This Episode is sponsored by Skillshare Carbon is the fundamental building block of
life, but it may soon be the fundamental building
block of the rest of the world too. So today we’re going to be looking at Graphene,
ultra-thin flat sheets of a superstrong substance that folks have been talking about the potential
of for over a decade now. We’ll be looking at what technologies it’s
useful for, what its impact on our economy and civilization could be, and why the hype
around it has died down somewhat. This episode is probably a bit more technical
than our usual content, but hopefully it doesn’t fall too flat - even if that pun probably
did. Let’s start with some basics. Graphene is an allotrope of carbon. Allotropes are the various forms of a single
element that differ only by how the atoms are arranged and bonded to each other. Oxygen has allotropes of O2 the we breathe
and ozone O3 that protects us from the sun’s ultraviolet rays. Phosphorus has allotropes of amorphous red
phosphorus, in which the atoms bond to each other but not in any regular repeating structure,
and white phosphorus or tetraphosphorus, in which each molecule contains four atoms bonded
in a tetrahedral arrangement. Carbon and phosphorus both have many allotropes
because they have four bonding sites on each atom and hence quite a variety of ways the
atoms can bond with each other. The prettiest and hardest allotrope of carbon
of course is diamond, but the most common is graphite, which is found in coal and is
the most stable lowest energy configuration of carbon. There are many others including amorphous
carbon also found in coal, nanotubes, buckyballs, and larger structures similar to buckyballs
like C70. But it’s graphite we are most interested
in today, because that’s where we can find Graphene. In the simplest form Graphene is a perfect
arrangement of carbon atoms into a hexagonal honeycomb sheet, but it’s important to get
a bit more detail on what Graphene is, as this isn’t commonly explained in most articles
talking about the substance, and is actually a really important distinction. In this case, what we’re talking about is
“true” or “pristine” graphene, which is a pure sheet of carbon atoms double-bonded. The lowest energy state of this type of bonding
has all of the carbon atoms form into that “honeycomb” configuration, where the bonds
create perfect hexagons within the two-dimensional arrangement of carbon atoms. This also explains why Graphene is so hard
to make. You’re trying to perfectly position a bunch
of carbon atoms into a hexagonal honeycomb, one atom thick, with no defects. Making two-dimensional compounds in their
true forms is extremely difficult because even the slightest contamination or defects
can dramatically affect their properties, and that kind of atomic-level precision in
manufacturing has yet to be achieved. On top of this, they like to stack up or “agglomerate”
due to Van Der Waals interactions, which is how Graphene becomes graphite, which is basically
a jumble of defective graphene sheets stacked on top of each other. Graphene was first theorized in 1947 by Canadian
scientist Phillip Wallace, who predicted that if a single laminated sheet of graphite were
to be isolated, it would exhibit some interesting and anomalous qualities. Graphene might have been accidentally isolated
in 1962, but the first provable publication of isolated graphene was in 2004 by Andre
Geim and Konstantin Novoselov at the University of Manchester by what’s usually called the
“Sticky tape” technique, where they used scotch tape to pull graphene layers off of
graphite and deposit them onto silicon wafers. This then allowed them to prove it was graphene
and confirm Wallace’s theory by observing the predicted Quantum Hall Effect in the material. This was what led to their 2010 nobel prize
in physics and the surge in popularity for Graphene. Graphene’s two-dimensionality gives it many
unique properties. It’s because of this quantum hall effect
that its electrons behave as if they’re massless, giving it a charge carrying capacity
one million times higher than copper, and this can only occur in a two dimensional material. 2-dimensional sheets of atoms, also called
a monolayer, can be made of other materials like boron, silicon, germanium, and phosphorus,
which then also have the appendix -ene tacked onto their names like Phosphorene or Germanene. Like Graphene, they have some unique properties
too: phosphorene has some fascinating electrical properties due to Phosphorus’s ability to
form five bonds. In many ways the future isn’t just graphene
but all of these sorts of monolayer materials, like Arsenene – the monolayer of Arsenic
– which is very valuable for LEDs and solar cells, or multi-atom type compounds like Molybdenum
DiSelenide. But of them all, Graphene is likely to be
the most ascendant star. It seems to have the most useful and scientifically
interesting properties, and if it isn’t used in some of the applications we discuss
today, it will only be because we find other things that do the job a bit better in that
application, or are easier to produce. Economics can often outweigh exceptionality
after all. Graphene is possibly most famous for having
a tensile strength of 130 Gigapascals, which is about 50 times stronger than our strongest
steel, and 240 times stronger than structural steel. As a result whenever talks about space elevators
or megastructures come up, Graphene often does as well, especially for giant megastructures
like those we’ll look at next week. The problem with this, however, is that it’s
often forgotten that this only applies to pristine graphene, and also that graphene
has a very low fracture toughness - it breaks like many ceramics. There is a very interesting exception to this,
however, as two sheets of pristine graphene layered on top of each other, known as diamene,
