So today's speaker is certainly some hero.

She is a professor of chemistry
at university Georgia

she got her bachelor's degree
in chemistry Columbia and Ph D.

also in chemistry Cal Tech and
today from start to U.C. Santa Barbara.

She works in industry H.R.
laboratories in California for a few years

working in the areas of energy storage and
fuel cells for going to U.G.A.

thousand and ten Most recently she is
an award the deal we really career.

Tell us about some research that
kind of made the news about what six

months ago is what some of the very
heavily advertised body is yes

and thank you.

I just like to begin by thanking David for
the very enthusiastic invitation and

for organizing such
a wonderful a lecture serious.

So today I'm going to tell you
about the nano science of metal

silicate base pigments and so
we're going to take a little adventure.

That's going to cover some chemistry some
material science some nano science and

we'll even touch upon some archaeology.

So our history and some chemical history.

Before I get into the meat
of the presentation.

I want Ignalina people who did
the work that you're going to see.

First Darragh Johnson McDaniel
she's a third year

graduate student in my group she did most
of the work that you're going to see.

Christopher Barrett my former
post-doc as Musharraf.

Another graduate student Richard why i'm
are in a say in Norris to undergraduates

who have worked with me.

And this work was funded
out of my startup funds.

That I receive from coming
to University of Georgia.

So let me start by setting the stage.

About the problem or
the question that we were trying to solve.

We were looking for
material with these four characteristics

material that was strongly luminescent
in the near I.R. material that

was stable respect to chemical
reactivity with respect to temperature.

One that was inexpensive.

Ideally made out of Earth
abundant elements and finally one

that could be processed using solution
based methods and I saw something that

could easily be manufactured incorporated
into devices using inexpensive techniques.

So this was our target.

And so you might be wondering
why these four characteristics.

But we have some particular
applications in mind.

Right near infrared radiation is used in

many telecommunication devices for
example on fiber optic devices.

So there's a large
application sphere there.

We envisioned that if we could

do something like print a near
infrared imaging material.

We could use it to counterfeit
to counteract forgery.

Right.
So in our money in our bills and

certificates.

There are many anti counterfeit.

Mechanisms that are in there.

And this could be yet another one and

then the third applications fear
isn't by a medical imaging.

And so this relates the fact that tissue.

Does not absorb near for

a great radiation very much compared
to other visible radiation and

so it can penetrate much more easily and
so it is by dint identified.

Is a very promising area for
imaging technologies.

So I'm thinking about these
four characteristics.

We identified this particular target.

So a copper S.-I four zero ten.

And so these are the alkali earth
copper Tetra silicate materials.

That were a is calcium
strontium herbarium.

So this is actually a well
known class of materials and

I'll go into a little bit
of the history in a moment.

First let me introduce
you to their structure.

So they're solid state materials
they have a layered structure.

You can see two of the layers here.

The most important part of
the material is the copper center.

So there's square planar copper here
in green surrounded by four Oxygen's.

And these copper centers are held
together by the touch of silicate units

in this fashion.

So you have layers upon layers
of the square planar copper.

And in between the layers are held
together by ionic interactions

provided by the calcium strontium
herbarium two plus ions.

So I mentioned this is a well
known class of materials and

their most famous
characteristic is their color.

And so you can see for all all three
derivatives the calcium strontium and

barium.

Right.
They have a beautiful vivid blue color.

And they've been used
throughout history as pigments.

Right.

So going back to even
the ancient Egyptians.

Right.

This calcium copper Tetra silicate
is known as Egyptian blue.

It's probably one of
the most famous pigments.

It was a ready being manufactured online.

Arge scale in the third millennium B.C..

Right.
So not only does it have

this material have an important
place in history in art history.

But also has an important
part of Chemical History or

so it was the first
synthetically produced pigment.

So here are just two examples to
illustrate the Egyptian blue which is

the calcium copper Tetra
silicate derivative.

And so the people made this pigment
using solid state synthesis and

then would grind into a powder mix
it with a binder to create a paint.

Which they would then apply in the form
of murals or to paint statues.

The barium derivative barium
copper Tetra silicate was used

as a pigment in a completely different
part of the world in ancient China.

And so this material is commonly
referred to as han blue.

You see an example here.

And so this powder was made and

then pressed into a form in this shape and
then refired.

It was also done with calcium copper
Tetra silicate to form small objects or

bowls etc.

So we were actually

more interested in the luminescence
properties of these materials.

