Preparation And Properties Of Polyvinylidene Fluoride/Carbon Nanotube Thermoelectric Materials

Polyvinylidene fluoride(PVDF) is a crystalline polymer, with high mechanical strength, wear resistance, corrosion resistance, high dielectric constant and good processability. Meanwhile, PVDF Peltier(Seebeck) factor is relatively high, good insulation properties, thermoelectric materials has broad application prospects. Low conductivity of poly vinylidene fluoride, inhibited its application. In order to enhance the thermoelectric properties of polyvinylidene fluoride, carry out the following work.(1) PVDF by adding different amounts of multi-walled carbon nanotubes(MWCNT) PVDF/MWCNT thermoelectric thin films with different contents of MWCNT were prepared. Studied its morphology, thermal properties, electrical conductivity and thermoelectric figure of merit of Seebeck coefficient, high power factor. Experimental results show that MWCNT after acidification with PVDF compatibility matrix has a good interface, and can disperse in the PVDF base and MWCNT joined the enhanced conductivity of PVDF, power factor, and thermoelectric figure of merit. When MWCNT filling quantity of 35 wt.% is reached, its conductivity reached 0.149S/cm, thermoelectric figure of merit has reached 2.37x10-4, compared with MWCNT filling quantity for 1WT.% improved by two orders of magnitude.(2) In order to further in the case of low carbon nanotubes filled, enhance the thermoelectric properties of PVDF composite, add small amounts of Ag particles in a PVDF/MWCNT. Test results show that after joining a small number of Ag particle, conductivity of composite films have been enhanced with high power factor and power worth it to improve. When adding 2wt.%Ag after the particle, content of MWCNT 7wt.% PVDF membrane conductance was increased from 6.9×10-3S/cm to 3.87×10-2S/cm. Thermoelectric figure of merit was increased from 2.69×10-5 to 2.55×10-4.(3) Add Ag particles prepared by electrcspinning nano fiber thin films of PVDF/MWCNT, studying its morphology, electrical conductivity, thermal conductivity, Seebeck coefficient, power factor, and thermoelectric figure of merit. Test results showed that fibroblasts films materials can improve the Seebeck coefficient of the material. Containing 2wt.%Ag particles and fibers of 1 wt.% of carbon nanotubes films, the Seebeck coefficient is 323μV/K, while the same proportion non fiber samples Seebeck coefficient 254μV/K. Material after fibre Seebeck coefficient is increased by 27%.