The Preparation And The Characteristic Analysis Of Electrochromic Fabric Based On Polyaniline

With the development of science and technology, intelligent textile is not only inthe conception but also quickly into the practical phase. They are widely applied tothe information, energy, electronic, military, daily life and other areas. Electrochromicfabrics can be developed when combined with electrochromic technology, which canbe widely used into all kinds of intelligent textile with color response behaviour.Electrochromic fabrics will bring great academic and industrial value. At the sametime, they will promote the development of the intelligent materials.Polyaniline will be prepared as the color-changed material. And it will bediscussed about its conductive and doping mechanism, the synthesis procession aswell as coating composite skill; Copper coated fabric is the cathode material ofelectrochromic device, if it is combined with polyaniline, electrolyte and conductivepole, electrochromic fabric will be obtained in a form of flexible electrochromicdevices in good conductivity and excellent electrochromic. The preparation andperformance of each layer will also be researched.When the working voltage ischanged, the phenomenon and behaviour of electrochromic fabric also change. One ofthe most important job of this article is to character the morphological structure, testand analysis various performance of the electrochromic fabric. The synthesisprocession of polyaniline, coating technology, structure design, choice of conductivefabric and encapsulation procession all have great influence on electrochromicfabric.The paper consists of four parts:1) Polyaniline emulsion is made by the method of chemical polymerization. Theoptimum reaction conditions is the molar ratio n （An/DBSA/APS）=1:1.5:1.5and the reaction temperature is from10to15℃resulted to the experiments. Then, it will becoated on the ITO conductive films in order to investigate polyaniline electrochromicperformance when put in the0.1mol/L HCl solution. Circulation current-voltagecurve shows that,the structure of polyaniline occurs from reduction state to oxidationstate with the rise of voltage between-1.5¹.5voltage range. and at the same time,colors of it change from yellow to green and then to blue.2)Electrolyte is an important part of the electrochromic device, and it conductsion and blocks electronic between electrochromic layer and ion storage layer.GPEbased on PMMA has high conductivity, specular transmittance, stablethermodynamics and electrochemical performance etc. When PMMA is dissolved inLiClO₄-PC solution, transparent and uniformity gel will be obtained at roomtemperature, and the ion conductivity is0.692×10-³S/cm. High molecular weight willnot only improve the viscosity of the gel but also can keep high conductivity, highestcontent of PMMA is around23%.3) Flexible electrochromic device has wider prospects compared with traditionalelectrochromic device. However, the selection of flexible transparent electrodes andthe packaging of each material restrict its preparation and application. ITO conductivefilm would be chosen as transparent conductive layer, polyaniline used aselectrochromic layer and ion storage layer, and PMMA based gel electrolyte appliedas ionic conduction layer for the preparation of the symmetric structure flexibleelectrochromic devices. Series of electrochemical performance testing such as theelectronic scanning electron microscopy （SEM）, ultraviolet spectrum, circulationcurrent-voltage and electrochemical spectrum etc would be devoted into theexperiment.4) Electrochromic device （ECD） generally has five layers. Two transparentconductive layers are located in the outside, electrochromic layer and ion storagelayer are the times outer, ionic conduction layer is in the middle of ECD.Electrochromic fabric can be prepared when one of transparent conductive layer isreplaced by conductive fabric and the structure of ECD is designed anew. Conductivefabric is flexible, lightweight and wearable as ECD cathode. Copper conductive fabric will be used as cathode material in the ECD, and polyaniline electrochromic fabricwill be obtained in the experiment. Series of electrochemical performance testingwould be devoted into the experiments.