will behave as reactive armor and harden when pressure is applied. The properties of these variations on graphene,
such as diamene, functionalized graphene, graphene oxide, holey graphene, or reduced
graphene oxide, are all relevant. These materials are not technically graphene,
but they are extremely useful and considered an important part of graphene research. The reason they aren’t considered such plays
into our next point: graphene’s two-dimensionality. Graphene, while flat, isn’t quite two-dimensional,
as a two dimensional object technically cannot exist, this is after all a 3-Dimensional universe. A perfect pristine graphene sheet, therefore,
tends to have a ripple running through part of it at all times, keeping it existing in
three dimensions. This could actually be useful, as it has been
proposed that this rippling effect can be used to generate electricity by harnessing
background energy by simply placing the conductive graphene sheet between an anode and a cathode,
though using it for this is a long way off if possible at all. This two dimensionality also gives it the
largest surface area possible, for the same reason a couple hundreds sheets of paper laid
out next to each other have more surface than a book made of those sheets bound together. This is extremely useful for storage applications,
particularly energy storage, and why graphene has been a major part of research into batteries
and supercapacitors. Pristine graphene is extremely difficult to
make, and is typically done by chemical vapor deposition of carbon atoms onto a copper sheet,
which stabilizes the lattice. However, making variations of graphene like
functionalized or reduced graphene oxide is typically done by chemically exfoliating graphite
with sulfuric acid, and this process is widely used to make graphene oxide sheets for supercapacitors
and batteries. This graphene has defects and functional carbon
groups, which keeps it from being “True” graphene, but also makes it harder for it
to agglomerate, easy to suspend in solution, and with treatment it can be porous which
facilitates electron and ion transport through the sheets. These types of graphenes have been used to
make supercapacitors with capacitances of more than a hundred times current industrial
capacitors, with much faster charge and discharge capabilities, creating a supercapacitor that
can be charged quickly and also discharged quickly for applications that require bursts
of power. Adding Graphene to Lithium Ion batteries,
or replacing the anodes themselves, increases their storage density by about two to three
times. In fact Tesla has just revealed that their
newest batteries are now using Graphene. Because Graphene is one of the most elastic
materials known to man, able to stretch up to an additional 33% of its length and snap
back, a lot of research has been directed to creating flexible batteries and capacitors
for portable electronics, as well as flexible electronic glass for display screens. There are other applications, some mundane
and some exotic, that revolve around what’s known as the “magic angle” that occurs
between misaligned graphene sheets. When graphene sheets are misaligned in very
specific ways, they can exhibit properties including semiconductivity, superconductivity,
and photoconductivity. This means that among other things, graphene
can make a solar panel that isn’t constrained by the Shockley-Quessier limit of roughly
30% on its efficiency, or a semiconductor with no band gap or even a PN junction, the
interface in semiconductor materials that allows one-way flow of electrons. We’ve known for a long time that many “high
temperature” superconductors - that is, superconductors operating between about -40
and -195 degrees celsius, tend to have flat tail-like structures on their molecules which
align into planes when supercooled, which allows the electrons to superconduct across
them. This has made inherently 2D materials like
Graphene a major area of research as a result, which has yielded some significant breakthroughs,
and Graphene or another 2D material is rather likely to end up being the first room temperature
superconductor. Obviously, this brings us to looking at Graphene’s
impact - and also what’s delaying that. There’s probably three major areas Graphene
is going to fundamentally transform: computing and electronics, energy and energy storage,
and structural engineering. In the world of computing, a two dimensional
semiconductor which doesn’t have n-p junctions avoids a lot of the issues with trying to
make semiconductors smaller, reducing the impact of many problems with trying to make
N-P semiconductors smaller, such as electron tunnelling, that’s a bit technical so we’ll
save anymore discussion of it for another day. But its far higher charge carrying capacity
makes it a lot faster than silicon semiconductors too. In fact it’s estimated graphene will increase
computing speeds by a factor of a thousand. Ultra-fast graphene computers will make all
our personal devices much faster, but also opens up a lot of new areas - particularly
in implanted medical electronics. Graphene is highly flexible, lightweight,
and mostly bio-compatible so it can be used to create implants that fix problems like
heartbeat arrhythmia, or used as a deployment agent for cancer drugs, or even be placed
directly on the brain. It can also serve as a platform for nanomachines,
although that’s a bit further out technologically. But your body could one day become an entire
suite of graphene devices for things ranging from just monitoring physical activity, to
self-repair and life-extension. See our episode on that topic for more. Obviously, superconducting and its incredible
storage properties make graphene a major enabler for the energy revolution. 3-D printing graphene supercapacitors and
batteries is extremely recent research, only about two or three years old, and is already
