Preparation And Properties Of Keratin-containing Composite Piezoelectric Fiber Membranes

Piezoelectric materials are considered as intelligent materials because they can convert the mechanical pressure acting on them into electrical signals(called direct piezoelectric effects)and electrical signals into mechanical signals(called reverse piezoelectric effects).In recent years,it has been widely concerned by researchers.Protein piezoelectric material is a kind of biological piezoelectric material,which is different from the traditional piezoelectric material,so it has unique research value.Protein piezoelectric materials have become a research hotspot because of their wide sources,inherent biocompatibility,biodegradability and mechanical durability.In this paper,the composite piezoelectric materials containing keratin were prepared by electrospinning with polyvinylpyrrolidone(PVP),polyester(PET)and polyacrylonitrile(PAN)Firstly,the effects of keratin/PVP ratio and spinning speed on the piezoelectric properties of keratin/PVP composite fiber membrane were studied.Through FTIR,mechanical properties,piezoelectric properties and stability tests,the reasons for the change of piezoelectric properties were studied.The results show that the composite films have piezoelectric properties because of the addition of keratin.When the ratio of keratin to PVP is 4:1 and the spinning speed is 100 mm/s,the piezoelectric properties are the best.The effects of film area,pressure and pressing frequency on the performance of piezoelectric components were also studied.The results show that the larger the sample film area,the greater the pressure and the higher the pressing frequency,the greater the piezoelectric voltage output.Secondly,the composite fiber membrane was prepared by blending keratin and pet.The effects of the ratio of keratin/PET and humidification on the piezoelectric properties of the composite film were studied.At the same time,the keratin/PET piezoelectric sensor was prepared.When the ratio of keratin to pet was 6:1,the piezoelectric properties of the composite fiber membrane were the best.Through SEM,mechanical properties test and FTIR analysis,it was confirmed that the piezoelectric property of keratin was related to the ?-helix structure.Humidification treatment restored the ?-helix stretching into ?-fold conformation in keratin.The keratin/PET piezoelectric sensor has good stability and sensitivity of 56.7 m V/N,which can be used for elbow bending detection and human motion detection.The larger the elbow is bent,the greater the piezoelectric output is.The maximum output voltage is 1.38 V when bending 120 °.At the same time,it can also identify three kinds of movement behaviors of walking,running and jumping.Finally,the fiber membrane was prepared by compounding pan and keratin.Through FTIR,XRD,mechanical properties and piezoelectric properties tests,the conclusion is as follows: when the ratio of keratin to pan is 6:1,the piezoelectric property of fiber membrane is the best.The sensitivity of the keratin/PAN piezoelectric sensor is 243 m V/N,which is more sensitive than that of the keratin/PET piezoelectric sensor.It can be used to monitor relatively small bending and more subtle human motion.The results show that the piezoelectric properties of the composite piezoelectric materials prepared by electrospinning with keratin are improved.