Introduction to Multi Walled Carbon Nanotubes: What You Should Know about Them

Never heard of multi-walled carbon nanotubes (MWNT) before? Then this article is just for you. In the following lines you will learn more about their structure, properties and applications. Let's get into it!

MWNT - What Are They? 

They are basically multiple nanotubes placed inside one in another or single layer of graphene - cylindrically shaped hollow allotropes of carbon - rolled up multiple times. The number of nanotubes forming MWNT can vary from 2 to over 20. Anyway, with the amount of walls increasing, the probability of defects occurring gets higher. For this reason the double or triple-wall variations are the most common. The diameter, length and purity may vary as well. 

The MWNTs were discovered after fullerenes in the year 1991 by Sumio Iijima. Despite the fact that simple nanotubes were known decades ago in the 1950s.

What Are Their Most Significant Properties? 

As based on graphene, and with weak bonds, they have extraordinary thermal, mechanical and electrical properties. Those can be chemically modified, too, while keeping their stability. These characteristics are precious in many fields of technology, mostly optics and electronics. You can imagine them in batteries, solar panels or heat proof spray coats as they have thermal resistance over 600°C. 

They also possess exceptional tensile strength - as they are even stronger than the steel, they can enhance the strength of compounds into which they are assimilated. 

What about the Other Practical Uses of MWNT? 

The major areas of the application are batteries, solar cells, nano-electronics, energy storage, transistors or flat panel displays. However, they are very useful in water filtration and appreciated in medicine as well. Let’s inspect some of the most interesting ones! 

Water Filtration

The graphene lattice turns out to be ideal for creating membranes of water filters. The holes in these membranes are so tiny that block materials with a large surface and let the molecules of water pass. Not only impurities could be effectively filtered, the crystals of salt could be, too. 

MWNT In Medicine 

In this field we still lack research conducted on human beings, anyway the tests on animals have already delivered very promising results. Carbon nanotubes, both single layer and multiple layer ones are considered as advanced drug delivery carriers. They can be used for targeting tumor organs and tissues while leaving a minimum of side effects.

MWNT are used for creating biosensors which are much quicker in diagnosing infections than other available methods.

Faster Rechargeable Batteries with Higher Performance 

Standard rechargeable batteries used by most of the portable devices are based on lithium-ions and 2 electrodes - graphite one side and metal oxide on the other. It was found out the capacity of storage can become double when graphite is substituted by MWNT. Carbon nanotubes are also much lighter and thinner and with greater conductivity. Recharging of this new generation of batteries would be also remarkably faster, not only referring to cell phones or laptops but also electric car batteries!

Now you know what multi walled carbon nanotubes are and the essentials e.x. what are their most valuable features and how they can be used. There are plenty of nanomaterials out there on the market and in labs , this one is relatively young, and it is still a subject of various research. However, as its potential is so strong and possibilities of its uses so wide, it's better to remember it and monitor it!

In which context did you hear of MWNT for the first time?