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Electrospinning - Science topic

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We are trying to make Silk fibroin and PVA blend solution in formic acid for electrospinning but it is not miscible. I tried following
1. I tried to dissolve both in 99% formic acid but the solution wasn't look proper for electrospinning.
2. I also tried to mix the both by dissolving individual in formic acid.
3. I also tried to mix by dissolving silk in formic acid and PVA in water.
In all three cased i didn't get the homogeneous solution for electrospinning
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Kindly follow the reported work
I hope it will help you.
Thanks and Regards
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Dear all, my spinnable solution is acidic aqueous PVA + Aluminum nitrate, and my collector is Aluminum foil, but the nanofibers don't settle on the collector. I know that the viscosity of my solution is ok. I tried with different voltages and distances but the problem still exists. do you know what the reason is?
#electrospinng
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Please have a look at the following free access paper, hope it is helpfull.
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Hello!
We are trying to electrospin SiC fibers for some applications. In every study mentioned in the literature, they used the chemical I mentioned in the question. But I couldn't find any supplier here in the US.
Is anyone aware of where can i find this chemical? Please let me know. Thanks in advance.
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Thank you so much for the links. That would be really helpful.
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It seems that the fiber morphology is still under the film. The fiber is well formed during spinning, and there is no obvious liquid drop on the receiving plate,humidity 50%, T=26℃,Voltage=14kv,The receiving device is aluminum foil, The solution is PES-C with a concentration of 18%, solvent DMF:NMP=6:4.
See the figure for details
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Most probable it's a mechanical smear. Something was dragged across a portion of your specimen and smoothed it. I think I can see parallel scrutcnes (but picture is not good enough to be sure).
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i have read about use of chitosan, PVA, and plga and pla-based nanofibre but which grade should be used for electrospinning and centrifugal forcing please guide me .
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Dear Shaikh Mohd Fareed, each polymer has an optimum window of electrospinnability. You should decide on a given polymer. The following RG free access document deals with the case of PCL. My Regards
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I prepared a solution of nickel nitrate hexahydrate and PVP in the 12 ml mixture of DMF(8ml) and Ethanol (4 ml). The magnetic stirring of the solution was carried out for 6 hours at room temperature then it was filled in a 10 ml syringe and electrospinning was performed at 18V, 650 rpm, and 120 mm distance. Then it was dried at 80-degree temperature in a hot air oven for 12 hours then was calcined at 500 degrees in the tubular furnace for 1 hr. But the nanofibers were not produced and SEM images showed some random images of flake. Please suggest how to improve the process.
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Take DMF:Ethanol in 7:3 ratio, starring at 35°C for 6-7 hour, place in 5/10ml syringe, process parameters optimized between 19-23kV, 900-1100rpm, 12-14 cm TCD, optimum flow rate & control parameter between 25-30°C. Collect NF on silver foil, dried at room temperature either 45°C at room temp.
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Hello Everyone,
I had set up an in-house electrospinning apparatus with a horizontally positioned solution electrode and collection plate. The fiber mat from the collector has varied thicknesses from the center of the collection plate to the edge.
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the variance is most likely due to Coulomb's law. This is because the difference between the charge on the fiber and the charge on the plate is the same everywhere, but the distance is different, so the place closest to the fiber output will have the thickest mat.
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This required for electrospinning of PCS at room temperature.
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Dear Shruti Dubey, I think no, but DMF and THF did. Please have a look at the following documents. My Regards
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I tried to make a mat of PLA by using the electrospinning method, but after achieving a certain thickness, there is a formation of blisters and lumps on the mat surface.
Is it because of humidity or temperature? set humidity was 40%, temperature 25-28C
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Processing polyesters such as PLA and PET are normally accompanied by at least one step dehumedification in oven due to their ability of moisture absorbance. I think eliminating humidity (whether is water or solvent) would be the answer.
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Good afternoon, I am trying to prepare solution for electrospinning with PEO,H2O and NaCl.
The MW of PEO is 1,000,000.
At the beginning I add 1,25% NaCl to 95,75% water under 25°C stirring, then I add 3% PEO and stir it under 80-90°C till it will be completely dissolved (+ - 4 hours). Instead of fbers I get solution droplets.
If anybody can say me where my mistake is ?
Also I tried - PEO 3%, H2O 95,25% and NaCl 1,75% /// PEO 3%,H2O 94,5% and NaCl 2,50%. , and PEO with concentration 1%,1.4%,1.63%,1.75%,2%,3.7%,4% - everything are failed.
Maybe someone can also say me what the parameter for PEO 1,000,000 will be the best for electrospinning?
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Great thanks to all of you for your answers !
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Would you kindly give me some requirements about fabricating core-shell fiber? Such as the requirements of the polymer solutions (miscible, immiscible?), the applied voltage, etc.?
Thank you.
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Dear Tran Khanh, at least tell the system you are working on, no one can guess that to give precise contribution. Please have a look at the attached files. My Regards
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Electrospinning
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Dear Akuleti Saikumar, you can change the ionic strength by adding small amount of salt, or use a higher conductivity constant solvent. What is the solvent used ? My Regards
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Hello Everyone!
