Is it possible to make Conductive Glue from Sugar Carbon

[Peterae]

OK thought i would give this a go.

An old tin can with some sugar in it heated by a blow torch in GARDEN on bricks makes a quiet coarse glassy carbon, i wanted to see if i can mix this with epoxy resin to test what sort of resistance it has and to see if it's a viable conductive glue.

I did not have a grinding mortar & pestle or ball mill so just used the flat end of a hammer to grind on a piece of paper.

Once ground i mixed a copious amount with epoxy resin and painted a strip.

Once it dries tomorrow i will try measuring it's ohmage.

So what do you think, MOhm,KOHM, 100's OHM, 10's Ohm  for 1cm of the painted strip.

[ion]

Interesting experiment Peter, but I can't even guess at the resistance you will wind up with.

[muDped]

Aye, very interesting experiment.  This is how we find the
answers to our questions!

When you heated the sugar to thermally decompose it
did you heat it to red heat?

Was the resultant carbon lump similar to graphite when
you crushed it into a powder?

We did this experiment (or something very similar) in
high school chemistry back in '57.  I think we discovered
that newsprint (newspaper) without the glossy colored
inks produced the best electrical carbon.  Possibly
because the black newspaper ink is powdered graphite.

We heated it in a test tube to red heat sealed from the
air as much as possible.

I wonder if high school chemistry classes today do the
same sort of experimenting?

[Peterae]

Thanks for taking a look guys.

The carbon was pyrolyzed, the water and hydrogen was burnt off during the process, quiet a vigorous reaction, big flames etc.

As i understand it a temperature of around 1300 Deg C is required to turn it to graphite, no i did not heat it until red

My this will be a total flop, results will be posted shortly 

[Peterae]

OK tested it.

Well done Dumped.

There is no conduction that i can see, not even a Meg OHM reading, so it looks like glassy carbon is a bad candidate for conductivity, although it could be the insulating epoxy as well maybe.

Looks like i need to give some graphite a go.

[Peterae]

I just tried conductive pencil lead ground up and mixed with epoxy resin, and there is no sign of it conducting when mixed with epoxy, yet without the epoxy i can measure it if drawn on paper, so i conclude that Epoxy 2 part resin glue is no good for this purpose, also worth noting is that the cheap conductive glue on ebay can be diluted with water, so it looks like they are using something like gum arabic to carry the graphite.

Also well done dumped, i took a lump of glassy sugar carbon and measured the lump for resistivity and i could see no measurement, i then heated using a butane flame to red hot and re measured the glassy mass, and it now reads 10's of ohms, yet it's appearance seems the same, still looks glassy and has no sign of graphite slipperiness between fingers, infact my fingers appear quiet clean after crumbling a lump, so i conclude from this that i have not made Graphite as the red glow colour is way too low a temperature but instead it must have burnt enough impurities off to allow conduction.

It is usable i would say in this form, so sugar carbon does indeed conduct but only after heating for a few seconds to red hot  

Thanks Dumped you were spot on.

Next i need to try some different gums or glues.

[Paul-R]

I think you should be concerned about the strength of your "glue". I hope you are not planning to glue magnets on to a rotating wheel. This could end up in tears.

I am pretty sure I contacted Ciba Geigy (actually now owned by Huntsman Advanced Materials) a while back on this very issue. I didn't get what I wanted but I am wondering if I got anything at all. I will try again.

[Peterae]

Hi Paul-R

It's not really meant to stick things and be structurally sound, it's meant to provide an electrical path, for instance you could paint conductive tracks or glue metal foil electrically not structurally.

I am in the process of trying different glues  

Thanks
Peter

[Paul-R]

.
.... a sort of cold solder?
.

[Peterae]

Yeah indeed, it would be possible to join components up using it, chips etc just by painting wires from the chip pins to the components, but i am not yet sure what the resistance is like, i doubt it would be really low ohms, but circuits that don't mind 10-100 ohms in the wires could certainly be made.

[Peterae]

OK i tried a naphtha petroleum based carpet spray glue, does not work.

