David Kirkpatrick

July 17, 2010

Manufacturing carbon nanotubes at room temperature

This document outlines a method of creating carbon nanotubes that doesn’t require high temperature or pressure. This potentially will dramtically lower the cost of manufacturing carbon nanotubes.

From the link:

We develop a new chemical route to carbon nanotubes at room temperature. Graphite powder was immersed in a mixed solution of nitric and sulphuric acid with potassium chloride. After heating the solution up to 70‰ and leaving them in the air for 3 days, we obtained carbon nanotube bundles. The process could readily give an easy way of preparing carbon nanotubes without high temperature and high pressure. We develop a new chemical route to carbon nanotubes at room temperature. Graphite powderwas immersed in a mixed solution of nitric and sulphuric acid with potassium chloride. After heatingthe solution up to 70‰ and leaving them in the air for 3 days, we obtained carbon nanotube bundles.The process could readily give an easy way of preparing carbon nanotubes without high temperatureand high pressure.
And:
In summary, we have presented a simple chemical method for producing CNTs in liquid solution at 70‰ without any pressure treatment. The CNTs form bundles containing crystalized and multi-walled single CNTs with a diameter of around 14.6nm. The electron diffraction patterns demonstrate its zigzag edge structure. We expect this new synthesizing method may produce cheap CNTs and as a result open an easy access to the industrial device based on CNTs.
Here’s an illustration and an image from the link:
FIG. 1: (a) mixture of graphite, sulfuric acid (H2SO4, and nitric acid (HNO3). (b) potassium chlorate (KClO3) was put in the solution. (c) floating carbons produced from the pro- cess (b) were transferred into DI water. (d) the sample was dried after filtration. The process (b) and (c) were repeated 4 times.

FIG. 3: (a) transmission electron microscope (TEM) images of CMT bundles. Panels (b) and (c) magnificently present the regions pointed by number 1 and 2 in panel (a), respectively. A single CNT noticed by an arrow in panel (b) proves CNT’s flexibility. (d) the enlarged region of panel (c) (arrow 3), revealing a multi-walled nanotube with a diameter of 14.6nm.

February 15, 2010

Synthetic biology marches on

Filed under: Science, Technology — Tags: , , , , , — David Kirkpatrick @ 3:36 pm

Via KurzweilAI.netSynthetic biology is here to stay and is branching out.

DNA 2.0: A new operating system for life is created
New Scientist Life, Feb. 14, 2010

University of Cambridge scientists have created a new way of using the genetic code, allowing proteins to be made with properties that have never been seen in the natural world.

The breakthrough could eventually lead to the creation of new or “improved” life forms incorporating these new materials into their tissue. For example, they could help make drugs that can be taken orally without being destroyed by the acids in the digestive tract, or produce entirely new polymers, such as plastic-like materials; organisms made of these cells could incorporate the stronger polymers and become stronger or more adaptable as a result.

In the genetic code that life has used up to now, there are 64 possible triplet combinations of the four nucleotide letters; these genetic “words” are called codons. Each codon either codes for an amino acid or tells the cell to stop making a protein chain. The researchers have created 256 blank four-letter codons that can be assigned to amino acids that don’t even exist yet.
Read Original Article>>

February 5, 2010

Graphane the superconductor

Back-to-back single-atom layer sheets of carbon nanotech posts today. Graphene and now graphane. (Hit this link for all my graphene blogging and this one for graphane blogging.)

I’m just going to let this physics arXiv blog post do the explaining on this news:

New calculations reveal that p-doped graphane should superconduct at 90K, making possible an entirely new generation of devices cooled by liquid nitrogen.

There’s a problem with high temperature superconductors. It’s now more than two decades since the discovery that certain copper oxides can superconduct at temperatures above 30 K.

And:

The implications of all this are astounding. First up is the possibility of useful superconducting devices cooled only by liquid nitrogen. At last!

But there’s another, more exotic implication: by creating transistor-like gates out of graphane doped in different ways, it should be possible to create devices in which the superconductivity can be switched on and off. That’ll make possible an entirely new class of switch.

Before all of that, however, somebody has to make p-doped graphane. That will be hard. Graphane itself was made for the first time only last year at the University of Manchester. It should be entertaining to follow the race to make and test a p-doped version.

July 31, 2009

Quantum computing — a breakthrough and a warning

The potential power of quantum computing is astonishing, and a lot of research is going into creating quantum computers. Of course there’s always a dark side to anything — a quantum computer that realizes the full potential of the technology will also render current security and encryption obsolete overnight.

This post is a about a breakthrough involving the building blocks of matter and how that adds to quantum computing research, and also a cautionary tale from a researcher who is preparing for the security needs when the first quantum computer arises.

First the warning:

So far, so good, despite an occasional breach. But our security and our data could be compromised overnight when the first quantum computer is built, says Dr. Julia Kempe of Tel Aviv University‘s Blavatnik School of Computer Science. These new computers, still in the theoretical stage, will be many times more powerful than the computers that protect our data now.

