Sciencemadness Discussion Board - Intercalating into graphite

Intercalating into graphite

zenmanenergy - 6-3-2018 at 08:45

I have been watching Robert Murray Smith videos for 3 months now (he has a LOT of content!) I have done a couple dozen graphite reactions along with made many many batches of ink, but I'm struggling with understanding the chemistry behind the intercalation process.

My goal is to make two inks, a p-type ink and an n-type ink. The theory being that if I connect these two together with conductors, provide a heat differential across them it will produce an electric voltage. So far I've produced microwatts, but it's probably just noise or residual acid. I want to get to milliwatts.

The p-types I plan to try are Boron or Aluminum, the n-types I'd plan to try are Nitrogen, Antimony or Bismuth.

First of all, has anyone here been successful intercalating any of these with graphite? If so, would you be willing to share your steps?

I tried AlCl3 hexahydrate four times now, twice using the hummers methods and twice using the RMS's heat pipe method. But I am not getting the same results he is. That said, he just verbally explains how to make it, he hasn't done a step by step video with AlCl3. There may be an inherent problem with the 6H2Os which could be the reason.

I'm struggling to find information on what actually causes some compounds to intercalate between the layers of graphene but not others. Can someone tell me if I'm on the right track and/or suggest things to study? Here is my basic understanding...

The common intercalating agents I've found from reading papers tend to be chlorides (I've tried AlCl3) which dissolve into sulfuric acid producing Aluminum sulfate and HCl. Sulfuric Acid will break the intermolecular bonds between the graphite layers. Then permanganate is added (making a cool...yet dangerous... purple gas!) which is removing electrons, is that causing the ions to bond within the layers of graphene? If not, what is causing the ions to bond between the layers of graphene? I have been unable to find any research explaining this.

[Edited on 6-3-2018 by zenmanenergy]

aga - 6-3-2018 at 09:08

Have you had any success with the 'graphite reactions' based on RMS's videos ?

zenmanenergy - 6-3-2018 at 09:20

Quote: Originally posted by aga

Have you had any success with the 'graphite reactions' based on RMS's videos ?

Yes, absolutely.

Maybe reaction is the wrong term. As I understand it, the IMF bonds between the layers of graphene are really what are breaking. Although the O and H on the edges of the carbon rings may also be breaking. I'm still learning.

I have done numerous batches of graphite in acetone&water sonicated for between 2-6 hours. I have made graphite oxide with sulfuric & potassium permanganate. I have attempted intercalating aluminum chloride in that process a couple times. I have attempted the heat pipe method with AlCl3 with an FeCl3 catalyst into a heat pipe and a toaster oven. Although I don't think the oven got hot enough. I was measuring 200C, i think it needs to hit 230C according to the paper i found on it. I tried a mix of HCl and H2PO4 with the hope that the Ps would intercalate. I thought that was working, but I didn't wash all the acid out and it messed up my results. I have made water based inks using gum arabic, but also a few batches of oil based using polyurethane.

Beyond his videos, I tried intercalating Bismuth Chloride by extracting BiCl3 from Pepto Bismol. That was a bit of a flop. I bought some Bismuth metal and tried to react it with HCl, melted it with a torch to make Bismuth oxide then react with HCl. No luck. I'm going to try Antimony next, but I'm a little nervous as Antimony is apparently explosive at high enough temperatures.

Anyway, yes, I have gotten many of the things he shows to work and have learned piles of information from him. Although he definitely leaves some information out. I suspect it is on purpose as he is creating a battery company and cannot give away all of his recipes.

[Edited on 6-3-2018 by zenmanenergy]

aga - 6-3-2018 at 11:13

Sure he leaves stuff out !

So what kinda results did you get ?
A working conductive ink ? If so, what kind of resistances are you seeing ?

A battery of any nature ?

Edit:

I'm a fan of his too.