Greetings!
I am planning to work in the area of Synthesis of Polymer matrix composites for various Industry applications.
We have a dedicated Lab comprising 'Electrospinning Machine'. So any collaborations and constructive remarks are most welcome.
Thank you
Regards
Dr. Namdev Ashok Patil
#planning #work #research #electrospinning
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Hello Dear Dr. Namdev A. Patil,
Suggestion: Owing to nanoporous fiber can be produced using electrospinning machine, self-healing for advance material (polymeter) composite is interested research area.
All the best brother.
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I want to use electrospinning technology to make collagen and PLGA nanofibers. I used to use DCM and DMF as the solvent to dissolve collagen, but I did not find any Nitrogen from EDS.
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Hello all,
I am trying to cut electospun nanofiber networks.
I made nanofiber networks with PEO solution by using near-field electrospinning on Si-wafer.
After depositing fibers on Si-wafer, now I am trying to cut nanofibers into rectangular shape. (Fiber diameter is about 350 nm and trying to cut 8 mm square shape)
Laser cutting will work but it takes so long time and expensive to cut up to 8 mm.
It will be really thankful if anyone can give me any advice.
Thank you
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Please check this paper.
Lou, Lihua, Jilong Wang, and Seshadri Ramkumar. "Optimization of testing parameters for tensile property evaluation of poly (vinyl alcohol) nanofibers webs." Journal of Applied Polymer Science 136.10 (2019): 47159.
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I am learning about emulsion electrospinning and most of the papers only mention about the definition or application. Can someone give me few detailed example about emulsion electrospinning (core/shell components, ratio, optimal condition) so I can learn practically about it?
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You can simply request a help from another lad at you vicinity.
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Hello everybody! :)
I apologize for the non-technical questions, but I hope you could help me! I feel like after the covid era I am still a bit "slowed down". Today I realized, that I forgot to check whether there are any conferences in tissue engineering, biomaterials, nanofibrous etc. during this summer 2022. I would truly like to FINALLY go somewhere, talk to other scientists in the field, present my research or at least to have a poster. Unfortunately, I wasn't able to find any conferences this summer, which are still open to applications. :( Could you, please, help me with this? Maybe you would have an idea about some local conference or summer school at your university (or research centre) in this field.
Thanks for your help and hopefully let's see each other during some summer appointment. :)
Marketa
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Thank you Monika Spasovová for the correction.
I also didn't know much about these conferences. Someone shared this link earlier, so I copied it here.
I have deleted my comment now.
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Hello,
Does anyone know the best polymer and solvent that can be used for the perfect creation of a nanofiber sample using electrospinning? Ideally for drug delivery purposes.
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Dear Luis Chavez, the best polymer/solvent combination is the one that answer your need. Most soluble polymers may be electrospun. Melt solventless electrospinning is another option. Please check the following sample documents. My Regards
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Would you kindly show me how to electrospin PDMS? I have never learnt about this technique, thank you.
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Dear Tran Khanh, PDMS can not be electrospun directly, usually it requires a polymer support or a special dispersion conditions. Please have a look at the following documents. My Regards
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I am just beginning my thesis on this topic and am looking for a nontoxic alternative to the acenes for functionalization and electrospinning with applications in pseudocapacitors and singlet fission if possible
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I've been trying to the synthesis of Al2O3 fiber with electrospinning method with Aluminum isopropoxide as precursor, but Al2O3 fiber is broken after calcination. Can anyone guide what could be the problem? I have made the fibers according to several articles but fibers are broken after calcination.
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Dear Nasim Ghorbani, what is the polymer used and the concentration ? My Regards
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I read a paper, that said they had dissolved PS by putting 7.5wt% PS in 46.25wt% HFIP and 46.25wt% DMF, stirring overnight. Is that true? How can I dissolve PS for electrospinning?
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I'm doing electrospinning on the same material but needle is getting blocked everytime maybe due to solidification of polymer inside it. Is there anyway to reuse it or each time we need to use new needle?
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GroupsConditionsA0.01% UHMWPE, 40 Psi, 15 cm distanceB0.02% UHMWPE, 40 Psi, 15 cm distanceC0.04% UHMWPE, 40 Psi, 15 cm distanceD0.01% UHMWPE, 60 Psi, 15 cm distanceE0.02% UHMWPE, 60 Psi, 15 cm distanceF0.04% UHMWPE, 60 Psi, 15 cm distanceG0.01% UHMWPE, 40 Psi, 30 cm distanceH0.02% UHMWPE, 40 Psi, 30 cm distanceI0.04% UHMWPE, 40 Psi, 30 cm distanceJ0.01% UHMWPE, 60 Psi, 30 cm distanceK0.02% UHMWPE, 60 Psi, 30 cm distanceL0.04% UHMWPE, 60 Psi, 30 cm distance.
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I have made Polystyrene electrospun fiber, it did not form a smooth surface and it always stick to my hand when I touched it, how can I make this fiber smoother and have higher durability.
