0:00:02 > 0:00:05This series is about the stuff we just can't live without.
0:00:05 > 0:00:07The cleaners, the cosmetics,
0:00:07 > 0:00:10the convenience items that we use every single day.
0:00:10 > 0:00:13How do these things actually work?
0:00:15 > 0:00:19'I'm Jane Moore and I've set out to discover the hidden science
0:00:19 > 0:00:23'in all those household essentials we simply take for granted.
0:00:24 > 0:00:28'My journey will put me to the test in the most unusual places...'
0:00:28 > 0:00:29Ta-da!
0:00:29 > 0:00:31We have made toothpaste!
0:00:31 > 0:00:34'..change the way I think about science...'
0:00:34 > 0:00:37That is utterly astonishing.
0:00:37 > 0:00:40'..and let me see myself in a whole new light.'
0:00:41 > 0:00:45Yes, take a product, any product, and chuck away the packaging.
0:00:45 > 0:00:49We're not interested in that because this series is about what's inside.
0:00:49 > 0:00:53My task is to find out which ingredients do the clever work
0:00:53 > 0:00:55and where those ingredients come from.
0:00:55 > 0:00:59'Welcome to the extraordinary hidden world of Wonderstuff.'
0:01:17 > 0:01:20'So far, I've been on an eye-opening trip
0:01:20 > 0:01:23'around some of Britain's most cutting-edge institutions
0:01:23 > 0:01:26'that dream up some of those lotions and potions
0:01:26 > 0:01:30'that help make our daily domestic lives so much easier.'
0:01:30 > 0:01:33But my Wonderstuff tour doesn't end there.
0:01:33 > 0:01:37No, the next stop - to stick or not to stick.
0:01:37 > 0:01:40That's the new question that's keeping me awake at night.
0:01:40 > 0:01:44'So, to help me sleep better, I want to get to the bottom of glue,
0:01:44 > 0:01:47'non-stick pans and paint.
0:01:47 > 0:01:50'Later in the show, my master of materials,
0:01:50 > 0:01:54'Dr Mark Miodownik, will be luring me deep into the unknown.'
0:01:54 > 0:01:56It's like Raiders Of The Lost Ark down here.
0:01:56 > 0:01:58'Before then, I'm off to get the low-down
0:01:58 > 0:02:01'on something that really does hold our lives together.'
0:02:01 > 0:02:04I'm on the trail of what makes things stick
0:02:04 > 0:02:07and, call me predictable, but to my mind,
0:02:07 > 0:02:09there's only one place to start - glue.
0:02:16 > 0:02:19Breakages in the home are a real pain,
0:02:19 > 0:02:22not helped by the fact that choosing the right glue
0:02:22 > 0:02:24is no simple matter.
0:02:24 > 0:02:26The choices available seem endless,
0:02:26 > 0:02:29but are all these glues really that different
0:02:29 > 0:02:33and is there a Wonderstuff that makes one particular type of glue
0:02:33 > 0:02:34the daddy of them all?
0:02:36 > 0:02:38To find out how glue works,
0:02:38 > 0:02:41I'm off to Cambridge to meet Dr Ewen Kellar,
0:02:41 > 0:02:43principle project leader at TWI,
0:02:43 > 0:02:46who advise everyone from the Ministry of Defence
0:02:46 > 0:02:49to Formula One about the right ways to stick stuff together.
0:02:49 > 0:02:53But despite all these high-tech applications,
0:02:53 > 0:02:56Ewen reckons the simplest way to understand glue
0:02:56 > 0:02:58is to start where the ancient Egyptians did -
0:02:58 > 0:03:03using milk, with a sticking power we've all seen in action.
0:03:03 > 0:03:06Glue made from milk has been around for many thousands of years.
0:03:06 > 0:03:09It's called casein. The name comes from the protein -
0:03:09 > 0:03:11the actual whiteness in the milk is casein.
0:03:11 > 0:03:15'If you fancy trying this at home, use skimmed milk
0:03:15 > 0:03:17'and curdle it by adding vinegar.'
0:03:17 > 0:03:21I don't know if you can see that, but it's become all rather lumpy.
0:03:21 > 0:03:25- It looks like the milk you find in a student's fridge.- Yeah.
0:03:25 > 0:03:28'Ewen then filters the mixture to get just the protein.'
0:03:28 > 0:03:31So, what we now want to do is we want to basically
0:03:31 > 0:03:34put this back into some sort of solution.
0:03:34 > 0:03:37So, this is bicarbonate of soda, baking soda.
0:03:37 > 0:03:40'Adding bicarb apparently neutralises the vinegar
0:03:40 > 0:03:43'and forces the milk proteins to stick together.'
0:03:43 > 0:03:46Little molecules join together, one after the other,
0:03:46 > 0:03:48and form very long chains.
0:03:48 > 0:03:51'Then, just add water and voila!'
0:03:51 > 0:03:53If we leave this now, for a few minutes,
0:03:53 > 0:03:56it will settle down into an almost clear liquid
0:03:56 > 0:03:58which can then be used as a glue.
