I have synthesized polyaniline by simple chemical oxidative method then dissolved it in NMP and used PVA for making this solution viscous. Then used this solution for electrospining. I got good coating of fibers on IDE. But when I was about to check connectivity of that fibers at Lab level by digital multimeter, it was not showing any connectivity. I have tried PMMA also instead of PVA but still I am facing same problem.
Try interfacial polymerization method for the synthesis of polyaniline nano fibers............i am sure you will get nanofibers..........
Thank you Vijay Kumar sir and Yuwei Fan sir, I have done the conductivity study of dried bulk material of Polyaniline by Four Probe method. It is showing good conductivity. And same material I have used for electrospinning by dissolving it into NMP to drawing fibers, but it is nonconducting. I will definitly use PAN for drawing nanofibers in future. Could you please suggest me by which instrument I can measure conductivity of Nanofibers?
I've electrospun PVA and it is non-conductive. What is your wt % of your PANI with respect to your PVA or PMMA? It could be that your PANI loading is too little and the the non-conducting properties of PVA is the major contribution of your electrospun fibers.
I've also electrospun Polyacrylonitrile (PAN), the as-spun fibers are non-conducting at all and have to be converted to carbon nanofibers in order to make the fibers conductive
PVA:PANI ration could play a significant role, since PVA is non-conducting. You could try core-shell (co-axial) electrospinning using PANI in the core and other PVA in the shell side. After spinning, you can remove the polymer in the shell side by using an appropriate solvent and this solvent should be a non solvent to the PANI so that you can get nanofibers of PANI. As John Gan said,you could make the as spun fibers to carbon fibers to make them more conductive.
Thanks John Gan sir and Lijo Francis Sir, I have taken 10:3 wt% ratio of PANI:PVA. I didnt try core-shell electrospining for the preparation of nanofibers. Does it require different type of set up of electrospining? The set up which we have in our lab, having the attachment of only one syring filled by polymer solution is possible.
Thanx Andrew Burris Sir, I refered this paper and from this I got the idea how to remove PMMA from PANI nanofibrs to achive good electrical conductivity of PAni nanofibers and the instrument by which I can measure the conductivity of PAni nanofibers. Thanx a lot and hope you will help me in future also for my work.
when you added PVA, does the color of the solution change?
Apart from the detrimental effect of PVA on the conductivity (insulating matrix), you might have changed the oxidation level of Pani and made it non conducting.
No, the color of Polyaniline solution doesn't change. I have used PVA solution only for making the PANI solution viscose and it become viscose but during electrospinning the coating on the substrate is white-green in color.
So, its Emeraldine base, I think its because of PVA (an insulator).
Yes sir, but now the question is " how can I remove insulating PVA from that synthesized nanofibers?" If I calcine that fibers at 200'C, I got the fibrus structure of PANI disturbed. I thought that PANI got disintegrate at that temperature.
Emaraldine Salt (Dark green or Black Colour) is conductive and You can easily synthesis it in Low temperature like 0-2 centigrates. PANI salt form could dissolve in Xylene . It will work !
Ok Thank you Yasun. I will try for Xylene. But could you tell me, if I dissolved PANI in Xylene then what will be the viscosity of the resulting solution. Means, will that solution be proper viscous so that I can draw its nanofibers from electrospinning technique or I have to use any carrier?
Actually we have to make Nanofibers of polymer with some precursor metal such as zinc acitate and then dip the fabricated Nanofibers in PANi to physically absorb on the surface of Nanofibers. After this use hot plate to remove liquid remaining by evaporation to have PANi coated Nanofibers.
Nirmala Rani
To make the emeraldine base of PANi conductive you need to dope it with an organic acid such as HCSA (a camphorsulfonic acid). Which route do you wish to use to fabricate PANi nanofibers? They can be made via in situ polymerization, electro-deposition, and by electrospinning I believe.I've done electrospinning-based fabrication of PANi nanofibers, see below:
Article Tunable Enhancement of a Graphene/Polyaniline/Poly(ethylene ...
Pallavi Patil The conductivity of the fibers will be in the semiconducting range, we used an SMU (source-measure unit) to apply voltage and measure current simultaneously. Make sure the PANi is acid-doped or it will not be conductive (we used HCSA). Irrespective of the solvent used, you will not be able to electrospin pure PANi, its backbone is too rigid and the polymer isn't large enough to provide sufficient molecular entanglement. You need a carrying polymer--maybe you can remove the carrier after spinning by dissolution or calcination. If the morphology is disturbed during calcination, try covering the sample and/or slowly ramping the temperature 1 deg/min. The melting points of PANi and PMMA are similar though. Most likely, however, you need to use coaxial electrospinning (see the MIT paper I referenced) which requires two separate sol gels, two syringe pumps and a special coaxial spinneret, which some vendors sell commercially now. With coaxial fibers it will be much easier to remove the carrying polymer shell.
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