Yes.

And I want

to thank you.

Thanks for the introduction and
thanks for inviting me.

It's been a real pleasure
to be here today.

Can everyone hear me
from both sides here so

what I want to talk about over
the next twenty five minutes or so

is the work that we've been doing since
I joined the state back in zero six and

this is in the area of course materials
and really trying to approach this

from a design standpoint where
instead of just making a material and

then testing what it can do we want to
come out from the other direction where we

look at an application where
we identify some need and

then figure out how can we make
a material that can do this.

So there are a lot of fundamental issues
before we actually achieve this design

approach so that's what I want to talk
about today is the work that we've been

doing to try to identify some of
the features and properties that we would

want in a material first for
different types of applications.

So just by way of overview of what
my research program is all about.

Like I said we're trying to design and
synthesize

be able to engineer materials that can be
functional in some way whether it's for

separations or tell us this or
some controlled storage and release.

So try to put properties in there that
we want and I listed some applications

here because this is what we have been
focusing on largely over the past year and

a half and search and separations in
particular and these are just a couple of

pictures of what nation polymers look at
look like and I put down here the driving

goal which is to develop the ability to
be able to design these materials with

molecules specific properties and these
materials are in organic organic hybrids.

So that opens up a lot of avenues for
not only deciding on the metal part but

also the organic part.

So it's really flexible in terms of which
pieces we use to assemble materials and so

that's that's what our goal is and I want
you to keep these applications in mind

as we go through all that I'm going to
focus largely on search and separations.

And before I move on into the sort of
the more formal introduction of what

the materials are just wanted to give
you a snapshot of the types of methods

we use in my group we approach
this from a three pronged

way where we're trying to not
only synthesize new material.

So you solid state chemistry but

we also do molecular modeling we want
to understand where the molecules go.

Why do they like to absorb at that spot.

How can we make the material better.

And so
it's open experiments are also important.

So all of these three these three
things feed into one another and

I really believe it's up that interface
where we're going to be successful in

coming up with some really nice functional
materials for different applications.

So that we have outlined so
you know where we're going.

I want to start out and really walk you
through a few examples of metal are going

to frameworks also called Coronation
polymers just to give you a taste.

How large this area is and

how unconstrained The problem is there's
been maybe fifteen thousand structures or

more that have been deposited into the
Cambridge structural database in the past.

I don't know five or ten years.

So there's more and
more published constantly so

we it's really difficult to keep up and
there are lots of structures we know very

little about their properties so
sort of leading away from

the design principles doing me if we
really are going to try to design the.

What do we know what do we need to
know how we're going to get there and

then finally talk about some synthesis of
materials that we've been sent to sizing

and then really get into a little more
details on the absorption properties for

both our experiments and
molecular modeling.

So to start what are moths so

metal organic frameworks I'm going
to refer to them as my office.

If you read about them.

You'll see them called an inclination
polymers porous cremation polymers

poorest metal organic materials so

there's a lot of different names but
there's a good way to keep up with them.

So like I said there are Danica in
organic hybrids we can functionalize them

in a lot of different waves either priest
emphasis so we can have a molecule or

a ligand that we modify a lot of different
ways to try to create a family of

structures we can make the structure then
try to do some chemistry on the organic

part the synthesis routes are relatively
flexible and we can end up with very

poor sizes I'll show you some examples of
that they have high prosody high surface

areas open metal sites is a really big
issue that you know we can perform to tell

us what's on they also are very selective
It's option sites when they're there.

So a lot of the materials that
we work on focus on this.

They also have large poor volumes and

as you might imagine behavior depends
on what these functional these

are what is the material look like
what is the poor size the poor shape.

What is the functionality of
the walls which are really

more like scaffolding in these cases but
also the.

Properties of the molecule matter so

is it Polar what's the shape of
the molecule the size of the molecule.

But we want to achieve more
than just a molecular sieving

we actually want to be more of a chemical
separation rather than just a size issue.

So this is just a cartoon to.

To give you an idea of
a very generic synthesis.

You start with a tetrahedral metal
cluster and a linear organic link or

so this is just an example they actually
assemble in many different shapes.

But ideally you just put these parts
together they self assemble into extended

three dimensional structures and this is
what we were probably from the sixty's all

the way up to the late ninety's the first
generation materials you take the solvent

out and it falls apart and you just end up
with some metal clusters attached to it

organic so you can't do much with that
we want the poor space to stay there.

So now since about ninety eight
ninety nine we really are more

in the center of the second generation of
material where the solvent molecules can

be taken out you can reverse only
adsorb and diesel or gases and liquids.

So this is where we are now or the idea
and the ultimate goal is to move towards

this third generation where you can
actually make functional dynamic response

a framework so we can make them do what we
want them to do and this isn't a new idea

and you can find examples of this
in other types of materials but for

example changing color when you absorb
something or do something we're

changing the shape of the poor
depending on what molecule is present.

We're just having functional eyes
structures with active center so

this these are just catalysts So
it's not new but

just trying to make these materials do
some of these things and what can be

really important because they are really
quite design able just by nature.

So now I want to move on and
talk about a few specific examples and

just to give you an idea of the breadth
of this area if you've looked

at any literature to do with polymers or
moths you've probably seen this one.

His ma five is what it was
originally published as and

this came out of Omar yagis group.

I believe it was at the University of
Michigan at the time he's now at U.C.L.A..

But this material looks just like
a square but it's actually a cube and

it extends out in all the X. Y.
Z. direction so you have this

whole network of pores and what I want
you to pay attention to in this figure.

