I had electrospun PAN/DMF solution at various concentrations in February and it spun well, i.e., without dripping. But when I replicated the experiment (concentration, distance, voltage were same) after a month, the solution was dripping as well as electrospinning.
What factor could be responsible for dripping? Could it be humidity or a change in viscosity of polymer solution even though the concentration was kept constant or any other factor?
Thank you for the answer B D S Deeraj. The concentration is 9wt% and 12wt%. Is the dripping also possible if polymer has absorbed moisture before mixing it with the solvent?
Hi Shashi, I'm also using DMF as solvent for electrospinning PVDF polymer. I'm also having the same problem with replicability. Note that DMF is hygroscopic i.e. it tends to absorb moisture from air. It would be best if you're electrospinning at low humidity. In my setup however, I don't have any control on the humidity (living in a highly humid country) and thus, performing my experiment at ambient conditions with 50% to 65% RH. I haven't perfected my fibers yet and I experienced dripping before. What I first did was I tried reducing the flow rate of the syringe pump to give more time for evaporation of the solvent. You can also adjust by increasing your polymer concentration if it still happens.
I hope this helps and good luck!
Dear Shashi, yes there are several factors effecting electrospinning. Betweem them humidity. Therefore, I strongly recommend to process freshly prepared solutions. Also, I agree with Ms. Bello, that DMF is higroscopic. The last factor to consider is degradation of PAN, which will decrease solution viscosity. Good luck with your work.
Dear Shashi .do you use powder PAN or prepared dope of PAN? .anyway in general if you used PAN powder since it is hydrophobic their is less tendency to be affected by RH but if you are using prepared dope which exposed to environment their will be degradation of PAN.12% is quite high for electrospinning of PAN so their should not be any dripping so examine the solution of your PAN
- Badges
- Science method