0:03:58 > 0:04:00This has been used to bond wood.
0:04:00 > 0:04:04It was used to bond furniture in Egyptian times.
0:04:04 > 0:04:08'You can also get natural glues from wheat, honey and cheese.'
0:04:10 > 0:04:11I'm impressed by that.
0:04:11 > 0:04:14I never knew you could actually just make glue from the stuff
0:04:14 > 0:04:16that you find in your kitchen.
0:04:17 > 0:04:21'Apparently, all modern glues use the same principle we've seen here
0:04:21 > 0:04:23'called polymerization,
0:04:23 > 0:04:27'where molecules form long chains that bind things together.
0:04:27 > 0:04:30'So, why are there so many different types of glue?
0:04:30 > 0:04:34'Ewen wants to show me how modern glues work best
0:04:34 > 0:04:36'when they're tailored to work on specific surfaces
0:04:36 > 0:04:38'and he's starting with a wood glue.'
0:04:39 > 0:04:43- So, that's the joint of the two bits of wood, yeah?- Yes.
0:04:43 > 0:04:46What we do is we basically put this in the machine
0:04:46 > 0:04:48which we see in front of us and we pull it apart.
0:04:48 > 0:04:53'A simple wood glue joint can hold together under enormous strain.'
0:04:53 > 0:04:55So, we're now at 270 kilos.
0:04:55 > 0:04:59That's several of me dangling off the end of this little bit of wood.
0:04:59 > 0:05:00Poor thing!
0:05:00 > 0:05:05'But try the same wood glue on metal and it's a different matter.'
0:05:05 > 0:05:08Here, we've got ten kilograms. The joint is virtually failed.
0:05:08 > 0:05:11I'm going to look really strong.
0:05:11 > 0:05:12Yay! Look at that!
0:05:12 > 0:05:16So, it genuinely is that there are glues that work better
0:05:16 > 0:05:18- on a specific surface?- Definitely.
0:05:19 > 0:05:22'OK, but is there a gluey Wonderstuff?
0:05:22 > 0:05:25'Something that could bond absolutely anything?
0:05:25 > 0:05:28'I'm wondering about what's in those little tubes
0:05:28 > 0:05:31'of instant super-strength glue like I use at home.'
0:05:31 > 0:05:34And what is this? It's cyanoacrylate.
0:05:34 > 0:05:38Yes, cyanoacrylate. It's basically the chemical name of these materials.
0:05:38 > 0:05:41So, basically, here, you've got very small molecules
0:05:41 > 0:05:45which combine together when you put them in contact with moisture.
0:05:45 > 0:05:47They go from being very, very runny
0:05:47 > 0:05:49to very, very viscous very, very quickly
0:05:49 > 0:05:52and ultimately go hard cos they entangle and lock together.
0:05:52 > 0:05:55But it happens incredibly fast - only a few seconds.
0:05:55 > 0:06:00Which is what makes it user-friendly because you want it to act fast.
0:06:00 > 0:06:05'Cyanoacrylate got its super reputation as a fast-acting adhesive
0:06:05 > 0:06:07'on the battlefields of Vietnam.
0:06:07 > 0:06:11'To show me how, Ewen's demonstrating with some pork.'
0:06:11 > 0:06:14Here's a cut. So, basically, what the doctor would do
0:06:14 > 0:06:18would be just literally lightly apply the adhesive
0:06:18 > 0:06:20on the outside of the cut.
0:06:20 > 0:06:23Imagine in a real situation, this wound may well be bleeding,
0:06:23 > 0:06:27so the adhesive's got a bit of a tough job to do.
0:06:27 > 0:06:29The cyanoacrylate is good at coagulating the blood
0:06:29 > 0:06:30and stopping bleeding.
0:06:30 > 0:06:35Then, all you would do - you would hold it together, like this.
0:06:35 > 0:06:39So, no stitches, just a straightforward bond.
0:06:39 > 0:06:43Much, much quicker, much, much less painful than otherwise.
0:06:43 > 0:06:45- That has really worked, hasn't it? - Yeah.
0:06:45 > 0:06:48'And now, medics do this with a sterile version
0:06:48 > 0:06:50'on our day-to-day wounds.
0:06:50 > 0:06:53'Fast-setting, super-strength cyanoacrylate
0:06:53 > 0:06:57'certainly sounds worthy of being a Wonderstuff.
0:06:57 > 0:07:00'But Ewen's got something he reckons is even better -
0:07:00 > 0:07:02'epoxy resin.'
0:07:03 > 0:07:07Cos it's so versatile, you know, you can use it virtually anywhere.
0:07:07 > 0:07:10The main thing to note, really, is there are two parts.
0:07:10 > 0:07:12You'll want to mix these two parts together.
0:07:12 > 0:07:16So, chemically, what is in each tube that causes that reaction?
0:07:16 > 0:07:20Right, well, on one side, we've got a hardener.