So the balloons here.

These are the zinc atoms there.

Those are the metal parts and

they're completely covered up by
the oxygen which are the red ones.

So the metal part the metal atoms in this
material are more Nativity saturated and

that's going to be important when we
talk about some other materials later

we often want the metals
to be on saturated.

So this material is made from acid and
equipments with the word

Kadam So there's three here the fourth
one is behind that center oxygen group.

So you these.

Self assemble and they form the core
structure you remove the solvent and

you're left with this.

So you can see it has
really high surface areas

to compare this to like is a typical Z.
allied.

Those are more like six hundred to nine
hundred meter squared so m² program this

is thirty three hundred so they're really
high surface areas and this debate about

whether or not that actually makes
a huge impact on absorption properties.

It does at the high pressure and but

sometimes you don't really care about
these large surface areas if you're doing

trace contaminants or
low pressure applications.

But we're going to come back to this
mature I'm going to compare some

absorption properties with this one.

When we get a little bit later on.

So as I mentioned before we can turn
the pore size we can change things

around just by switching out the linker or
by modifying it in some way.

So this example is a set of ice over
tickler metal organic frameworks which

just means they have the same shape but
they're just expanded out so

if you look this is the one that
was on the previous slide and

the yellow spheres are just to show you
the poor space there is not a molecule or

anything and if you look at this one and
this is the one.

I mean face and the middle one
has two faces and this is three.

So what we're doing is just doubling the
poor volume and tripling the poor volume

so just by changing out the linker
they're still linear and

they still assemble with the same
zinc oxide cluster in the corners but

it just lets you expand out the poor size.

If you look at the ones on the bottom.

This still uses the one aromatic ring like
this one but now we functionalized it so

this one has an amino group and
this one has some alcohol chain.

So it gives you a way to not
only change the core size but

to modify the poor space as well so

that will impact which molecules can enter
the poor space and exit the poor space.

This example is of a mixed metal and

often you can see it's made with nickel
and sodium the purple ones are the nickel.

I mean sodium and I don't think you can
see the nickel it's somewhere behind in

there but what's really interesting about
this material has very small pores that

have about four Angstrom pores and

it's actually interconnected
to each other on the inside.

You can't see it from this view but
this material is stable up to

one hundred sixty degrees C. So it's it's
pretty stable and it also demonstrated

carbon monoxide oxidation behavior so that
was pretty new at the time when this was

published off had not shown any type
of catalytic abilities at that time.

So one thing that was really remark
about this material though is that not

only did it oxidizes carbon monoxide but
the conversion rate stayed constant when

compared to a nickel over the same period
of time so you didn't lose conversion

rate as quickly as you would with some
of the other typical materials and it's

believed it's because you have this very
organized distribution of metal sites.

They're not sitting in the core space.

They're part of the poor space so
that can make some difference.

And this is a material will definitely
come back to again my group has been

working a lot on this is.

Actually the first one that we ever made.

And I think is the easiest one to make if
you're interested in trying to herself but

this is copper B T C It's formed
from bins in tri cup a silicon acid.

So the try to pick a roll known to
form this nice paddle will structure.

So you have for the Logans that
coordinate with two copper Adams and

it forms this nice part of will
where you end up with broader or

ethanol coordinated to the other faces.

So once you've assembled the material
in this way and you have

solvent that's coronated to the copper
site you can remove it and then you're

left with exposed metal sites so that's
what this shows the green ones are copper.

So you can see the difference between this
one and the first one I showed you is that

the metal is open and
able to interact with incoming molecules.

So this is a front view this
poor diameter is about nine and

in the corners you have three and
a half inks from pores.

So if you look this is rotated slightly so
that cop out.

Is this one.

So it's just slightly rotated
around the vertical axis.

So that you can see this
poor space in the center.

So this one works much like the Allied
if you're familiar with the lights

it's very similar to the shape and
size of a four using a light.

Except we have all of these
nice functionality with no

metal sites taking up more space.

It's also relatively stable we see
the decomposition temperatures about two

hundred seventy five degrees C..

This is one that we sized in
my lab a couple of months back

from a lamp in a lamp and
I'm in this B two B. leg and here and

we basically mix with life and
nitrate in D.M.F.

ninety degrees C. and
it forms the structure and I just want to.

So this one on the right shows
the coronation environment but

here it's a little blurry but
if you see it's

a it's a honeycomb structure where
you have these circles form.

One layer and underneath it's just offset.

So there's a second layer underneath
that offsets from the first one and

the bottom would do the same so
they stack on top of each other and

the coronation environment here.

The length of them has eight coronation
mode so you have seven B two B.

Legan's and one water.

So you can take the water off and again
you're left with an exposed metal site.

So I'm just showing you these to try to
give you an idea of how many different

material you can make just really
depends on the synthesis conditions and

the parts that you choose.

I think that's the last one.

So this is what I want to
show you before we move on.

This is another one.

We recently synthesize in my group
using the same BT leg and but

now were assembling it with copper.

So this from the completely different
structure where we have these two

dimensional type of player where we still
from the paddle wheel because we have to

try to pick we're going to still so we're
forming the paddle we'll smelling the unit

and we remove the solvent and we're left
with the green open copper atoms there.

So you form these sheets and if we turn it
on the side and look at it on the side and

actually chains on the sides and
this would just be one way or and

they actually stack their hydrogen
bonding behind one other so

they're not porous in
a traditional sense but

to put those do more just as
a result of the layer stacking up

behind me to that I'll show you some data
that we have for this a little later on.

