Date: 26/03/2013 08:02:03
From: Spiny Norman
ID: 286792
Subject: The Lightest Material Ever Made

Scientists have developed a solid material so light it can be balanced atop the petals of a flower.

Researchers from Zhejiang university in Hangzhou, China, showed off their newly developed graphene aerogel by balancing a block of the stuff on a delicate cherry blossom.

The sponge-like matter is made of freeze-dried carbon and graphene oxide and is the lightest solid material in the world.

With a weight of just 0.16 milligrams per cubic centimetre, it is just twice the density of hydrogen – the simplest of all elements – and less dense than helium.

First developed by two Russian scientists playing about with Scotch tape at Manchester University, graphene has already been hailed as a ‘wonder material’ that promises to transform the future.

Its discovery earned Professors Andre Geim and Kostya Novoselov a joint Nobel prize in physics, with the committee making a special mention of the ‘playfulness’ of their experiments, and a knighthood each.

In its pure state, the substance is a two-dimensional crystal of pure carbon atoms arranged in a honeycomb lattice described by some as ‘atomic chickenwire’.

That makes it the thinnest material ever made. You would need to stack three million graphene sheets on top of each other to get a pile one milimetre high.

But this unique structure makes it very light and strong, with a one-square-metre sheet weighing only 0.77 milligrams – yet strong enough to support the weight of a 4kg adult cat.

A sheet of graphene as thin as clingfilm could hold the weight of an elephant. According to one calculation, an Nelly would need to balance precariously on the end of a pencil to break through that same sheet.

Despite its strength, it is also extremely flexible and can be stretched by 20 per cent without any damage, and it’s almost transparent.

It is also a superb conductor of electricity — far better than copper, traditionally used for wiring — and is the best conductor of heat on the planet.

It is also, further research discovered, an incredible filter – it blocks all liquids and gases except water, which made for the potential for one stereotypically Russian experiment by its inventors.

‘Just for a laugh, we sealed a bottle of vodka with our membranes and found that the distilled solution became stronger and stronger with time,’ said Dr Rahul Nair, who co-authored a study describing the results last year.

Professors Geim and Novoselov serendipitously discovered graphene almost by accident while investigating the electrical properties of carbon graphite – the common material that pencils are made of.

Borrowing a technique used by microscopy researchers to clean the mineral before examining it close up, they found they could peel it into ever thinner flakes using Scotch tape.

After repeatedly sticking and peeling back the Scotch tape they realised they could get down to the thinnest layer physically possible – just one atom thick.

They then attached it to a silicon plate which allowed them to identify its tiny layers through a microscope.

Graphene’s discovery has triggered a boom for material science, with its potential applications appearing almost limitless.

But most important of all, its core constituent, carbon, is the basic element of life, which means graphene could spur a new industrial revolution based on components that are biodegradable and sustainable.

‘We are talking of a number of unique properties combined in one material which probably hasn’t happened before,’ said Professor Novoselov in 2011.

‘You might want to compare it to plastic. But graphene is as versatile as all the plastics put together.

‘It’s a big claim, but it’s not bold. That’s exactly why there are so many researchers working on it.’

I don’t have a link sorry.
But golly-gosh that’s cool.

Reply Quote

Date: 26/03/2013 08:49:19
From: mollwollfumble
ID: 286802
Subject: re: The Lightest Material Ever Made

> With a weight of just 0.16 milligrams per cubic centimetre, it is just twice the density of hydrogen – the simplest of all elements – and less dense than helium.

That’s extremely light.

Put it in a vacuum and it would be one of the best thermal insulators ever made, and able to handle extremely high temperatures. The spacecraft proposed for flying to the Sun should be coated in this.

I don’t yet understand how it is made. Graphene is flat rather than 3-D. “Graphene oxide” would be better known as carbon monoxide wouldn’t it?

Reply Quote

Date: 26/03/2013 08:52:17
From: Spiny Norman
ID: 286803
Subject: re: The Lightest Material Ever Made

mollwollfumble said:

The spacecraft proposed for flying to the Sun should be coated in this.

Couldn’t they just go at night?
(groan)

mollwollfumble said:

I don’t yet understand how it is made. Graphene is flat rather than 3-D. “Graphene oxide” would be better known as carbon monoxide wouldn’t it?

I’d like to know as well.

Reply Quote

Date: 26/03/2013 08:55:21
From: Wocky
ID: 286804
Subject: re: The Lightest Material Ever Made

That article is from the Daily Mail, http://www.dailymail.co.uk/sciencetech/article-2296223/Lightest-material-Graphene-aerogel-balanced-atop-petals-flower.html

Reply Quote

Date: 26/03/2013 08:58:14
From: Spiny Norman
ID: 286805
Subject: re: The Lightest Material Ever Made

Wocky said:

That article is from the Daily Mail, http://www.dailymail.co.uk/sciencetech/article-2296223/Lightest-material-Graphene-aerogel-balanced-atop-petals-flower.html

Thanks for that.

