Preparation And Application Of Thermochromic And Piezoresistive Sensing Polypyrrole Coated Fabrics

Smart clothing is an important direction for the development of apparel in the further.Thermochromic and flexible sensing fabric are important parts of smart textiles.In the paper,polypyrrole coated fabric was prepared by in-situ polymerization.The conductivity of polypyrrole coated fabric was improved by adding hydrochloric acid as dopant.The stability of polypyrrole coated fabric was improved by polydopamine as surface modification.The thermochromic fabric was prepared by fusible interlining and polypyrrole coated fabric with pressing method.The fusible interlining was covered by thermochromic ink.The flexible piezoresistive sensor with the sandwich structure was prepared by using flexible printed copper film and polypyrrole coated fabric modified by polydopamine.The performance of polypyrrole fabric,thermochromic fabric and piezoresistive sensor was characterized by the thermal field emission scanning electron microscopy,X-ray photoelectron spectroscopy,digital multimeter,fabric thermal performance tester and universal strength tester.The experiment result shows the fabric is covered by polypyrrole with in-situ polymerization.When the time is 80min,the polymerization is the best.The hydrochloric acid was used as a dopant to reduce the electrical resistance of polypyrrole coated fabrics.When the concentration of hydrochloric acid is 0.2,0.4,0.6mol/L and the voltage was 14v,the maximum heating temperature of fabric reaches to 190 ?.The heating temperature of the coated fabric increases with the increase of the applied voltage.The heating temperature and power meet a high linear.The thermochromic fabric is made by this polypyrrole coated fabric and fusible interlining.This thermochromic fabric becomes achromatic when the voltage is added to heat the fabric.The polypyrrole coated fabric modified by polydopamine reduces granules and improves the smoothness of the surface.The piezoresistive sensor is made by this fabric and flexible printed copper film.Under the same condition,the sensitivity of the sensor prepared by the knitted fabric is better than the space fabric.The knitted fabric and space cotton pretreated by polydopamine are used as the substrate of the sensor.The stability effective range increases by 45.79%and 619.44%.Thermochromic fabric and piezoresistive sensor have broad application in smart clothing.