So before we go on.

I told you we're going to talk about
absorption separations a little bit but

I'm off for absorption applications I
mean we've absorptions been around since

forever I mean activated carbons were
used back in the nineteenth century and

earlier for water purification which
is just an absorption process so and

I wanted to point out some of the good and

the bad about these materials because
there are a lot of different issues but

we start only advantage of side up
touched on these a little already but

like I said before you have a uniform
distribution on metal sites.

That's really good especially
if you're trying to care.

Derives the different types of
absorption behavior and trying to see

where active sites are we know where
the atoms are we can get single crystal X.

ray diffraction That's how been able
to make a lot of these pictures we

know where the atoms are and also these
sites are actually part of the frame

are there not just sitting there taking
up or space they're not moving around.

We know where they are the poor
size can be tailored and

as a few studies have shown we
may be able to provide reactivity

with no loss of performance over a period
of time compared to traditional materials.

So these are just a few to keep in
mind as far as the disadvantage is.

Framework stability can be a problem.

I mean any time any time you're creating
a material through cooperation of.

You know oxygen groups to metal.

Water can be disruptive.

It can come in there and break
the bonds apart the coronation bonds so

you end up with something
that's non-porous so

effective moisture is really
important reverse ability for

using it for and insertion separation
you want to be able to days or.

The molecules and get them back out.

So that's a huge concern and

you don't want them to be stuck
once they've absorbed there and

then from a more macro level of
incorporation into engineered systems.

So if we're going to make
the use as a new separation.

Then we need to be able to
engineer it into pellets for

fix it in some way that you can put it
in a fixed bed because a lot of these

when we synthesize these are very
they're very fluffy powders and

if you put them in a fixed bed and
try to blow gas through there.

They're just going to go everywhere so
that can be a problem.

How's that going to change the properties
once you pelletised maybe you

have to add a binder.

So how's that going to change things.

But so far I think that advantages are
worth pursuing the materials you just have

to keep in mind what the disadvantages are
and try to solve those as you go along.

OK So design strategies.

What do we know how do we get there and

I think this is where maybe my approach
is a little bit different from.

Others in that I think we know a lot
from absorption fundamentals and

we can really use this to aid our design.

So instead of just trying to explore
new chemistries which is good and

we do that too but

from a design standpoint if you're looking
at a specific separation in this case.

Think about what properties do you
need in order to get this molecule out

of the mixture.

So I think that from absorption
fundamentals we can use this to

aid some of our design criteria.

So just a couple of very quick examples.

From classical absorption fundamentals
the slip poor model is one of the oldest

examples of for studying absorption
there was often it's often used to model

carbon spores carbons So for
example just looking at this at this

illustration you have some intuition that
if you're this molecule these molecules

are the same size and you have poor roles
that are exactly identical except this one

is closer together and this means for
other part you have some intuition that

the molecule in this one is going to
be much more favorable to absorb there

is going to like to absorb there more
than when the balls are really five part.

So for one thing then you need to
consider the size of your molecule and

try to increase the potential
Well if you're trying to

of the molecule you're trying to remove.

As far as the material that have
open metal sites we can translate or

transfer a lot of information we know from
for example de Knox could tell us this if

you go through the literature there are
tons of papers published on looking at how

can you perform this could tell us this
in different types of the allies so this

is a silica alumina and silica and then
you have the copper and I'm sitting here.

So we do know a lot about how molecules
interact with different surfaces

we just need to bring that over into
the the coordination polymer field.

So some of the previous strategies or
this materials and

I didn't go into the history of how
Pollard's have developed but they really

sort of hit their stride in the very
late ninety's and around two thousand.

And that was because of the potential for

using I mean gas storage in
particular hydrogen storage and

methane storage so because of that all of
the studies that sort of came after it.

People were trying to really maximize the
surface area and get as much per volume as

you can get to make them really large
really open structures which is great for

gas storage because you need high capacity
use it relatively high pressures.

Now if you want to use this for

separations it's not as useful
because everything can go in.

So if you have just
imagine a like a huge box.

If you have a fifty percent mixture
in the gas phase we're going

to get fifty percent mixture and
had sort face.

So you really have to do some different
things rather than just making a big open

structure.

So this is the way polymers really got
going was targeting best storage so.

Some of our strategy even has been.

To continue to look for good proxies and

good surface areas because that's
that's important for any absorbent but

try to think about fitting the poor size
a little better to the molecule and you

don't want exact Are you start to make it
more difficult for the molecule to go in.

But you know the open
structures are not best.

So looking about that but you've got to
be aware of this balance with the problem

with water so they get to Small
going to have capillary effects and

you're going to have a huge problem for
there's any moisture in the air.

A couple of these so
in part special chemistries and

reactivity I'm not going to get
too much into that today but.

A major thing we've been doing then
has been focusing on these pedal unit

materials where you have
exposed metal sites.

So if you get the plus sized right.

And we've increased the energetics
with metal sites being there and

you can functionalized the organic part.

Then you really start to move
towards a system that you can

design specifically to interact with
a molecule that you're interested in.

So now moving along into a little more
of the simplest this information.

So what I want to talk about next.

Is the efforts we've been doing on
trying to synthesize some structures and

I want to go over some of the different
methods reviews which include interface to

fusion solvent their methods just point
out that depending on the reaction

conditions which could be ph or
temperature solvent any of these things

you can get a completely
different structure.

