Electrospinning is depends on the MW of the polymers. So, higher the Mw of the polymer- easy to electrospun into the nanofibers.
If ethyl cellulose have 20,000 to 30,000 MW, than solution concentration is must be higher than 18%. Applied voltage is 15-25kV. Flow rate is dwpends on viscosity of the polymer solution. Higher the viscosity- lesser the flight time of the taylor cone. So, increase the flow rate when viscosity is high. If go w rate is high and viscosity is lower than the Taylor cone spend less tjme on needle and causes not proper elongation means beaded fibers.
So you have to see what is the best flow rate for electrospinning.
Secondly, solvent- solvent choose which have low Boiling point (i.e, ethanol, methanol, chloroform) also you choose mixture of solvents like (ethanol:chloroform or ethyl acetate).
If your polymer have higher than 50,000 MW than its 5-15% solution is enough to fabricate the nanofibers (depends on viscosity). Applied volatege is same as mentioned above.
Distanece is depends on viscosity of solution and applied voltage. If your polymer solution have higher viscosity, than it is difficult to sprey from the needle tip and taylor cone could not reach at collector.
So you have to change parameters with respect to each other to get optimise parameters of electrospinning of polymers.
If, it is difficult to electrospun then add another polymer contant into the solution which is easily electeospun into nanofibers.
Hope these may help you.
Best of luck.
Hi
If using aromatic hydrocarbons the solution of ethyl cellulose would be very viscous which probably not desirable for your application. Ethanol and methanol yield solution with lower viscosity but you might not get good film/fibre properties at the end. I think a mixture would be good giving you a balanced viscosity and a strong fibre/film
Thanks Mehdihasan Shekh for your detailed and helpful explanation. Actually we use a kind of ETHOCEL™ Premium for electrospinning and I'm not sure about its MW. But when we tried different concentration it seemed 15% was good. The main problem was that we couldn't get a continuous jet. Every few minutes the jet was disconnected and the needle blocked with dry polymer! and we needed to restart everything.
thanks Amin for your great answer. According to literature we have chosen a mixture of water/ethanol but as I told we still have some problem in solvent evaporation. Have you ever used any special mixture for electrospinning of ethyl cellulose?
Blocking of needle is due to the high voltage, High viscosity and low flow rate. Higher voltage can easily evoparate the solvent and thus needle blocked. And one thing also make sure that the viscosity of the polymer solution is ambiant so feeding is easy from injection. If viscosity is higher then feeding is not properly at lower flow rate.In your case, just increase the flow rate you can get results.
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