I realize using the burner is just one small step in a series of steps to produce something useful, but I think the possibilities for DIY components are widely opened up with this method.
I'm excited by this development. Graphene has such huge potential to revolutionize the entire material economy. To see significant advancements in complex technology being made with a readily accessible $50 device is very encouraging. The question is this - are their manufacturing pathways to graphene production that can be made with readily available everyday materials? In other words, along with the localization of the means of production (desktop manufacturing, 3d printing, etc), can there also be a localized raw materials revolution? It is my understanding that graphite (oxide), the precursor material, and the one used in every-day pencils, is actually a very centralized material, only available form a very few select sites in the world. If a way can be found to turn everyday carbon (which is in everything) into graphene, then a full localized graphene economy can emerge.
<giovanni.lostu...@gmail.com> wrote: > I've been looking into printing ultrafilters- perhaps nanometer wide > membrane pores could be etched with lasers this way as well...
> On Monday, March 19, 2012 5:17:44 PM UTC-4, Andrew Shindyapin wrote:
>> I realize using the burner is just one small step in a series of steps to >> produce something useful, but I think the possibilities for DIY components >> are widely opened up with this method.
Keep in mind there are other projects using DVD and BluRay readers (and burners) as well, including LSCM and other nanoscale manipulation and lithography projects. See if you can't see what others are up to so you can get some perspective on what's been proven possible. IIRC someone was working on and had made a more than prototype project of molecular / nano-scale microscopes over in Korea not too long ago and was using the reader heads from DVD burners, then using off the shelf hardware like cantilevers and what have you for the holding and manipulation of the samples.
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On Tue, Mar 27, 2012 at 15:13, Paul Hughes <psi...@gmail.com> wrote: > I'm excited by this development. Graphene has such huge potential to > revolutionize the entire material economy. To see significant > advancements in complex technology being made with a readily > accessible $50 device is very encouraging. The question is this - are > their manufacturing pathways to graphene production that can be made > with readily available everyday materials? In other words, along with > the localization of the means of production (desktop manufacturing, 3d > printing, etc), can there also be a localized raw materials > revolution? It is my understanding that graphite (oxide), the > precursor material, and the one used in every-day pencils, is actually > a very centralized material, only available form a very few select > sites in the world. If a way can be found to turn everyday carbon > (which is in everything) into graphene, then a full localized graphene > economy can emerge.
> On Sat, Mar 24, 2012 at 5:34 AM, Giovanni Lostumbo > <giovanni.lostu...@gmail.com> wrote: > > I've been looking into printing ultrafilters- perhaps nanometer wide > > membrane pores could be etched with lasers this way as well...
> > On Monday, March 19, 2012 5:17:44 PM UTC-4, Andrew Shindyapin wrote:
> >> I realize using the burner is just one small step in a series of steps > to > >> produce something useful, but I think the possibilities for DIY > components > >> are widely opened up with this method.
> -- > You received this message because you are subscribed to the Google Groups > "Open Manufacturing" group. > To post to this group, send email to openmanufacturing@googlegroups.com. > To unsubscribe from this group, send email to > openmanufacturing+unsubscribe@googlegroups.com. > For more options, visit this group at > http://groups.google.com/group/openmanufacturing?hl=en.
Producing graphene for supercapacitors in this manner was amazing. Given the size (large by graphene standards), I was wondering what the mechanical properties of the material would be? Could it be used as a structural material for enclosures?
On Tue, Mar 27, 2012 at 10:13 PM, Paul Hughes <psi...@gmail.com> wrote: > I'm excited by this development. Graphene has such huge potential to > revolutionize the entire material economy. To see significant > advancements in complex technology being made with a readily > accessible $50 device is very encouraging. The question is this - are > their manufacturing pathways to graphene production that can be made > with readily available everyday materials? In other words, along with > the localization of the means of production (desktop manufacturing, 3d > printing, etc), can there also be a localized raw materials > revolution? It is my understanding that graphite (oxide), the > precursor material, and the one used in every-day pencils, is actually > a very centralized material, only available form a very few select > sites in the world. If a way can be found to turn everyday carbon > (which is in everything) into graphene, then a full localized graphene > economy can emerge.