Well the blue color is nice.

Right.

Not exactly high tech
by our standards today.

There was a paper that came
out in two thousand and nine.

By of course the it all that provided some
of the key data that caught our interest.

So you can see here.

There's acceptation curve for

calcium copper Tetra silicate
absorption curve and emission curves.

And you can correlate each
one of these features to

the molecular orbital diagram for
copper copper two plus.

You know square planar geometry.

This is fairly straightforward.

And the thing that really caught our
interest is the sea mission at nine

hundred ten nanometers.

So this is in the near infrared region.

And it is a strong emission at the quantum
efficiency is over ten percent.

And it has a relatively long life time

luminescence life time on the orders
of a few hundred microseconds.

And this is very remarkable and

most other Lumet near I.R. emitting
materials are based on last night.

IOW it's rare earth.

It's.

And yes they could outperform
a material like this in terms

of quantum efficiency and lifetime.

Remember this material
is copper based right so

it meets our qualification of all Earth
abundant elements inexpensive material.

All you have is calcium copper silicon and
oxygen.

So before going on to what
we did with the material.

I really have to mention one application
of this luminescence property.

And that's used in the archaeology field.

So here's an example from
scientists at the British Museum.

We all know the Parthenon in Greece.

And back when the Parthenon was intact.

There was a series of sculptures like
this that are now at the British Museum

that decorated the pediment on
top of this triangular section.

And a long standing
question was whether or

not these sculptures were painted
back when they were originally made.

And so by using the luminescent
properties of Egyptian blue

the scientists at the British Museum
were able to answer this question.

So here is one particular.

Fragment of a sculpture of.

Iris.

And here on the left you can
see just a regular photograph

of this sculpture and here on the right
is the near infrared image right so

this is simply done by taking a camera and
modifying it by taking out the filter so

that you are picking up the near infrared
light instead of the visible light.

And you can see here along this belt.

There is a white glow of material.

And so this corresponds to single particle
single grains of this calcium copper Tetra

silicate that are remaining sort of lodged
in the marble that are not visible by eye.

That you'd be very hard pressed to go and
find even with a microscope for

the luminescence the so strong.

This is can be used to
locate those grates.

And so we can see.

The archaeologist can reconstruct at
the Parthenon originally was painted and

probably very colorfully painted like so.

OK So back to our target.

Calcium copper Tetra silicate
as I just showed you

meet the qualification of being
a strong near I.R. emitter that's good.

It meets the qualification of
being a stable material and

so proof of that is in its longevity.

It has survived on these artifacts
through through the millennia and

we still have them intact.

Is an inexpensive and so

the last criterion is that it
be solution process that will.

Now calcium copper Tetra silicate
solid state material ceramic material

not solution process of all
right up until this point.

So in fact it's even to use
it as a paint is difficult.

So you have the raw material the crystals
that you make by solid state synthesis and

you start to grind them as you grind
them into finer finer particle size

you actually start to lose the blue color.

So as the particle size becomes small
enough becomes very light blue and

then ultimately gray and I'll show
you a picture of that in a moment.

So it's not as if you can
just take the material and

make nano particles and
expect to retain all the properties.

So our strategy for
making an animate serial is a little

bit different sort of nanoparticles
we're going to make nano sheets.

And the fact that calcium copper
touches Silica is a layered material

makes it amenable to the strategy.

I said Just think of here are all
the layers of the calcium copper

touches silicate in
a three dimensional piece.

And then if we could essentially
disassemble this material

into just the single layers.

We would have something that had nano
dimension in terms of thickness.

And would still retain
the organization of those copper ions

right which is really where all
the function comes in the material.

So my group knows how to do this.

This is our specialty and
our specialty isn't

starting with three dimensional
bulk materials and developing

chemistry methods to turn them into two
dimensional forms eaten into sheets.

And I just show this is an overview
of some of the classes of materials

that my group works on.

So everything from the well known

metal dacha Kaja nods like
religion by sulfide Dyesebel and

I have cetera that are Vander walls
materials layered Vander walls materials.

We study metal phosphate like
lithium manganese phosphate

has a layer type structure
with corner sharing hold.

The layers together.

We study things like metal Boron It's
like magnesium dye Bora Bora etc

where you have layers of boron with
the metal ions in between layers.

And finally things like
complex metal oxides.

So I show this to put
the synthetic synthetic problem

of calcium copper Tetra
silicate into context.

So you notice that I've located
calcium copper Tetra silicate here

along the spectrum.