Even using the same parts so

if you use the same metal in the same
league and depending on the reaction

conditions you can end up with
a three dimensional structure.

No structure or some one dimensional
chain so that really matters.

And any time we're going through this.

We always try to obtain
a single crystal for X.

ray diffraction because we want
to identify where the atoms are.

We also have been a lot of work with just
looking at promising structures from

literature and following the recipes for
those and trying to make those structures

and really learn more about their
absorption properties because

often what you see are really interesting
structures that are published but

maybe there is no more data
other than the structure.

So a lot of times we've been doing that's
actually how we started was by choosing

some structures from the literature just
so that we could verify our methods and

make sure we were using the right
techniques and so I would say over

the past eight months or so we've really
been focusing more on new structures.

And then screening the surface
area with BT measurements.

I sort of view surface areas and moths
with a little bit of a critical eye just

because I don't think it quite means
the same thing as we're used to it.

Meaning for other materials but it is
a good benchmark and it helps us know

relative one material to another how
we're doing on prosody you know if

you get if you measure this and you get to
a meter square program then you know that

it's pretty much non-porous So it gives us
a good idea if we've been successful or

not without having to go through the X.
ray diffraction.

So like I said there
synthesis method really my.

So I want to go over a couple of
examples of things that we found

the product depends on
the method that we use.

So the height of the reaction and I'll
just show you just a picture here we have

these digestion bomb so we have these
Teflon containers that fit into here.

So you just put the solution of
your leg and with solvent and

the metal into the Teflon container
put it in the bottom and heat it up.

So that's how we do the solid solid thermo
method and if we do that with this leg and

here and copper.

So you put copper nitrate.

In the mixture with the slogan.

Using methanol and a router as
the solvent and heated up to one hundred

twenty degrees than me and up with these
red crystals which were not what we were

trying to get if instead we use interface
to fusion which looks like this.

So this is a much more small
scale type reaction and

it's it's done under ambient conditions so

it can take weeks before anything forms
but you can see these are just test tubes

where we have a layered approach for
trying to produce the material and.

In particular what we would do with in
this case is in the bottom of the test

tube you would put the ligand in solution
with water and E.M.F. in the middle you

put methanol in water and at the top you
put the copper source copper nitrate and

methanol and what happens over time is
that the copper in the ligand will diffuse

towards one another and
they stop assemble at the interface.

That's why it's called interface to fusion
so this is just done at room temperature.

So we did it this way we got blue crystals
which appeared around the interface and

that actually was what we were trying
to get so it's all the same parts but

just putting them together
in a different way and

using different temperatures creates
completely different structures.

So the product also depends
on the Sabbath that you use.

So if we use this break in now.

So the sodium comes off that's
where the quotation centers.

The sodium comes off and
the copper record make there

you can see all the same
temperature we use just water.

Nothing happens which wasn't
surprising if used E.M.F.

you get some oily type products.

If you use methanol you start to achieve
some powder at the bottom of your

container me bring it out and
ethanol you get more powder but

it still wasn't really what we were trying
to get so we tried to mixture of water and

methanol and then that's where
we got the blue crystals so

it was a system we sort of knew what
it should look like so that helped but

otherwise it's really much of trial and
error but once you've done a few of these

you start to get a feel for what types
of solvents are going to work best for

certain Lincolns but it really is
somewhat of an art at the beginning.

And then the last one the product
also depends on the temperature.

So one of the materials that I showed
you before they want to have the chain.

So that's this between the leg and
that we made with copper and

the solvent is water in ethanol.

So if we conducted the reaction
in eighty degrees.

We ended up with just a metal or
granite chain so

you have the ligand with a copper
in another leg and so forth.

It was just like a one dimensional kind
of just chain of we're going to metal

if we increase the temperature of
the reaction in ninety five degrees.

We ended up with a two D. sheet but there
is no layering they were just a discrete

kind of squares and if we perform
the reaction of one hundred ten degrees C.

that's when we got the material of the one
that I showed you in the other picture.

So it's really very sensitive to to
all the reaction conditions which

isn't surprising but it does make it more
difficult to determine sort of a priority.

What you're going to end up with.

So now I want to show you.

I think three different materials that we
have synthesised and characterized and

then I'm going to compare some of
the absorption data we've measured.

So I want to go through all three
when I'm showing you the data and

I'm going to put little
pictures of the material so

you can sort of keep track
of where we are and the.

First one which I've already
shown you is copper B T C.

And it has the open metal
sites the copper sites.

Here's the paddle structure again so

you have the two copper Adams
in the four B T C Legan's.

And the way we synthesize this
trait dissolved in D.I.I.

water the been asked if it
is dissolved in ethanol and

we put it all together in one
of our Teflon lined containers

heated up to thirty three Kelvin after
eight hours we've formed the material

when she quit off you Russia with ethanol
in evacuate the sample overnight.

So like I said this one is actually pretty
easy to make and it's very repeatable.

There's a surface area of a room
twelve fifteen to twelve fifty

meters squared program.

That's next.
Material is a mix of them off.

So pretty much everything I've shown you
up to now we use just one type of organic

molecules and make the material this one
uses too for this uses the benzene Dicus

or like acid but it also uses teta
which is throwing in Diamine so it uses

a mixed bag and system we can make it in
three different flavors of copper and

cobalt the results are going to show your
for the zinc material and that's what this

S.C.M. is from so you can see it's highly
Crystal in there forms really nice cubic.

Structures from from R.C.M. picture here
and it's quite stable up to two hundred

seventy degrees C. and has a surface
area of around sixteen fifty and one.

