about aluminium

because it's a long time

over five years

since we made the first one

and... we didn't say very much.

Aluminium

is a surprisingly abundand element.

If you look at this periodic table here,

where the area of the different elements

gives you a rough idea of the abundance

you can see that aluminium

is one of the most abundant metals

up there with sodium, magnesium and calcium.

More aluminum than potassium;

about the same or perhaps even more than iron.

We're never going to run out of aluminium.

The problem with aluminium is that

you don't find aluminium metal in nature

as a metal.

It's always tied up with other compounds;

mostly with oxygen,

in clays.

You know what clays are,

the sort of muddy stuff

that you get stuck on your shoes

when it's raining.

To get the aluminium out of the clay,

that is, to break the aluminium/oxygen bonds,

which are very strong;

requires a lot of energy,

which comes from electricity.

So, making aluminium

is very energy intensive.

That's why

people like to recycle aluminium

because once you've got it, it's worth preserving;

but it's fantastically important

because aluminium is a very light metal.

And it's often used as an alloy

because the aluminium alloys

are stronger than the aluminium itself,

so, if you're using it for aircraft

or some other use like that

where you want to combine lightness

with strength

then the stronger you can make it, the better.

But when it was first made,

in the 19th century,

isolated as a metal

it was terrifically valuable

and there are stories of the French Emperor

serving his honored guests

with aluminium plates

or aluminium cutlery

while the less important people had silver or gold;

but those times have passed

and now

you can get cupcakes and things like that

surrounded by

foil of aluminium.

Aluminium is a very good metal

for making things

because it has a very thin coating

of aluminium oxide on the surface

which prevents it [from] reacting with things.

But as soon as that coating goes

it becomes very reactive.

Alfred Worden: Hadley Base, do you read Houston?

David Scott: Yeah. Now, 5 by, Joe.

Worden: Okay.

Worden: And I guess we're standing by for your

high-gain alignment per the checklist.

Scott: Okay, stand by.

You may have seen our video

where we put copper chloride in one of these

cupcake holders...

[First of all

I'm going to dissolve some up

and make a fairly concentrated solution.

I'm going to place this here.]

...and what came out

was this,

or rather the copper chloride

came out through the hole.

[It starts

boiling really quite nicely.

Now, imagine

I was doing this for my children

who were quite small at that time,

and...

VOOSH!]

And the aluminium was completely dissolved up

forming aluminium chloride

and copper metal.

In my own research,

aluminium is quite important;

quite a lot of our equipment uses aluminium.

Not so much for the

high pressure tubing that we use

because quite a lot of my reaserch involves high pressures

but we use it for the metal blocks

that we put round the tubing

so that we can heat it up.

Aluminium has a good

electrical conductivity,

and it's also easy to machine.

This is a piece of equipment here

where we have a tube going down the middle.

You can see the diameter of the tube here.

Around it

is an aluminium block

and an electrical heater.

Now, this particular case

there was an accident,

or a mishap,

because

the thermocouple

that was controlling the temperature of this

fell out.

So, the heater got hotter

and hotter,

and eventually,

the aluminium melted

and poured down here.

And I think this is really beautiful.

Well,

fortunately, I was not in the lab

or I would've got very angry with my students

but

I think when it happened

it was quite exciting;

this would have been glowing almost red

because the melting point of aluminium is around

500 degrees centigrade.

But then once it formed

originally it was very shiny

but quickly, it again developed

the surface layer of aluminium oxide.

If you have fine particles of Aluminium

and blow them into a flame...

...then they will burn quite spectacularly

and you form aluminium oxide.

Now, on the face of it, aluminium oxide

sounds a rather boring compound

but it's really very useful

and we use it quite a lot in our research

in all sorts of different ways.

It looks like a white powder.

Not very exciting.

But in our group

this aluminium oxide has been a fantastic catalyst

All sorts of reactions

that we didn't expect

have gone with this material.

My students keep it in a bottle

almost like a magic catalyst

and I've only been given a little to show you.

It acts as a solid acid

which can be used at very high temperature

and will get various acid-catalyzed reactions

of organic compounds.

It will make ethers,

we have made various alkynes

and a whole series of different compounds

and my students still use it very much.

If you melt the aluminium oxide,

which we can't do here but can be done industrially,

you can make single crystals

which are transparent like glass

and then you can grow a single crystal tube,

like this one,

which because it's a single crystal,

it's terrifically strong.

It's the defects that make something weak

and so if you have just one crystal

there are no defects

and so it's very strong.

So you can put a very high pressure inside this tube

without it blowing up.

Brady: But you could make that tube out of metal, professor.

Professor: But, if you have a metal

then you can't see what's going on inside,

and we're using these tubes

for photochemical reactions.

So, we take a light like this,

and shine it on the chemicals going through the tube

under high pressure

and we can convert one chemical into another.

We can do this very efficiently

because the light is absorbed by

the molecules that we want to react

and so we dont waste the energy on everything else.

And using LEDs, which are a very efficient light source,

you can get a process that is very energy efficient

and it all depends on having this sapphire tube.

This is synthetic sapphire.

The real sapphire, the gems,

have impurities in them, of other metals,

which give them the nice colors,

particularly the blue.

Princess Kate has a blue sapphire ring

which belonged to her husband's mother, Princess Di,

before her.

And so, these are very valuable ones.

But synthetic sapphire is also expensive

but not in the same class as a natural gem.

Brady: What can nature do that the guys at the sapphire factory

can't do?

Professor: Nature has time.

The people who grow this

will take hours or days or perhaps weeks to grow it.

Nature can spend

thousands or millions of years growing a particular gem

and therefore they can heat it up and cool it down

in natural surroundings, in volcanoes... or whatever

far more slowly

than people can afford to do industrially.

There's a lot of argument

whether you should call it

aluminum or aluminium

Now, there isn't a totally correct one because

both forms are acceptable.

But, all or nearly all

chemists use aluminium

because it's very important to use a

standardized nomenclature right across the world.

And I think aluminium sounds nicer.

Student: Hi professor, my question is

is it aluminum or aluminium?

'Cause I want to know what to call my aluminium model.

Apparantly, there was a decision in 1990

by IUPAC

the International Union of Pure and Applied Chemistry

that it should definately be called

A L U M I N I U M

but then they relented three years later

and said you could use aluminum as well.

But if you're a serious chemist

you really need to say aluminium, because otherwise

people won't find your papers, your publications,

when they search because they'll almost certainly put an "i"' in the name.

Aluminium is frequently used

or used [to be] frequently used

kkfor sauce pans, for cooking in

because it's easy to make, easy to machine

and particularly when people used electric stoves

it was easy to make a flat bottom

so that you got good contact between the

electric element and the sauce pan.

The problem with aluminium sauce pans

is that if you're cooking some fairly acidic food,

for example boiling lemons or rhubarb

something like that which is quite acidic

you can dissolve some of the aluminium

and people got quite worried about

getting aluminium in their food.

Also, if you cook red cabbage,

which is an indicator;

blue for alkali, red for acid,

then if you boil it in an aluminium sauce pan

it goes blue.

And earlier in my carreer

I used a red cabbage together with a white one

to make a Union Jack, a U.K. flag

with a mixture of red and blue-red cabbage

and the white from the white cabbage.

Unfortionately, I've lost the photo; Brady is very cross with me.

But it was quite fun cooking it in the kitchen.

I did it once myself, but it was such a lot of work

that the second time a got one of my students to do it.