Preparation And Research Of Polyaniline/Carbon Nanostructured Electrochromic Materials Based On Interfacial Covalent Bond

The glass curtainwall in modem buildings occupies more and more proportion of building exterior wall.The glass curtainwall can enhance the architectural aesthetics.While the energy consumptions are increased due to extra requirement of heating and air conditioning.The electrochromic devices can adjust the light and heat entering the room to decrease the energy consumption in different season and under different light condition.Polyaniline(PANI)is a kind of electrochromic materials with high contrast and fast response speed characteristics.But compared with inorganic material,it has low stability,so we intend to prepare the polyaniline/carbon nanocomposite electrochromic materials based on interfacial covalent bond to improve its performance.At the same time,we have studied film formation process using spraying technology.It can be used as the experimental basis for application of PANI based electrochromic materials.In this article,PANI/carbon nanocomposites electrochromic materials based on interfacial covalent bond were prepared by combining of PANI and functionalized carbon nanomaterials including carbon nanotubes(CNTs)and graphene oxide(GO).The materials and morphologies of composites were characterized by SEM,TEM,TGA,FTIR and Raman,The electrochemical and electrochemical performances were tested by Cyclic Voltammetry,Electrochemical Impedance Spectroscopy,UV-vis spectrometer and electrochemical workstation.Finally,spraying technology were used to form large area electrochemical film.The electrochromic properties of sprayed films were tested.The specific experimental results are as follows:(1)First,GO was prepared by the modified Hummers method,then the GO was functionalized with p-phenylenediamine.Finally,functionalized GO and PANI were combined to prepare PANI/GO electrochromic materials.Experimental tests show that GO is evenly distributed with layered structure in the composite material.As compared with PANI,the thermal stabilities of composites are higher.The contrast has 23%enhancement.The coloring/bleaching time is shorter.The charge transfer resistance Rct is decreased.With the increasing of GO loading,the electrochromic properties of composites follow a trend of increasing at first stage and then decreasing.With 3%of GO,the composites possess best electrochromic properties.(2)The CNTs were acidified by the mixed acid,and then the acidified CNTs wre functionalized with p-phenylenediamine.Then,the PANI was compounded with the functionalized CNTs to prepare PANI/CNTs electrochromic materials.The experimental results show that CNTs are embedded by PANI.The composites have better thermal stability,increased contrast and short coloring/bleaching time.With the CNTs loading increasing,the composites'electrochromic properties increase.(3)The spraying technique was used to prepare large area electrochromic film.To optimize the distance and pressure of spraying technique,the influence of spraying parameter on the morphologies of films was investigated.The results show that when the spraying distance is 30cm and the pressure is 0.2MPa,PANI film has homogeneous morphology on ITO substrate.The thickness of film can be increased with increasing of spraying times,while no linear relationship between the thickness and spraying time can be found.Furthermore,the uniformity of film can be deteriorated by increasing of the spraying times.