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Dear all, the following free access document deals with the different influencing processing parameters on the surface state of electrospun nanofibers. My Regards
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I am about to make a TENG with Polycaprolactone (PCL), the only problem that I am not sure about is if this material is very positive, like Nylon 66, cotton.. or very negative like PVDF, PDMS... Can someone help me with that? Thank you.
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Thank you Prof. Neji Ladhari
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Can someone give me some parameters about the electrospinning process of the Nylon 6,6/Formic Acid solution? (concentration, flow rate, Voltage, etc.)
I tried Nylon/Formic Acid 20wt% (4 grams Nylon, 16 grams Formic Acid but it resulted in short, discontinuous fibers and sometimes the solution dropped directly on the collector. Any help is greatly appreciated. Thank you.
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Dear all, fiber diameter is function of solution viscosity, usually the simplest way to controle it is via temperature up or down, since the stretchability increases (temp. up) and decreases (temp. down) with temperature.
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I prepare TiO2 compact layer with spin coating on to the FTO surface then , I prepare TiO2 nano fibers with electrospinning technique but after calcination at 500c 2h, fibers disconnects from the surface, how İ can solve this problem? ( I heat the furnace gradually to 5c/min)
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Because the surface tension changes when it dries up.
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I am currently working on electrospinning of polymers. I am looking for a solvent that can dissolve polysulfone or PVDF-HFP, but it is almost immiscible in water and alcohol. Also, I would prefer that the solvent is available on the market. Does anybody have a suggestion? 
Thank you
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Acetone dissolves PVDF-HFP properly with some heat
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Looking forward to make polymer-nanocomposite based fiber film for temperature sensing in the range 25 to 40 °C. Looking for such polymer which will be flexible, and can be electrospin easily.
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Dear all, please have a look at the following review paper. My Regards
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I am making PVDF solution for electrospinning, I only have DMF and acetone as solvents, so can you tell me the optimal conditions for this process? (ratio, temperature, time, stirring speed). Any other chemicals are fine, I'll buy them but please let me know the mentioned conditions.
Thank you.
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Dear Tran Khanh, please have a look at the following RG thread and the attached file. My Regards
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Ladies and gentlemen... I want a guide explaining the electrical nanofiber system
How to use the electrospinning nanofiber system
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Here a couple of good references showcasing a comprehensive overview of electrospinning methods and relevant parameters for the process:
  • Xue et al., Electrospinning and Electrospun Nanofibers: Methods, Materials, and Applications, Chem Rev 119(8): 5298–5415 (2019)
  • Electrospinning fundamentals, Chapter 2 in: Nanofibres in Drug Delivery (2018) by G.R. Williams, B.T. Raimi-Abraham & C.J. Luo, UCL Press
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PBS poly(butylene succinate) electrospinning process conditions.
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Dear H. Bilge Isgen Cebisli, literature is full of investigations on the matter subject of the question. The following references are only examples. My Regards
10.1016/j.polymer.2005.07.100
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I am wondering if there are natural or synthetic polymers for electrospinning bearing negative functional groups?
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I'm electrospinning 10%wt PLA in Chloroform:DMF at a ratio of 2:1. The solution dries up and clogs the tip after about 5-10mins. Could this be due to the low outside temperature and humidity during winter increasing the solution's viscosity?
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you can increase the ratio of DMF to make the process more electrospinnability. Regarding increasing the humidity, you can increase it by using humidifier.
Best Regards
Dr. Bilal Zaarour
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I am looking for studies that investigate the effect of electrospinning parameters (solution and process parameters) on the thermal stability of nanofibers. Generally, the effect of nanofiller concentration on the degradation temperature was studied and TGA analysis was not applied for investigating the effect of process parameters on the weight change and degradation temperature.
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Dear Ümran Aşçı, it is very expected that a strong influence of electrospinning process parameters strongly influence the thermal features of fibers. This is because different morphologies/microstructures are built up. Variation in Tm, Tg, degradation threshold temp., and swellability, all varies accordingly. Please have a look at the attached sample document. My Regards
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I came across papers where researchers have used multiple polymers including both synthetic and natural for synthesizing electrospun nanofibers. But if we use these nanofibers in photocatalytic applications like degradation the polymer gets evaporated during calcination because we have to use the photocatalyst in powder form. So what remains the purpose of using multiple polymers?
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Matheus Mendes thaks for your valuable suggestion
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Does anyone know what causes the current leakage to the nozzle pump during electrospinning?
During vertical electrospinning with ionic liquid, at high voltage, for example, 20 kV, an electrical current of 40% is established and the nozzle pump starts to sound. The %current increases with increasing voltage. (The numbers change each time the test is performed)
For testing, electrospinning was done with PVA solution (low conductivity solutions) and I still have the same problem.
I completely isolated the location of the syringe on the pump and I still have this problem.
The nozzle pump device has an earth connection wire.
The High Voltage power supply we used has the following characterization:
0-40 kV range, with a maximum current of 0.75 mA.