offering capacitances an order of magnitude better than current graphene-based energy
storage devices. Graphene supercapacitors would be perfect
for applications like smoothing out the energy beaming of an orbital solar array, where microwaves
are being sent in pulses to a rectenna, making it more efficient and less impactful than
a continuous transmission. See our episode on Power Satellites for more
on that. Lithium Ion batteries, or sulfide batteries
stabilized with graphene, offer energy storage capacity three times what it is today,. They’re also more environmentally friendly. And Graphene based solar panels with efficiencies
far higher than the current 24% of silicon photovoltaics would make the renewable energy
revolution far cheaper, faster, and less environmentally impactful as well. They may well beat out the much-talked about
perovskite panels in short order. See our episode on Mitigating Climate Change
for more about near-future solar energy options. One of the most talked about applications
is in structural engineering. As we already mentioned, this can’t be as
direct as some people like, but the use of graphene or carbon nanotubes, which are technically
just rolled up sheets of graphene, in structural applications will open a lot of new avenues
due to not only their light weight and high tensile strength, but also the fact they can
make materials that aren’t electrically or thermally conductive, conductive. For example, for decades scientists have been
looking for a good thermally conductive alloy of titanium, and the process known as covetics
enables that, as we mentioned earlier. But if we can develop materials that take
advantage of most of Graphene’s tensile strength, it makes a lot of the megastructures
we talk about on this channel feasible. And again we’ll look at such titanic structures
next week. There’s plenty of other suggestions too:
filtration is a big one, and graphene membranes for hydrogen electrodes will be a big part
of revolutionizing that technology, allowing us to carefully control what goes through
a membrane and what does not, even very small things compared to what most filters can handle,
like hydrogen. In fact it’s great for anything having to
do with Hydrogen, since it’s the only material hydrogen can’t permeate, though can be made
to selectively allow hydrogen to permeate, which could be quite handy in other applications
too. Hydrogen also isn’t just hard to store from
being smaller than the gaps in materials we put it in it, so it can leak through, but
also can be very damaging to those materials as it can get absorbed by them and cause hydrogen
embrittlement. A thin protective layer of graphene between
the hydrogen and the main material can prevent that. So protecting materials from hydrogen embrittlement
will be a major application of Graphene in the future. For that reason it could also prove useful
for hydrogen or deuterium Fusion energy, another much loved topic on the show. In fact it’s already been researched for
use in traditional nuclear energy as well, as it could be used to directly capture and
convert the energy of moving decay particles. It’s also been shown to slow the embrittlement
of materials from alpha and beta decay particles, and possibly neutrons as well. And of course it possible warm or room-temperature
superconducting properties might be very handy for fusion too. So for a material with applications literally
everywhere in society, what’s holding it back? There’s a few big reasons: the first is
that it’s still mostly in the R&D phase of technological readiness. There’s a lot we don’t know about graphene,
particularly in how it interacts with the body, as we don’t want it to turn out to
be the next asbestos. Graphene sheets are the sharpest objects in
the world, and can cut cells open, or wrap around and suffocate them. We know certain proteins can break down graphene
in the body, and that it doesn’t seem to be carcinogenic, but a lot more research in
this area is needed. There’s also questions about how it interacts
with the environment and food chains. Again, we don’t want this to end up like
DDT, where it may be relatively non-toxic on Humans, but it turns out it decimates bird
populations. The Graphene Flagship project in Europe, which
is a more than 2 billion dollar initiative to commercialize the material, is spearheading
a lot of this research. Another big issue is simply proprietary rights. A lot of the graphene technologies are gobbled
up by a handful of conglomerates, so advances end up being stuck in a long intellectual
property battle before they can get to market. This is why the graphene technologies that
are being commercialized now are based on experiments that were conducted in 2009 or
2010. The massive advances we’ve made since then,
like 3-D printed graphene aerogels or flexible supercapacitors, may not be seen until the
late 2020’s. Also, Graphene is still hard to make, and
expensive. A pristine graphene sheet of 4 square inches
will run about 50 dollars a square inch, on the cheap side of things. That doesn’t seem like a lot, but now consider
that graphene is a one atom thick, and applications will use dozens, hundreds, or thousands of
layers of graphene. Suddenly the graphene anode for your battery
becomes as expensive as the rest of the electric car you want to put it in, or the composite
for your support beam is as expensive as a whole skyscraper. There are cheaper methods, if you’re not
using pristine graphene, but materials like graphene oxide have to be sourced from very
high purity graphite, as even the slightest silicon contamination has massive impacts
on their efficiency. Cheap, low quality graphene is already seeing
widespread uses - it’s being composited in everything from tennis rackets to bicycle
frames by some companies if you’re willing to spend a lot of money. And higher quality stuff is being used in
