Preparation Of Piezoelectric Textile Based On Zinc Oxide Nanorods

Zinc oxide is a wide band gap semiconducting material with a direct wide band gap(3.37eV)and a large exciton binding energy(60 meV at room temperature), which shows good mechanical,thermal, optical, electrical and other different propertie. Zinc oxide is a kind of functional materials, due to its remarkable performance in coupling semiconductor and piezoelectric properties, the use of it in self-powered micro-nano systems field to be promising. Combining the piezoelectric property of zinc oxide and the flexible of textile can not only realize the wearability of zinc oxide nanogenerator, but also achieve the function of textiles. Good morphology of the nanorods is the key factor for preparing piezoelectric textiles.Based on systematic summary the at home and abroad preparation methods of zinc oxide, in this paper, choosing hydrothermal method to grow zinc oxide nanorods. The method was applied on polyester cotton blended fabric and pure polyester fabric substrate. This paper was focused on the controllable growth of zinc oxide nanorods, by continuously adjusting the process conditions to optimize the growth state of zinc oxide nanorods on the substrate, and strive to prepare zinc oxide vertical closely aligned on the substrate. Then using the best condition to prepare piezoelectric textile. The main points can be summarized as follows:(1)Synthesis and optimization of ZnO nanorods with good morphology : Select polyester cotton fabric instead of traditional hard material as the substrate, directly grow zinc oxide nanorods on the fabric. By controlling the concentration of growth solution, ammonia volume and growth time to optimize the growth state of nanorods. The samples were tested by scanning electron microscope, to select the better preparation process of zinc oxiede nanorods. The testing results showed that on the condition of growth concentration 30 mM, ammonia volume 7.7mL and growth time 4h, can get hexagonal wurtzite structure zinc oxide nanorods and vertical closely aligned on the surface of fabric.(2)Preparing of piezoelectric textile: Consider the surface of polyester fabric has more hairiness, the substrate is not flat, using pure polyester fabric instead of polyester cotton fabric as substrate for the preparation of piezoelectric textiles. In order to test the piezoelectric properties,the surface of the fabric should coated with a layer of silver film as a lead-out electrode before grow zinc oxide nanorods on the substrate.(3)Testing analysis of piezoelectric textile: Using field emission scanning electron microscopy(FESEM), X-ray diffraction(XRD) and atomic force microscope(AFM), the morphology, crystal type, orientation and piezoelectric properties of zinc oxide nanorods were measured. The results revealed that the zinc oxide nanorods with hexagonal wurtzite structure were highly dense, vertically aligned on the fabric. Oriented nanorods along c-axis can be got by hydrothermal method, with the diameter ranging from 0.3?m to 1?m. It can be seen from the I-V curves that zinc oxide nanorods have obvious semiconductor properties and the repeatability is good. When apply a force on the surface of zinc oxide growing region,the current curves have a significantly enhanced signal indicating that the textile we got have good piezoelectric performance.