[Edited on 6-3-2018 by aga]

zenmanenergy - 6-3-2018 at 13:06

Quote: Originally posted by aga

Sure he leaves stuff out !

So what kinda results did you get ?
[Edited on 6-3-2018 by aga]

The results I got are probably very different than you're expecting as they are not all purely based on numbers...

My lab notebook is rather lengthy and I haven't put it on the web anywhere, i'll do that eventually, but to summarize a few things....

1) I am still alive!

2) I didn't blow up my workshop WOOOT! My wife set those parameters.

3) Yes, I've made many variations of conductive inks. Some with graphite, some graphene, some graphite oxide, some with AlCl3 some with BiCl3, some water based, some oil based. They have wide variations in conductivity. Generally more carbon improves conductivity. I don't feel my intercalated versions were made correctly, so some of my data is utter bunk. My conductivies go as low as 32 ohms @0.17mm, but those aren't as good as 235 ohms at 0.1mm... So thickness matters.

4) Not cleaning the acid out of the compounds completely fucks everything up! I had this one batch that was giving me awesome results (this is all relative... I was normally getting around 16-20 microwatts (~16-20mV @~1mA)... my *awesome* results were 100 microwatts, I even repeated the test and it gave me similar results. I was getting excited until someone said: "Maybe there is still acid in your sample and it's just making a shitty battery" sure enough, that was it. So I every other day I find I go back to the drawing board and start over.

5) I *think* the added waters in AlCl3+6H2O make it so the aluminum doesn't get intercalated.

6) I now feel comfortable concentrating sulfuric acid from battery acid, by boiling it, but I was not comfortable enough to let it boil to 98%. So now I just buy it concentrated from dudadeisel. They have good prices.

7) After a couple hundred hours of khanacademy videos I can run rings around my older self from 25 years ago in college chemistry

8) Teaching 3rd graders how to make conductive ink is super fun, but for some reason many of them want to know if they can eat nasty black ink. What in the hell??!

9) Turning Bismuth metal into BiCl3 is an f'ing nightmare, I tried a dozen different ways and was unsuccessful. Maybe someone here can help me.

I have another 50 pages of notes, I'm just tired of typing.

zenmanenergy - 6-3-2018 at 13:09

Quote: Originally posted by aga

A battery of any nature ?
[Edited on 6-3-2018 by aga]

btw... i did make a battery, but it was purely by accident. It was a shitty battery putting out ~100 microwatts, but it was a battery.

Although, I'm not trying to make a battery. So that wasn't actually a good thing. haha

I'm trying to make a thermal electric generator, which I did. It does react to heat, but it's not making enough power to really matter.

aga - 6-3-2018 at 13:56

Funny - today i had a mess with some of that pyrolysed bread.

It definitely reacts to heat.

A chunk approx 60 x 15 x 15mm was set up with croc clips at either end and measured around 15 ohm.

Heating it over a spirit burner dropped the resistance to 4.6 ohms !
(took about 5 mins for it to go that low)

I'll check the voltage tomorrow.

violet sin - 6-3-2018 at 15:15

Take a peek here, https://www.nature.com/articles/s41598-017-06730-x

A novel hierarchical porous nitrogen-doped carbon derived from bamboo shoot for high performance supercapacitor.

"Taking the advantages of the structure and composition, the hierarchical N-doped carbon materials displayed an outstanding electrochemical capacitive performance in KOH electrolyte and long cycling stability"

Bamboo shoots dried, powdered, stirred with sulfuric acid, charged in autoclave with said sulfuric acid, rinsed, dried powder was heated to final temp in N₂ gas stream.

