Preparation And Property Research On Thermoelectric Materials Of Poly(3,4-ethylenedioxythiophene)Nanostructure And Carbon Nanoparticles Aerogels

As energy shortage and low resource utilization problem increasingly prominent,thermoelectric materials,which can realize the conversion of heat energy and electric energy,have attracted extensive attention.Organic conductive polymers and high performance carbon nanoparticles have become the research focus of thermoelectric materials.In this dissertation,the thermoelectric materials including nanostructured conducting polymers and carbon nanoparticles aerogels were synthesized and their thermoelectric properties were studied.The main contents include the following points:1.Poly(3,4-ethylenedioxythiophene)(PEDOT)nanorods were synthesized by polymerization in an aqueous surfactant solution or reverse micellar solution and their thermoelectric performance was measured.Then the PEDOT nanorods obtained from reverse micelle method were treated with sulfuric acid solution,followed by chemical reduction with different time by using sodium sulfite solution.It was found that after post-treatment,the oxidation level and doping level of PEDOT nanorods can be effectively adjusted and the regularity and polarization state of the molecular chain are improved,thus improving the thermoelectric properties of PEDOT nanorods.2.The hybrid aerogels were prepared by chemical reduction of graphene oxide and acidified single-walled carbon nanotubes(a-SWCNT).The porosity of the aerogel material and the thermoelectric parameters were tested for the materials.It was found that 1)the special network structure of aerogels provides multiple paths for electronic transmission,thus improving the conductivity;2)the rich interface makes the aerogel show better energy filtering effect,and the Seebeck coefficient increases;3)the high porosity can effectively restrain the phonon transmission and the aerogel materials have extremely low thermal conductivity.Therefore,the as-synthesized aerogel materials have excellent thermoelectric properties.Moreover,the aerogel materials exhibit high absorption efficiency for different organic solvents and good cycling performance for low boiling point organic solvents.3.The N type thermoelectric materials Mo S2/SWCNT was prepard by acid treatment for SWCNT,introduction of carboxylic acid groups on the surface of SWCNT and reduction using hydrazine hydrate as reducing agent and ammonium molybdate as the precursor of Mo S2.Due to the effective surface modification and doping of SWNT,the conductivity of single-walled carbon nanotubes is changed from hole conduction to electron conduction,which is from P type semiconductor to N type semiconductor.The Mo S2/a-SWCNT has high stability and the thermoelectric properties of the materials cannot decrease with time in the air.