الفهرس 
General Background on ElectrospinningOnly 14 pages are availabe for public view
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Abstract
Electrospinning technique became powerful tool to production of polymeric nanofiber at the end of twentieth century. Also, nanomaterials have different and attractive properties from its properties in bulk state. In our study, the steps of optimization of electrospinning technique were presented. Also, the different parameters that used to produce nanofiber from natural and synthetic polymers were presented in detail.
Sodium alginate is a natural polysaccharide polymer, and has various properties such as: biocompatible, biodegradable, non-toxic and water soluble. In our work, some experiments were performed to produce nanofiber from sodium alginate solution but with negative results. So that, synthetic polymer such as polyvinyl alcohol was used to enhance the electrospinnability of sodium alginate.
Nanofiber from pure PVA was prepared successfully at optimal process condition; distance, rotational speed, flow rate and voltage equal to 9 cm, 5500 rpm, 0.03 mL/Min, 20 KV respectively.
Based on the previous step Nanofiber sheet from Na Alg and PVA was successfully at optimal process condition; distance, rotational speed, flow rate and voltage equal to 9 cm, 2000 rpm, 0.009 mL/Min, 20 KV respectively.
After that, to improve the mechanical properties of the produced nanofiber, plasticizer such as glycerin was used. Then the plasticized
nanofiber was prepared at optimal process condition; distance, rotational speed, flow rate and voltage equal to 9 cm, 5500 rpm, 0.011 mL/Min, 20 KV, respectively.
As a result of the high solubility of Na Alg and PVA nanofiber, ferric chloride was used as crosslinker agent to make the produced nanofiber non-soluble.
Different spectroscopic techniques were used to characterize the prepared Na Alg / PVA nanofiber such as: Ultraviolet/visible (UV/Vis.) spectroscopy, Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM).
The optical band gap of raw materials and that of the prepared nanofiber sheets was calculated from the UV-Vis. absorption spectra. FTIR results showed that molecular structure of raw materials was changed due to electrospinning process which refers to the complexation and formation of hydrogen bonds between the individual polymers. Finally, the surface morphology of all prepared nanofibers was examined using SEM.
As an application PVA/Na Alg crosslinked nanofiber tested to be biosensor for glycine amino acid and the results confirm it can be used as an effective sensor.
Finally, molecular modeling was carried out to confirm the analytical results for the prepared structures. Density functional theory (DFT) at DFT/6-31g (d,p) was used to study the electronic properties of raw
materials (Na Alg, PVA and Glycerin) due to blending. Total dipole moment (TDM), HOMO/LUMO energy gap and electrostatic potential (ESP) are incorporated to study the changes that occurred in the electronic properties of the studied structures. The results of TDM, HOMO/LUMO energy gap and ESP indicated that the model molecules representing Na Alg, PVA and Glycerin and the blended structures are suitable for application in energy storage devices as well as electrochemical devices. Where, the TDM increased, HOMO/LUMO energy gap decreased and electro-negativity increased for the structures under study.
Additionally, the obtained results of QSAR descriptors as well as the thermal parameters were in good agreement with the experimental results.