Preparation And Properties Of Polyaniline And Its Derivatives Electroinduced Emissivity Thin Films

Electrochromic material is a kind of material whose optical characteristic response changes significantly by applying electrical signals from outside.The changes of optical characteristics of materials include the reflectivity,transmittance,infrared emissivity and color change of materials.At present,electrochromic materials are also widely used in spacecraft intelligent thermal control,electrochromic materials such as polyaniline,polypyrrole,etc.can be prepared into intelligent thermal control coating,spread on the surface of spacecraft,compared with the traditional thermal control mode,not only improve the safety of spacecraft,but also effectively reduce the quality of spacecraft.In this paper,sulfuric acid doped polyaniline films were prepared by electrogalvanic method.In addition,polyaniline binary copolymerization films were prepared by copolymerization of o-halogenated aniline and aniline monomers to modify the pure polyaniline films,and the properties of the prepared polyaniline and o-halogenated aniline binary copolymerization films were studied and analyzed.After determining the optimal preparation process of the two types of monolayer films,two types of electroinduced emissivity devices were assembled,and the performance differences of the two types of devices were comprehensively compared.Polyaniline films with cyclic discoloration were successfully prepared on gilt nylon films by constant current method.When the concentration ratio of sulfuric acid to aniline monomer is 6:1,the film is in good condition.The microstructure of polyaniline was found to be reticular crosslinked by the morpHology characterization of the films.The electrochemical properties of polyaniline prepared under different polymerization energies were tested.It was found that the quinone structure and benzene structure of polyaniline changed alternately during the cycle.The infrared emittance of polyaniline film was tested,and it was found that the adjustment range of polyaniline film in the infrared band was the largest when the polymerization electricity was 3.0c,up to 31%.Binary copolymers of polyaniline and its derivatives were prepared by means of constant-current polymerization.When the ratio of sulfuric acid to aniline monomer and aniline monomer is 10:1:2,the prepared film is in good condition.By comparing the SEM pHotos of three kinds of binary copolymer films,it can be found that the three kinds of films have obvious differences in microstructure.It is found that the prepared binary copolymer films show different color changes in the visible band under different external voltage.In the infrared band,the regulation ability of infrared emittance of binary copolymer films is also different.It was found that when the polymerization electricity was 4.8c,the rate of energy change of polyaniline and o-fluoroaniline binary copolymerized films was the largest,up to 34%.Based on the electrochromic films of polyaniline and its derivatives,the electrochromic properties,cyclic stability and infrared variational emissivity of the assembled devices were analyzed and studied.Compared with the regulation ability of infrared emissivity of monolayer,the regulation range of binary copolymerized film is larger than that of pure polyaniline monolayer.It was found that the devices prepared by using the binary monolayer of polyaniline and o-fluoroaniline with high infrared emissivity regulation ability have poor infrared emissivity regulation ability and poor cycling performance.The eletropic emittance device assembled by pure polyaniline film has a good regulation ability for infrared emittance.