Silesian scientists have solved the problem of nanotube selection using a method from 150 years ago
Researchers at the Silesian University of Technology have developed a solution to a fundamental problem associated with carbon nanomaterials. The new method is based on a 150-year-old concept and is additionally fast and cheap.
The lack of the necessary degree of control during the manufacturing process over the structure of the carbon nanotube remains a majoroThe major factor hindering significant progressoWhen using this material. In recent years, a number of promising methods have emerged to solve this problem by sorting nanotubes with appropriate parameters. However, all of them are unfortunately multistage in nature.
Researchers at the Silesian University of Technology have come up with a one-step solution, and it’s using a method from more than 150 years ago. With this approach, nanotubes with desirable parameters can be separated from the crowd of others. In addition, the developed technique is fast, cheap and relatively simple. To apply it, all that is needed is 5 compoundsoin a chemical and blender.
The results of the research were published in „Scientific Reports”.
The production process produces about 30-50 rotion of different typesoin nanotubes in a single material. Unfortunately, there is currently no such process for making nanotubes, thanks to whichoThe same structures would be formed. At most, it is possible to control the production process in such a wayob so that about half met the set conditions.
Therefore, a selection process is necessary to pick out the right ones from the black powder, because that’s what the nanotubes look like when seen with the naked eye. The situation is not improved by the fact that nanotubes are extremely small. Their diameter is 100 times smaller than a human hair.
– The nanotube is made of carbon and hollow inside. It is formed by rolling up a plane of graphene, like a sheet of paper, into a tiny roll. The problem is that such a piece of paper can be rolled up for many roThe difference in properties of nanotubesow under roa major angle. And then the nanotubes have radically r from each otherotic properties – mowi in an interview with PAP dr. hab. Dawid Janas of the Silesian University of Technology, ktory has developed a new method.
Some conduct electricity better, others are useful in building transistorsow. The researcher, whoory would like to build a transistor with certain parameters, he must choose nanotubes ponancial nanotubes with a particular way of coiling. Minimal roThe difference in the way the nanotubes are coiled results in aoThe difference in the properties of eacholnych nanotubes.
But the uses of this material are many. – In research conducted at a clinic in New York, solutions of nanotubes are injected into the blood of ratsow, making it possible to assess the state of the disease and the functioning of the organism. On the one hand, we may be horrified by the introduction of nanoparticles into the living organism. But – on the other hand – not only does it take a much lower concentration to image the inside of an organ, but studies have shown it to be less toxic than substances currently in use. In the cancer clinic, there are no good solutions for imaging all tumorow. In this case, anything is a lifesaver. In addition, it is possible to direct the nanotubes for very sensitive imaging of a particular location – admits Dr. hab. Janas in an interview with PAP’s Science in Poland service.
Previous methods of segregating nanotubes required expensive equipment. It is all about the right vortexowks, chemical reagents or other electrical devices capable of capturing roThe differences in the size of nanomaterials. For this, the methods used were multi-step and inefficient.
Proposed by the scientistow from Silesia, the idea is based on a method dating back to 1885. During one of the experiments Martinus Beijerinck – author of the method – Mixed two water solutions: agar and gelatin. He noted, they form two separate phases. We face a similar situation when we pour oil into water – both substances separate from each other. Since then, the method has been continuously developed and is now used in many fields.
This so-called. The two-phase system can also be used in the selection process of nanotubes. When the right factors are used, one can make some nanotubes float to the surface and some pohe goes to the bottom. After several such treatments using rotive factorow you can obtain the type of your choice. Dr. Janas along with coohe researchers optimized the process to a single step.
Scientists „have determined that the lower phase should be an aqueous solution of theor of dextran (a compound composed of sugarow), and on gorze must find poly(ethylene glycol). Dr. hab. Janas decided to introduce one more chemical compound, whichory affects „wanderowka” nanotubes in solution. He wanted to force the selected type of nanotubes to select a specific phase, and the rest of the – to abandon this loner” – we read in an interview with Dr. Janas.
This compound turned out to be ammonia or hydrazine. Using the right concentration of this compound, a specific type of nanotubes can be selected. In this wayob can be selected rothat would make different types of nanotubes, even those that are in the minority. Successfully managed to obtain even such a type, whichory accounted for only 6 percent of the. of the whole mixture.
The developed method is extremely precise. As Dr. Janas admits, thanks to no separable nanotube rothat differ from each other by one-tenth of a nanometer – is the radius of a hydrogen atom. This method could find roAlso the application in the purification of drugsow. Although there will probably be more applications for this concept in the future.
Source:osource: PAP – Science in Poland, fot. Mstroeck/ Wikimedia Commons