> On Sat, Mar 24, 2012 at 5:34 AM, Giovanni Lostumbo > <giovanni.lostu...@gmail.com> wrote: > > I've been looking into printing ultrafilters- perhaps nanometer wide > > membrane pores could be etched with lasers this way as well...
> > On Monday, March 19, 2012 5:17:44 PM UTC-4, Andrew Shindyapin wrote:
> >> I realize using the burner is just one small step in a series of steps > to > >> produce something useful, but I think the possibilities for DIY > components > >> are widely opened up with this method.
> -- > You received this message because you are subscribed to the Google Groups > "Open Manufacturing" group. > To post to this group, send email to openmanufacturing@googlegroups.com. > To unsubscribe from this group, send email to > openmanufacturing+unsubscribe@googlegroups.com. > For more options, visit this group at > http://groups.google.com/group/openmanufacturing?hl=en.
I read the original 1958 paper by Hummers and Offeman (http://pubs.acs.org/doi/pdfplus/10.1021/ja01539a017) in which they described a method to manufacture graphite oxide and it didn't seem very complicated to me. The method only employed sulfuric acid, sodium nitrate and potassium permanganate (apart from graphite, of course) and mild temperatures. As you say, graphite can be found in every day pencils. Although a pencil may have very little graphite on it, the interesting thing about graphene is that you don't really need too much to make something useful out of it. The capacitor built by these guys at UCLA comprised just a couple of 100-micron-thick layers of a few squared centimeters each.
For bulk quantities, getting access to graphite may be more complicated, but definitely easier than accessing lithium. The world production comes from mining of naturally ocurring mineral but also from synthesis from oil. So it is, in principle, slightly less centralized than oil, which is not very centralized itself.
> I'm excited by this development. Graphene has such huge potential to > revolutionize the entire material economy. To see significant > advancements in complex technology being made with a readily > accessible $50 device is very encouraging. The question is this - are > their manufacturing pathways to graphene production that can be made > with readily available everyday materials? In other words, along with > the localization of the means of production (desktop manufacturing, 3d > printing, etc), can there also be a localized raw materials > revolution? It is my understanding that graphite (oxide), the > precursor material, and the one used in every-day pencils, is actually > a very centralized material, only available form a very few select > sites in the world. If a way can be found to turn everyday carbon > (which is in everything) into graphene, then a full localized graphene > economy can emerge.
> On Sat, Mar 24, 2012 at 5:34 AM, Giovanni Lostumbo > <giovanni.lostu...@gmail.com> wrote: >> I've been looking into printing ultrafilters- perhaps nanometer wide >> membrane pores could be etched with lasers this way as well...
>>> I realize using the burner is just one small step in a series of steps to >>> produce something useful, but I think the possibilities for DIY components >>> are widely opened up with this method.
It seems that the first process to do so was discovered in 1890. It requires very high temperatures (2300-3000 C), which is tricky, because you can't get that high using flames. Not any carbon compound can be used, obviously.
> I'm excited by this development. Graphene has such huge potential to > revolutionize the entire material economy. To see significant > advancements in complex technology being made with a readily > accessible $50 device is very encouraging. The question is this - are > their manufacturing pathways to graphene production that can be made > with readily available everyday materials? In other words, along with > the localization of the means of production (desktop manufacturing, 3d > printing, etc), can there also be a localized raw materials > revolution? It is my understanding that graphite (oxide), the > precursor material, and the one used in every-day pencils, is actually > a very centralized material, only available form a very few select > sites in the world. If a way can be found to turn everyday carbon > (which is in everything) into graphene, then a full localized graphene > economy can emerge.
> On Sat, Mar 24, 2012 at 5:34 AM, Giovanni Lostumbo > <giovanni.lostu...@gmail.com> wrote: >> I've been looking into printing ultrafilters- perhaps nanometer wide >> membrane pores could be etched with lasers this way as well...
>>> I realize using the burner is just one small step in a series of steps to >>> produce something useful, but I think the possibilities for DIY components >>> are widely opened up with this method.
> It seems that the first process to do so was discovered in 1890. It
> requires very high temperatures (2300-3000 C), which is tricky, because
> you can't get that high using flames.
