Thermoelectric Properties Of Aniline Oligomer-Block-Polyethylene Glycol-Block-Aniline Oligomer Triblock Copolymers/Carbon Nanotubes

In recent years,in the face of increasingly serious energy crisis and environmental pollution,it is of utmost importance to find a new type of highly efficient energy material.As a functional material that converts heat energy and electric energy,a thermoelectric material can recover waste heat from industrial production and daily life,and can be reused.Thermoelectric materials have a wide prospect of application,and can be applied to waste heat recovery and utilization,temperature difference power generation,temperature control and thermoelectric refrigeration.However,most thermoelectric materials are inorganic materials at present because of their high price,complicated processing technology,or their composition.Rare elements and high toxicity greatly limit the development and application of thermoelectric materials.Therefore,the development of a new type of thermoelectric material with low cost,simple process,and environmental protection has become a major issue that needs to be solved urgently.In this paper,aniline oligomer-oxyethylene-aniline oligomer triblock copolymers were synthesized from diphenylamine and polyethylene glycol as raw materials,and they were composited with carbon nanotubes to prepare oligoaniline oligomers-oxyethylene-aniline oligomers.Triblock copolymer/carbon nanotube composites.The following work was carried out:1)Firstly,dianiline was used as raw material to synthesize aniline oligomers through oxidative coupling.Then,polyethylene glycol was used as middle block to synthesize aniline oligomer-oxyethylene-aniline oligomer triblock copolymers.The synthesized block copolymers were characterized by ¹H NMR spectroscopy,IR spectroscopy?IR?and Raman spectroscopy?Ramin?.Then,the thermoelectric properties of the block copolymers were tested.The Seebeck coefficient and conductivity of the block copolymer materials were-1171?V K^-1 and 10^-2 S cm^-1,respectively.Furthermore,the?ANI?_n-b-PEO-b-?ANI?_n had a p-n transition with the increase of the Seebeck coefficient,and exhibits excellent temperature sensitivity based on the thermoelectric properties,and could prepare excellent temperature sensitive devices.2)?ANI?n-b-PEO-b-?ANI?n/CNTs composites were successfully prepared by ultrasonication.The effect of aniline block copolymers on the electrochemical properties of carbon nanotubes was studied.Infrared spectroscopy?FTIR?and transmission electron microscopy?TEM?were used to characterize the composition and structure of the material.The experimental results showed that the triblock copolymer forms a very thin coating layer on the surface of the carbon nanotubes,and had strong?-?interaction and doping behavior with the carbon nanotubes.A series of electrochemical performance tests including CV,CD and EIS were used to characterize the electrochemical performance of the?ANI?n-b-PEO-b-?ANI?n/CNTs composites.Significant improvement,in which?ANI?₁₆-b-PEO-b-?ANI?₁₆/CNTs had a specific capacitance of 477 F/g,and the electrochemical performance was very good.3)By measuring the thermoelectric properties of the?ANI?n-b-PEO-b-?ANI?n/CNTs composites,it was found that both conductivity and Seebeck coefficient showed a dependence on temperature,and gradually increased with increasing temperature.As it increased,its power factor also increased.The conductivity test results showed that compared to the pure block copolymer conductivity of 10^-2 S/cm,the conductivity of the aniline block copolymer increased significantly after doping carbon nanotubes at room temperature,The conductivity of?ANI?₁₆-b-PEO-b-?ANI?₁₆/CNTs is 798.46 S/cm,which indicated very good conductance and an increasing trend with increasing temperature,while the Seebeck coefficient decreased to 18²3?V K^-1;?ANI?₁₆-b-PEO-b-?ANI?₁₆/CNTs composites exhibited higher power factor.