I use chloroform to dissolve the PLA 10wt%. But when I try to electrospinning I don't get the uniform diameter of the fiber.Most of the fiber is iced in the need tip (in the attached file).Some fiber goes to the collector.I tried different concentration (5wt%,7wt%,10wt%),Different voltage(15KV,20KV,25KV).All concentration have the same problem.How to solve this problem?
Dear Farzana Khan
What you are experience is a clogging of the needle due to the fast evaporation of the solvent.
Over the link below you can find many ways to circumvent this:
http://electrospintech.com/mpchallenge.html#.VZD2LUZmdsg
I've spun a lot ot PLA in CHCl3 and my favorite solution is a Gas shield around the nozzle. This suppressed the evaporation of the spinning solvent, hence it allows to continuously electrospin highly volatile solutions like Dichloromethane or Chloroform solutions. [Larsen et al 2004] With this you can spin for hours to days and you get uniform fiber diameter because you maintain a stable Talyor cone.
See the movie attached with an extreme case of needle clogging with/without gas shield.
Regards
Marc
what is the weight of the PLA you are using. From the pic it looks like either is low viscosity and/or the mol.wt and hence the chain length of the polymer is lower.
One need to understand that the electric field/potential helps in evaporating the solvent but it the chain entanglement which forms a continuous fibers. Short fibers ot too less fibers will form differential diameter fiber, pinching and necking at random places and at the end accumulation on needle tip
My suggestion, increases the concentration at 12.5% and 15% and it will solve you problem
Dear Farzana,
In my experience with PLA (Mw>200kDa) and electrospinning I used dichloromethane and dimethylformamide (9:1 volume ratio). Addition of DMF made the solution less volatile and electrospinning went smoothly. You can find some details in my paper (easy to find in my profile).
Marc also gave you good tip. However, I think it might be cheaper for you to first try to find another way of preparing your solution.
Best regards and good luck,
Michał W.
Hi
you can use DMF/THF blend as asolvent
approximately you must test 15-30 wt% off polymer to have a good viscosity and stable taylor cone
Hello Mohammad Khorsand-ghayeni,
Thank you so much for your suggestion.
Could you please suggest me what ratio will be good for DMF/THF blend solvent?
Ankur Shah r can you tell me how to calculate concentrations? i am new to electro spinning?
- Badges
- Science topic
- Similar topics
- Biological Science
- Biota
- Eukaryota
- Fungi