Sure you can, even with oxyacetylene. From wikipedia:-
"Approximately 20 percent of acetylene is consumed for oxyacetylene
gas welding and cutting due to the high temperature of the flame;
combustion of acetylene with oxygen produces a flame of over 3600 K
(3300 °C, 6000 °F), releasing 11.8 kJ/g. Oxyacetylene is the hottest
burning common fuel gas.[11] Acetylene is the third hottest natural
chemical flame after cyanogen at 4798 K (4525 °C, 8180 °F) and
dicyanoacetylene's 5260 K (4990 °C, 9010 °F)."
And you can burn those things in ozone or various fluorine-oxygen
compounds to get even hotter flames. P.M.Lawrence.
> On 03/27/2012 10:13 PM, Paul Hughes wrote:
> > I'm excited by this development. Graphene has such huge potential to
> > revolutionize the entire material economy. To see significant
> > advancements in complex technology being made with a readily
> > accessible $50 device is very encouraging. The question is this - are
> > their manufacturing pathways to graphene production that can be made
> > with readily available everyday materials? In other words, along with
> > the localization of the means of production (desktop manufacturing, 3d
> > printing, etc), can there also be a localized raw materials
> > revolution? It is my understanding that graphite (oxide), the
> > precursor material, and the one used in every-day pencils, is actually
> > a very centralized material, only available form a very few select
> > sites in the world. If a way can be found to turn everyday carbon
> > (which is in everything) into graphene, then a full localized graphene
> > economy can emerge.
> > On Sat, Mar 24, 2012 at 5:34 AM, Giovanni Lostumbo
> > <giovanni.lostu...@gmail.com> wrote:
> >> I've been looking into printing ultrafilters- perhaps nanometer wide
> >> membrane pores could be etched with lasers this way as well...
> >>> I realize using the burner is just one small step in a series of steps to
> >>> produce something useful, but I think the possibilities for DIY components
> >>> are widely opened up with this method.
>> It seems that the first process to do so was discovered in 1890. It >> requires very high temperatures (2300-3000 C), which is tricky, because >> you can't get that high using flames. > Sure you can, even with oxyacetylene. From wikipedia:-
> "Approximately 20 percent of acetylene is consumed for oxyacetylene > gas welding and cutting due to the high temperature of the flame; > combustion of acetylene with oxygen produces a flame of over 3600 K > (3300 °C, 6000 °F), releasing 11.8 kJ/g. Oxyacetylene is the hottest > burning common fuel gas.[11] Acetylene is the third hottest natural > chemical flame after cyanogen at 4798 K (4525 °C, 8180 °F) and > dicyanoacetylene's 5260 K (4990 °C, 9010 °F)."
> And you can burn those things in ozone or various fluorine-oxygen > compounds to get even hotter flames. P.M.Lawrence.
> Not any carbon compound can be >> used, obviously.
>> -David
>> On 03/27/2012 10:13 PM, Paul Hughes wrote: >>> I'm excited by this development. Graphene has such huge potential to >>> revolutionize the entire material economy. To see significant >>> advancements in complex technology being made with a readily >>> accessible $50 device is very encouraging. The question is this - are >>> their manufacturing pathways to graphene production that can be made >>> with readily available everyday materials? In other words, along with >>> the localization of the means of production (desktop manufacturing, 3d >>> printing, etc), can there also be a localized raw materials >>> revolution? It is my understanding that graphite (oxide), the >>> precursor material, and the one used in every-day pencils, is actually >>> a very centralized material, only available form a very few select >>> sites in the world. If a way can be found to turn everyday carbon >>> (which is in everything) into graphene, then a full localized graphene >>> economy can emerge.
>>> On Sat, Mar 24, 2012 at 5:34 AM, Giovanni Lostumbo >>> <giovanni.lostu...@gmail.com> wrote: >>>> I've been looking into printing ultrafilters- perhaps nanometer wide >>>> membrane pores could be etched with lasers this way as well...
>>>>> I realize using the burner is just one small step in a series of steps to >>>>> produce something useful, but I think the possibilities for DIY components >>>>> are widely opened up with this method.
On Wed, Mar 28, 2012 at 01:42:32AM +0200, David wrote: > I read the original 1958 paper by Hummers and Offeman > (http://pubs.acs.org/doi/pdfplus/10.1021/ja01539a017) in which they > described a method to manufacture graphite oxide and it didn't seem very > complicated to me. The method only employed sulfuric acid, sodium
Chemistry in general is easy.
