Study And Application Of PANI Nanofiber Controlled Deposition Technology

Since the early 1990s, the concept of Nano-materials is gradually known, and catches the eyes of scholars widely due to their special and superior performance. Nano-materials are widely used in many fields, such as biomedical materials, electrochemistry, sensors, etc. Electro spinning technology, as a simple, effective, relatively easy-controllable method to prepare Nano-materials, has already been accepted.Now, polymeric nanofibers prepared by electrospinning technology are mostly irregularly arranged because of the collector, and it's very hard to achieve the aligned and controlled deposition by technical operation. However, some studies show that the simply unordered nanofibers accumulated will have limit in applications because their excellent performance (such as mechanical and electrical property) as Nano-materials are greatly suppressed, compared with arranged nanofibers. Generally believed that in the electrospinning process along with the continuous volatilization of solvent, thinning of fibers and other changes, it is the splitting instability to influence the diameter and arrangement of fibers deposited, signally.In this paper, author does further research and optimizes the controlled deposition of gas sensing single fiber based on electrospinning, and builds a PANI nano fiber gas sensor structure, applied in test of low concentration ammonia. In concrete terms, my research mainly covers the following details:(1) Dopting PANI that can detect NH3 to improve its conductivity. (2) improve the device, and utilize the orthogonal test to gain the optimal parameters (to fibers'diameter; to alignment; to dosipoted region) and the degree of influence to fibers'morphotogy, then achieve the desired arranged structures (such as parallel structures); (3) Prepare the polyaniline nanofibers gas sensors based on a single PANI nano fiber, aligned and unaligned PANI nanofibers, etc. (4) Test and compare the gas sensing performance, among irregularly arranged nanofiber sensors, well arranged nanometer fiber sensors and single-nano fiber gas sensors. Conclusion:(1) A higher revolving speed of roller leads to smaller diameter, higher alignment and less deposited region of elecirspun nano fibers. Thus, it's true that the tractive force from the roller can refine the fibers and control the splitting instability of electrospun jet. With the revolving speed of 1300 r/min, the nanofibers deposited show the best alignment, and the value is up to 92%. And it's calculated that the depositing velocity of fibers is about 1.2m/s. (2) it is proved that the sensor based on a single PANI nanofiber is well sensitive to ammonia, and the speed of response is quick, to 12s. Then, the sensors based on aligned nanofibers, compared with unaligned nanofibers, show the better sensitivity.