HELP Vol. 01: How to Spin Gelatin Effectively
The launch of ‘HELP’ has finally begun!
In the first session, we conducted an experiment on how to effectively spin ‘gelatin,’ which tends to solidify easily.
Members who participated in this ‘HELP’ experiment: Gao, Masagaki, and Wang.
Making solution for spinning nanofibers using gelatin
The three( Gao, Masagaki, and Wang) began preparing the solution for spinning gelatin using our electrospinning device, NANON.
However…
The 30wt% gelatin aqueous solution solidified!
Gelatin solidifies so quickly…
Is there any way to prevent it from solidifying?
Isn’t there an experienced spinning expert at MECC?
Let’s go ask in the lab!
They went and asked the lab member Ms. Nakatsuka for help.
Nakatsuka-san! HELP PLEASE!!
We wanted to spin gelatin and made a solution, but it turned solid.
Gelatin solidifies with only water, so I think you should mix it with something.
For example?
PEO and PVA, which are easier to spin…
Also, there’s a method of dissolving gelatin in acetic acid instead of water.
As expected, she is knowledgeble for spining!
They received the advice and started making a solution again!
The three of them made their own gelatin solution with reference to the know-how taught by Ms. Nakatsuka.
Then I’m going to mix PEO in a 15wt% gelatin aqueous solution in a 3:7 ratio!
If it’s acetic acid, increasing the concentration of gelatin may work.
I think I’ll mix PVA in a 30wt% gelatin acetic acid solution in a 5:5 ratio!
I’ll try to put it all in! I will mix PVA and PEO in a 30wt% gelatin acetic acid aqueous solution in a 5:2.5:2.5 ratio♪
- Gao: 15wt% gelatin aqueous solution: PEO 3:7
- Masagaki: 30wt% gelatin acetic acid solution: PVA 5:5
- Wang: 30wt% Gelatin Acetic Acid Aqueous Solution: PVA: PEO 5:2.5:2.5
They led these solutions sit overnight.
The result of the solution of gelatin that we made
What happened to each gelatin solution …
- Gao: 15wt% gelatin aqueous solution: PEO 3:7
⇒ turned solid
- Masagaki: 30wt% gelatin acetic acid solution: PVA 5:5
⇒turned solid
- Wang: 30wt% Gelatin Acetic Acid Aqueous Solution: PVA: PEO 5:2.5:2.5
⇒didn’t turn solid。
Even though they followed Mr. Nakatsuka’s advice and made the solution, two of our three solutions solidified again.
So, they asked Ms. Nakatsuka for HELP again and received the following advice:
- Gao: 15wt% gelatin aqueous solution: PEO 3:7
⇒If you heat it and spin it while it is warm, it may work.
- Masagaki: 30wt% gelatin acetic acid solution: PVA 5:5
⇒Try lowering the concentration from 30 wt% to 20 wt%.
Finally they succeeded in making a gelatin solution
Spinning experiment a gelatin solution using NANON
This time will be a short time spinning so let’s start with this parameter below using a tubeless spinnerette that can spin even a small amount of solution without waste!
・Voltage: 15~20kV
・FR 1ml/h
・Spinning distance: 150mm
・NEEDLE THICKNESS: 27G
Start spinning experiments!
The spinning result of 15wt% gelatin aqueous solution: PEO
＼ 15wt% gelatin aqueous solution: PEO 3:7 ／
- Spinning can be done in the range of voltage 12~26kV.
- When lowered to 11 kV, droplets drip
- When raised to 27 kV, the jet does not come out
I thought it would cool down and turned solied in about 10 minutes and stop spinning, but It was able to be spinning for almost 30 minutes!
20wt% gelatin acetate solution: fiber diameter of PVA
- Spinning at 18kV: 398.1615nm
- Spinning at 25kV: 462.82nm
When the voltage was increased, uniform fibers could be spun.
Even if it turned solied, it was possible to spin it without using organic solvents by heating it, so the range of applications for gelatin in the medical and beauty fields seems to be expanding!
Spinning results of 20wt% gelatin acetic acid solution: PVA
＼ 20wt% gelatin acetic acid solution: PVA ／
- Spinning can be done in the range of voltage 15kV~30kV
- When lowered to 10 kV, droplets drip
- When I started at 15 kV and went up to 20 kV, the jet was not stable.
When the voltage was lowered until a droplet appeared and the voltage was raised again, and the jet became stable at 23 kV. After that, we were able to confirm that it can spin up to 30 kV.
20wt% gelatin acetate solution: fiber diameter of PVA
- Spinning circle end: 111.3563nm
- Median spinning circle: 100.3597nm
There are many beads in the center of the spinning circle, and the fiber diameter is thinner than the nanofibers of the other two!
The center of the spinning circle is so dark and wet that you can see it visually, so it may be improved by spinning while moving it sideways instead of spinning at one point.
Spinning result of 30wt% gelatin acetic acid aqueous solution: PVA:PEO
＼ 30wt% gelatin acetic acid aqueous solution: PVA: PEO／
- Spinning voltage up to 12~30kV
- When lowered to 11 kV, droplets drip
I feel that fibers spun in the range of 18kV ~ 25kV and fibers spun in the range of 25kV ~ 30kV look different in terms of gloss. Maybe the fibers have changed!
30wt% Gelatin Acetic Acid Aqueous Solution: PVA:PEO Fiber Diameter
- Spinning at 12kV: 610.75nm
- Spinning at 25~30kV: 375.516nm
Compared to those spun with other solutions, the fiber diameter is thicker! When the voltage was high, the fibers became thinner, but the fibers were no longer uniform. When the voltage was low, the fiber diameter became thicker and more uniform.
In order to produce nanofibers successfully by spinning a gelatin solution,
What did you think of the first HELP project?
Gelatin with a concentration of 15 wt%~30 wt% was successfully with different approaches.
What we learned to spin gelatin, which tends to solidified easily
- When the solution solidified, try heating it.
- Mix easy-to-spin materials such as PEO and PVA
- Reducing the concentration of gelatin
Tell us! HELP！
When the gelatin was spun, the jet seemed to be stable, but droplets sometimes dripped along the way. I wonder why.
I wonder if there is a way to spin gelatin alone。
How can you spin it well?
If you have any advice, please let us know. HELP！