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Hello,
It is normal to have leakage current in the nozzle pump. In order to remove this current from the system, the pump must be grounded. But I see that your main problem is that the pump is exposed to the electric field. Moving the pump away from the electric field as much as possible will reduce this leakage current. You may want to consider pumping the solution into the nozzle with a PTFE or PE hose. Also make sure the power supply is grounded and ground or negative high voltage must be connected to the collector. We can help you better if you picture how you set up.
Best regards.
The attached figure is taken from the article below.
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I am preparing PVDF solution for electrospinning by mixing 20 wt% PVDF in 7:3 DMSO:Acetone and stirring it at 75°C and 1000 RPM. But every time almost after an hour of preparation it is turning yellowish and too much viscous such that in middle of experiment syringe and needle gets jammed. I am not able to perform electrospinning for more than 30 minutes due to this.
What could be the possible reasons for this (such as lower ambient temperature, inappropriate solvents, solvent ratios, or any other )?
How can I overcome this problem?
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In electrospinning after depositing nanofibers on Al foil, after how much time the foil can be taken out from the mandrel? Can we keep it on mandrel for some time to get the collected mesh solidified?
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You can take out the foil out of the collector just after the collection of NFs material on the collector. But in some cases if the temperature conditions are not given and the collected mesh is somewhat not pure solidified you have to process it through some temp. Condition or leave it in room temperature unless it gets solidified.
Here is a recent paper of mine in which i have fabricated electrospun nfs at room temperature and the whole process have been given over there. i hope it would help you
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I was trying to electrospun a nano-fiber sheet used as electrode. The material I used is 14wt% PAN (150,000 MW) solution (solvent: DMF). The PAN solution was electrospun directly onto a Nickel substrate (Fig 1). After electrospining, this sample undergoes following heat treatments.
1. 240 degree C in muffle furnace for 2 hrs. Heat rate 1 deg C/min. Air atmosphere. To make the PAN from a thermoplastic to a thermoset material. (Fig 2)
2. 900 degree C in tube furnace for 1 hr. Heat rate 5 deg C/min. Argon atmosphere. To carbonize the PAN and make it electroconductive.
However, after the carbonization process, the PAN sheet shows a severe deformation(Fig 3). Looks like it is shrunken. And the Ni substrate bent. (Fig 4)
I was trying to make the PAN sheet covering the Ni substrate entirely after carbonization. Anyone knows the reason for the deformation of PAN sheet? Any suggestion on how to modify the process?
Thank you!
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The reason for the deformation is internal tension within the nanofibers. The polymers get stretched during electrospinning and when the solvent rapidly evaporates the polymers remain in a configuration with low entropy/high order. When you heat the polymers they can move relative to eachother and coil to reduce entropy. This causes shrinkage and deformation.
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Can we use electrospun PVDF mat for temperature sensing? If yes, how to make an effective PVDF solution for electrospinning?
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After synthesis of electrospun solution via sol-gel process, the solution is ready to be filled in the syringe to be electrospun. By which methods we can check the viscosity of this solution.
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Dear Ankush Sharma, I think a Brookfield viscometer is the simplest tool. In the following paper it is mentionned the range of viscosity for electrospinning, but it depends on many other parameters, such as polymer type, MW, concentration, quality of the solvent, and so on. My Regards
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while doing electrospinning fibre is getting attracted towards needle and making a connection of floating fibre from collector to needle which is interrupting in fibre deposition. Lease suggest its solution and explain the reason behind this
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During fabrication of nanofibers via electrospinning process, the voltage applied plays a very major role to ensure the fabrication of fibers having aligned, beadless and smooth surface. So, make ensure to vary the voltage and then find the best voltage during fabrication for a particular solution as different materials are electrospun at different voltages. I also suggest you to change the distance between the tip of the syringe and the collector, that also plays a major role.
I hope you will find you solution by doing this.
Have a happy research journey.
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Hello
I dissolve PVDF using DMaC/Acetone(1/1 and 6/4 mixture) and heated to 60 degrees to melt well.
And the solution was used for electrospinning, and the solution was cooled.
When i want to use the solution again, I raise it back to 60 degrees, but the solution doesn't become clear...
I don't know Why the PVDF solution doesn't melt again..
If you know, Please help me..
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My suggestion is to grind the mass and redissolve it again. There will be some changes due to the mechanical degradation. This may help you to continue your work. My Regards
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Does anyone have experience of a fault in an electrospinner which causes voltage to leak into the polymer solution/line?
Video attached to demonstrate electrical 'lightning' trying to ground itself from the syringe fittings. Burning appears within the polymer line.
Syringe is clean/there are no leaks. You receive a strong static electricity type shock if you touch any tubing/syringe/pump/anything conductive near the electrospinner while it is switched on.
I've tested multiple solutions - no pattern HOWEVER low conductivity solutions (with water for example) appear to need much higher voltage than usual to allow electrospinning - can't even get a fibre from PVA:H20 until up near 23kV (and it's still not really a stable fibre) when I should be able to spin PVA:H20 at much lower (9-13kV).