some supercapacitors, batteries, or filters, but they’re not exactly economically competitive
at this time. And if we can make a lithium ion battery more
efficient and cheaper without graphene, then its use may be delayed even further. Graphene indeed may not be the best material
for every job, but it will revolutionize the future, and we can definitely expect to be
seeing a lot more about it soon. We couldn’t cover everything in this episode,
but Graphene-Info.com is a great resource to learn more about this revolutionary material,
and keep track of news about it from the industry. As to its best known feature, it’s very
high-tensile strength, we’ll be looking at that more next week as we contemplate building
Continent Sized Rotating Space Habitats. So we’ve got some announcements and the schedule to get to, but before that… A lot of folks have suddenly found themselves
working from home at their regular job or trying their hand at a new business or creative
venture and since I mostly work at home I’ve gotten asked by various friends trying this
out how I manage to get anything done and stay productive. The tricky thing is that there is no one-size-fits-all
approach to staying productive, at home or elsewhere. How to avoid distractions, how to schedule
out what you’re doing and so on tends to vary from person to person and it's not the
sort of thing you learn in school. You need to tailor to your own habits, strengths,
style, and circumstance and constantly work on improving it, but you don’t have to re-invent
the wheel either, you can borrow and adapt other folks’ patterns till you find what
works for you. What let’s you get stuff done while feeling
relaxed and in control, and if you can do that you’ll soon find you get more stuff
done, and done better, and in less time with way less stress. If you’re looking to find some top-notch
advice on enhancing your productivity, there’s a ton of great classes for it over on Skillshare,
and I’d particularly recommend Greg McKeown’s class “Simple Productivity”. Perhaps you’re trying to adjust to working
in a new environment or just looking to pick up some new skill or hobby, Skillshare has
a course for it, whether you’re a beginner, a pro, a dabler, or a master, Skillshare has
thousands of classes on a wide variety of topics from experts to help you learn. Skillshare is an online learning community
for creatives, where millions come together to take the next step in their creative journey,
and Members get unlimited access to thousands of inspiring classes, with hands-on projects
and feedback from a community of millions. If you’d like to give it a try the first
1000 of my subscribers to click the link in the description will get a 2 month free trial
of Premium Membership so you can explore your creativity. Act now, and start learning, today. Before we get to the upcoming schedule of
episodes, I wanted to take a quick moment to thank one of our long time script editors
here, Evan Schultheis, who is a Graphene Researcher and contributed so much to the writing of
this episode. He’s also a historian and author of the
book “The Battle of the Catalaunian Fields, AD 451” and I’ll leave a link to that
in the episode description for all you history buffs. I get to work with a lot of talented folks
on this show who volunteer their time to help make this show great and they rarely get the
credit they deserve, which as a reminder is in the show’s credit roll at the end of
every episode, after our episode schedule and announcements. Speaking of that schedule, as mentioned next
week we’ll be taking a look at some of the megastructures we might be able to build with
help of Graphene, in Continent Sized Rotating Space Habitats. But before that we’ll be having our monthly
Livestream Q&A, Sunday June 28, at 4pm Eastern Time. Join us live then to get all your questions
answered. And then in two weeks will be taking a look
at what it might be like to be living as a Brain in Jar… and how you could tell if
maybe you already are one. If you want alerts when those and other episodes
come out, make sure to subscribe to the channel, and if you’d like to help support future
episodes, you can donate to us on Patreon, which is linked in the episode description
below, along with all of our various social media forums where you can get updates and
chat with others about the concepts in the episodes and many other futuristic ideas. Until next time, thanks for watching, and have a great week!
Incorporating pentagons into the graphene sheet lets you make things like buckyballs or the end caps for nanotubes. Incorporating heptagons lets you make a non-flat surface. This can warp up into a bulge that attaches to a carbon nano-tube. It is not clear how we can place the carbon atoms into the right spots. But if you could get them there it would be stable.
I love it: Pulling layers of graphene off of graphite with tape eventually leads to a nobel prize! I know there was way more to it than that, it's just amazing how humble the beginning was.
Yes but what about graphene condoms?
It's pretty neat stuff, if you can mass-manufacture it cost-effectively. That's the big limiter right now - we can make graphene flakes that can be mixed into other stuff, but actually making sheets of pristine graphene is really difficult.
The stuff about the batteries is pretty neat. I hadn't realized how much of a difference it made with Lithium-Ion batteries. A four-fold improvement would not only be great for electric cars/trucks, but it would make electric planes a lot more viable.
Perhaps a new cheap method to produce mass quantities of high-quality Graphene will change the equation, not unlike Bessemer did for steel. P-}
Funny how it's all about graphene nowadays, I remember when it was carbon nanotubes that were supposed to be the wonder material of the future.