Carbon nanotubes are already considered as one the best material of the future thanks to their properties. However, they are far from perfect therefore scientists are trying to improve them so that they can be used in more domains.

Scientists are trying to exploit them at their full potential in order to use carbon nanotubes at macroscale, not only in nanotechnology, but for thin films and other membranes, you have to assemble trillions of these which is very expensive and not very efficient.

These macroscale thin-films and membranes are called buckypapers and they are made of intertwined carbon nanobutes(CNTs). Buckypapers are macroscopic aggregates and they are regarded as the most thermally-conductive materials in the world therefore they could lead to more efficient heat sinks, more efficient and brighter displays, or like a more protective material for electrical circuits.

Also, buckypapers are not currently acting at their full potential because of their fabrication methods which are technically limited as their don’t provide high homogeneity and uniformity, their structure and thickness is hard to control, and the production efficiency is very low therefore CNT membranes are mechanically, electrically, and optically reliable.

For the moment, buckypapers are no match for individual carbon nanotubes, but thanks to a technique inspired by the textile industry, researchers believe that they can improve them. This fabrication method would lead to better buckypapers as their structure and thickness could be controlled, the production will be more efficient, and they will be cheap to manufacture.

“Our hydroentangling method is the result of converging two completely different fields, i.e., nanotechnology and modern textile technology, and can revolutionize the way we make nanomaterials.Our hydroentangled CNT membranes have significantly greater mechanical and electrical properties than the state-of-the-art CNT buckypapers made from filtration,” said Dr. Xiangwu Zhang.

Xiangwu Zhang, who is an assistant professor at the College of Textiles from the North Carolina State University, claims that the managed to create improved CNT membranes using hydroentangling, or hydraulic needling.

“In addition, these CNT membranes maintain all the multifunctional properties of individual CNTs, and hence they have many potential applications such as field emission displays, catalyst supports, biomedical electronics, solar collection, hydrogen storage, sensors, fuel cells, and batteries,” added Dr. Zhang.

The hydraulic needling is different from conventional textile processes as the stack of untangled fibers is treated as a whole which leads so stronger CNT membranes.

“Using this setup, we completed the hydroentangling of CNTs between 5 seconds and 2 minutes, depending on the membrane thickness. The resultant membranes have a diameter of 25 millimeters. The fabrication of CNT membranes with larger sizes can be realized using the continuous process or a bench-top setup with a larger-diameter support,” said Zhang.

Zhang’s claims are backed by the fact that he showed that the tensile strength of his 100 µm CNT membranes is of 51 MPa which is three times bigger than the best conventional buckypaper. So it seems like hydroentangling is better than regular fabrication methods of CNT membranes like spin coating, drop casting, and Langmuir-Blodgett deposition among others.

“By infiltrating polymers into hydroentangled CNT membranes, we can obtain CNT-based polymer composites with even higher mechanical properties. For example, the introduction of polyethylene oxide (PEO) into hydroentangled CNT membrane can increase the strength by 37%, which indicates that PEO chains can minimize the nanotube slippages and stabilize the entanglements during the tensile loading,” explained Dr. Zhang.

Even if the researchers demonstrated the capacities of the hydroentangled CNT membranes, they don’t really know what happens during this process therefore there is a long way to go before this technology is “recognized” among the best. However, its potential seems gigantic as it could also lead to high-performant fuel cells, super capacitors and batteries, and it could help building stronger cars and airplanes.