Kind of remarkable thing about this
material is that once we've activated it.

It does not it does not
reabsorb water out of the air.

The other material the one I just
showed you will immediately absorb

water you can see a color change
actually and not one but this one.

There are no open metal sites.

At all.

So it's all just showing these aromatic
groups to anything trying to come in.

So it's actually quite hydrophobic it
doesn't absorb any water wants you back

to be that it would have to be
really high relative humidity.

I'm to take a broader point.

So the way we.

This one is Ted a dissolve it and D.M.F.

he did so all these are solvent thermal
methods and Russian would be enough.

So this one takes longer and

we usually keep this one for about sixty
hours to get the material to assemble.

And then the last one in the copper b t b
what I showed you before it has the chain

and you could see see the difference here.

These are more like shards compared to
the to the nice crystalline structure or

the cubic structure of this one.

So just to give you a little more detail
this one is a quite show everything but

what I was talking about the layers
you have these this baby ab type

really are going so you have the two that
are close together by how demanding and

then you have sort of this inner woven
structure of the other pendant arms

that are hanging off because it has a
whole group of carbon so like acid groups

that are unquote made it so that's what
you get sort of sticking into them.

So it does create some prosody but it's
not really the same as the other materials

which have a very distinct three
dimensional interconnected prosody.

And this is the coronation
environment of that you have for

more years to copper atoms and that's why
there's two over here and you have for

more between the lines that coordinate
with each with the two copper I don't.

So it's just a very typical pedal unit
it's just expanded out because BT is

a much friendlier
molecule than than B T C.

And the synthesis for

this is just mixing similar to
the others mixing the copper nitrate.

And we use rather in
ethanol as the solvent and

we form these really nice green diamond
shaped crystals so this when we had

no trouble getting crystals out
of it after we found the right.

Reaction temperature and so
we heated at one ten For

about sixteen hours and notice that
this one has a pretty road surface area.

I mean from office.

This is really low what you would almost
just discarded when you see this but

we wanted to look at it anyway because
it does have the open metal sites.

And.

OK So that gets us through synthesis of
the three materials I just showed you

those are the ones I want to discuss
some of the properties for and

we're going to look first at
just absorption of C O two and

some other light gases and
then I'm going to show you some work we've

done on molecular modeling that
sort of fits in with all of this.

So just to bring it back together because
I've shown you a lot of materials I wanted

to put this chart of first.

So the idea behind this.

Obviously we want to use these materials
for absorption separations but

first we need to know how they had stored
things and since this is a relatively new

class of materials we don't know a lot
about their absorption properties.

Its been much more published on
it in the past five years but

it's way behind the other
types of porous material so

the first thing we wanted to do
was just try to get a sense for

how do the different structural properties
affect their absorption properties so

we tried to choose materials that gave us
a good cross-section of different types of

properties so we have to here that have
open metal sites these two do not.

The surface areas sort of range from
six hundred all the way up to thirty

three hundred so
here's their MAF want to get in.

And pour sizes also range pretty widely
and the dimension of the poor structure so

this one does ink MOF And so
this is the mixed bag and off zinc MOF and

I'm off one they really have a nice to
find three dimensional interconnectivity

Like I said it's more like to
mention all sheep that stacks.

So we're trying to really characterize
these and see how the All these properties

affected there so the first we're
going to show you is methane.

And what I want you to notice first
is that the top two eyes of the arms.

So the top one here this is copper
B T C that has the open metal sites.

This is the zinc moth where there
are no open metal sites and

most I sent them to track
along together pretty well and

this isn't surprising that
methane is essentially non-polar.

So we wouldn't expect having this
huge project charge on a copper

atom to make a big difference.

There's no electrostatic interactions.

So we do see these tracking along
together I've put thirteen X.

which is just a commercial Z. A lot of
put that here just for comparison sake.

So you see that one running along here.

And then the copper B T B the two
dimensional sheet is coming in down

at the bottom which is not very surprising
there's no real prosody So we just have

a sheet with some metal sites basically
and thermal in a sort of in between.

So so far it seems like maybe poor size
dominates the mechanism for methane.

If we look at C O two and first I want to
zoom in on the low pressure before we go

back to that but if we look this is from
zero to five hundred killer Pascoe and

if we look at the very low so
below one bar.

If we look at what I said
there was are doing here.

So look at the Greenland.

This is thirteen X. again thirteen X.
thirteen X. has roughly seven and

a half Angstrom pillar and it has sodium
count ions that sit inside the core space.

So the C O two really likes thirteen X.

at low pressure so
you see that they're out there.

However it's saturate it's really quickly.

Whereas the MAF still continue to
take up C O two at higher pressures.

If we look at the next greatest absorber
this is copper B two C. So here we

have the material that has the upper metal
sites and the three dimensional prosody.

If we look at busy come off which has no

other metal sites that
one is coming in here.

So almost a similar behavior is methane
although we do see that the the metal

sites actually are much more important for
C O two which have sort of

a weak moment so
we would expect it to to behave this way.

Compared to methane.

Also notice coming in down here.

This is arm off one.

So this is this one of the really large
open cage structure that has pores

of about fifteen extra.

So the C O two doesn't really
like the arm off when.

Pressure.

Now if we go back to the all the way
up to twenty five hundred kill Pascale

if you look at the highest
pressure on here.

When I actually went out in the end but
it has a really high poor volume so

you can pack in a lot of C O two at high
pressure if we look at these two ice with

arms again are kind of tracking
the wrong together although the open.