0:07:20 > 0:07:22On the other side, we've got what's called a resin.
0:07:22 > 0:07:25So, the resin is like the long polymeric part -
0:07:25 > 0:07:27that's like long chains of spaghetti,
0:07:27 > 0:07:30which is very, very sticky molecules.
0:07:30 > 0:07:33The hardener on the other side has essentially...
0:07:33 > 0:07:37Has the ability to join one chain of spaghetti to the other,
0:07:37 > 0:07:41like rungs on a ladder to form like a cross-link network.
0:07:41 > 0:07:44So it solidifies it in that way.
0:07:45 > 0:07:46'Sounds impressive,
0:07:46 > 0:07:49'but I'm still siding with my cyanoacrylate superglue.
0:07:52 > 0:07:56'So, the only way to decide which one's going to be my Wonderstuff
0:07:56 > 0:07:57'is a head-to-head.'
0:08:02 > 0:08:04Wow! Now, this is what I call a weight!
0:08:04 > 0:08:07'We're putting them to the ultimate strength test-
0:08:07 > 0:08:10'to lift a bag of sand weighing nearly a tonne.'
0:08:10 > 0:08:14OK. Well, let's give the old super-strength glue a test, then.
0:08:15 > 0:08:18'This is the equivalent of sticking a small car to the ceiling
0:08:18 > 0:08:21'with a square inch of glue
0:08:21 > 0:08:25'and the power of my cyanoacrylate has actually got Ewen worried.'
0:08:25 > 0:08:28So, it's taking a load, now.
0:08:29 > 0:08:31I don't believe it!
0:08:33 > 0:08:37Cor, blimey! Did it come off the ground?
0:08:37 > 0:08:40- It did come off the ground... - Yeah, a little bit.
0:08:40 > 0:08:42..for a nano-second.
0:08:44 > 0:08:47It's a good job I've got a strong heart, isn't it?
0:08:47 > 0:08:52'But can Ewen's poxy little epoxy resin beat that?'
0:08:52 > 0:08:53Maestro, lift!
0:08:55 > 0:09:00- Judging by the big bang last time, I'm standing well back. - You're not going to get up close?
0:09:00 > 0:09:02No. Too right I'm not.
0:09:02 > 0:09:03OK.
0:09:05 > 0:09:07It's starting to lift off the floor.
0:09:11 > 0:09:13Look at that!
0:09:15 > 0:09:17Well lifted off the floor, that is.
0:09:20 > 0:09:23So, if you really wanted, we could lift this really high
0:09:23 > 0:09:25- and you could stand underneath it, if you wanted.- Yeah.
0:09:25 > 0:09:30Thank you very much. My days in the circus are long over. Thank you.
0:09:30 > 0:09:33It's absolutely holding steadfast, though, isn't it?
0:09:33 > 0:09:35'I'm not always so gracious in defeat,
0:09:35 > 0:09:38'but it's a clear victory for epoxy resin.
0:09:38 > 0:09:41'No wonder this glue turns up in high places.'
0:09:41 > 0:09:43- Is that an aeroplane wing?- Yeah.
0:09:43 > 0:09:47- You can't glue an aeroplane wing on, can you?- Yes, you can.
0:09:47 > 0:09:50In fact, it's actually starting to happen, now.
0:09:50 > 0:09:53Glue's coming back, now, to being used more and more,
0:09:53 > 0:09:55especially with more modern materials which...
0:09:55 > 0:09:58It's difficult to know how else to join them together.
0:09:58 > 0:10:01I mean, even down to the fact that your brake pads are all glued on.
0:10:01 > 0:10:05So, you're trusting your life every day, every time you brake, to glue.
0:10:05 > 0:10:09Ewen, I'm getting the train home, or are they glued as well?
0:10:09 > 0:10:11Quite a lot of them are, yeah.
0:10:13 > 0:10:16'In fact, epoxy resin is so reliable,
0:10:16 > 0:10:18'we use it in the construction of aircraft, cars,
0:10:18 > 0:10:21'boats, golf clubs, skis and snowboards.
0:10:21 > 0:10:25'In fact, anywhere where super high-strength bonds are required,
0:10:25 > 0:10:29'and epoxy glues can stick wood, metal, glass, stone and plastic.
0:10:29 > 0:10:31'A Wonderstuff indeed.
0:10:34 > 0:10:38'Ewen said that glue's brilliance lies in it being a polymer,
0:10:38 > 0:10:40'but what exactly is a polymer?
0:10:42 > 0:10:45'Materials scientist Mark's been raiding his stationery cupboard
0:10:45 > 0:10:48'in order to explain what he reckons
0:10:48 > 0:10:51'are some of our most marvellous molecules.'
0:10:53 > 0:10:56Hello, strange little man on park bench.
0:10:56 > 0:10:59- Fancy seeing you here. - Just having a sit down and a think.
0:10:59 > 0:11:00What's all this about?
0:11:00 > 0:11:02You've been talking about glue.