Any help greatly appreciated, even technical staff at the supplier seem stumped.
Thank you!
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Dear Rhiannon,
In the video it seems there is an "electric arc" flowing from the metal (ground) and syringe or the opposite matter of polarity. I guess the problem is that the syringe is electrically connected to the counter electrode, maybe your polymer is conductor and works like a wire so the current "goes up" trough the solution and jumps to the grounded metal clamp. Indeed enhance the isolation could work because you will increase the gap trough the syringe and the metal (ground). I think a fully covered clamp would work better, you could try to put it inside a rubber glove for example because I guess if you doesn't isolate the metal clamp the arc will "jump" just in another region. You could consider increase the gap between the tube and counter electrode, decrease concentration in a way there would be no electrical connection between counter electrode and the extremity of the "delivering tube". You should have coulombic attraction of charged particles in direction of counter electrode and not a electrical connection it means the current should be Zero. But it is just a guess !
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electrospinning, PLA, DMSO
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could you dissolve PLA in DMSO?
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Hi,
I would like to know if anyone has cut their electrospun material before into small round disks? Which precision device did you use (or can recommend) and did it disturb the morphology/architecture of fibres during the process? I do not have access to a laser cutter. I think a regular hole puncher would damage my fibres.
I am working with PCL electrospun fibres and would like to cut them to disks with a diameter of 14mm to fit into wells with 15.6mm diameters within a 24 well plate.
Thanks!
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I may also suggest biopsy punch-out knives. We us those to punch circular samples from paper and nonwoven webs. They might be a less expensive way to do this.
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TiO2 has been extensively explored as the Photocatalytic material for a number of applications. what are the current mega trends that are in this field? What are the challenges that are still to be achieved and overcome?
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@francisco thanks for your valuable answer.
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I am currently doing an Electrospinning project, and I need to create an Hydroxyapatite solution that yields fibers. I plan to grind up HA into a powder and disperse it through Acetone (or IPA if I do not have enough Acetone). Can someone please tell me the steps on how I would approach this? I do not know if I have access to a sonication machine, but I do have a magnetic stirring machine. Any past experience would be appreciated.
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Dear Matthew Lawson, literature is full of studies on this subject. Please follow these references. My Regards
10.1166/jnn.2017.12620
10.1111/j.1151-2916.2004.tb06351.x
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I am looking for studies on neat PEG electrospinning. Generally what I found is electrospinning of PEG with other polymers or nanomaterials.
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Following is another interesting document on PEO electrospinning. Good Luck
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When electrospinning polyhydroxyburyrate (PHB) dissolved in chloroform or dichloromethane, it often solidifies and clogs the needle. It has to be cleaned from time to time.
How to avoid this clogging?
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Dear Prajakta Bhende, what are the solution concentration and flow rate ? My Regards
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I am currently trying to dissolve Hydroxyapatite pellets in Acetone to create a solution for nanofibers created in an electrospinning system. Other dissolving agents are available (such as isopropyl alcohol) though I am hoping to find advice specifically for acetone. I am mainly having trouble finding the volume percentages, how much of each must be used to obtain roughly 67 ml of solution and still create nanofibers. Any help would be appreciated, thank you.
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Hi dear Matthew Lawson.
You don't need to solve hydroxyapatite and also it never solve 😃 you just need to disperse HA.
Iso propyle acohol (IPA), acetone and ethanol are popular solvent to disperse the HA and need sonnication and after this procedure, you can electrospin 👌
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Good evening everybody;
I am doing a research to produce a nanofiber membrane for HEPA (H14) filter production via electrospinning.
I have some questions:
1. I am spinning on a nonwoven substrate, should I calculate its area density (gsm) in the total gsm of the spun mat?
2. how could I judge on electrospun nanofiber based on the air permeability test results? i.e. I will check it according to standards (e.g. EN ISO 9237), the values will decrease by increasing gsm, when can I stop (range in mm/s)? before doing filtration efficiency test.
3. with your experience; should I keep some beads in the nanofiber web? or the spun mat should be beads-free? in literature both points of view are found.
Best Regards,
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Dear Jafar, thank your for posting interesting technical question on RG. Please note that I'm not a specialist in this field, as we are synthetic inorganic chemists. However, can suggest to you the following potentially useful articles which might help you in your analysis:
Air permeability of nanofiber membrane with hierarchical structure
This article is freely available as public full text on RG, so that you can download it as pdf file.
Optimization of electrospinning parameters for polyacrylonitrile-MgO nanofibers applied in air filtration
and
Incorporation of Electrospun Nanofibers Into Functional Structures
(see attached pdf file)
For the second part of your question ("how could I judge on electrospun nanofiber based on the air permeability test results?") the following RG links should be quite informative:
In vivo evaluation of electrospun poly (vinyl alcohol)/sodium alginate nanofibrous mat as wound dressing
and
Design of polyamide nanofiber air filter media with glass particles
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Hello,
I would like to measure the residual charge of the beads and fibers after electrospinning and compare them together. I would appreciate it if someone would introduce an experimental method for this purpose. Based on my educational guess, the beads should have a lower residual charge density than the fiber. Does anybody know a reference to support or reject this idea?
