- This topic has 2 voices and 4 replies.
- September 28, 2012 at 2:59 am #344273
[size=12pt]Chemists create nanotube structures that can expand and contract without breaking down[/size]
A group of chemists from China, Japan and Korea have succeeded in creating nanotubes that can be made to expand and contract in response to warm or cold water. Led by Myongsoo Lee of Seoul University, the team, as they describe in their paper published in the journal Science, manipulated a series of molecules into forming hexagons, which when stacked resulted in the formation of a nanotube. Upon subjecting the nanotube to warm or cold water, the nanotube was made to expand or contract on demand.
To create the nanotubes, researchers bent six molecules which caused them to automatically assemble themselves into a hexagon. Several of the hexagons were then stacked, creating a nanotube which displayed properties of expanding and contracting in the presence of warm or cold water. The expanding and contracting occurs due to the central molecule being a hydrocarbon called pyridine, which has a nitrogen atom attached to it. That atom attracts water molecules, causing some degree of expansion until the water is heated to 60 °C. At that point, the water molecule attraction is disrupted causing contraction.
The expansion and contraction was so well defined that the team was able to cause their nanotube to expel a buckyball that was placed inside leading to speculation that the nanotube might somehow be fashioned into a nano sized pump, or circulatory system, with one application being a very tiny drug delivery system. The results by this team represent a milestone, as it's the first time anyone has been able to get a nanotube to expand or contract without having its structure modified in the process, which means the same tube can be used over and over. It also shows that nano structures in general can be created that can be made to do things without them being broken down in the process, which is significant, because most attempts to do so thus far have resulted in failure. The problem is of course, is that it's extremely difficult to manipulate things at such a tiny scale. The contraction of the nanotube in this study, for example, was just 11 nanometers down to 7; a nanometer is one billionth of a meter. In a related perspective piece also published in Science, Wei Zhang and Takuzo Aida tie the development of the expanding/contracting nanotube to the seemingly never ending search for the artificial creation of cardiac muscle cells that could pulsate autonomously, resulting perhaps, in a cure for heart disease.
Read more at: http://phys.org/news/2012-09-chemists-nanotube.html#jCpSeptember 28, 2012 at 3:00 am #398514
A step closer to space elevatorSeptember 28, 2012 at 6:15 am #398515
Interesting, I have to look into this. I wonder if this could be used to expand capillaries in the brain to reduce the risk of stroke?September 28, 2012 at 11:38 am #398516
AnonymousQuote:Interesting, I have to look into this. I wonder if this could be used to expand capillaries in the brain to reduce the risk of stroke?
I far as I remember there are micro robots for such medical purposes
When I mentioned space elevator I had something like this in mind:
The Space Elevator – no longer Science FictionSeptember 28, 2012 at 11:49 am #398517
And the benefits are following:
Going Up: The Space Elevator [Final]
You must be logged in to reply to this topic.