> nitrate and potassium permanganate (apart from graphite, of course) and > mild temperatures. As you say, graphite can be found in every day > pencils. Although a pencil may have very little graphite on it, the
Not pure graphite. It's typically a clay/graphite mix. There are few locations where more or less pure graphite is mineable, so in practice it's made synthetically.
For nanostuff it's all HOPG, aka highly oriented pyrographite. Made from gas phase.
> interesting thing about graphene is that you don't really need too much > to make something useful out of it. The capacitor built by these guys at > UCLA comprised just a couple of 100-micron-thick layers of a few squared > centimeters each.
Exactly, just buy some HOPG and experiment away.
> For bulk quantities, getting access to graphite may be more complicated,
I don't see why.
> but definitely easier than accessing lithium. The world production comes
I also don't see why. Lithium is cheap enough.
> from mining of naturally ocurring mineral but also from synthesis from > oil. So it is, in principle, slightly less centralized than oil, which > is not very centralized itself.
Carbon is everywhere, both in carbonates of the crust, air, biomass. The difficulty is low-defect high-purity stuff, which is however still much easier and cheaper to make the semiconductor-grade monocrystaline Si.
On Wed, Mar 28, 2012 at 01:56:21AM +0200, David wrote: > Here is an interesting description of the process to manufacture > synthetic graphite out of carbon precursors:
> It seems that the first process to do so was discovered in 1890. It > requires very high temperatures (2300-3000 C), which is tricky, because
Not tricky at all, electric arc. The difficulty with HOPG is that you need high-pressure to boot. That's for bulk, you can grow it on metal (e.g. Cu) from gas phase.
On Sat, Mar 24, 2012 at 8:34 AM, Giovanni Lostumbo
<giovanni.lostu...@gmail.com> wrote: > I've been looking into printing ultrafilters- perhaps nanometer wide > membrane pores could be etched with lasers this way as well...
I don't think that would work, because its well below the diffraction limit (which is tricky to get around, uses interference)... i.e. Intel is only doing 14 nm fab which is still in lab research stage
-- Nathan McCorkle Rochester Institute of Technology College of Science, Biotechnology/Bioinformatics
Generally true though. While I did mention widths in the nanometer range as a definite goal one day, there will still be a use for microfilters in the race to the bottom.
"Membrane pore sizes can vary from 0.1 nanometres (3.9×10−9 in) to 5,000 nanometres (0.00020 in) depending on filter type. "Particle filtration" removes particles of 1 micrometre (3.9×10−5 in) or larger. Microfiltration<https://en.wikipedia.org/wiki/Microfiltration>removes particles of 50 nm or larger. "Ultrafiltration" removes particles of roughly 3 nm or larger. "Nanofiltration" removes particles of 1 nm or larger. Reverse osmosis is in the final category of membrane filtration, "hyperfiltration", and removes particles larger than 0.1 nm."
On Wednesday, March 28, 2012 1:17:36 PM UTC-4, Nathan McCorkle wrote:
> On Sat, Mar 24, 2012 at 8:34 AM, Giovanni Lostumbo
> < <giovanni.lostu...@gmail.com>> wrote:
> > I've been looking into printing ultrafilters- perhaps nanometer wide
> > membrane pores could be etched with lasers this way as well...
> I don't think that would work, because its well below the diffraction
> limit (which is tricky to get around, uses interference)... i.e. Intel
> is only doing 14 nm fab which is still in lab research stage
> -- > Nathan McCorkle
> Rochester Institute of Technology
> College of Science, Biotechnology/Bioinformatics
>> For bulk quantities, getting access to graphite may be more complicated, > I don't see why.
>> > but definitely easier than accessing lithium. The world production comes > I also don't see why. Lithium is cheap enough.
I didn't mean "price", but "accessibility" in a wider sense. Market price may be low, but the product is controlled by a few mining companies, that don't sell or may choose not to sell to any random guy that knocks at their door. That's what I think Paul meant when he said that graphite "is actually a very centralized material". Not really that it is expensive, but that it is something you can't easily grow in your backyard, so you depend on some big corporation to get access to it. I don't know if I grasped his intention correctly.