0:11:02 > 0:11:05There are examples of things called polymers,
0:11:05 > 0:11:07which is sort of man's attempt to kind of
0:11:07 > 0:11:11recreate the wonderful range of materials that nature can create.
0:11:11 > 0:11:15These soft, flexible materials that repel water
0:11:15 > 0:11:17and can stick to things or not stick to them.
0:11:17 > 0:11:20All of that kind of thing that we see in nature all around us.
0:11:20 > 0:11:25'Silk, starch, cotton, asbestos and DNA are natural polymers,
0:11:25 > 0:11:29'all built from chains of carbon-containing molecules,
0:11:29 > 0:11:31'known as monomers.'
0:11:31 > 0:11:35Add the monomers together to make these different length molecules.
0:11:35 > 0:11:38'Joining together and repeating these same molecules
0:11:38 > 0:11:40'is what creates a polymer.'
0:11:40 > 0:11:44So, a polymer isn't a chemical, as such.
0:11:44 > 0:11:47- It's a sort of... A molecular structure.- Yes.
0:11:47 > 0:11:51Polymer is a category of material in the same way that metals are.
0:11:51 > 0:11:54'But why is making chains of molecules so useful?'
0:11:54 > 0:11:58By varying the length of the chain, how many units you put together,
0:11:58 > 0:12:01you can make something become harder and harder. That's cool.
0:12:01 > 0:12:03'Just like I saw in glue.
0:12:03 > 0:12:06'Mark tells me that the behaviour of polymers
0:12:06 > 0:12:08'is crucial in explaining the science
0:12:08 > 0:12:11'of something that does the exact opposite of sticking -
0:12:11 > 0:12:12'non-stick.
0:12:17 > 0:12:20'In the kitchen, I'd be hard pushed to think of an invention
0:12:20 > 0:12:22'that's more useful than non-stick.
0:12:24 > 0:12:26'I have no idea what's on my pans,
0:12:26 > 0:12:28'so it means my sausages stay unstuck.
0:12:28 > 0:12:32'So I'm off to try and find out what sort of wonder material
0:12:32 > 0:12:35'could have such a spotless reputation.
0:12:36 > 0:12:39'To show me, know-it-all Mark has dragged me down the hill
0:12:39 > 0:12:41'to the Millennium Dome?!'
0:12:41 > 0:12:45- What are we doing here? - We're at one of the most amazing buildings in London.
0:12:45 > 0:12:48Look at this. Magnificent, isn't it?
0:12:48 > 0:12:50Well, yes, it's a magnificent structure,
0:12:50 > 0:12:54- but what's that got to do with why we're here? - PTFE in that roof.
0:12:54 > 0:12:55Look, this is the stuff. Again.
0:12:55 > 0:12:58Blimey! I thought that would be like a ping-pong ball
0:12:58 > 0:13:01- and it's really heavy. - Heavier than you think.
0:13:01 > 0:13:03Yeah, it's really tough, isn't it?
0:13:04 > 0:13:08'It turns out that PTFE is a fancy kind of plastic.
0:13:08 > 0:13:10'Another one of those clever polymers, by the way,
0:13:10 > 0:13:14'and because it has an extraordinary trick up its sleeve,
0:13:14 > 0:13:16'it can be found on both the roof of the Millennium Dome
0:13:16 > 0:13:19'and inside my frying pan.'
0:13:19 > 0:13:21It's the slipperiest material in the world.
0:13:21 > 0:13:23Nothing sticks to this stuff.
0:13:23 > 0:13:26Even geckos, which can climb up anything at all,
0:13:26 > 0:13:27cannot climb up PTFE.
0:13:27 > 0:13:31It's so slippery that all the dust slides off it.
0:13:31 > 0:13:35- And the bird poo? - And the bird poo, yes.- Handily.
0:13:35 > 0:13:38- So, it's 600,000 square feet of PTFE.- Wow!
0:13:38 > 0:13:40That's a lot of frying pans.
0:13:40 > 0:13:45- It is. How many frying pans is that? Let's calculate it.- Let's not.- OK.
0:13:46 > 0:13:49'We rely on PTFE's super slipperiness
0:13:49 > 0:13:52'for all sorts of other essential jobs, too.'
0:13:52 > 0:13:55Famously, the astronauts who walked on the moon
0:13:55 > 0:13:58had PTFE coated inside their space suits
0:13:58 > 0:14:00because when they're moving about in space,
0:14:00 > 0:14:02they can't have friction on the inside
0:14:02 > 0:14:06which might cause a little hole to form cos then, they would die.
0:14:06 > 0:14:08It's starting to be used inside the body.
0:14:08 > 0:14:10So, like an artificial hip.
0:14:10 > 0:14:12Cos it's going inside,
0:14:12 > 0:14:15you've got the friction constantly of the socket and the joint.
0:14:15 > 0:14:17Coated with PTFE.