I tried PVA waterproof glue and i am getting a reading of about 1.2 MOhm for a thin 1cm strip, so the first water based glue is showing signs of working.
Lots of room for improvement yet.LOL

[Slider2732]

Oh i'm all about this right now (sorry Peter, I think it's an Amercanism i've picked up)

I think the key to it is a thin glue, good carbon and then scrubbing the stuff like graphene to a very thin 'height' if the resistance proves unwieldy.
Am basing it on recent graphene experiments and the work of our buddy Robert Murray-Smith of course. He did mention gum arabic in a recent video.

So, which glues are thin, dry completely rather than end up spongy and then what makes the best carbon ?
Is standard white school glue out of the picture if watered down ?

My thoughts were charcoal from all the dead bits of tree in a pile in our back garden. Burn it BBQ style, looking like a BBQ so that authorities and SWAT teams don't turn up, the resulting embers then to be squished with a hammer to a fine powder.

An ink would be great.


Can sugar bond easily ? I would say so, if dissolved well in warm water. Then burn the result after it dries. I wonder if that would be an idea. Perhaps mix dead tree charcoal with it. Might well try that myself as i'd like to make something similar and there must be 'kitchen' routes to stable conductive inks.

[BEP]

I wonder if Mark Goldes ultra-conductor polymers could be made into a printable ink. 
I think TPTB kept him from revolutionizing the power industry. Maybe, a good starting point would be to provide super-conductor like performance in printed circuits 

Carbon, in most forms, is not considered a conductor. At one extreme, it is a very poor conductor then semi-conductor all the way to diamond form where it is and extremely good conductor of heat while being an electrical insulator.

Even graphite conducts current in a very different way than metals.

[Peterae]

Hi Slider

You have a lot of things there, definitely got to try Guar Gum.

From what i have seen so far, it's all about carbon/ glue interface and carbon % composition, the problem is that glue is generally an insulator and therefore we need as much carbon as possible to overcome the insulation impurities, so we will never get really good conduction unless we ditch the glue and compress the carbon into say a rod, graphene is different because it's a pure structure, i think we need thick layers to get resistance down.

The carbon i made from sugar is actually really good, i can take a lump of glassy carbon 1cm cubed in shape and once heat treated as per dumped suggestion to red hot, i can get readings in the low 10's of Ohms, so the carbon is good i think.

I think i am doing it wrong though, i heat treat the glassy sugar lump and then crush it, i think i need to crush it first and then heat treat it because it maybe a case of once the glassy heat treated carbon is broken, it reveals a surface that was not directly heat treated and maybe impurities were not fully burnt off, trouble is that it is so light in ground form it gets blown away by the propane torch, really i could do with a ceramic crucible to fire it.

I am not sure about charcoal, i will give this a go, trouble i can see is that it cannot be heat treated? i mean if you heat charcoal it will burn to ash, and i don't think charcoal conducts, at the end of a BBQ you don't find pure graphite in the ashes but just ashes??

Hi WW
Super conductive inkjet printing could catch on  
I would need to read up on this as i am not familiar with his work
Arie De Gues seems to hint at it by using very thin coatings of metal.

I'm wondering if passing a current through it while drying would increase the conduction, or maybe passing a few KV through the dried wire will carbon the interface between the glue and carbon atoms.

[ion]

For ideas, try Masterbond and Creative Materials

They both have a big line of electrically conductive compounds, glues, epoxies etc.

[Mookie]

Peterae,

I'd be happy to send you a 2"x2 " sample of this made in China multi-layered sheet, if you think it might be useful to you.
Just send me a private PM with your mailing address.

http://www.dhresource.com/albu_767303540_00-1.0x0/wholesale-new-5pcs-lot-cell-phone-heat-sink.jpg

[Peterae]

Hi ION
Thanks for those manufacturer references, amazing they both use Epoxy systems, there must be a trick and the Creative Materials resistance data is eye wateringly low ohmage/cm.

Hi Mookie
Thats a very impressive material, difficult to work out, but it looks like a compression heat transfer system though.