Laying the groundwork to keep governments, companies and individuals safe, Dr. Kempe is working to understand the power of quantum computers by designing algorithms that fit them. At the same time, she is figuring out the limits of quantum computers, something especially important so we can build safety systems against quantum hackers.

“If a very rich person worked secretly to fund the building of a quantum computer, there is no reason in principle that it couldn’t be used for malevolent power within the next decade,” she says. “Governments, large corporations, entrepreneurs and common everyday people will have no ability to protect themselves. So we have to plan ahead.”

And now the breakthrough:

Discovery about behavior of building block of nature could lead to computer revolution

A team of physicists from the Universities of Cambridge and Birmingham have shown that electrons in narrow wires can divide into two new particles called spinons and a holons.

The electron is a fundamental building block of nature and is indivisible in isolation, yet a new experiment has shown that electrons, if crowded into narrow wires, are seen to split apart.

The electron is responsible for carrying electricity in wires and for making magnets. These two properties of magnetism and electric charge are carried by electrons which seem to have no size or shape and are impossible to break apart.

However, what is true about the properties of a single electron does not seem to be the case when electrons are brought together. Instead the like-charged electrons repel each other and need to modify the way they move to avoid getting too close to each other. In ordinary metals this does not usually make much difference to their behaviour. However, if the electrons are put in a very narrow wire the effects are exacerbated as they find it much harder to move past each other.

In 1981, physicist Duncan Haldane conjectured theoretically that under these circumstances and at the lowest temperatures the electrons would always modify the way they behaved so that their magnetism and their charge would separate into two new types of particle called spinons and holons.

The challenge was to confine electrons tightly in a ‘quantum wire’ and bring this wire close enough to an ordinary metal so that the electrons in that metal could ‘jump’ by quantum tunneling into the wire. By observing how the rate of jumping varies with an applied magnetic field the experiment reveals how the electron, on entering the quantum wire, has to fall apart into spinons and holons. The conditions to make this work comprised a comb of wires above a flat metal cloud of electrons. The Cambridge physicists, Yodchay Jompol and Chris Ford, clearly saw the distinct signatures of the two new particles as the Birmingham theorists, Tim Silk and Andy Schofield, had predicted.

Dr Chris Ford from the University of Cambridge’s Cavendish Laboratory says, ‘We had to develop the technology to pass a current between a wire and a sheet only 30 atomic widths apart.

‘The measurements have to be made at extremely low temperatures, about a tenth of a degree above absolute zero.

‘Quantum wires are widely used to connect up quantum “dots”, which may in the future form the basis of a new type of computer, called a quantum computer. Thus understanding their properties may be important for such quantum technologies, as well as helping to develop more complete theories of superconductivity and conduction in solids in general. This could lead to a new computer revolution.’

Professor Andy Schofield from the University of Birmingham’s School of Physics and Astronomy says, ‘The experiment to test this is based on an idea I had together with three colleagues almost 10 years ago. At that time the technology required to implement the experiment was still a long way off.

‘What is remarkable about this new experiment is not just the clarity of the observation of the spinon and holon, which confirms some earlier studies, but that the spinon and holon are seen well beyond the region that Duncan Haldane originally conjectured.

‘Our ability to control the behaviour of a single electron is responsible for the semiconductor revolution which has led to cheaper computers, iPods and more. Whether we will be able to control these new particles as successfully as we have the single electron remains to be seen. What it does reveal is that bringing electrons together can lead to new properties and even new particles.’

 ###

 Notes to Editors

1. The paper is published in Science 10.1126/science.1171769 at http://dx.doi.org/10.1126/science.1171769

2. The experiment was performed in Cambridge’s Cavendish Laboratory with theoretical support from scientists at the University of Birmingham’s School of Physics and Astronomy.

June 18, 2009

Turning Buckyballs into Buckywires

Filed under: Science — Tags: , , , , — David Kirkpatrick @ 1:29 am

Buckyballs are a nanotech that seems to be rarely discussed these days with all the breakthroughs in other areas. Scientists at the University of Cambridge have found a way to turn Buckyballs into Buckywires through polymerization. This steps adds to the utility of Buckyballs considerably. Buckywires should be better than carbon nanotubes in price and possibly performance.

From the link:

The trick that Geng and co have found is a way to connect two buckyballs together using a molecule of 1,2,4-trimethylbenzene–a colorless aromatic hydrocarbon. Repeat that and you’ve got a way to connect any number of buckyballs. And to prove it, the researchers have created and studied these buckywires in their lab, saying that the wires are highly stable.

Buckywires ought to be handy for all kinds of biological, electrical, optical, and magnetic applications. The gist of the paper is that anything that traditional carbon nanotubes can do, buckywires can do better. Or at least more cheaply.

The exciting thing about this breakthrough is the potential to grow buckywires on an industrial scale from buckyballs dissolved in a vat of bubbling oil. Since the buckywires are insoluble, they precipitate out, forming crystals. (Here it ought to be said that various other groups are said to have made buckywires of one kind or another, but none seem to have nailed it from an industrial perspective.)