0:14:17 > 0:14:19It's inert. That's the other great thing -
0:14:19 > 0:14:21it doesn't react with anything.
0:14:21 > 0:14:23So you can put it in the body and it's going to be fine.
0:14:25 > 0:14:28'I'm chuffed to have discovered that the coating on my frying pan
0:14:28 > 0:14:31'is the world's most slippery plastic,
0:14:31 > 0:14:33'Mark isn't satisfied.
0:14:33 > 0:14:36'He reckons the true Wonderstuff in this story
0:14:36 > 0:14:37'and the key to why it works,
0:14:37 > 0:14:40'is not the non-stick polymer itself,
0:14:40 > 0:14:43'but a remarkable natural ingredient in PTFE.
0:14:45 > 0:14:47'He wants to get to the bottom of it, literally,
0:14:47 > 0:14:50'in this mine in Derbyshire.
0:14:51 > 0:14:52'Here we go.'
0:14:52 > 0:14:54Have I mentioned that I'm claustrophobic?
0:14:54 > 0:14:57It does involve a bit of down. I have to admit that.
0:14:57 > 0:15:04'The Blue John crystal mine goes down 245 steps.'
0:15:06 > 0:15:09We're going right underneath the Pennines, Jane.
0:15:09 > 0:15:11Down, down, down.
0:15:11 > 0:15:13This had so better be worth it.
0:15:16 > 0:15:18It's like Raiders Of The Lost Ark down here.
0:15:18 > 0:15:22Or Raiders Of The Lost Mark, hopefully, in a minute!
0:15:24 > 0:15:26'But what on earth is all the way down here
0:15:26 > 0:15:29'that could be my Wonderstuff?'
0:15:29 > 0:15:33I've brought you here to see a very special piece of rock.
0:15:33 > 0:15:35It's all around us. This is a mineral fluorspar.
0:15:35 > 0:15:38It has in it this element fluorine
0:15:38 > 0:15:41and we react fluorine with the ingredients of polyethene
0:15:41 > 0:15:44and we get this amazing other plastic,
0:15:44 > 0:15:46which revolutionises your life.
0:15:46 > 0:15:50'I still don't get how the fluorine you extract from these rocks
0:15:50 > 0:15:54'makes PTFE such a super slippery plastic.'
0:15:54 > 0:15:57- I've got some here, actually. - Oh, it's a gas.
0:15:57 > 0:16:00It's a green gas and it's incredibly reactive.
0:16:00 > 0:16:02It's so reactive we had to put it into two containers,
0:16:02 > 0:16:04and even then, it's trying to get out.
0:16:04 > 0:16:07This stuff will react with almost anything.
0:16:07 > 0:16:09So, you never find it on its own
0:16:09 > 0:16:12because anything it comes across, it just forms a compound with.
0:16:12 > 0:16:15'I'm sure I want something that reactive
0:16:15 > 0:16:17'coming into contact with my food.
0:16:17 > 0:16:20'But Mark tells me that it's this super reactivity
0:16:20 > 0:16:23'and the strength of the attraction between the fluorine
0:16:23 > 0:16:24'and other elements in PTFE
0:16:24 > 0:16:27'that are the secret to its slippery success.'
0:16:27 > 0:16:30The fluorine bonds in the PTFE -
0:16:30 > 0:16:34they are so uninterested in bonding to anything else
0:16:34 > 0:16:36that they make it non-stick.
0:16:36 > 0:16:39All they're doing is handing over the energy, the heat,
0:16:39 > 0:16:42and they're not laying claim to anything else.
0:16:42 > 0:16:45'So it was worth sticking with Mark all along.
0:16:45 > 0:16:48'Scratching the surface of non-stick frying pans
0:16:48 > 0:16:52'revealed the true Wonderstuff to be fluorine gas.
0:16:54 > 0:16:58'Fluorine is a dangerously powerful oxidiser
0:16:58 > 0:17:02'and so reactive it only exists in its pure form out in space.
0:17:02 > 0:17:03'Here on Earth,
0:17:03 > 0:17:06'its ability to react with a wide range of other substances
0:17:06 > 0:17:08'make it extremely useful.
0:17:08 > 0:17:11'Plus, it's gentle enough to be added to toothpaste
0:17:11 > 0:17:13'to keep our tooth enamel strong.
0:17:15 > 0:17:17'So, I've discovered some of the stickiest
0:17:17 > 0:17:20'and the slipperiest substances on the planet,
0:17:20 > 0:17:23'but I'm still stuck on one other question.'
0:17:23 > 0:17:26What's the stuff that every home is literally covered in?
0:17:26 > 0:17:29In fact, it's probably staring you in the face right now.
0:17:29 > 0:17:32'I'm talking about household paint.
0:17:32 > 0:17:35'How can it be runny enough for us to roll on,
0:17:35 > 0:17:38'yet still sticky enough to stay on the wall?
0:17:44 > 0:17:47'So if I'm searching for the Wonderstuff in paint,
0:17:47 > 0:17:50'surely that means a nice trip to the Sistine Chapel?'