Reply Quote

Date: 26/03/2013 09:01:05
From: The Rev Dodgson
ID: 286806
Subject: re: The Lightest Material Ever Made

yet strong enough to support the weight of a 4kg adult cat.

But will it support a 4kg baby dog?

Reply Quote

Date: 26/03/2013 09:02:25
From: Wocky
ID: 286807
Subject: re: The Lightest Material Ever Made

Details of the material’s production and experimental results, from the original paper in the Royal Society’s Journal of Materials Chemistry here: http://www.rsc.org/suppdata/jm/c1/c1jm10239g/c1jm10239g.pdf

Abstract and link (through paywall) to article in RSC: http://pubs.rsc.org/en/Content/ArticleLanding/2011/JM/c1jm10239g

Reply Quote

Date: 26/03/2013 09:04:40
From: Wocky
ID: 286808
Subject: re: The Lightest Material Ever Made

Wocky said:

Details of the material’s production and experimental results, from the original paper in the Royal Society’s Journal of Materials Chemistry here: http://www.rsc.org/suppdata/jm/c1/c1jm10239g/c1jm10239g.pdf

Abstract and link (through paywall) to article in RSC: http://pubs.rsc.org/en/Content/ArticleLanding/2011/JM/c1jm10239g

Interestingly, that journal article was published in April 2011.

Reply Quote

Date: 26/03/2013 09:05:00
From: mollwollfumble
ID: 286809
Subject: re: The Lightest Material Ever Made

This is a better version of the news article: http://www.gizmag.com/graphene-aerogel-worlds-lightest/26784/

Although first created in 1931 by American scientist and chemical engineer, Samuel Stephens Kistler, aerogels have recently become a hotly contested area of scientific research. A “multiwalled carbon nanotube (MCNT) aerogel” dubbed “frozen smoke” with a density of 4 mg/cm3 lost its world’s lightest material title in 2011 to a micro-lattice material with a density of 0.9 mg/cm3. Less than a year later, aerographite claimed the crown with its density of 0.18 mg/cm^3. Now a new title-holder has been crowned, with the graphene aerogel created by Gao and his team boasting a density of just 0.16 mg/cm^3. …

Instead of the sol-gel method and template-oriented methods generally used to create aerogels, Gao and his team used a new freeze-drying method that involved freeze-drying solutions of carbon nanotubes and graphene to create a carbon sponge that can be arbitrarily adjusted to any shape. “With no need for templates, its size only depends on that of the container,” said Prof. Gao. “Bigger container can help produce the aerogel in bigger size, even to thousands of cubic centimeters or larger.”

The result is a material the team claims is very strong and extremely elastic, bouncing back after being compressed. It can also absorb up to 900 times its own weight in oil and do so quickly, with one gram of aerogel able to absorb up to 68.8 grams of organics per second – making it attractive for mopping up oil spills at sea. “Maybe one day when oil spill occurs, we can scatter them on the sea and absorb the oil quickly,” said Gao. “Due to its elasticity, both the oil absorbed and the aerogel can be recycled.”

The researchers are examining other possible applications and say it also has potential as a phase change energy storage insulation material, catalytic carrier or efficient composite.

———————

That oil absorption is a very good idea.

> it also has potential as a phase change energy storage insulation material

I had a look as part of my CSIRO work at phase change energy storage insulation material. The most popular and best behaved were the paraffins. The second most popular are salts that dissolve in their own water of crystallization. An aerogel like this would be ideal for holding both. The aerogel network is needed for holding liquid paraffin or salts in a suspended state so that it won’t ever drip or gravity-separate. My CSIRO work was trying out a range of liquid holding materials including plasters, clays, timbers, aerated cements. I hadn’t been able to get access to an aerogel but would very much have liked to.

Reply Quote

Date: 26/03/2013 10:36:30
From: Ian
ID: 286848
Subject: re: The Lightest Material Ever Made

>the ultra-light aerogel has a density lower than that of helium and just twice that of hydrogen.

Why doesn’t it float?

Reply Quote

Date: 26/03/2013 10:37:51
From: Ian
ID: 286849
Subject: re: The Lightest Material Ever Made

in air that is

Reply Quote

Date: 26/03/2013 10:39:45
From: Boris
ID: 286850
Subject: re: The Lightest Material Ever Made

guess. the substance is heavier than water and because it is such a good sponge all spaces within it are filled with water and thus it doesn’t float. though i can’t see a reference to it not floating in the article.

Reply Quote

Date: 26/03/2013 10:41:04
From: Boris
ID: 286851
Subject: re: The Lightest Material Ever Made

now you tell me.

Reply Quote

Date: 26/03/2013 10:41:57
From: Ian
ID: 286852
Subject: re: The Lightest Material Ever Made

OP shows it balanced atop the petals of a flower.