I keep saying though kombucha "mother" would probably be superior to bamboo for interwoven and fairly consistent structural carbon source.

zenmanenergy - 6-3-2018 at 21:14

Quote: Originally posted by violet sin

Take a peek here, https://www.nature.com/articles/s41598-017-06730-x

coolness! I'll give this a read tomorrow. There was another one I read last week that looked like it did a similar thing using hydrazine. But I have exactly zero desire to play with rocket fuel. F that! But Bamboo... that's another story.

aga - 7-3-2018 at 05:58

Quote: Originally posted by zenmanenergy

... I've made many variations of conductive inks. Some with graphite, some graphene, some graphite oxide, some with AlCl3 some with BiCl3, some water based, some oil based.

Nice.

How did you do the grinding step after mixing the ink ingredients ?

I think that's the bit where i keep going wrong with my own conductive ink experiments.

zenmanenergy - 7-3-2018 at 06:22

Quote: Originally posted by aga

How did you do the grinding step after mixing the ink ingredients ?

I think that's the bit where i keep going wrong with my own conductive ink experiments.

I've just been mixing it by hand while boiling it. With graphite and graphene-ish (I'm honestly not sure what the percentage of few layer graphene I've made, it's probably very low) I found there is a bit of art to getting the right amount of water when you do that as it starts to boil off. Plus I've been working with teeeny sizes so I can try different ideas with my limited supplies.

But with my intercalated inks have been very lumpy just like you're saying. The one I made with BiCl3 (from Pepto Bismol) was horrible. It was like sand paper! The same with my last batch of AlCl3+6H2O using the heat pipe method.

I made one batch of AlCl3+6H2O using the sulfuric acid process where I used a mortar and pestle on the aluminum chloride before I put it into the sulfuric. That ink was actually pretty smooth although it doesn't seem to exhibit the properties it should, so I'm speculating the AlCl3 didn't get intercalated.

He uses that Indian spice grinder in one of his recent videos. Maybe that's the solution?

zenmanenergy - 7-3-2018 at 06:36

I'm going to try SbCl3 today using the sulfuric method. That's commonly used in thermal electric generators.

I'm still planning my safety at the moment. It has an NFPA instability of 1, but I'm not sure what temperature it becomes unstable at. It has a melting point at 73C and boiling at 223C, but I'm getting the feeling it is higher than that. Do you happen to know?

zenmanenergy - 7-3-2018 at 06:44

Another one I want to try is boric acid. That stuff is super cheap and not very dangerous. But it's not a chloride compound, so I don't have the faintest idea if it will intercalate with graphite. The ones RMS uses seem to be chlorides. This is the bit of information that I have struggled to find any good resource on, explaining what causes a compound to intercalate with graphite.

zenmanenergy - 7-3-2018 at 07:04

Quote: Originally posted by zenmanenergy

Another one I want to try is boric acid.

I may try Boron before the antimony. This paper is pretty detailed

https://scielo.conicyt.cl/scielo.php?script=sci_arttext&...

aga - 8-3-2018 at 07:02

"I'll check the voltage tomorrow." ... or may be the day after, which is today.

The chunk of carbon was held between two clips and heated with the spirit burner.

A voltmeter registered a maximum of 200uV - uselessly low, but it's still a voltage.

Another experiment running now is the one where RMS says he makes graphene using a graphite rod, stainless electrode and a sodium sulphate solution. Run @ 2V for 2 minutes, then crank up to 12V to produce 'worms' of graphene.

Not a lot is happening with this chunk of carbon, despite running at 17V @ 1.5A for 30 minutes.

Lots of electrolysis going on, but hardly any change to the carbon that i can see, apart from it getting slightly warm.

S'pose now a rig is set up, may as well try a graphite rod.

zenmanenergy - 8-3-2018 at 13:08

I am stilll washing a batch of boric acid GIC. The pH is being a pain in ass, I think I have gone through 8 f'ing liters of distilled to get to a pH of 6-7. i will post my lab notes and videos in a day or so.

I am crossing my fingers that the formal charge of 3+ on boron will make it a p-type ink. But I don't have the faintest idea if the boric acid compound breaks up during the intercalation process or not.

Here is a disgusting martini from today