Electrospinning method different morphologies

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. 

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... 

The nanofiber mat has extremely high specific surface area, adequate porosity and small pores due to their small diameters. The fiber size and morphology depends on various parameters involved in the preparation method. Electrospun fibrous membranes are highly porous structures that can be produced from a number of polymer/solvent combinations. Pore sizes ranging from 0.1 to 6 nm in diameter can be produced from solvent electrospinning. In this study different ways of producing porous sfructures are investigated. Then porosity measurement relationships are reviewed. 

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