Reply Quote

Date: 26/03/2013 10:43:20
From: poikilotherm
ID: 286853
Subject: re: The Lightest Material Ever Made

Ian said:


in air that is

Gravity.

Reply Quote

Date: 26/03/2013 10:44:56
From: Boris
ID: 286854
Subject: re: The Lightest Material Ever Made

hmmmmm maybe the difference between weight and density. eg, liquid helium wont float in air, i don’t think so anyway.

Reply Quote

Date: 26/03/2013 12:29:48
From: Bubblecar
ID: 286861
Subject: re: The Lightest Material Ever Made

Helium is a gas which expands (when allowed) to fill a volume that is then less dense than the surrounding air. This stuff is solid.

Reply Quote

Date: 26/03/2013 12:34:34
From: Bubblecar
ID: 286862
Subject: re: The Lightest Material Ever Made

Wonder what it tastes like.

Reply Quote

Date: 26/03/2013 12:45:41
From: poikilotherm
ID: 286865
Subject: re: The Lightest Material Ever Made

Bubblecar said:


Wonder what it tastes like.

Chicken.

Reply Quote

Date: 26/03/2013 12:46:14
From: Bubblecar
ID: 286866
Subject: re: The Lightest Material Ever Made

Hmm, chicken-flavoured chicken wire.

Reply Quote

Date: 26/03/2013 12:49:49
From: morrie
ID: 286867
Subject: re: The Lightest Material Ever Made

Ian said:


>the ultra-light aerogel has a density lower than that of helium and just twice that of hydrogen.

Why doesn’t it float?


It has open porosity, rather than closed porosity.

Reply Quote

Date: 26/03/2013 18:52:56
From: Dropbear
ID: 286993
Subject: re: The Lightest Material Ever Made

>>Put it in a vacuum and it would be one of the best thermal insulators ever made,

ummmm how can something be a good electrical conductor and a thermal insulator?

Reply Quote

Date: 27/03/2013 23:28:59
From: Kingy
ID: 287484
Subject: re: The Lightest Material Ever Made

Dropbear said:


>>Put it in a vacuum and it would be one of the best thermal insulators ever made,

ummmm how can something be a good electrical conductor and a thermal insulator?

Because science.

Keep up!

Reply Quote

Date: 27/03/2013 23:32:44
From: Stealth
ID: 287490
Subject: re: The Lightest Material Ever Made

Kingy said:


Dropbear said:

>>Put it in a vacuum and it would be one of the best thermal insulators ever made,

ummmm how can something be a good electrical conductor and a thermal insulator?

Because science.

Keep up!


Well OK, but how can something that is “It is also a superb conductor of electricity — far better than copper, traditionally used for wiring — and is the best conductor of heat on the planet.” be a good insulator?

Reply Quote

Date: 31/03/2013 18:38:50
From: PM 2Ring
ID: 288855
Subject: re: The Lightest Material Ever Made

Ian said:


>the ultra-light aerogel has a density lower than that of helium and just twice that of hydrogen.

Why doesn’t it float?

The pores in the aerogel block contain air (&/or carbon dioxide), which increases the mean density of the block and stops it floating in air. But if you somehow replaced that gas with one that’s less dense than air, the block would certainly float. You’d probably need to seal the block to stop the gas from escaping, and the sealant would weigh the block down a bit, but that shouldn’t be too much of a problem if the block’s large enough & the amount of sealant is small enough.

You could fill it with hydrogen, but that’s probably not a good choice, as hydrogen likes to react with elemental carbon. Helium would be OK density-wise, but it’s hard to contain. Neon or argon would probably work well.

morrie said:


It has open porosity, rather than closed porosity.

I guess so, since it’d be hard to get the ultra-low density with a closed structure.

Reply Quote

Date: 31/03/2013 19:39:15
From: morrie
ID: 288876
Subject: re: The Lightest Material Ever Made

>Neon or argon would probably work well.

Argon is heavier than air though. Makes fun ‘heavy’ balloons.

Reply Quote

Date: 31/03/2013 19:45:49
From: morrie
ID: 288877
Subject: re: The Lightest Material Ever Made

>You could fill it with hydrogen, but that’s probably not a good choice, as hydrogen likes to react with elemental carbon

Usually requires a catalyst I think. But It made me think that there might be an adsorbed layer with a higher density than the gaseous element. I mean, thats how you measure surface areas of these materials. Adsorption of helium.

Reply Quote

Date: 1/04/2013 11:09:41
From: PM 2Ring
ID: 289058
Subject: re: The Lightest Material Ever Made

morrie said:


>Neon or argon would probably work well.

Argon is heavier than air though. Makes fun ‘heavy’ balloons.


Oops! So it is. I mis-remembered its atomic number of 18 as its mass, which is actually 39.948 amu. I should’ve Googled…

:embarrassed:

Reply Quote