For me the really cool thing would be that you could somehow make crystalline graphite out of biomass, for instance, or out of "domestic" plastics (PET, ABS), something that anyone can get where they live. I guess that's out of question. Correct me if I'm wrong, because I'd be very interested in that possibility.
>> Although a pencil may have very little graphite on it... > Not pure graphite. It's typically a clay/graphite mix. There are few > locations where more or less pure graphite is mineable, so in practice > it's made synthetically.
I read that the proportion in the mix depends on the hardness of the pencil. Do you think a really soft pencil could serve as a source for "pure-enough" graphite?
> Do you think a really soft pencil could serve as a source for "pure-enough" graphite?
This method is supposed to make graphene oxide form graphite with a high yield, and it is wet chemistry with sulfuric acid, so the clay would just be dissolved silica and dirt, and probably just reduce yield. Have not found a full text outside a paywall yet, getting my UT library card updated soon... Dr. Tour brags it was one of the top twenty downloads from ACS Nano, (through the paywall $$$).
Marcano, D. C.; Kosynkin, D. V.; Berlin, J. M.; Sinitskii, A.; Sun, Z.; Slesarev, A.; Alemany, L. B.; Lu, W.; Tour, J. M. “Improved Synthesis of Graphene Oxide,” ACS Nano 2010, 4, 4806-4814.
"Rice University Professor James Tour and graduate student Daniela Marcano discuss their ACS Nano paper "Improved Synthesis of Graphene Oxide," one of the most-accessed ACS journal articles for 2010."
They improved Hummers procedure, which involves sifting and filtering...which probably tolerates some clay in it... It's a procedure for processing ore from the earth...
David wrote:
> On 03/28/2012 07:13 PM, Eugen Leitl wrote:
> >> For bulk quantities, getting access to graphite may be more complicated,
> > I don't see why.
> >> > but definitely easier than accessing lithium. The world production comes
> > I also don't see why. Lithium is cheap enough.
> I didn't mean "price", but "accessibility" in a wider sense. Market
> price may be low, but the product is controlled by a few mining
> companies, that don't sell or may choose not to sell to any random guy
> that knocks at their door. That's what I think Paul meant when he said
> that graphite "is actually a very centralized material". Not really that
> it is expensive, but that it is something you can't easily grow in your
> backyard, so you depend on some big corporation to get access to it. I
> don't know if I grasped his intention correctly.
> For me the really cool thing would be that you could somehow make
> crystalline graphite out of biomass, for instance, or out of "domestic"
> plastics (PET, ABS), something that anyone can get where they live. I
> guess that's out of question. Correct me if I'm wrong, because I'd be
> very interested in that possibility.
It's only the "crystalline" part that's a problem, because it's very
easy to make very pure sugar charcoal, which is just
(microcrystalline) graphite, thus:-
- Starting with commercially available white sugar, dissolve it in
distilled water and purify it as much further as you want using
fractional crystallisation.
- For a less pure version (because it will contain some caramel), just
heat it in an inert atmosphere to drive off water from the
carbohydrate.
- For a purer version, just sprinkle it slowly on concentrated
sulphuric acid. This will pull out all the water in the sugar, leaving
carbon dust which can be filtered off, rinsed with more distilled
water, and then dried - microcrystalline graphite. The sulphuric acid
can be reconcentrated for re-use by some combination of boiling,
sparging with a hot, dry, inert gas, or electrolysing out hydrogen and
oxygen (which is the simplest way, though it takes more energy).
For some purposes, just compressing the product in a vacuum with a
hydraulic ram will be good enough, but I think not for what this
thread has in mind. For that, I think the processes used to bake
precursors into carbon fibre are about as simple as you can get (the
secret is that they don't bring oxygen to the party) - but bear in
mind that the quality varies with the (sometimes anisotropic) pressure
tensor applied during baking. P.M.Lawrence.
On Wed, Mar 28, 2012 at 10:42:34PM +0200, David wrote: > On 03/28/2012 07:13 PM, Eugen Leitl wrote: >>> For bulk quantities, getting access to graphite may be more complicated, >> I don't see why.
>>> > but definitely easier than accessing lithium. The world production comes >> I also don't see why. Lithium is cheap enough.
