| Activated polyacrylonitrile (PAN) fibers are known to contract and elongate by more than 100% when immersed in acidic and basic solutions respectively. The response time of the conventional fibers was observed to be high for pH actuation (few seconds) and electrical actuation (several minutes). The mathematical analysis of the kinetics of polymer gel is done to study the effect of radius of the fiber on response time. It is shown here that decrease in radius of the fiber decreases the response time. Commercially available fibers have diameters in 10s of micrometers. The process of electrospinning is used to produce sub-micron diameter fibers of PAN. An electrospinning setup is designed, built and electrospinning of PAN is studied. Standard parameters; concentration of polymer solution, tip to collector distance, flow rate, for electrospinning of PAN are determined to produce PAN fibers to be used in actuator applications. Oriented fibers are made using parallel-plate collector system. A relation between the electric current in the electrospinning process, type of polymer jet and quality of fibers is determined. (Abstract shortened by UMI.)... |