Thank you,
Iman
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Hi Iman
I have no direct answer but some names to start looking for help:
Have a look at Schreuder-Gibson work as a starting point, she was one of the first to look into charge retention on electrospun structures. For ideas on measuring charge on spun fibers, I would check the work of Urszula Stachewicz at AGH.
Regards
Marc
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For preparing TiO2 /PVP nanocomposite by electrospinning, I mixed a TTIP/2-propanol (20 wt%) + 2 mL glacial acetic acid + 2.5 mL PVP/2-propanol (10 wt% or 8 wt%). Upon dropwise adding TTIP/2-propanol (20 wt%) to acidic polymer solution the solution turned cloudy instead of remaining transparent (used PVP is 360,000 g/mol).
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Thank you very much for your answer Soraya
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At the moment of meassuring a polymer viscosity which one would you recomend? reomether, digital viscosymeter or glass viscocymeter.
It's for a biopolymer in solution that's is undergoing electrospinning.
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Dear all, since it is concerned by electrospinning, knowing the MW and the range of viscosity/concentration are essential for the electrospinnability. Capillary viscometers are nowdays fully automated, the operators errors are at least significance. So, I recommand an Ubelhode viscometer. My Regards
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Electrospinning of Insoluble PVA nanofiber
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Dear Racheal Afolabi,
  • Water + 0.2 M NaNO3 + 0.01 M NaH2PO4 at pH=7 at 25˚C
  • Water + 0.25 M NaNO3 + 0.01 M NaH2PO4 at pH=7 at 25˚C
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I am trying electrospin chitosan with 50%, 70% and 90% acetic acid, 23kV and 10cm distance from the needle to the collecting drum. Any idea how i can get fine nanofiber without beads. I am to encapsulate an active ingredient, thus i cannot use TFA in the process.
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Dear all, electrospinnability of chitosan is mainly a function of the three following operating parameters : 1- degree of (de)acetylation, 2- MW, and 3- concentration. Monitoring these three parameters lead to a successfull process. The following documents delimit the processability window for chitosan electrospinning. It is worth also to mention that needleless electrospinning gives also another easy solution for chitosan electrospinning. Please check the following documents. My Regards
DOI: 10.5772/intechopen.76037
10.1016/j.carbpol.2017.08.115
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Hello, everyone!
I am using metal oxide/Graphene composite and electrospinning it using PVA/Water polymeric medium. When I deposit on the aluminum foil the surface is uniform with fewer flakes. I am speculating that this may be due to the polymer/solvent non-uniform evaporation from the surface due to annealing (450C for 2 hours). Can anyone suggest something from their experience about the annealing of metal oxide electrospun film for robust adhesion and uniform deposition? is these flakes normal? or do I need to change the polymer or solvent?
thanks in advance.
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This looks like it could come from the low wettability of the water on your substrate. You could measure the contact angle with your solution to make sure. In case this angle is effectively high you could try to do a plasma treatment of your substrate to increase wettability (if it can support it) but the best option would probably be to change the solvent.
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Hi !
I am getting very thin membranes from electrospinning, so it is difficult to perform a mechanical characterization in a universal testing machine. Is there any form that is useful for estimating the tensile strength and / or elastic modulus of nanofibres?
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See the paper: How Nanofibers Carry the Load: Toward a Universal and Reliable Approach for Tensile Testing of Polymeric Nanofibrous Membranes
Macromolecular Materials and Engineering, 2021, 2100183
Currently, ASTM or ISO standards for tensile properties evaluation of electrospun nanofibers/nanofibrous mats are not available.
Most researchers recommend using a paper frame to fix the nanofibrous membrane for preventing nanofibers damage and better handling the specimen.
However, a more critical problem is the correct normalization of the force recorded by the load cell during the tensile test to obtain the stress-strain curve and, consequently, calculate elastic modulus (Young's modulus) and strength. Indeed, to calculate the stress, the membrane thickness measurement is necessary. However, the measured thickness is affected by the pressure applied to the porous mat during its measurement, so it is impossible to measure the "right" thickness and, as a consequence, the specimen section. To bypass this problem, a load normalization based on sample mass instead of its cross-section area is helpful.
Since the mass measurement is reliable, the calculated stress, elastic modulus, and strength are, in turn, reliable. Furthermore, this method reduces errors in load normalization owing to any thickness variation in the specimen, and the contribution of the mat porosity is discarded. Moreover, it is very powerful when dealing with membranes with a very low thickness, being in such cases the thickness measurement very tricky and completely not reliable.
More information about the tensile test data normalization based on specimen mass (and other very easy-to-measure quantities) can be found on the research article:
---> How Nanofibers Carry the Load: Toward a Universal and Reliable Approach for Tensile Testing of Polymeric Nanofibrous Membranes
Macromolecular Materials and Engineering, 2021, 2100183
This paper also presents a data fitting model applicable to tensile test data of nanofibrous mats, as well as the effect of nanofiber diameter and nanofibers crossings on the tensile behaviour of membranes made of nanofibers.