> I didn't mean "price", but "accessibility" in a wider sense. Market > price may be low, but the product is controlled by a few mining > companies, that don't sell or may choose not to sell to any random guy > that knocks at their door. That's what I think Paul meant when he said
You will get lithium metal from any large chemical supplier (as a business; both elementary iodine and lithium are watched due to clandestine drug production). Lithium will be also easily recoverable from lithium batteries.
> that graphite "is actually a very centralized material". Not really that > it is expensive, but that it is something you can't easily grow in your > backyard, so you depend on some big corporation to get access to it. I
But you have no problems growing either graphene or diamond films from gas phase or almost a dozen of other methods.
> don't know if I grasped his intention correctly.
> For me the really cool thing would be that you could somehow make > crystalline graphite out of biomass, for instance, or out of "domestic"
You can make graphene from sucrose or plexiglas.
> plastics (PET, ABS), something that anyone can get where they live. I
You should be able to get high-purity carbon from thermolysis of natural gas (methane). You can probably produce straight graphite by building a microwave-powered methane thermolysis reactor.
> guess that's out of question. Correct me if I'm wrong, because I'd be > very interested in that possibility.
I don't see much reasons for making straight graphite, other than to convert it to graphite oxide for graphene production. DIY will most likely want to make high-quality graphene in small batches.
In general graphene isn't all that good as a drop-in replacement for Si, you'd do better with carbon nanotube (different chiralities/doped) and graphene nanoribbons.
On Wed, Mar 28, 2012 at 10:45:05PM +0200, David wrote: > I read that the proportion in the mix depends on the hardness of the > pencil. Do you think a really soft pencil could serve as a source for > "pure-enough" graphite?
It depends. For what purpose? You can definitely use it to do chemistry with. I've used as graphite electrodes for electrolysis (or electrosynthesis). I presume you'll get some graphite oxide on the anode with sulfuric acid or KOH. Unglazed clay will do as a makeshift semipermeable membrane to separate the electrolyte spaces while allowing ions to move.
You can probably anneal it quite a lot by electric heating. It would be interesting to see what you could do to small carbon samples in a suitable crucible in your microwave. Electrowelding can do a lot more.
> It's only the "crystalline" part that's a problem, because it's very > easy to make very pure sugar charcoal, which is just > (microcrystalline) graphite
If you start with this, and do Hummer's procedure to get graphene oxide, will the crystal size stay tiny?
Will starting crystal size matter for results of being a supercapacitor anode, where large surface area is a plus?
At some point size of crystals must matter for conductivity, which is also a desirable part of supercapacitor terminals.
>> Do you think a really soft pencil could serve as a source for >> "pure-enough" graphite?
> This method is supposed to make graphene oxide form graphite with a high > yield, > and it is wet chemistry with sulfuric acid, so the clay would just be > dissolved silica > and dirt, and probably just reduce yield. Have not found a full text > outside a paywall yet, > getting my UT library card updated soon... Dr. Tour brags it was one of > the top twenty downloads > from ACS Nano, (through the paywall $$$).
> Marcano, D. C.; Kosynkin, D. V.; Berlin, J. M.; Sinitskii, A.; Sun, Z.; > Slesarev, A.; Alemany, L. B.; Lu, W.; Tour, J. M. “Improved Synthesis of > Graphene Oxide,” ACS Nano 2010, 4, 4806-4814.
> "Rice University Professor James Tour and graduate student Daniela Marcano > discuss their ACS Nano paper "Improved Synthesis of Graphene Oxide," one of > the most-accessed ACS journal articles for 2010."
> They improved Hummers procedure, which involves sifting and > filtering...which probably tolerates > some clay in it... It's a procedure for processing ore from the earth...
> -- > You received this message because you are subscribed to the Google Groups > "Open Manufacturing" group. > To post to this group, send email to openmanufacturing@**googlegroups.com<openmanufacturing@googlegroups.com> > . > To unsubscribe from this group, send email to > openmanufacturing+unsubscribe@**googlegroups.com<openmanufacturing%2Bunsubs cribe@googlegroups.com> > . > For more options, visit this group at http://groups.google.com/** > group/openmanufacturing?hl=en<http://groups.google.com/group/openmanufacturing?hl=en> > .
For us beginners. Could someone prepare a detailed instructables on how to do this? I would like to try it; but my technical skills in this area are woeful. But I think if someone could walk us through it we could go on to expand the experimentation.
