The best electret material?


The best electret material?
« on November 13th, 2015, 03:53 PM »Last edited on November 13th, 2015, 08:39 PM by Cycle
I got to thinking about electret batteries. Usually, it's a combination of carnauba wax, beeswax (to make the material less brittle) and rosin. You melt the wax and rosin together, then pour it into a mold that's got a high voltage across it. Once the wax hardens, you've created the electrical equivalent of a magnet.

Now, in another thread, I'd said that single-atom-thick graphene sheets would spontaneously convert to diamond at room temperature when exposed to pure hydrogen. And what is the dielectric strength of diamond? 2000. That's compared, for example, to 3 for air, 173 for Teflon, 25 for lead zirconate titanate, and 2.9 for carnauba wax.

So, if we were able to align the molecules of graphene in a high voltage electrostatic field prior to introducing hydrogen and causing it to convert to diamond, we'd have a diamond that was an electret, with the hardness to withstand "de-electrification" (the electrical equivalent of demagnetization).

I'd discussed a method of growing large graphene sheets in a sugar bath here:
6) An easy way to make large-sized graphene: sugar. Yeah, sounds weird. But graphene is "self-repairing" when it's in contact with carbon-rich compounds such as sugar or hydrocarbons and subjected to energetic conditions. It'll grab carbon from that carbon rich compound and add it into its matrix of graphene, growing as it goes or repairing any holes in itself. So you put graphite powder and soapy water (ie: water and a surfactant) into a high-speed blender to shear out small graphene patches, blend on "High" for a long time, separate out the graphite from the graphene, wash out the surfactant, paint a plexiglass sheet with sugar water, let it dry, paint the plexiglass sheet with the graphene, then hit it with a laser to provide the energy for the graphene to grab the carbon from the sugar and self-replicate / self-repair into a contiguous sheet of graphene. Once you're sure your graphene is contiguous, wash with water to remove impurities.

7) I wonder if it would be possible to grow graphene in-situ... in a sugar water bath within a square transparent container, you start with a small patch of graphene that was cleaved from a hunk of graphite, hanging in the water from an attachment at the top of the container. You hit the hanging graphene with a laser to provide the energy to the graphene to requisition that carbon in the sugar water for itself in order to grow / self repair. The graphene should self-assemble into a contiguous sheet around the hanging graphene patch. Since you can control where the laser points, you can control the size and shape of the graphene sheet you're constructing. Because it's in a sugar water bath rather than on a substrate, you don't have to worry about contamination or changing the electrical properties of the graphene due to the surface it's being built on, since there isn't one. The assembly process could even be computer automated... pristine graphene (ie: no defects) when subjected to 30-fs pulses from a Ti:sapphire laser exhibits photo-luminescence. So if your laser is hitting a patch of graphene and your photo-detector sees no photo-luminescence, it continues to stay in that spot to build out that section of the graphene sheet. If it sees photo-luminescence, the computer controlling laser position knows to move on to the next spot.
Of course, we could also use benzene (C6H6), acetylene (C2H2), vinylacetylene (C4H4), phenylethene (C8H8), etc., to get rid of the oxygen in sugar (C12H22O11). That'd allow both building out the graphene sheet and hydrogen-converting it to DLC simultaneously. But you'd have to be extremely careful, since the hydrocarbon route is flammable.

So what we'd essentially be doing is creating a DLC (Diamond Like Carbon) film.

The graphene would be in a high electrostatic field (perhaps an air ionizer type setup), laying flat with the emitter of the electrostatic source above, and the graphene laying on a ground plate. You'd lay your graphene in there, seal up the chamber, turn on the electrostatic field, purge with nitrogen gas to remove all traces of oxygen (to prevent explosions) and to "dope" the graphene to improve its electrical conductivity, then introduce the hydrogen while keeping the electrostatic field on. The graphene sheet would spontaneously convert to diamond, and would be "electrified" on each face, so you could stack them together between two plates that would have wires going to your load, and you would get higher voltage. The larger the size of each graphene sheet, the more amperage you'd get.

The only disadvantage to this is that the sheet, once converted to diamond, would be extremely brittle (more so than graphene already is), so it would require very careful handling. But once it's compressed between the two plates of your electret "battery", there would be very little chance of breakage.

One disadvantage of the carnauba wax type electret battery is that you either have to have it hooked to a load, or you have to wrap the wax disc in aluminum foil, or the "domains" (in magnetic parlance) will "flip"... somewhat akin to what happened in the older, softer magnets, which is why they had magnet keepers. With a diamond battery, the material is hard enough to resist this.

Because we'd be using a pristine graphene sample (ie: it's "built out" so there are no flaws in it), the resultant DLC would also be flawless, with no grain boundaries or defects which act as charge trapping and recombination centers, lowering the output capability of the DLC, thus we'd have a high-output permanent voltage.


Re: The best electret material?
« Reply #1,  »Last edited
Sorry for picking up this 2 yr old thread, but I just wanted to throw in a suggestion: I've heard of ceramic electrets, and  you can make what is called a "Chemically Bonded Phosphate Ceramic" (like Ceramicrete) very easily:

Now I have absolutely no evidence to suggest that this might actually work, nor equipment to try it out myself, just a hunch: that if you mix up the components in a watery slurry, and place it in a strong electric field as it hardens (in just minutes), it may possibly "freeze" as an electret.
Again, this is just a hunch.
Best regards,


Re: The best electret material?
« Reply #2,  »
You may be on to something radon.  Your post made me think of another medium we could use.
The plastic glue that hardens when UV light hits it.


Re: The best electret material?
« Reply #3,  »
Quote from chuff1 on November 22nd, 2017, 06:00 PM
You may be on to something radon.  Your post made me think of another medium we could use.
The plastic glue that hardens when UV light hits it.
That would be really interesting to try out.. and better than Ceramicrete.for small controlled applications.  cf : Printed Electrets, a la Searle's Printed Magnet idea.