Preparation of Core-Sheath and Hollow Nanofibers

Thermal spraying of polymers is gaining increased attention because the abiUty to apply coatings of polymers onto a wide variety of materials is seen as an effective method to produce protective barrier coatings. 

Polymer powder is injected into a heat source (flame or plasma) and transported to a preheated substrate. The thickness of the coating is governed by the niunber of repeated passes of the spray gim across the substrate. A large particle size or molecular weight distribution may facilitate the formation of numerous heterogeneities within the microstructure of the coated siuface such as creating voids, trapped gasses, immelted particles, splats and pyrolized material. 

This method was applied for in-situ formation of ultrathin (-3000 A) cellulose acetate (CA) phase inversion membranes on glassy carbon electrodes [26]. Aalami-Aleagha et al. [27] used the spraying method for the preparation of porous metallic membranes. This work focused on characterization of the metalhc membranes produced by this technique based on porosity, oxide content, and the pore size distribution. 

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