Thanks.
On Sun, Apr 1, 2012 at 12:14 PM, Robb Greathouse <robb.greatho...@gmail.com>wrote:
> On Thu, Mar 29, 2012 at 1:04 AM, John Griessen <j...@industromatic.com>wrote:
>> On 03/28/2012 03:45 PM, David wrote:
>>> Do you think a really soft pencil could serve as a source for >>> "pure-enough" graphite?
>> This method is supposed to make graphene oxide form graphite with a high >> yield, >> and it is wet chemistry with sulfuric acid, so the clay would just be >> dissolved silica >> and dirt, and probably just reduce yield. Have not found a full text >> outside a paywall yet, >> getting my UT library card updated soon... Dr. Tour brags it was one of >> the top twenty downloads >> from ACS Nano, (through the paywall $$$).
>> Marcano, D. C.; Kosynkin, D. V.; Berlin, J. M.; Sinitskii, A.; Sun, Z.; >> Slesarev, A.; Alemany, L. B.; Lu, W.; Tour, J. M. “Improved Synthesis of >> Graphene Oxide,” ACS Nano 2010, 4, 4806-4814.
>> "Rice University Professor James Tour and graduate student Daniela >> Marcano discuss their ACS Nano paper "Improved Synthesis of Graphene >> Oxide," one of the most-accessed ACS journal articles for 2010."
>> They improved Hummers procedure, which involves sifting and >> filtering...which probably tolerates >> some clay in it... It's a procedure for processing ore from the earth...
>> -- >> You received this message because you are subscribed to the Google Groups >> "Open Manufacturing" group. >> To post to this group, send email to openmanufacturing@**googlegroups.com<openmanufacturing@googlegroups.com> >> . >> To unsubscribe from this group, send email to >> openmanufacturing+unsubscribe@**googlegroups.com<openmanufacturing%2Bunsubs cribe@googlegroups.com> >> . >> For more options, visit this group at http://groups.google.com/** >> group/openmanufacturing?hl=en<http://groups.google.com/group/openmanufacturing?hl=en> >> .
> if someone could walk us through it we could go on to expand the experimentation.
I'm planning to research it further. Since so many of the papers are non-free, that means trips to the university library. As in semiconductors, and all batteries, the big thing is the contacts to get to a copper wire from the thin graphene films.
This method looks promising to make functionalized graphene in bulk quantity:
"Researchers placed graphite and frozen carbon dioxide in a ball miller, which is a canister filled with stainless steel balls. The canister was turned for two days and the mechanical force produced flakes of graphite with edges essentially opened up to chemical interaction by carboxylic acid formed during the milling.
The carboxylated edges make the graphite soluble in a class of solvents called protic solvents, which include water and methanol, and another class called polar aprotic solvents, which includes dimethyl sulfoxide.
Once dispersed in a solvent, the flakes separate into graphene naonsheets of five or fewer layers.
To test whether the material would work in direct formation of molded objects for electronic applications, samples were compressed into pellets. In a comparison, these pellets were 688 times better at conducting electricity than pellets yielded from the acid oxidation of graphite.
After heating the pellets at 900 degrees Celsius for two hours, the edges of the ball-mill–derived sheets were decarboxylated, that is, the edges of the nanosheets became linked with strong hydrogen bonding to neighboring sheets, remaining cohesive. The compressed acid-oxidation pellet shattered during heating.
To form large-area graphene nanosheet films, a solution of solvent and the edge-carboxylated graphene nanosheets was cast on silicon wafers 3.5 centimeters by 5 centimeters, and heated to 900 degrees Celsius. Again, the heat decarboxylated the edges, which then bonded with edges of neighboring pieces. The researchers say this process is limited only by the size of the wafer. The electrical conductivity of the resultant large-area films, even at a high optical transmittance, was still much higher than that of their counterparts from the acid oxidation.
By using ammonia or sulfur trioxide as substitutes for dry ice and by using different solvents, “you can customize the edges for different applications,” Baek said. “You can customize for electronics, supercapacitors, metal-free catalysts to replace platinum in fuel cells. You can customize the edges to assemble in two-dimensional and three-dimensional structures."