And so to me all the way here
on this side on the left.

These are the easiest materials
to disassemble or to expose it.

And this has to do with the kind of
bonding that's inside the solid.

Right.
The Vander walls

interactions between the layers
here are relatively weak.

This is the same situation that you have
in graph graphite that allows you to

make graphene.

So this is easy to expel the eight or
term for disassembling the material.

Things like metal phosphates
Middleboro sides and

others have much stronger Ionic and
or covalent interactions.

So here metal silicates sort of you
know should not be that difficult

to disassemble by this analysis.

So I'm going to spend the rest of

the talk describing how we actually
went about accomplishing this.

So first you need to prepare your

material and yes you could go and
buy it but what fun would that be.

And there are a few suppliers
of artist materials that

you can buy pigments from you
cannot buy from same Aldridge.

So the services that we use there
is in the literature is basically

based on how the ancient Egyptians made
it even back in the third millennium B.C.

it's a fairly robust
synthesis it worked well.

Then it still works well now.

If they need a copper source.

Back in the day it was copper metal or
Malakai it.

Now we just use synthetic Malakai
which is a copper carbonate

hydroxide new source of silicon.

Which is just silica for can dioxide.

Or you could use just sand or quartz.

You took a source of calcium.

This is easy.

This is limestone or
just calcium carbonate.

Your oxygen source is
just oxygen from the air.

And then we have a key part of the
synthesis with which is the addition of

a flux.

And so a flux and solid state since
the surface is like a solvent.

That's the way I think of it and
AIDS in the mobility of your ions so that

you can decrease the reaction temperature
and increase the reaction rates.

So.

Thank shouldn't people probably use
a flux of potassium carbonate or

sodium chloride or some mixture of.

Readily available materials.

We have a sort of an optimized flux that
sodium carbonate sodium chloride and

sodium bore it.

And so you grind these
materials together put them in

a platinum Crucible put
it into your box furnace.

And with the addition of the flux you only
need to heat this at age seventy five for

let's say a day to get complete reaction.

In comparison.

Without the flux.

You need to do this synthesis
at above a thousand degrees.

And so we know of a point
of historical interest that

using rudimentary kilns
like was available back.

In ancient Egypt they could
not reach a thousand degrees.

Maybe the maximum you could
reach was nine hundred and so

the certainly were using adding a flux.

Even back then.

So you do your sentences
you wash away the flux and

you're left with powder material or
Crystal material.

If you do use the melt flux right.

You get a powder that looks like this
has the characteristic blue color.

If you look at the material by S.C.M.

you'll see that the individual
Crystal Light or

grains are on the order of twenty five
at least twenty five microns in size.

Up until much larger
when you actually sort

of crush the material as you're making
it which decreases the saw someone.

In comparison.

If you do the solace
a synthesis without the flux.

You get this is your product and
so it's just it doesn't

have the characteristic blue color
it's just sort of a dull gray.

Right and this is a direct
reflection of the particle size.

If you can see that these particles
are maybe a micron in size and

each one of these aggregates are formed of
many many small crystal lights right so

you only get the color when
you have enough copper islands

that are aligned right
in the same in the same

order to provide the color which you
do in this case but not in this.

What we did next.

Is react.

The calcium copper Tetra
silicate in hot water.

So here's a picture of the reaction.

On This is eighty degree water
with a condenser for a few days.

With stirring.

And at the end if you can see even maybe
a little hard to see in this light.

There is a blue solution here
that has pearlescent right.

So especially when you actually see it
in person and it's stirring it's moving.

You can see the shimmering
pearlescent effect.

Right which is.

Elated to sew a liquid crystal type
effect as you have these nano sheets.

Right.
So the three dimensional material

has disassembled into
the two dimensional form.

And then you get because they're so
and isotropic you get randoms

of restacking in solution or aggregation
solution which gives you this progresses.

Over here in this optical
microscope image.

You can see a comparison of the color
here as the starting material and

then this is the very light blue
color of this nano sheet material.

Now I get this question a lot.

Why did you try just
stirring in hot water.

It seems like such a simple
way to do chemistry and

the truth is that we didn't
start with just hot water.

We actually started with something that
we thought was more clever a little bit

more sophisticated we were trying
to take small organic molecules and

in Turkle ate them in between
the layers of the calcium copper Tetra

silicate which is a well known strategy.

And they were my student did
the control experiment but

no organic molecule there just the water.

We saw that it also worked.

