I wish to perform electrochemical study for a TMDC but I am unable to get a fine film for it. Please suggest binders or any other possible methods for it.
Thanks
Hi Ankita Singh
More information are needed about the method you have tried to make this film.
However, I think you could apply a biopolymer like chitosan, for example. You need to investigate if one of the different types of chitosan has the potential to incapsulate what you want and make a film of it. Or maybe you might make a complex involving chitosan with Ag or Au to bind with TMDC.
Hello Ankita,
It's difficult to be very specific, without knowing your experimental intent, however, some possible methods for thin/thick film production are:
Method a) Fibrillation bonding with PTFE (produces a handleable flexible material of limited mechanical strength, suitable for a stand-alone electrode.)
The Dichalcogenide material is first comminuted mechanically to a fine powder
Al Holmes thank you for your suggestion i used ptfe dispersion in 70 percent water with my powdered samples but i end of getting cracks in the film. What can be done for it?
Thanks
Hello Ankita,
I have used the PTFE dispersion route on Carbon/Molybdenum Oxide, Carbon/Zinc Metal & Aluminium Metal / Carbon/Silica mixes to produce ‘film’ pieces about 24mm x 35mm and for use in electrochemical experiments.
I believe that the technique should work with TMDC’s if the following are addressed:
1. Stability (suspension & pH control during storage) of the PTFE dispersion - the dispersions can deteriorate during storage as regards suspension of PTFE, and the container should be ‘rolled’ or mixed for 20min pror to using. (what material are you using?)
2. Particulate sizing control of material to be bonded, then mechanically mill with PTFE dispersion/water/methanol. Back-calculate to assure quantities will give sufficient PTFE in cured material for adequate bonding, after loss of volatiles in thermal cycle. (but no more than about 10%w/w PTFE present in ‘film’ after heat treatment)
3. Pre-dry the ‘screened’ film under a regime that prevents cracks from occurring, preferably a slow dry-out at room temperature, prior to a ramp and dwell heat treatment cycle.
4. Example: 12 hours drying of film at 55RH and 20-25C prior to the heat treatment cycle.
5. Ramp from room temperature, & hold at 100-120C for 0.5H to drive off residual water, then ramp @ 7C/min to around 300C, followed by Newtonian cooling in the oven down to about 45C.
6. Material can also be screened onto glass-fibre filter paper for better strength.
7. Note: the materials produced by PTFE bonding are not ‘Perfect’ films, merely easily handled , semi-flexible electrode materials of fairly low mechanical strength.
8. Some variation of the above may be necessary to deal with the TMDC species.
Regards
Alan Holmes
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