Sciencemadness Discussion Board

Glassy carbon preparation tread

plante1999 - 26-8-2011 at 15:07

First I have an pdf about carbon that is more than 2mb , how can I post it?

Glassy carbon is produced when a thermositing polymer is heated slowly to 1000 degree celcius , some polymer will produce only graphitisable carbon witch cannot be use for glassy carbon , PVC is one of them. Generaly Aromatic polymer is prefered because more carbon is formed.
Some polymer witch have good yield of carbon or is simple to find:

Polyfurfural 54% Carbon
PolyFurfuryl alcohol 50% carbon
Poly vinyl alcohol 10% carbon
Phenolic resin 60% carbon
Pure cellulose 20% carbon

20% carbon CAN give somewath good POROUS anode. But 40-65% is the optimal conssentration.

Personnaly I prefer to use Polyfurfural because you only need some NaHSO4 NaCl and Corn cobs/Oat bran and a small amount of H2SO4 witch can be substituted by NaHSO4 , For the equipement 2 steel Paint can and one 500 ml glass jar. the principle is:
Distill water to get water vapor , pass it in NaHSO4/NaCl organic mater and condence the vapor in the glass jar witch is in ice. than take the furfural cast it in the mold you want and ad H2SO4 to polymerise it.

I have made a 10ml piece and , in place of heating it slowly I heat it fast , The yield was impressing , the piece was porous but strong and have lost half of its weigh.

Now I have made this tread for every one that attemp glassy carbon production can report there observation , process and help other to make an suitable piece of glassy carbon , Personaly my objective is to make an anode that WONT make particule in the solution.

Thanks!!


blogfast25 - 27-8-2011 at 05:04

The method you describe for furfural gives low yields, in all likelihood even more so if you use your crude set up (there's a long and interesting thread on furfural preparation on the organic section , by Magpie). Any crude furfural obtained this way needs distilling before you can comfortably call it... erm, furfural.

As a result you've been polymerising/carbonising junk and claim it's 'glassy carbon'!

Hey, I can do that too: take some tobacco, heat it up in the absence of air and Bob's your uncle: carbonaceous matter!

Magpie’s thread on furfural:

http://www.sciencemadness.org/talk/viewthread.php?tid=15774&...

Despite the sophisticated set up, he obtained 7.5 g crude furfural from 114 g of corn cobs: 6.5 % yield only!

You’re gonna have to do a hell of a lot better to convince me, plante…

How about just carbonising good old white sugar (sucrose)?

m1tanker78 - 27-8-2011 at 08:11

Regardless of where the carbon comes from, the trickiest part of making glassy carbon is removing all of the gas pockets. All of my attempts have resulted in glassy carbon sponge. I simply don't have the inclination to anneal this stuff for weeks/months! :(

Tank

plante1999 - 27-8-2011 at 10:02

Quote: Originally posted by blogfast25  


You’re gonna have to do a hell of a lot better to convince me, plante…

How about just carbonising good old white sugar (sucrose)?


My methode for Synthetising furfural give very very low yield , So low that I wont use that again , for 1000 gram of Oat bran witch give me 10ml of furfural. Carbonizing sucrose will not make glassy carbon because it is not a polymer, I supose starch can be used.

m1tanker78: My 10ml piece is also a ''glassy carbon sponge''.

I am making test for melamine- methanal resin as the polymer.

Blogfast:You’re gonna have to do a hell of a lot better to convince me, plante…

I know that I need to make better set up , precursor... but I was already a good start because my glassy carbon sponge witch was made with poor condition/precursor is hard and brittle.

Carbon PDF (There is a section about glassy carbon):

http://www.mediafire.com/?p8ah09954k7i6dh

blogfast25 - 27-8-2011 at 12:35

Quote: Originally posted by plante1999  
I know that I need to make better set up , precursor... but I was already a good start because my glassy carbon sponge witch was made with poor condition/precursor is hard and brittle.

Carbon PDF (There is a section about glassy carbon):

http://www.mediafire.com/?p8ah09954k7i6dh


Try and publish some decent photos of your material.

[Edited on 27-8-2011 by blogfast25]

plante1999 - 29-8-2011 at 08:54

Melamine resin cannot be used as a precursor , it simply make to mush gas.

I am attempting to make a good quantity of furfural by pyrolisis of starch.

plante1999 - 16-9-2011 at 15:54

Finnaly I have buy a 6 inch by 10 mesh of iridium oxide/ruthenium oxide mix on titatium for anode but I continu to want to make glassy carbon , I have buy few thing that will help for making a suitable precursor. Picture will be aded later . I have found 1lb of fructose , a 5 carbon sugar that from what I read could be converted to furfural , I have buy starch that is supose to give furfural by pyrolisis. and finaly I have buy molasse that is suposed to be a great aditive to the precursor.

Side note , I want make NaClO3 to understand exactly the mecanism of oxidation by ClO3- , I know that NO3- is already understand but chlorate is not, and I canot get nitrate.