So it always pays to be thorough
in your experiments and

zero is through the control.

So let me prove to you that we've
actually made these nano sheets.

And here's some of my cross could be data.

Over here on the left you can see A.T.M.
image of a single

calcium copper Tetris silicate nano sheet
and it's on the lacy carbon grid and

you can see it's so thin that you can
see the grid behind the Nano sheet.

In terms of lateral dimensions
this particular sheet is microns

multiple microns and lateral dimensions.

Here is a elect.

Around a fraction pattern.

So proving to you how Crystal in this
material is very strong intensity and

regular pattern.

And so in this view right.

You're seeing this.

Orientation of the sheet.

Right.
So the the the thin part is this the C.

axis is along the C. axis the material.

And the A in the B.
axes are the long ones.

So looks thin but

this doesn't actually prove how thin
it is for that we need to use A.F.M..

And so here's an A.F.M. image.

With a single nano sheet.

Atop a graphic image.

If you look at the height along this
line which is shown here in this plot.

You can see that it's about one point two
point three nanometers and thickness.

So if you look at again the structure
of the material you can

theoretically predict that a single layer
should be about point nine nanometers.

Remember these here are the calcium ions
that would be holding the layers together.

But of course those calcium ions are not
just hanging out bare on the surface right

there in equities and Vironment there
certainly are hydroxyl groups or water

molecules that are coordinated to both the
top and the bottom surface of the sheet.

So if you take this into
account then you can explain

the total one point two nanometer
thickness that we have served.

This strategy also works for

the other derivatives for the strong Tim
and the barium copper Tetra silicate.

And so here is a few more images of
the calcium copper Tetra silicate

from material that was originally a small
grain size and a much larger grain saw us.

Here's a strong T.
into revenue from a small grain size and

barium from a large grain size and
I bring that up because the lateral

dimensions of the Nano sheet that you
get directly correspond to the grain

size of the crystals that you started
with and this is as you would expect.

We can take these powders and do X.

ray diffraction So
yes some more information about them.

I have three sets of data here.

The top two plots top two patterns are for

calcium copper Tetra silicate we
have the bulk starting material and

then up top the Nano sheet so going from
a three D. to two D. in the same for

the strong T.M. bulk and then a sheet and
barium bulk and then a sheet.

So beyond just identifying that
we have the right material.

You'll notice that there are some peaks
here that are noted with an asterisk.

And these are the peaks that correspond
to the zero zero L. series of material.

And this tells us that we have
preferred orientation in our sample and

so we make these samples by taking our
aqueous colloidal dispersion of Nana

sheets drop casting them on a slide.

Right in this process as they dry the
material naturally assembles into layers

because it's so in isotropic and
that's why we see

this change in intensity along the zero
zero L. series for all three cases.

Another experiment.

That's interesting is to take
the Nano sheets and then Neil them.

So the idea is that you started with
a three dimensional material and

made it two dimensional then can you
take the two dimensional sheets and

basically reassemble them to get
back your original material.

And in fact this works so.

You saw this image earlier you have
the original starting material calcium

copper Tetra silicate
these are the Nano sheets.

If you take these and then kneel
them at about nine hundred degrees.

You get back this material and

so we've recovered the original
the deep blue color of.

Egyptian blue.

Here's another example where we
used filtration to form a paper or

a disc of our nano sheets and
then Rhian yelled it.

Of course here it's quite flexible.

Because the Nano sheets are not
bonded together they can slide.

And then once we kneel
it sort of fragments and

it becomes very much
a ceramic material again.

And we've regained the deep blue color.

OK So now some luminescence data and so

our whole concept hinges on whether when
we have this to dimensional nano sheet.

Do we retain the near I.R.

emitting properties because if we
don't then although this was fun.

It doesn't really have much
of a practical application.

Right to implement this in any kind
of application we need to retain

the luminescence.

And so here are some extra Taishan and
emission data for

calcium copper Tetra silicate and
so we have our IN THE BLUE

trace was our starting material
commercial calcium copper Tetra silicate

the black line our nano sheets the X.
fully into material and

the red curve is the Nields material and
so

we have two three dimensional and
one two dimensional example.

So first we know so
few things first that in all three cases

we retain the emission at
one hundred ten nanometers.

So this is excellent and
this bodes well for for efficacious.

Then here in the.

In this set of curves.

We can see that the three
dimensional examples.

Look like this and then this peak
intensity drops substantially for

the exposed two dimensional material.