0:17:50 > 0:17:53Some reporters get to cover the Oscars,
0:17:53 > 0:17:55others get to go down the Amazon.
0:17:55 > 0:17:59I get to come to a paint factory in Slough.
0:18:01 > 0:18:05'And that's because Slough is home to AkzoNobel,
0:18:05 > 0:18:09'who discovered that famous polymer so crucial in PTFE -
0:18:09 > 0:18:10'polyethene.
0:18:10 > 0:18:12'They also make a lot of paint.
0:18:13 > 0:18:17'Richard Barcock is their UK Paint Technical Manager
0:18:17 > 0:18:19'For Decorative Coatings, no less.'
0:18:19 > 0:18:23So, Richard, in general terms, what is paint exactly?
0:18:23 > 0:18:28Paint is a coloured powder in a liquid glue-like medium,
0:18:28 > 0:18:31which you can easily apply to surfaces in your home.
0:18:34 > 0:18:39'Richard breaks down exactly what's in a basic paint for me.
0:18:39 > 0:18:41'There's water,
0:18:41 > 0:18:45- 'something to make it opaque...' - Which gives you this good covering.
0:18:45 > 0:18:49- '..thickener...' - To increase viscosity of the paint.
0:18:49 > 0:18:52'..a surfactant and an anti-foaming agent...'
0:18:52 > 0:18:53To keep that level of bubbles down.
0:18:53 > 0:18:57'..and then, there's a binder, which I'm told is basically,
0:18:57 > 0:19:00'yes, you've guessed it - glue.
0:19:02 > 0:19:06'The boffins here test different gluey binders to destruction.
0:19:06 > 0:19:09'They're stretched, scuffed and exposed to the elements
0:19:09 > 0:19:13'to find the binder best suited for any surface
0:19:13 > 0:19:14'you might choose to paint.
0:19:16 > 0:19:19'And they've perfected another clever property in their paint as -
0:19:19 > 0:19:22'watch out, here comes another fancy title -
0:19:22 > 0:19:24'Physical Characterisation Team Leader,
0:19:24 > 0:19:27'Dr Tom Kerwin explains.'
0:19:27 > 0:19:29One of the tests that we do here
0:19:29 > 0:19:31to get a feel for the consistency of the paint
0:19:31 > 0:19:34is actually just try and cut a cube from it.
0:19:35 > 0:19:37You'll see that,
0:19:37 > 0:19:40- we can cut this cube out. - Look at that!
0:19:40 > 0:19:41A slice of paint.
0:19:41 > 0:19:44'So, in the tub, it's solid,
0:19:44 > 0:19:47'but stir it up and it goes all liquidy.'
0:19:47 > 0:19:50Can I have a go? I like a bit of mixing.
0:19:50 > 0:19:51Yeah, have a go.
0:19:51 > 0:19:54Give it a mix and then have a go at cutting another cube.
0:19:54 > 0:19:58Look at that. Trying to cut a cube out of the paint.
0:20:01 > 0:20:02That is fantastic.
0:20:02 > 0:20:06That, now, would go on a wall very nicely indeed.
0:20:06 > 0:20:08'It's now miraculously lost its stickiness
0:20:08 > 0:20:12'and is much easier to apply to the walls.'
0:20:12 > 0:20:14It has this key property known as shear-thinning.
0:20:14 > 0:20:16That means that the viscosity,
0:20:16 > 0:20:19the resistance of the paint to flowing,
0:20:19 > 0:20:21decreases the harder you try and push it.
0:20:21 > 0:20:25And when you stop sort of, applying a force to it,
0:20:25 > 0:20:27does it then solidify again?
0:20:27 > 0:20:30Exactly. That structure we built with the thickeners
0:20:30 > 0:20:33comes back and stops it slipping back off the wall.
0:20:33 > 0:20:37'So the clever paint polymer goes sticky again
0:20:37 > 0:20:39'and dries hard and fast to the wall.'
0:20:39 > 0:20:42- Clever!- Indeed.- Yeah, fantastic.
0:20:42 > 0:20:47'Seeing how much science goes into a pot of household paint
0:20:47 > 0:20:50'has made me come over a bit EMULSION-al!
0:20:51 > 0:20:55'But hold on. Even though I now understand how it sticks to my wall,
0:20:55 > 0:20:58'aren't we forgetting the most obvious thing about paint -
0:20:58 > 0:20:59'its colour?'
0:21:01 > 0:21:04For example, Bongo Jazz, anyone?
0:21:04 > 0:21:05It's orange, apparently.
0:21:05 > 0:21:11We buy 300 million litres a year of this stuff.
0:21:11 > 0:21:15'We can now get hold of just about any shade under the sun.
0:21:17 > 0:21:20'So is there any hidden genius I need to know
0:21:20 > 0:21:23'about what gives paint its colour?
0:21:23 > 0:21:26'I've agreed to a rendezvous in a secret location outside Oxford
0:21:26 > 0:21:30'with architectural colour consultant Patrick Baty...'