Hmm... I wonder what would happen if you tried Kolbe electrolysis (see
http://en.wikipedia.org/wiki/Kolbe_electrolysis) on mellitic acid or
on these mechanically made carboxylic acids, maybe at various
temperatures and pressures? P.M.Lawrence.
m d wrote:
> This method looks promising to make functionalized graphene in bulk quantity:
> "Researchers placed graphite and frozen carbon dioxide in a ball miller, which is a canister filled
> with stainless steel balls. The canister was turned for two days and the mechanical force produced
> flakes of graphite with edges essentially opened up to chemical interaction by carboxylic acid
> formed during the milling.
> The carboxylated edges make the graphite soluble in a class of solvents called protic solvents,
> which include water and methanol, and another class called polar aprotic solvents, which includes
> dimethyl sulfoxide.
> Once dispersed in a solvent, the flakes separate into graphene naonsheets of five or fewer layers.
> To test whether the material would work in direct formation of molded objects for electronic
> applications, samples were compressed into pellets. In a comparison, these pellets were 688 times
> better at conducting electricity than pellets yielded from the acid oxidation of graphite.
> After heating the pellets at 900 degrees Celsius for two hours, the edges of the ball-mill–derived
> sheets were decarboxylated, that is, the edges of the nanosheets became linked with strong hydrogen
> bonding to neighboring sheets, remaining cohesive. The compressed acid-oxidation pellet shattered
> during heating.
> To form large-area graphene nanosheet films, a solution of solvent and the edge-carboxylated
> graphene nanosheets was cast on silicon wafers 3.5 centimeters by 5 centimeters, and heated to 900
> degrees Celsius. Again, the heat decarboxylated the edges, which then bonded with edges of
> neighboring pieces. The researchers say this process is limited only by the size of the wafer. The
> electrical conductivity of the resultant large-area films, even at a high optical transmittance, was
> still much higher than that of their counterparts from the acid oxidation.
> By using ammonia or sulfur trioxide as substitutes for dry ice and by using different solvents, “you
> can customize the edges for different applications,” Baek said. “You can customize for electronics,
> supercapacitors, metal-free catalysts to replace platinum in fuel cells. You can customize the edges
> to assemble in two-dimensional and three-dimensional structures."
On Wed, Mar 28, 2012 at 1:48 PM, m d <2md...@gmail.com> wrote: > This method looks promising to make functionalized graphene in bulk > quantity:
> "Researchers placed graphite and frozen carbon dioxide in a ball miller, > which is a canister filled > with stainless steel balls. The canister was turned for two days and the > mechanical force produced > flakes of graphite with edges essentially opened up to chemical > interaction by carboxylic acid > formed during the milling.
> The carboxylated edges make the graphite soluble in a class of solvents > called protic solvents, > which include water and methanol, and another class called polar aprotic > solvents, which includes > dimethyl sulfoxide.
> Once dispersed in a solvent, the flakes separate into graphene naonsheets > of five or fewer layers.
> To test whether the material would work in direct formation of molded > objects for electronic > applications, samples were compressed into pellets. In a comparison, these > pellets were 688 times > better at conducting electricity than pellets yielded from the acid > oxidation of graphite.
> After heating the pellets at 900 degrees Celsius for two hours, the edges > of the ball-mill–derived > sheets were decarboxylated, that is, the edges of the nanosheets became > linked with strong hydrogen > bonding to neighboring sheets, remaining cohesive. The compressed > acid-oxidation pellet shattered > during heating.
> To form large-area graphene nanosheet films, a solution of solvent and the > edge-carboxylated > graphene nanosheets was cast on silicon wafers 3.5 centimeters by 5 > centimeters, and heated to 900 > degrees Celsius. Again, the heat decarboxylated the edges, which then > bonded with edges of > neighboring pieces. The researchers say this process is limited only by > the size of the wafer. The > electrical conductivity of the resultant large-area films, even at a high > optical transmittance, was > still much higher than that of their counterparts from the acid oxidation.
> By using ammonia or sulfur trioxide as substitutes for dry ice and by > using different solvents, “you > can customize the edges for different applications,” Baek said. “You can > customize for electronics, > supercapacitors, metal-free catalysts to replace platinum in fuel cells. > You can customize the edges > to assemble in two-dimensional and three-dimensional structures."
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