And this is consistent.

So even if we look at the data for

barium copper Tetra silicate right
we see the same drop tensity

from going from the three dimensional
to the two dimensional material.

Basically everything else stays the same.

And so we can explain this
by considering that one

of the important interactions
is between the layers.

So the interaction between the calcium or
barium ions holding the layers together.

And so
when this is lost in going from three D.

to Tootie this is the change in intensity
that you see at this feature here.

OK so now we've confirmed we
can retain the properties.

Our last criterion was
Solution processing.

So if we have a colloidal
dispersion in water.

We can also form colloidal dispersions and
other solvents right that might be more

amenable to making a ink that was stable
over long term for at least days.

And so we took our calcium
copper Tetra silicates and

dispersed them in the organic solvent
like and vinyl Parola to known.

Whether some others and
we used a materials in chip printer.

Like you have here.

A dramatic spring or
to print the series of

calcium copper Tetris it silicate in
a sheet squares on a glass slide.

OK So these are five just very
simple just five millimeter.

On a side squares.

And our point are two points where to
prove that we could do this with an ink

made of these nano sheets and then also to
prove that we could retain the near I.R.

luminescence after we
print as you would expect.

So in this portion of the slide you can
see the visible image and this portion.

You can see the near infrared
image near infrared photograph.

Another way to do solution
processing to make a macro sized

sample is again to take this disk of
material that I showed you before.

So to make this we just take
a dispersion of our nano sheets and

we filter it through a filter
there a membrane filter

it was a poor size of one or
two hundred nanometers.

The nano sheets orient themselves as
they pass the solution passes through.

And you can see here in this S.C.M.
image right.

The alignment of the layers.

In the cross-section.

And so then you can use this to
fabricate something you can anneal it.

If you want to reassemble the layers
together then there's many possibilities

and we've also tried spin coating
spray coating very simple techniques

that are scalable those also work as
well as layer by layer deposition.

Right which is a technique
that can allow you control

of incorporating other
components into a thin film.

So we were after getting these results.

We were naturally very curious

about the long jeopardy of the Egyptian
blue in the archaeological context.

Even though this is not
something that a chemist would

usually study it was just a natural
question if this is a lamb.

Nation of six foliation can occur so
easily just in water

then maybe it's happening there in
the field in an actual ancient samples.

We thought we should check.

So the first experiment we did was
room temperature data lamination.

So obviously we don't have artifacts
that are sitting in eighty degree water.

But they can be sitting in humid
conditions room temperature for

a very long time.

So in fact we can do laminate

calcium copper Tetra silicate
just at room temperature.

Although it's slow and so

here are some nano sheets that we've
pulled out of the reaction flask.

After two months and
if you just let this go longer as more and

more of the form over time.

Just just at room temperature.

And you'll notice that they they look
a bit more wrinkly than the Nana sheets

I showed earlier and this pick is because
they're not much single layer name or

sheets they're multi-layers.

And we can see that you know if we
take A.F.M. of a representative.

Man or sheet the thickness of the sheet
is maybe about five point five nanometers

which indicates that several layers that
are still remain stacked together and

so we don't get completely like
we do at higher temperatures.

So this is interesting in that it does
show that it would be possible for

the six foliation just to be occurring
under environmental conditions.

And then we found a few people who
were willing to loan us give us

some actual archaeological samples.

So that in this top set of images.

We received from England.

And so these were Egyptian blue particles
that were found as part of a soil sample

and so these particle saw.

Wet room temperature conditions
over a long period of time.

This bottom sample came
from the Carlos Museum.

At Emory University.

So it came from one of
their Egyptian coffins

that originated from the temple
complex a car neck and

so this sample would have seen very dry
conditions over a long period of time.

And then here we have a reference
to serve modern materials.

And so what we're looking for
in the what we were looking for

in this series of S.C.M.
images was whether we could see

actual evidence of expose the a surety
lamination from the surface.

Right so

pieces of nano sheet that would be still
partially it attached sticking up.

And you just see so and this is this
example here you can see some cleavage

plains right where material has
the laminated from the surface.

Actually in all of these
samples you can see that.

But the problem is this can occur
just from physical the lamination

because it's a layered material.

So just from mechanical forces
grinding rubbing anything

can cause this kind of effect.

And we in fact did not see
definitive evidence of

the lamination on these samples.

So although I think it's
possible that this is happening.

We don't have proof of it.

So let me leave you with
some final thoughts.