0:21:30 > 0:21:33A yellow ochre pigment in this country.
0:21:33 > 0:21:36'..and avid pigment expert Keith Edwards.
0:21:36 > 0:21:40'His speciality - digging colours right out of the ground.'
0:21:40 > 0:21:41Hi, Keith.
0:21:41 > 0:21:45To my untrained eye, I'd think that was sand.
0:21:45 > 0:21:47Well, it is partly sand,
0:21:47 > 0:21:50but mostly, it's very pure ochre pigment.
0:21:50 > 0:21:54It was used by famous artists such as Constable, Turner,
0:21:54 > 0:21:59from probably the 17th century up until the early 20th century.
0:21:59 > 0:22:00So special stuff?
0:22:00 > 0:22:02Very special stuff.
0:22:02 > 0:22:05It feels like cumin or something like that.
0:22:05 > 0:22:07It is very like it, yes.
0:22:09 > 0:22:12'Apparently, natural paint pigments like this
0:22:12 > 0:22:16'have been used for over 30,000 years.
0:22:16 > 0:22:20'Keith's spent most of his lifetime in pursuit of perfection.'
0:22:20 > 0:22:23We've got some lovely colours. What's this purple one?
0:22:23 > 0:22:28It's murex purple - it's the most expensive pigment ever produced.
0:22:28 > 0:22:34- Its present value is about £50,000 a single ounce.- Goodness me!
0:22:34 > 0:22:37- So where does it come from? - It comes from the murex shellfish -
0:22:37 > 0:22:40a sea snail from the Mediterranean.
0:22:40 > 0:22:42'Keith's commitment to colours is astonishing.'
0:22:42 > 0:22:46Keith, can I just ask you, what colour is your living room?
0:22:46 > 0:22:48That's a hard one.
0:22:48 > 0:22:52- Don't say magnolia! - Yes, actually, it is.
0:22:52 > 0:22:55'But in my hunt for what gives paint its colour,
0:22:55 > 0:22:57'he's got a bit of a shocking revelation.'
0:22:57 > 0:23:00These, really, are only stains.
0:23:00 > 0:23:03That's the basis of modern paint.
0:23:03 > 0:23:05We can't do without titanium dioxide.
0:23:05 > 0:23:07It's the purest white we have, really.
0:23:07 > 0:23:10Yes. It is the purest, most opaque white we have.
0:23:10 > 0:23:12Paint without titanium dioxide
0:23:12 > 0:23:15would be like making a sandwich without bread.
0:23:15 > 0:23:18'But why is this white pigment so special?
0:23:18 > 0:23:21'Apparently, it's because titanium dioxide
0:23:21 > 0:23:23'makes such a dense and bright colour.
0:23:24 > 0:23:28'Back in London at Patrick's shop, I learn that titanium dioxide
0:23:28 > 0:23:30'is now in pretty much every pot of paint we buy,
0:23:30 > 0:23:32'whatever the colour.
0:23:36 > 0:23:39'And Patrick owns a unique piece of history -
0:23:39 > 0:23:44'a tiny chip of paint that shows why titanium white became so invaluable.'
0:23:44 > 0:23:49What we've got here are 71 individual schemes of paint.
0:23:49 > 0:23:52These were applied to the outside of a building
0:23:52 > 0:23:54that we know was built in 1705.
0:23:54 > 0:23:57What we've got there is the full history of the house,
0:23:57 > 0:23:59which takes us right the way through
0:23:59 > 0:24:01things like the discovery of Australia.
0:24:01 > 0:24:05History encapsulated in a little chip of paint.
0:24:05 > 0:24:07A little chip of paint.
0:24:07 > 0:24:10'Patrick's had a photograph made so we can see what's happening up close.
0:24:10 > 0:24:15'It turns out the old base for paint was downright dangerous.'
0:24:15 > 0:24:20From 1705 to about 1939, here,
0:24:20 > 0:24:23all of these are based on lead carbonate.
0:24:23 > 0:24:26- That is the main constituent of these paints.- Poison?- Indeed.
0:24:26 > 0:24:28- Highly toxic.- Good grief!
0:24:28 > 0:24:31So, we've got lead carbonate through to the Second World War.
0:24:31 > 0:24:34We then have a couple of schemes based on zinc oxide.
0:24:34 > 0:24:37We've got the introduction of brilliant white.
0:24:37 > 0:24:40You can see this much brighter sequence of coats,
0:24:40 > 0:24:43which is about 1960, 1962.
0:24:43 > 0:24:47- So, that's when they started to use the words brilliant white... - Absolutely.
0:24:47 > 0:24:50It was quite impossible to achieve a colour like that,
0:24:50 > 0:24:52a bright white, in these earlier days.
0:24:52 > 0:24:56'And all that's down to good old titanium dioxide.'
0:24:56 > 0:25:01It's non-toxic. It's readily available. It's not too expensive.