Metal side material does beat the zinc
off and at the bottom here this one again

it's sort of matches up with some of these
materials in the very low pressure but

we didn't have enough data at that
pressure so I didn't want to.

So that tonight.

It was sort of noisy about at that point.

So we see that for methane up in metal
sites make a very little difference for

C O two that makes some difference but
not a huge difference.

And so finally carbon monoxide is
the other one that we've looked at so

immediately should notice a huge
difference between this molecule and

the other two I've shown you.

So first of all the zinc moth this one
is way down here at the bottom for

C O two and
methane it's been up at the top.

It's been one of the best performers for
so for

carbon monoxide it's not working well
at all and that I show here is for

a because C O doesn't absorb very well in
thirteen X. because the pores are pretty

large so you can see for a here you have
the rectangular type when I sit there and

you have a really good interaction at
the low pressure but the next best one is

the copper B T C So it has the open metal
sites the three dimensional pore space and

what's interesting though for for carbon
monoxide compared to the other molecules

if you look at this one are two
dimensional sheet material.

At this lower pressure.

It's better than the other two.

So we actually see that it
makes a huge difference to

have the open metal sites there so
once you remove those and just have.

The carbon chains that are being presented
with a poor space doesn't care so

much for that for that material anymore.

So you can see this one.

So I'm off one actually performs
the worst of any of them.

So it really shows.

This what some of the factors
are that control the mechanisms here.

So now I want to talk a little
about the molecular modeling

adsorption data sort of feed our model and

we can get a lot of information by
looking at both sides of this problem.

So I'm going to focus mainly
on C O two carbon monoxide and

what we do with this we perform grain
canonical money Carlo simulations and

the reason we use the grand canonical
ensemble is because it most

closely resembles the way we would
measure and absorption ice over.

So you can hold the volume constant
the temperature constant and

the chemical potential and
you allow the molecules to fluctuate.

So you can do random translations within
the system you can insert molecules or

you can delete them.

And so what this does you do a random
translation insertion deletion

until the adverb phase is in
equilibrium with the bulk fluid.

So this most closely resembles
the way we measure data.

So we can calculate the answer and
I suffer in this way and

then compare it with the data
that we've measured.

So I'm going to briefly touch
on some of the simulation model.

That we've used we use an atomistic
representation of the material

in this case I'm going to show you results
for the copper B T C M Because that was

what our most dramatic nights
with arms were for and

in this model we hold them off out fixed
at their crystal a graphic ordinance.

So we don't allow them to move at all.

Once we put the model the X. Y.
Z. coordinates they stay there.

They don't fry X. they don't do anything
so they're completely rigid we use

the lunar Jones parameters from
the universal force field and

we put charges on the framework so
there's going to be partial charges on all

the atoms especially the copper atoms and
we choose those based on quantum

chemical calculations so you can see
the reference that we took these from.

And they've been for this material they've
been tested a lot so they actually

give us really good agreement
with with our absorption data and

the mixing rules we use.

To get the cross term so the the sorbate
mob crossed terms we would use

the mixing verse there for the lunar Jones
interaction parameters for the star bait.

And sort of ignore methane is just
a United out of model but for

carbon monoxide here we use a Forsyte
model remember what we want to mimic

the polarity of these molecules so

carbon monoxide has a dipole moment and
these force fields are taken from

simulations that match broke
liquid equilibrium experiments.

So they do have some connection to
experimental data and with the C.E.O.

molecule.

We build it up this way where you
put point charges on the carbon and

the oxygen but then you have these dummy
sites that also have point charges.

So the whole molecule is neutral but
you can mimic the dipole.

And you can see references
that we took this from.

For carbon dioxide to use a similar model

where we're trying to
mimic the quater moment.

So we put point charges at the center of
mass of each atom of the molecule and

then to find the bottom line it's.

OK So what question are we
really trying to do so.

The model sets us up.

We can calculate absorption
equilibrium data for

all of those molecules that we have
models for inside this material.

So what is it we're trying
to actually find and for

this based on its option data we found
what we were trying to understand is how

do the unsaturated copper atoms actually
contribute to the absorption behavior so

to do this and
that's what makes what makes modeling so

great is that you can turn
different things on and off.

So you can consider some interactions.

You can consider others you can turn
some off and other things back on.

So it really gives you a good way
of trying to see how things affect

the absorption properties.

So the first model that I'm going to talk
about includes all of the electronic

electrostatic effects where we look at the
C O two interaction with them off atom.

So the.

Point charges on the C O two molecule
how they interact with the pressure

charges of the flame are those
electrostatic interaction.

We also consider the C O two
interacting with itself so

that quite a moment and then of course the
lunar Jones interaction spandrels forces.

So that's the full model we
consider all of those things.

So once we do that we can go back and
recalculate and I sat there and

where we turn off say the C O
two MAF electrostatic effect.

So instead we ignore the mock actual
charges pretend like there's nothing there

and just consider how C O two
interacts with itself and

how the lunar journeys interactions
impact the absorption.

So these are the types of things
that we were considering when me.

Calculated Our And I said therms
before showing you those results just

sort of give you some
confidence in our results.

I want to show you how it
compares to experiment and so

these are three materials the middle
line is the copper B T C So you can see

the the big money Carlo simulations
are the open symbols and the experiments

are the close symbols so we get really
good agreement with experimental data.

Typically we we feel more
comfortable in our simulations

give us higher numbers
than our experiments.