The first is the unlimited potential for
new knowledge.

So you would have thought since these
materials have been known for so

many millennia that we would know
all about their chemistry and

their physical properties.

They have been around for us to study for
so long but in fact this was not true.

There was something really new to discover
even about something that's so well known.

The second point is one
of my favorite quotes.

I'm sure that most of you
have heard this right that

chance favors the prepared mind.

I am one hundred percent
sure that people before us

made these calcium copper touches so
we came into sheets and sort of

you know by accident as a byproduct of
whatever it was that they were doing.

Just nobody had looked to confirm
to see what they were making.

Part of it also is that now
we actually have the tools to

do this we have the microscopy techniques

that can allow us to characterize things
on the nanoscale that we didn't before.

I finally my third point is so
new possibilities for

metal silicates as functional materials.

That we all know about the importance
of silicate materials.

I mean just think of
the example of zealots and

all of their important
real world applications.

So here's an example where we have
a copper center incorporated and

very interesting optical properties.

That could lead to
applications down the line and

with that over the floor for
any questions.

Thank you

all or when you write so

you see the movie great when you write and

buy one that you'll want to know about.

Right.

Well that's just not enough good good B.G.

I mean you go to you you're
changing your story or your story.

Your story.

You know read.

Yes So ideally it would better just go.

So ideally it would just be goes
colorless not gray right so gray is.

But if you know it was
in there why do it and

it'll be what it was why not.

How does it.

You know when he mentions.

Well.

So it's a dichroic material.

Right.
So you only see the color if you were have

a large piece which Crystal you
would only see the blue color.

If you look along the sea axis.

Right.
So

you need to have that alignment of the all
the copper ions in the material right.

So as it becomes smaller and
smaller particle size or

you just have this random jumble you
see much more of the egg and the B.

axes and so the blue color becomes lost.

Right.
So I understand your point.

So possibly if you could just have
one of these and actually oriented.

So you're looking.

Along the sea axis probably
would still be blue but

in the bulk just as the powder
form then you lose the color.

Not just gathering them like a wavelength.

Size is like.

Well if you get that small that
could add to the effect as well.

Yeah that's definitely true.

But you can see a definite
progression as you grind smaller

smaller particle size goes
light blue lighter blue gray.

Yes

So when you say one layer do you mean.

One monolayer No no no.

So when we're into printing.

I mean these are they're small drops but
I mean relatively large right so

the we were trying to prove that
just we could pattered the material

in this way to get Romana layers.

We go to layer by layer deposition.

So we put down a charge polymer and
then we just

let the Nano sheets absorb and
sort of sort of a self limiting process.

So a single model layer absorbs.

So that's how to control it at that level.

Yes yes.

To find

control over the stacking you

know.

Yes So you have to add more polymer So
it's a charge based process.

So you have like polymer model
layer polymer model layer and

then at the end you can remove
your Gana component but

there's no orientation in
that kind of a scheme.

There's no F. a taxi no orientation so

she just random however they form
over they go down on the on the layer

you just

go to the with its color but

you know it is the picture when you want

if you like lose color.

Sure.

So I mean you notice even in the.

The powder of the NATO sheet.

It wasn't colorless was a pale blue or
a pale blue gray.

So there's some orientation.

They just naturally because they're so

an isotropic there is some level
of organization of the material.

But it's not until you a Neal it
actually basically rechristened Ally's

those layers together that you get
the color of the deep blue of the stars.

Tiriel.

So it's sort of you're poorly
organized you see a light blue.

Because the compensation concert.

So you can sort of dilute it to thirty.

That's right that's right.

Yeah so it doesn't behave like a dye
it really behaves like a particle

of a pigment particle

or.

Yes so for
a material like graphene for example.

That's only a single atom thick.

But you see you can see very
extensive wrinkling unfolding.

I think because our materials
are thicker than that and

right they have the silicate network
that's holding the copper together.

That provides a bit more rigidity.

So we actually usually see
pretty flat nano sheets and

they might have some waves in them but
we don't see any rolling.

We don't see extensive wrinkling.

We do see that with some of the other
materials but not with the system.

Right.
So actually they don't go any direction

because they're so an isotropic right so
it's like you had these

you know giant sheets of paper
just a jumble of them and

they just naturally want to stack
one on top of each other they

don't just stack randomly
like a like a cast of cards

right because the the the lateral
dimensions are so many microns.

So it's I think of it as sort of
a liquid crystal and kind of effect.