wg48temp9
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Electrospinning experiments
I did a crude experiment to try some electrospinning. I used a -5kV supply connected a hypodermic needle using a glycerol solution (e-liquid). I was
unable observe any spray but the liquid flowed back along the needle and formed drops. I decided the grounded counter electrode was needed so I
positioned one by hand. Ouch I got zapped, only 50uA plus whatever the output C current was.
Unexpectedly the sharp needle allows a spark to jump about 20mm while between blunt wires it’s only a few mm. I had no idea a really sharp point
could extend the sparking distance so much. On closer examination of the needle there was a brush discharge from needle and a mild wind smelling of
ozone.
My electrospinning experiments continue more carefully LOL.
I wounder if I can electrospin candy floss at 50kV or perhaps ceramic fiber.
I am wg48 but not on my usual pc hence the temp handle.
Thank goodness for Fleming and the fungi.
Old codger' lives matters, wear a mask and help save them.
Be aware of demagoguery, keep your frontal lobes fully engaged.
I don't know who invented mRNA vaccines but they should get a fancy medal and I hope they made a shed load of money from it.
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wg48
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Improvments in the set up
So I lapped the tip of the hypodermic needle flat and square and fixed the syringe in a clamp. I then placed a large washer in front of the needle
with needles axis thru the middle of the hole in washer and about 10mm from the needle tip a few mm greater than the sparking distance.
With a drop of liquid at the needle tip I turned on the HT. The drop disappeared and a small wet patch appeared on the paper placed 20mm from the far
side of the washer. Success the liquid was propelled through washer's hole and hit the paper. I then tried gently depressing syringe plunger force
more liquid from the needle. No visible drop formed on the needle tip as it was immediately propelled in the direction of the washer. Some hit the
washer and some hit the paper in various spots some 30deg of axis. The paper was mounted on plastic i suspect the paper and plastic charged up
deflecting the liquid stream. The blunt needle reduced the brush discharge (still visible in the dark about 1 to 2mm defuse glow at the tip of the
needle) and the ionic wind was much weaker but still noticeable. That ionic wind was probably charging up anything insulated and deflecting the
liquid. The first spot on switch on was on axis.
I need a better set up preferably with a variable HT supply and linear actuated to dispense the liquid. I also need to use a fiber forming liquid and
or add a dye to the liquid to make it more visible. I also need to have only grounded metal after the washer and mount the paper on a metal plate
So this still crude apparatus proves 5kV across 10mm readily propels liquid from the blunt needle and projects it at least 30mm.
I will take some pics next time. The liquid stream is invisible to the naked eye even with a 25W LED light illuminating it from 300mm away. I am
particularly curious as to how far the liquid can be propelled after it is accelerated by only 5kV
.
Borosilicate glass:
Good temperature resistance and good thermal shock resistance but finite.
For normal, standard service typically 200-230°C, for short-term (minutes) service max 400°C
Maximum thermal shock resistance is 160°C
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wg48temp9
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Here is a practiicalcal troubleshooting guide
Attachment: electro spinning.pdf (266kB)
This file has been downloaded 2052 times
Leach, M.K., Feng, Z., Tuck, S.J., Corey, J.M. Electrospinning Fundamentals: Optimizing Solution and Apparatus Parameters. J. Vis. Exp.
(47), e2494 10.3791/2494, DOI : 10.3791/2494 (2011).
and a video and more excellent and practical info at https://www.jove.com/video/2494/electrospinning-fundamentals...
[Edited on 31-12-2018 by wg48temp9]
I am wg48 but not on my usual pc hence the temp handle.
Thank goodness for Fleming and the fungi.
Old codger' lives matters, wear a mask and help save them.
Be aware of demagoguery, keep your frontal lobes fully engaged.
I don't know who invented mRNA vaccines but they should get a fancy medal and I hope they made a shed load of money from it.
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happyfooddance
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Watching this f.y.i.
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zed
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Remember, I am not recording the vision of a madman. The sun does not more certainly shine in the heavens than that which I now affirm is true. Some
miracle might have produced it, yet the stages of the discovery were distinct and probable. After days and nights of incredible labour and fatigue, I
succeeded in discovering the cause of generation and life; nay, more, I became myself capable of bestowing animation upon lifeless matter.
Mary Shelley
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wg48temp9
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I done some additional experiments. Perhaps surprisingly 5kV can propel the liquid from the needle tip to a grounded disc of stainless steel (base of
a SS beaker) placed about 100mm away that is only about . 1.25kV/cm.
Below is a pic of the previous arrangement using a washer.
I presently boxing up the HT supply (a HT module from a photocopier) . adding a quad multiplier to the AC HT output to reach 20kV and adding about a
1:3 front panel voltage adjustment.
I am hoping to use a film forming solution, perhaps polystyrene dissolved in acetone. Apparently my red azo dye dissolves in acetone too.
Oops sorry apparently the system does not like my file format??? I think my new laptop hopeless.
I am wg48 but not on my usual pc hence the temp handle.
Thank goodness for Fleming and the fungi.
Old codger' lives matters, wear a mask and help save them.
Be aware of demagoguery, keep your frontal lobes fully engaged.
I don't know who invented mRNA vaccines but they should get a fancy medal and I hope they made a shed load of money from it.
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TheMrbunGee
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This was something completely new to me, thanks! Seems interesting!
To my knowledge - polystyrene does not dissolve in acetone, it just softens creating a dough like blob sunk to the bottom of acetone.
But that's with styrofoam, not sure about purity of it.
[Edited on 7-1-2019 by TheMrbunGee]
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wg48temp9
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Quote: Originally posted by TheMrbunGee  | This was something completely new to me, thanks! Seems interesting!
To my knowledge - polystyrene does not dissolve in acetone, it just softens creating a dough like blob sunk to the bottom of acetone.
But that's with styrofoam, not sure about purity of it.
[Edited on 7-1-2019 by TheMrbunGee] |
i have had a similar experience using Styrofoam. I assumed it was cross-linked. I searched but I was not able to find any reference to confirm that.
Apparently cross-linked polystyrene is made but only for specialist proposes which I now assume is not expanded polystyrene.
I was going to use solid material. I will try both.
I am wg48 but not on my usual pc hence the temp handle.
Thank goodness for Fleming and the fungi.
Old codger' lives matters, wear a mask and help save them.
Be aware of demagoguery, keep your frontal lobes fully engaged.
I don't know who invented mRNA vaccines but they should get a fancy medal and I hope they made a shed load of money from it.
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