Just because with the simulation we're
considering a perfect crystal structure

and our experiments
the crystals are never perfect.

So you typically will get higher values
when you're doing simulations compared to

what you would get with experiments.

So we got a good agreement
with our model and

we felt good that we could
move forward with that.

OK So this is where carbon dioxide and
these are all it to ninety eight.

Kelvin and what we see so
the top one is the first model.

So this includes all of the electrostatic
interactions the one in the middle is

the one that considers only
C O two with itself and

the layer John and so we turned off
them off charges for this one and

the bottom one just
considers mandibles forces.

So you can see it makes a huge difference
in what its values we get based on which

interactions are there and
our experimental data actually falls some.

There in between these two.

So we're somewhere in between.

So the C O two interaction with itself
is actually really important but also

interaction interacting with the material
partial charges as important as well.

So we see electrostatics
do make a difference for

C O two for carbon monoxide.

We see much different behavior which
sort of supports what we saw with our

experiments is that what the Fed model
appear and this is where the data fall.

So the plots I showed you were before
a model but the big difference.

We see is that if we turn off
the partial charges on the framework

the drops all the way down is the same
as if we're just only considering

then I would also forces so
carbon monoxide has negligible interaction

with itself as far as how it
contributes to absorption loadings for

the electrostatic effects for
carbon monoxide are really important.

And then just a couple of slides on on

separations this is a simulation
snapshot of carbon monoxide and

methane and I think you can kind of see.

So the framework here.

The carbon monoxide is green and

the methane is purple and
it's a five percent C. a mixture and

what we're looking at here is to try to
see where the preferred absorption sites.

So you run a money Carlo simulation for

a certain pressure at the end of the run
when it's a quote abraded you can

get these snapshots where you see where
the atoms are at that equilibrium spot.

So that's what this represents.

So one thing you can notice is
that carbon monoxide always

tends to cluster around the framework.

Whereas the methane sort of
disperses out into the pore space so

there's no real specific absorption
sites for the methane while the C.E.O.

really loves the framework and
loves to be around the metal sites so

that was one thing we were trying to
understand because the selective It is

a really pretty row but
that's because the pressure space is so

big that even if you get this preferential
interaction that the framework.

There's enough for space but the methane.

Still fit even if the C.E.O. is there so

it really lowers the absorption
selectivity is because of the the prosody

and then the last one
here is the copper B T B.

So this was our two dimensional sheet.

So remember it actually had lower
capacities at the higher pressure compared

to other materials but because we get this
preferred interaction with the metal sides

and we know that methane doesn't really
interact that way we thought that perhaps

we could get some really nice selective
ities And in fact we do this is a plot of

the C O two absorption I sat there and
methane in this material and

this side is a part of the selective
eddies So the top curve here this black

one is calculated using the ideal
absorb solution theory and the bottom

curve is calculating selectivity is just
based on pure component ice with arms.

So just a quick glance what it shows you
is that it actually does have a preference

for C O two.

So what we're trying to see
is how much of the selective

eighty was based on just the differences
in the peer component absorption.

So some of it is based on that but

other the rest of it is just because
it actually prefer C O two of her.

Methane.
Now

compare some of the selectively
numbers with other materials.

So if we look at the Selectively for
the same mixture at the same pressure.

It's a fifty percent
mixture to ninety eight.

Kelvin at one bar the copper B two C.
has a selective any of six.

I'm off one has a selective
selective any of two.

So there's really no special
interactions that could make them

off one select selectively
remove C O two or methane.

But if you look at our material copper
B T V We actually get a selective any of

them around thirteen so
that's pretty high for this mixture.

Especially compared to some of
the other points materials this is

one of the highest selectivity S..

That you can find so.

So we're really encouraged by that because
it shows that you can actually manipulate

some of the selectivity is based
on if you have metal sites.

They're not so

that was sort of one small piece of
the puzzle that we've been working on.

So I think that brings me to me and
this was a lot of information.

So I just wanted to take a few minutes to
summarize what it was I was talking about.

So first starting out with the three
molecules that we discussed for methane.

I think we can say that the poor size
controls the absorption mechanism.

So it doesn't matter if
metal sites are there.

You really need to have good prosody
is what's important for C O two.

We found some similar
results to the methane.

So our two X. with their arms that were
sort of tracking along together but

we also found evidence of the C O two
interacting with itself which was almost

as important as the pressure charges
on the framework carbon monoxide was

the most different of all of them and

we see the metal sites are really
critical to see it would sort ssion And

in fact if you didn't have open sites
open metal sites you would need

to have very tiny pores in order to try
to achieve the same absorption potential.

So it's really important to try to
have that there for that molecule.

In by way of a sort of broader summering.

I think when sorbate sorbate
interactions dominate So

that's the molecule molecule
molecule interactions dominate.

Materials that have put words near the
size of the molecule kinetic diameter can

have the same effect on exertion as larger
pours that possess over metal sites.

So it's kind of a trade off the metal
sites increase the energetics but

dialing down the poor
size will also do that.

However if you have a molecule.

And the material
interactions that dominate.

So like carbon monoxide.

There's electrostatic interactions
dominate than the relative of

course size has a much smaller
impact on the absorption.

I mean we saw that these two dimensional
sheaves have a really good uptake of

carbon monoxide even though there's no
real paucity but it does have the a metal

sites and then finally for
words separations a polar molecules or

molecules over non Moloch
non-polar molecules you.

Really enhance this by having
open metal sites there so.