See also the following videos:
---> How to correctly prepare nanofibrous mat specimens for tensile testing
---> Reliable tensile testing of nanofibrous mats
In the following papers, the proposed mass-based normalization method was positively applied to different nanofibrous mats, even rubber (elastomeric) nanofibers:
---> Rubbery nanofibers by co-electrospinning of almost immiscible NBR and PCL blends
---> Morphology, thermal, mechanical properties and ageing of nylon 6,6/graphene nanofibers as Nano2 materials
---> Rubbery-Modified CFRPs with Improved Mode I Fracture Toughness: Effect of Nanofibrous Mat Grammage and Positioning on Tanδ Behaviour
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Hello,
From experience I know that the majority of electrospun mats are quite fragile, just the process of getting them off the collector can introduce stretching into the fibers.
I've tried sticking the electrospun mat on to a template and and then testing it, but one issue with that is the films often snap close to where they are glued onto the template, which makes me think the glue introduces some sort of stress concentration at the point it is applied (change in fiber shape, etc).
I've not been able to find a standard method for testing the tensile properties of electrospun mats, if there is one please share it...
Thanks
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Currently, ASTM or ISO standards for tensile properties evaluation of electrospun nanofibers/nanofibrous mats are not available.
Most researchers recommend using a paper frame to fix the nanofibrous membrane for preventing nanofibers damage and better handling the specimen.
However, a more critical problem is the correct normalization of the force recorded by the load cell during the tensile test to obtain the stress-strain curve and, consequently, calculate elastic modulus (Young's modulus) and strength. Indeed, to calculate the stress, the membrane thickness measurement is necessary. However, the measured thickness is affected by the pressure applied to the porous mat during its measurement, so it is impossible to measure the "right" thickness and, as a consequence, the specimen section.
To bypass this problem, a load normalization based on sample mass instead of its cross-section area is helpful. Since the mass measurement is reliable, the calculated stress, elastic modulus, and strength are, in turn, reliable. Furthermore, this method reduces errors in load normalization owing to any thickness variation in the specimen, and the contribution of the mat porosity is discarded. Moreover, it is very powerful when dealing with membranes with a very low thickness, being in such cases the thickness measurement very tricky and completely not reliable.
More information about the tensile test data normalization based on specimen mass (and other very easy-to-measure quantities) can be found on the research article:
How Nanofibers Carry the Load: Toward a Universal and Reliable Approach for Tensile Testing of Polymeric Nanofibrous Membranes
Macromolecular Materials and Engineering, 2021, 2100183
This paper also presents a data fitting model applicable to tensile test data of nanofibrous mats, as well as the effect of nanofiber diameter and nanofibers crossings on the tensile behaviour of membranes made of nanofibers.
See also the following videos:
How to correctly prepare nanofibrous mat specimens for tensile testing
Reliable tensile testing of nanofibrous mats
In the following papers, the proposed mass-based normalization method was positively applied to different nanofibrous mats, even rubber (elastomeric) nanofibers:
Rubbery nanofibers by co-electrospinning of almost immiscible NBR and PCL blends
Morphology, thermal, mechanical properties and ageing of nylon 6,6/graphene nanofibers as Nano2 materials
Rubbery-Modified CFRPs with Improved Mode I Fracture Toughness: Effect of Nanofibrous Mat Grammage and Positioning on Tanδ Behaviour
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Dissolving of polymers for electrospinning.
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Dear Racheal Afolabi, the attached files cover many aspects of PEO electrospinning. My Regards
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Thank you everyone for your answers
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I had experience in electrospinning and my phd is ongoing on this instrument.please contact to s.ankalgi99@gmail.com or WhatsApp +919370654969
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I have tried to do it in mixed solution 1:9 v/v% DMF: DCM at 12%w/v. But fibers have a few beads.
#electrospining# PCL#PEG#fibers#nano#micro
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No thanks, it depends on the MWs, the higher they are, the longer time is required (assuming they are in good solvents mixtures). In general, I have seen from 2 hours to few days. Best of Luck in your work.
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I tried to prepare CNF via electrospinning. The Taylor cone was seen to have been formed and the spray looked quite good. However, after the spinning process, a powder-like material (which can easily be wiped out by rubbing the surface of the aluminium foil) was deposited instead of fiber mat. I would appreciate all your suggestions please.
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The solution looks quite viscous. Polymer (3g) + 0. 5ml phytic acid in 16 ml DMF/acetone (1:1) Nooshin Banitaba
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I want to use PLA polymer for electrospinning. Recently I have used it with DCM but it freezed very quickly on the tip of the nozzle. Any solution for this? 
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For electrospinning PLA, solvents such as DMF and DCM are a good start to formulate a polymeric solution.
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The effect of the material type, whether it is crystalline or amorphous.
The temperature at which the polymer decomposes.
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For water filtration applications, we find PVDF (semi-crystalline polymer, m.p ~ 177 C) as one of most suitable candidates for water filtration. In our experience with it in the lab, we find it to be appropriate because of its inertness, biocompatibility, and porosity that enable excellent filtration capabilities.
