Preparation And Properties Of Multi-walled Carbon Nanotubes/4-amido-phthalocyanine-mental Poly (Viriylidene Fluoride) Composites With High Dielectric Constant

With the continuous development of human society, the human demand forelectricity storage materials has been continuously improved. Therefore, thepreparation of a dielectric material such as a high dielectric constant, low loss andalso have high-temperature stability, and good workability become a research hotspotrecently. Preparing a high dielectric constant composites in the usual practice of thecomposite material is a particle diameter of100nm of the inorganic particles is filledin to the polymer matrix, this polymer composite materials have a wide range ofapplication in the field of automobiles, electronics, plug-in type such as a capacitorapplication. In recent years, multi-walled carbon nanotubes （MWCNTs） ashigh-performance nanoscale carbon materials has been extensive research andapplication. The multi-walled carbon nanotube is a graphite type material curled intoa the circular tubular carbon material, as compared with the conventional inorganicfiller, in addition to having good electrical and thermal properties, good can enhancethe mechanical properties of the material. The application of carbon nanotubes inpolymer nanocomposites major obstacle to large aspect ratio particles can easilyintertwined within the matrix reunion, so how carbon nanotubes are uniformlydispersed in the matrix material is a research focus.In this paper, the MWCNTs was functionalized through physic adsorption andchemical graft. The functionalized MWCNTs was mixed with PVDF and analysis itelectric, morphology and thermal properties.Firstly, the Ï€-Ï€ stacking effect was employed to form a coating of4-amido-phthalocyanine copper （4NH₂-CuPc） on carboxylic oxidized multi-walledcarbon nanotubes （MWCNTs1） and to fabricate MWCNT/4NH₂-CuPc composites.These composites were added to a matrix of poly（vinylidene fluoride）（PVDF） forproducing MWCNT/4NH₂-CuPc/PVDF composites. X-ray photoelectronspectroscopy （XPS） and transmission electron microscopy （TEM） analyses were usedto confirm the coating of4NH₂-CuPc. This insulated coating can be controlled by the solvent concentration. Moreover, thermogravimetric analysis （TGA） showed thatalmost64%of4NH₂-CuPc was fixed on the surface of MWCNTs. The coatedMWCNTs/PVDF composites displayed more outstanding dielectric properties thanthe MWCNTs/PVDF composites. At1kHz, composites with9wt%MWCNTs and64%of adsorbed4NH₂-CuPc with a MWCNTs:4NH₂-CuPc mass ratio of1.5:1showed a large dielectric constant of3200and a dielectric loss of only2.1. Theseoutstanding dielectric properties can be attributed to the excellent dispersion ofMWCNTs, the shielding effect of the insulated coating, and a huge number ofmini-capacitors.Secondly, the4-amido-phthalocyanine copper （4NH₂-CuPc） was grafted onsurface of carboxylic multi-walled carbon nanotube （MWCNTs） to fabricate theMWCNTs-4NH₂-CuPc by amido link. The MWCNTs and4NH₂-CuPc/poly（vinylidene fluoride）（PVDF） composites was fabricated by mixing the solutionof fillers and PVDF. X-ray photoelectron spectroscopy （XPS） and transmissionelectron microscope （TEM） showed that4NH₂-CuPc had been introduced on surfaceof MWCNTS. Electron spin resonance spectrometer （ESR） showed that the structureof Ï€-Ï€ conjugated electron of MWCNTs and4NH₂-CuPc had not been changed by theintroduction of amido linkage. The thermal stability of4NH₂-CuPc had beenenhanced through chemical functionalization. The modify also change the dielectricproperties of MWCNTs, the loss of MWCNTs-4NH₂-CuPc/PVDF composites wasjust0.06and dielectric constant was23at1KHz, which can be attributed that organiclayer promotes the dispersion of MWCNTs and hinder electron transporting betweenfillers.