I think with that I'll finish up with some
acknowledgements my postdoc Dr Lee She

did a lot of the Synthesis and she's my ex
R.D. guru or she can refine any structure

that you get for the Ph D. students been
moved measured some of the absorption and

helped with synthesis help with
synthesis and ready to donuts all of

the molecular modeling that I showed you
as well as some of the absorption data and

then I'm I like to think my funding
from the research office and

the National Science Foundation.

So with that I will take any questions.

Thank you for
your attention this afternoon.

Yes.

Yes and up to a certain pressure
of the structure holds.

If you get there is there was a certain
pressure that we've still been trying

to explore what happens with this but
up to a certain point I think that's why

if you noticed the pressure was lower on
that one because it went above that we

couldn't get the C.E.O. back out and
our structure was kind of ruined.

So that was just found
by kind of by accident.

We had increased the pressure and it just
kept slowly increasing the loading and

then we couldn't do sorbet it so
yeah we did so

we have checked all of
them after the absorption.

So they're pretty stable for
these molecules.

So they could be.

If you.

Yeah me.

Yeah we have been in fact the copper B T C
You could buy it from Sigma we still just

prefer to make our own but they B.S.F.
took over some of the patents

from Omar's group and also a professor
of Middle Boise INSTITUTE FOR

A They both have some different
materials that they patented.

And so be it.

South first took that material and
scale it up and so

now Sigma sells it so it is doable.

I mean we were mostly constrained
by the way our lab is set up so

we can't do large quantities but
but it's easy to do.

I mean we can make the copper B two C.

we make in three gram quantities the brand
new materials are much smaller to start.

And once we've made the structure
we want then we start

working on scale up to first scale
up is around the ground level.

We have certainly doable if you.

Like.

Where one application that

we're actually very involved with it's
some idea the funding is to put it into

a single pass respirators their current
material they use as an impregnated carbon

that is completely ineffective
against high vapor pressure chemicals.

So we're looking at these especially for
ammonia and

at the lean oxide we have a whole list of
chemicals and they actually are hoping

I mean this is a pretty quick kind of
turnaround on things where they actually

test our materials and they want to
figure out how to put them in there.

So for successful it should be and

we've already shown materials that can do
give them great improvements over their

impregnated carbons So I think it's fair
and I think I think could tell us this is

maybe further off but I think as far
as gas separations and mild separations

that I think the applications can be
here quickly we can get the material.

Pelletised properly.

Yes.

Over the same time I mean
eventually it'll decay.

I just meant compared to the.

Nickel by like the nickel why.

So the conversion would be sort of up and
then down and

when it's gone down the MAF is
still continuing to convert.

Yes yes.

Right.

They say active longer because I think
because there are no metal oxides that

are forming a lot of times
you get the metal sides or

deactivating because of oxide formation
but it could be that since these metals

are actually quite mated to other things
that somehow delays that from happening.

It can very weird there on the order
of microns but some of them are even so

far smaller than that but
that's sort of our average I guess.

Of a particle.

We have been we have been
looking into that because

some of the time we have
a really hard time.

So our crystals are pretty small.

So then it would be difficult
to get really good X.

ray diffraction data so
we have been really very recently like

within the past three months looking
at how can we make larger crystals.

But when we haven't done
very much with that yet.

It's pretty much a put it into
a container hit it up and

see what you get at the end so.

We hope for crystals and.

Yeah.

So we're talking about days or being.

OK we don't see so up to the pressures
that we tested we don't see

any difference with that if you pull a
vacuum the molecules come right back off.

You also get heated up and
get the same thing so so

they both come out showing
where the molecules located.

If if the pros were small enough you
might have that as a different example so

like a Z. a light thirteen X.

If you absorb a heavy component first
then that component will stay there.

Even when you introduce
a different molecule for

material like this you can have constant
displacement there's and there's

no special it's not strong enough to hold
there when you put something else in.

So the methane can displace the C.E.O.
So that's why I said that snapshot that it

shows you where they locate but it doesn't
necessarily mean that it's that strong.

We want to increase the strength
of the interaction actually.

Right.
There's no history says that what you're

wondering if we get the days or
passion is the same you know.

If you had thought.

Of what you think.

Yeah I think

we've had so
we pretty much just what I've showed you.

That's the sort of thing
we've been doing we're.

We tried different things and
see what I was what our product is but

one thing that we've noticed and I've seen
this in other publications too is that

especially D.M.F. associates very
strongly with the framework and

the methanol in the ethanol
the alcohols are not a strong and.

What happens then when you make you may be
able to form a structure in any of those

solvents that when you try to remove
the D.M.F. when you activate it.

It's hanging on so tightly to the poor
to the poor wall that it puts it apart

the methanol the ethanol are much easier
to evaporate off and get out so so

far that's that's been a common theme
that keeps coming up over and over.

So I'm not sure I don't know any
deeper kind of detail in but.

We have tried if D.M.F.
and if we do try to use D.M.F.

we can often do a solvent exchange and try
to exchange it with like click chloroform

and then we're able to get it for
one amount but

just a program found in a break
it apart almost every time.

I want to.

Yeah.

That's a good question.

You know I don't really know the answer to
that I'm not sure how far how long range

the order is I mean we get really good
we can always tell if we have bad order.

Just because we can't get
it to the fact properly but

as far as the actual links I'm really
not sure I would have to check on that.

That's a good question and.

I think.

So yeah yeah they are so

magnetic properties optical properties all
those types of things are being explored.

I think it's a great
you're given the time and

energy just been expended
like this to get it for me.