28]  Zhi-Min Dang,et al.  Effect of tensile strain on morphology and dielectric property in nanotube/polymer nanocomposites , 2007 .

[29]  J. Figueiredo,et al.  Characterization of Active Sites on Carbon Catalysts , 2007 .

[30]  S. Hwang,et al.  Physical Properties of Multi-Walled Carbon Nanotube-Filled PVDF Composites Prepared by Melt Compounding , 2007 .

[31]  Xuehong Lu,et al.  Electrospinning of polyvinylidene difluoride with carbon nanotubes: synergistic effects of extensional force and interfacial interaction on crystalline structures. , 2008, Langmuir : the ACS journal of surfaces and colloids.

[32]  Xili Gao,et al.  Large dielectric constant of the chemically functionalized carbon nanotube/polymer composites , 2008 .

[33]  W. Bauhofer,et al.  A review and analysis of electrical percolation in carbon nanotube polymer composites , 2009 .

[34]  Z. Ounaies,et al.  Characterization of Solution‐Processed Double‐Walled Carbon Nanotube/Poly(vinylidene fluoride) Nanocomposites , 2008 .

[35]  J. G. Rocha,et al.  The effect of fibre concentration on the α to β-phase transformation, degree of crystallinity and electrical properties of vapour grown carbon nanofibre/poly(vinylidene fluoride) composites , 2009 .

[36]  Xili Gao,et al.  Temperature dependence of the electrical properties of the carbon nanotube/polymer composites , 2009 .

[37]  Weitao Zheng,et al.  Electrical conductivity of poly(vinylidene fluoride)/carbon nanotube composites with a spherical substructure , 2009 .

[38]  Senentxu Lanceros-Méndez,et al.  α to β Phase Transformation and Microestructural Changes of PVDF Films Induced by Uniaxial Stretch , 2009 .

[39]  R. Vaia,et al.  Low percolation transitions in carbon nanotube networks dispersed in a polymer matrix: dielectric properties, simulations and experiments , 2009, Nanotechnology.

[40]  Influence of fiber aspect ratio and orientation on the dielectric properties of polymer-based nanocomposites , 2010 .

[41]  Ying‐Ling Liu,et al.  Functionalization of multi-walled carbon nanotubes with non-reactive polymers through an ozone-mediated process for the preparation of a wide range of high performance polymer/carbon nanotube composites , 2010 .

[42]  Yang Shen,et al.  Physical Properties of Composites Near Percolation , 2010 .

[43]  J. Figueiredo,et al.  Influence of the surface chemistry of multi-walled carbon nanotubes on their activity as ozonation catalysts , 2010 .

[44]  Ricardo Simões,et al.  Applying complex network theory to the understanding of high-aspect-ratio carbon-filled composites , 2011 .

[45]  S. Lanceros‐Méndez,et al.  Nucleation of the Electroactive γ Phase and Enhancement of the Optical Transparency in Low Filler Content Poly(vinylidene)/Clay Nanocomposites , 2011 .

[46]  S. Lanceros‐Méndez,et al.  Effect of the carbon nanotube surface characteristics on the conductivity and dielectric constant of carbon nanotube/poly(vinylidene fluoride) composites , 2011, Nanoscale research letters.

[47]  J. Skinner,et al.  Nanotube surface functionalization effects in blended multiwalled carbon nanotube/PVDF composites , 2011 .

[48]  G. Barra,et al.  Electrical and rheological percolation in poly(vinylidene fluoride)/multi‐walled carbon nanotube nanocomposites , 2011 .

[49]  S. Lanceros‐Méndez,et al.  The influence of matrix mediated hopping conductivity, filler concentration, aspect ratio and orientation on the electrical response of carbon nanotube/polymer nanocomposites , 2011 .