Electrospinning voltage

The membranes obtained with different electrospinning voltages and grafted imder die same conditions present varied contact angles Roughness, however, is so complicated that it is difficult to develop a general method for the roughness measurement. 

PVA is also one of the most studied polymers to produce fibers by electrospinning. PVA/CNTs electrospun fibers have first been reported in 2005 (43) and the interaction between PVA and nanotubes in these particular fibers was studied in 2007 (44). A mixture of purified MWNTs and water is sonicated and then added to a PVA solution. The resulting dispersion is electrospun via a voltage of 20 kV. This leads to the production of very thin fibers of typically 300 nm in diameter, as shown in Figure 11.3. 

Figure 11 a). SEM micrographs of P(LLA-CL) fibers electrospun from a polymer concentration of 5wt% at different applied voltage (a) 9 kV (b) 12 kV and (c) 15 kV.b) Relation between fiber diameter and applied voltage in the electrospinning with 5wt% P(LLA-CL) solution [64]. 

Fiber jet speed and material elasticity are two of the most important parameters involved in the jet-mandrel interaction and each of these properties are influenced by multiple electrospinning parameters, such as solution conductivity, viscosity, voltage, and feed rate. In addition, material properties cannot be accurately predicted without knowing the exact degree of solvent evaporation at the point when fibers are taken up by the collector. 

Despite the fact that the electrospinning technique is relatively easy to use, there are a number of process parameters that can greatly affect fiber formation and structure. Listed in order of relative impact to the electrospinning process, the most important parameters are applied voltage, polymer flow rate, and capillary-collector distance. All three parameters can influence the formation of nanofibers with bead-like defects. 

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