Electrodes electrospinning

Another limitation that is specific to the parallel plate electrospinning technique is the collection of extremely thin nanofibers, which have been observed to break because they were unable to sustain the forces of their own weight and of the repulsive charges from other fibers [62]. An electrically resistive substrate inserted into the gap between the plates can provide support to fibers suspended between the plates without influencing fiber quality [62], and may also help to shield any conductive materials below the air gap, which may attract unwanted non-aligned nanofibers. Substrates with bulk resistivity greater than 10 Q cm, such as quartz and polystyrene, are suitable for placement between parallel electrodes, while materials with bulk resistivity of less than 10 Q cm, such as glass, may result in random fiber orientations [67, 68]. 

Fig. 4 (a) Electrospinning setup with counter electrodes used to focus the area of fiber deposition, (b-e) Images of resultant nanofiber mats electrospun with (b) no auxiliary electrodes, (c) one auxiliary counter electrode, and (d, e) both counter and like electrodes with different separation distances between them [48]... 

Fig. 5 (a) Electrospinning setup using an auxiliary counter electrode to direction the path of an electrospinning jet. (b, c) A tubular structure with diagonally oriented aligned nanofibers was fabricated when a mandrel was placed in the path of the jet at an angle [87]... 

Kim GH (2006) Electrospinning process using field-controllable electrodes. J Polym Sci B Polym Phys 44(10) 1426-1433... 

Electrospinning based on the application of a static electric field on a polymer solution or melt through a spinneret appears to be a simple and well-controllable technique able to produce polymeric nanofibers. A typical experimental setup is based on a capillary injection tip, a high-voltage source able to apply electric fields of 100-500 KVm , and a metallic collector, or counter electrode. Electric current in electrospinning experiments is usually in the order of a few milliamperes. ... 

A typical apparatus for electrospinning of polymers consists of a nozzle, a high-voltage power supply, a container for polymer fluid, and an electrode collector of an injection pump with a hypodermic syringe (Fig. 1.2]. The solution is pumped through the needle/ nozzle, a grounded collector that can be either stationary or rotating. Experiments can also be carried out in a box in order to precisely control environmental conditions such as temperature and relative humidity. 

The positive electrode is the metal part of the needle and the negative part of the electrode is the metal collector. About 5 to 180 minutes of operation time was applied for the deposition of fibers on wax paper, aluminum foil, and ITO PET. A horizontal setup was chosen for the electrospinning process. A representative picture of design of electrospinning is illustrated in Fig. 4.5. 

The acetone bath was used for the formation of pure polyaniline fibers by electrospinning method. " The fibres were collected in an acetone bath placed on the collector electrode. Because by placing the acetone bath make the excess of solvent to diffuse into the acetone allowing the pure polyaniline fiber formation. In another study, PANI/silica hybrid nanofiber webs were prepared by using... 

Kim, C., and K.S. Yang. 2003. Electrochemical properties of carbon nanofiber web as an electrode for supercapacitor prepared by electrospinning. Appl Phys Lett 83 1216. 

---