Electrospinning solution

The reaction mixtures were stirred for 24 hours at room temperature. The resulting dark-brown dispersions were used to prepare electrospinning solutions after adding DMF to the final solutions (details of characterizations of PEDOT/PVAC and PEDOT-PSS/PVAc systems are given in Chapters 5 and 6). 

Preparation of Electrospinning Solutions PEDOT-PSS in a PVAc Matrix... 

Experiments have shown that a minimum viscosity for polymer solution is required to yield fibers without beads, the solution of the PI.50 sample was determined the best electrospinning solution because of the continuous electrospinning process for this study. 

Figure 6.9 UV-Vis spectrum of the PEDOT-PSS, cerlum(IV) ammonium nitrate, and PEDOT/PVAc composite electrospinning solution (with 25 pi EDOT). 120...

The relatively low molecular weight of conductive pol miers, decrease in specific viscosity of composites resulted a small nanofiber diameters. Interaction of PPy with matrix creates a decrease in viscosity, and that causes the smaller diameter of nanofibers. Moreover, electrospinning solutions of nanofibers with small average diameters have exhibited higher conductivity. 

Figure 8.6 shows the TEM images of silver/polypyrrole/ polyacrylonitrile composite nanofibrous mats prepared. It was reported that low AgN03 content could decrease the diameters of the Ag/PAN fibers and higher AgNOs concentration led to increase in the diameters of the hybrid fibers due to the high content of the solute in the electrospinning solution. ... 

An electrospinning solution was prepared as follows 0.1 g of PANl/PSSA was dissolved in 5 mL DMF and a different amount of PEO, and PVB was used as a matrix (impedance change from 10 to 10 fl over the range of 11-95% relative humidity). ... 

In order to prepare the electrospinning solution, a 10% (w/w) aqueous solution of PVA should first be prepared. The required amount of oxidant (ammonium persulfate or ferric chloride) should then be added to the prepared PVA solution and should be stirred using a mechanical stirrer to form a homogenous solution. Mixtures containing various PVA/oxidant weight ratios should be prepared and used for electrospiiming. 

PPy should be deposited on the PVA nanofibres during electrospinning. Polymerisation of the PPy should be performed in the vapour phase in the presence of different oxidant types and oxidant content in the electrospinning solution. For this purpose, a chamber can be designed and electrospinning can be done in this chamber (Figure 3.8). 

The materials are obtained by electrospinning solutions containing tetracycline along with PLA, ethylene vinyl acetate (EVA) or a combination of PLA and EVA. The release of tetracycline hydrochloride was determined by spectroscopic measurements. 

The vapor phase chemical deposition of PPy on the surface of the electrospun PVA nanofibers was successfully performed. Morphology of the nanofibers and successful deposition of the PPy onto the nanofibers is governed by the oxidant type and its concentration in the electrospinning solution. At the best studied condition, a layer of PPy with the thickness of 1,000 nm is formed onto the PVA nanofibers surface using ammonium persulfate as oxidant. In contrast, surface coating was not observed in the case of FeClj as oxidant. The electrical conductivity of the coated nanofiber mats depends on the coating conditions and reaches to 10 S/cm. Large surface area of the sensor material with the electrochemical activity is one of the most important properties for sensor application. Since, it is obvious that the surface area of PPy coated non-... 

Figure 10.14. Electrospinning apparatus which operates with wire electrode [91]. 1 electrospinning solution, 2 take-up drum, 3 wire electrode, 4 electrospinning space, 5 collector, 6 rotating mandrel...

Data on electrospinning solutions of PS in several different solvents, reported by Megelski et al. (2002), might be used to further illustrate this approach. Using PS of = 190,000 g/mol, attempts at eleetrospinning... 

The electrospinning process fundamentally requires the transfer of electric charge from the electrode to the spinning droplet at the terminus of the tip. A minimal electrical conductivity in the solution is therefore essential for electrospinning solutions of zero conductivity cannot be electrospun. Solvents commonly used in electrospinning have conductivities that are... 

A similar technique was used by Min et al. (2004d) to electrospin copolymers of lactide with glycolide (PLGA) nanofibers from hexafluoroisopropa-nol (HFP) solvent from one capillary tip and regenerated chitin in formic acid electrosprayed from a separate tip, onto the same grounded collector drum. In this case, however, both electrospinning solutions carried a positive charge. 

Electrospinning ultrafine fibers and process parameters. A small amount of pyridine added to the electrospinning solution avoided formation of beaded nanofibers at low concentrations. 

The solvent selected for PMMA and GO was a 2 1 mixmre of AfA -dimethylforma-mide (DMF) and THF. Mixture analysis was conducted and validated with the experimentally observed nanofiber morphology and dispersion to determine the optimum level for the three constituents of the electrospinning solution, namely, PMMA, GO, and DMF + THF. 

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