Electrospinning method structures

A simple method was recently introduced for preparing core-shell nanostructured conductive PPy composite [45]. The PPy core particles were first introduced in flexible shell solutions by in situ polymerization, and then different core-shell structures could be obtained by the electrospinning method (Figure 4.12). In that study, PPy was selected as the as-dispersed phase (cores) and polyacrylonitrile (PAN) as the continuous phase (shell) the morphology of the resulted nanostructures can be controlled by changing the concentration of the solutions. This method is very useful in the design and preparation of nanosized core-shell structures using electroconductive polymers. 

Teo, W. E., M. Kotaki, X. M. Mo, and S. Ramakrishna (2005). Porous tubular structures with controlled fibre orientation using a modified electrospinning method. Nanotechnology 16(6) 918-924. 

Recently, with the developed technique, the hydrothermal synthesis has been established as an efficient way to fabricate multifunctional materials with different morphologies. Thanks to the advantages of hydrothermal synthesis, various kinds of micro-Znanofibers with versatile secondary hierarchical structures can be obtained easily. Chang designed a facile and effective strategy that combines electrospinning method with hydrothermal process to prepare firecracker-shaped ZnO/polyimide (PI) hybrid nanofibers (Fig. 18.14) [54], Firstly, PI nanofibers were prepared. In this case, the polyamic acid (PAA) solution produced from pyromellitic dianhydride... 

Teo, W.E., Kotaki, M., Mo, X.M., and Ramakrishna, S., Porous Tubular Structures with Controlled Fibre Orientation Using a Modified Electrospinning Method , Nanotechnology, 16, 918-924, 2005. 

In another application electrospinning [189] of PS-fo-P4VP(PDP)i.o supra-molecules was used to produce internally structured fibers with diameters in the range of 200-400 nm. Due to the block copolymer sample selected, self-assembly resulted in spherical P4VP(PDP) domains with the well-known internal lamellar structure. After the PDP was extracted from the fibers using methanol, porous fibers were obtained [190]. With this method, the thickness of the fibers can be tuned by adjusting the spinning conditions, and the size and nature of the pores can be controlled by the choice of block copolymer and amount of amphiphile. 

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