However, it is not the only one. You can consider other electrospun polymers such as, Cellulose Acetate, PES, and PAN.
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I'm working on setting up (bespoke) Electrospinning machine (multi emitter syringe pump, high voltage power supply, rotating/flat collector, etc. I'm thinking to perfrom hot electrospinning of the polymer (polyvinyl alcohol PVA) at a higher temperature ~ 250 DegC.
The questions I have in mind are the following:
i. Has anybody done this or similar to this kind, before or even is it possible?
ii. The problem is that the PVA polymer is in powder form and I don't want to load the syringes with aqueous solution of PVA; as I'm after 100% electrospun PVA nanofiber membrane.
Is there any method or machine unit that is available to do the job; to melt the PVA powder (melting point of PVA is 210 DegC) and somehow simultaneously electrospin onto the collector?
Actually, the problem is melting of the PVA powder is a separate process, then manually infusing into syringes (pipettes) is another and then at last loading on to the syringe pump for electrospinng, therefore, all experimental steps are performed at different temperatures. I know if I left the molten PVA in the syringes it will solidify and block the syringe barrel and also emitter needle, and syringe pump will also not be operational...
Shall wait for any advice from you guys.Many thanks for your time and support.
Best regards,
Baber
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PVA is more suited to solution electrospinning as it is a water-soluble polymer. However, for the case of melt electrospinning, it is best to consider high temp. durable grade material for components when setting up a melt electrospinner. Peripherals such as the container, pumps and tubes need to withstand high temperatures. In addition to this, you may need to think about setting up a heating compartment for the polymer-filled syringe or container to maintain the temperature when the polymeric melt (liquid polymer) is pumping all the way to anode, it should not cool down and solidify before reaching the HV anode.
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Is it possible to electrospin freeze dried cellulose nanofibres extracted from plant material?
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Of course, possible. make sure that cellulose nanofibers could not damage because of the vigorous stirring.
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My question is very basic since I'm starter in the field of electrospinning. I want to prepare a PAN/gelatine blend by following the parameters already given by literature, but I don't understand the instruction of the solution preparation.
How should I exactly understand the following sentence " The spinning solution contained 16% PAN in DMSO and 9% gelatine". I can understand this in 3 ways:
a)A PAN solution with (16%wt) in DMSO and a gelatine solution (9%wt) in DMSO were prepared separetely and mixed together.
b) A PAN solution with (16%wt) in DMSO was prepared and afterwards gelatin was added to it so that the gelatin content at the end is 9%wt of the total solution mass
c) The solution was prepared in a way that the final solution consisted of 16%wt PAN and 9%wt gelatin.
Thank you!!
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I suggest you read these papers:
1. Maneuvering surface structures of polyvinylidene fluoride nanofibers by controlling solvent systems and polymer concentration. Textile Research Journal. 89 (12), 2406-2422, 2019. DOI: 10.1177/0040517518792748.
2. Controlling the secondary surface morphology of electrospun PVDF nanofibers by regulating the solvent and relative humidity. Nanoscale research letters. 13 (1), 285-295, 2018. DOI: 10.1186/s11671-018-2705-0.
Best Regards,
Dr. Bilal Maan Zaarour
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Does anyone know what these strange structures (A,B,C,D,E) could possibly be?
Some informations that might be useful:
-This is a PAN nanofiber mat (10%wt in DMF) that was electrospun with a NanoSpiderTM NS Lab 500 S (Elmarco s.r.o., Czech Republic) using a wire electrode.
-These SEM images were taken few hours after the mat was electrospun (-> There might still be some solvent in the mat)
-The same structures are also present in a mat electrospun months ago by another person in the same lab (this mat was vacuum dried for days). Since this mat was stored for a long time, I tought that these structures could be microorganisms. But if this was true, these structures shouldn't be present in the mat that was electrospun today.
I would appreciate any theories/ideas about what these structures could be.
Thank you!
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Hi
This strange structure does not seem to be a microorganism and is related to droplets. These defects in nanofibers are generally observed due to the low concentration of the polymer solution or the short electrospinning distance. It may be possible to minimize these structures by changing electrospinning parameters such as increasing the electrospinning distance and using the optimal voltage, etc.
Good luck
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I'm Juan Carlos, a high school student who is working with electropinning, I made an electropinning machine with a 21g needle and a 30kv high voltage source and the distance between my needle is 5cm (these conditions are already complex that I would not like to know if in their research they obtained that the higher the density, the higher the high voltage must be or if there is any relationship because the electrospinning worked twice but I did not know the density (it was more than 20w/v) and now that I try to find the density trying No I can find it. the solution is pva,i already tried with 20,25,30,35,40 (w/v) without any dopand. i should tried with w/v less than 10w/v? (i dont have a bomb).you can check the video o from one of those times that worked. and the drop is de pva with silver nanoparticles.but now i only lokking for pva electrospining without something. the power supply is a half of medium wave rectified