## 3 Results and Discussion
### Morphology of LENMs  
Figure 3 and Table 3 show the morphology of nanofibers of LENM-1, LENM-2, and LENM-3. LENM-1 and LENM-2 exhibited good morphology with an average fiber diameter of 279 \(\pm\) 52 nm and 272 \(\pm\) 51 nm, respectively. However, LENM-3, which was made with 30 wt % of LE extract, was composed of beaded-fibers and had an average diameter of 177 \(\pm\) 45 (\(p\) < 0.01). The presence of beaded fibers is ascribed to the viscosity and electrical conduction of electrospinning solution, and PENM-9 had a viscosity of 1562 \(\pm\) 31 cP, electrical conduction of 551 \(\upmu\)S/cm, and an average diameter of 316 nm. For LENM-3, the blending ratio of PVA to LE was 70/30 \(w/w\), the viscosity was 760 \(\pm\) 71 cP, the electrical conductivity was 177 \(\upmu\)S/cm, and the average diameter was 177 nm. Namely, viscosity, electrical conductivity, and fiber diameter decreased by 70.5%, 60.6%, and 43.9%, respectively. The variations in the properties of electrospinning solution are ascribed to the increasing amount of LE  
\begin{table}
\begin{tabular}{l c c c c} \hline
**Sample** & **Field Strength (kV/cm)** & **Flow Rate (mL/h)** & **Fiber Diameter (nm)** & **Average Diameter (nm)** \\ \hline PENM-1 & 2.5 & 0.5 & 400–1000 & 683 & \(\pm\)196 \\ PENM-2 & 2.5 & 0.75 & 300–900 & 585 & \(\pm\)157 \\ PENM-3 & 2.5 & 1.0 & 360–620 & 481 & \(\pm\)60 \\ PENM-4 & 2.0 & 0.5 & 250–660 & 418 & \(\pm\)111 \\ PENM-5 & 2.0 & 0.75 & 320–960 & 544 & \(\pm\)156 \\ PENM-6 & 2.0 & 1.0 & 320–620 & 443 & \(\pm\)73 \\ PENM-7 & 1.5 & 0.5 & 230–570 & 411 & \(\pm\)70 \\ PENM-8 & 1.5 & 0.75 & 250–490 & 350 & \(\pm\)58 \\ PENM-9 & 1.5 & 1.0 & 240–390 & 316 & \(\pm\)37 ** \\ \hline \end{tabular} Note: Data shown as mean \(\pm\) SD. **_p_ < 0.01 vs. PENM group (excluding PENM-8).  
\end{table}
Table 2: The average diameter of the polyvinyl alcohol electrospun nanofibus membranes (PENM).  
Figure 2: Scanning electron microscope (SEM) nanofibers of (**a**) PENM-1; (**b**) PENM-2; (**c**) PENM-3; (**d**) PENM-4; (**e**) PENM-5; (**f**) PENM-6; (**g**) PENM-7; (**h**) PENM-8 and (**i**) PENM-9.  
extract. LE extract has ethanol solution as its solvent, and ethanol is almost electrically insulating and has a low viscosity of 1 cP, which have a negative influence on LENM-3. Moreover, the concentration of polymer is a key factor in the electrospinning process, as well as in relation to the viscosity [22]. The preparation and formation of nanofibers are dependent on the viscosity of the polymer solution. When the viscosity is lower than the critical value of entanglement, applying a voltage to it may cause sprays or bead-shaped nanofibers [23; 24]. When the concentration of the polymer solution is higher than the critical value of entanglement, the amount and size of the bead-shaped fibers decrease, eventually leading to the presence of bead-free fibers [25]. However, an excessive viscosity of the polymer solution fails to create evenly formed nanofibers [26]. When the electrospinning solution composed of an LE solution is over 30 wt %, a low viscosity and a low electrical conductivity prevents the entanglement of low concentration polymers. As a result, electrospinning is not performed continuously, and the interrupted electrospinning solution results in a great amount of beads and bead-shaped nanofibers. The optimal blending ratio was determined to be 80/20 (LENM-2) and is thus used for the following discussion.