0:25:01 > 0:25:03Most importantly for a paint, it covers very well indeed.
0:25:03 > 0:25:06A couple of coats, that's all you need.
0:25:06 > 0:25:09- So, it revolutionised the paint industry?- Completely.
0:25:09 > 0:25:13'With cheap, safe titanium dioxide in your paint,
0:25:13 > 0:25:16'all you need is a couple of coats to get good coverage
0:25:16 > 0:25:18'and rich colour.
0:25:18 > 0:25:21'But exactly how is this extraordinary ingredient
0:25:21 > 0:25:23'achieving this? Back to Mark.'
0:25:23 > 0:25:25I've got a sample of wallpaper,
0:25:25 > 0:25:28which you may or may not want to get rid of.
0:25:28 > 0:25:30It's all the rage now again, you know, florals.
0:25:30 > 0:25:33- We'll have an argument about this. - I don't think I'd have it on my wall.
0:25:33 > 0:25:36We want to get rid of it with some white paint.
0:25:37 > 0:25:40'Time for the ultimate paint challenge.
0:25:40 > 0:25:44'Mark has mixed up some titanium dioxide and plain water
0:25:44 > 0:25:49'to see how well it covers up the horrors of his floral wallpaper.
0:25:49 > 0:25:53'After just one coat, the results are striking.'
0:25:53 > 0:25:55These titanium particles are little crystals.
0:25:55 > 0:25:57The light's coming in,
0:25:57 > 0:26:00and it's only getting through a small part of the crystal
0:26:00 > 0:26:02before it gets pinged out again
0:26:02 > 0:26:05because it's got a very high refractive index.
0:26:05 > 0:26:08'That means it's like thousands of tiny mirrors
0:26:08 > 0:26:11'bouncing the light back out, and that's not all.'
0:26:11 > 0:26:15It does some other weird things, too. It makes surfaces self-clean.
0:26:15 > 0:26:17It's photocatalytic. So, when light hits it,
0:26:17 > 0:26:20if there's any organic matter near it,
0:26:20 > 0:26:22it makes it disintegrate.
0:26:22 > 0:26:24That sound astonishingly clever.
0:26:24 > 0:26:28'When sunlight hits a titanium dioxide coating,
0:26:28 > 0:26:32'any dirt rapidly oxidises and can then be washed off by the rain.'
0:26:32 > 0:26:36- TD, let's hear it for TD. - I totally agree with you.
0:26:37 > 0:26:40We use four million tonnes
0:26:40 > 0:26:43of this naturally occurring mineral every year
0:26:43 > 0:26:45as a base for paint of any colour.
0:26:45 > 0:26:47Its ability to give excellent coverage
0:26:47 > 0:26:51means it also turns up in cosmetics and sun creams.
0:26:51 > 0:26:54Pretty much everything that's white in your house
0:26:54 > 0:26:56contains titanium dioxide.
0:26:56 > 0:26:59Your white goods, your writing paper.
0:26:59 > 0:27:03It's even in your food as E number 171.
0:27:03 > 0:27:06Cottage cheese with added microscopic mirrors, anyone?
0:27:09 > 0:27:11For me, the search for the Wonderstuff
0:27:11 > 0:27:13behind why things stick or don't stick
0:27:13 > 0:27:16has really brought it home how we rely on clever chemistry
0:27:16 > 0:27:19every single day without even realising it.
0:27:19 > 0:27:23The chance discovery of the world's most reactive element, fluorine,
0:27:23 > 0:27:25led to the chance discovery
0:27:25 > 0:27:29of one of the world's most slippery substances, PTFE
0:27:29 > 0:27:32which in turn, led to the culinary revolution,
0:27:32 > 0:27:35enabled by the non-stick pan.
0:27:35 > 0:27:39So who would've thought there was such a fascinating history
0:27:39 > 0:27:42behind an everyday object we all take for granted?
0:27:42 > 0:27:46'Next time, I get under the skin of preening products...'
0:27:46 > 0:27:47Ow!
0:27:47 > 0:27:52'..in my search for the magical mist-grabber in moisturiser.'
0:27:52 > 0:27:55I'm absolutely amazed that just a clear liquid
0:27:55 > 0:27:57can do this amazing thing.
0:27:57 > 0:28:00'Mark tries to explain how anti-perspirant
0:28:00 > 0:28:02'prevents pungent pongs.'
0:28:02 > 0:28:05What if too much comes out? Then you feel uncomfortable.
0:28:05 > 0:28:08I wouldn't like to meet a man who sweated quite that much.
0:28:08 > 0:28:11'And on the hunt for the Wonderstuff in sunscreen,
0:28:11 > 0:28:14'I stoically endure utter humiliation,
0:28:14 > 0:28:15'all in the name of science.'
0:28:15 > 0:28:19Oh! Oh! Oh, God!
0:28:35 > 0:28:38Subtitles by Red Bee Media Ltd
0:28:38 > 0:28:41E-mail subtitling@bbc.co.uk