In a discovery that does much to encapsulate the range of new possibilities available with nanomaterials, a team of researchers have discovered a way to grow nanofibers into multi-skilled coatings. By adapting the shape of these 2D layers into 3D structures, the coatings can be given different properties; sticky, repellent, insulating, light emitting or more.
Such is the scale of the discovery that Joerg Lahann, a professor of chemical engineering at the University of Michigan and senior author of the study, said, "This is so removed from anything I've ever seen that I would have thought it was impossible."
This has led to a period of dreaming the previously unimaginable, as nanomaterial specialists wonder what they are now able to create. They have started by looking to natural science and the amazing abilities of nature’s coatings; polar bear fur that is able to let in light whilst trapping in heat, nanoscale hairs that make a gecko’s feet super-sticky, and water-repelling lotus leaves that are coated with arrays of microscopic waxy tubules.
But this breakthrough actually began by accident, when an experiment to make liquid crystal sensors that could detect single molecules went wrong.
As the journal Science Daily explains, the team originally planned to “evaporate single links in a chain [of molecules] and coax them to condense onto surfaces. But the thin polymer films sometimes didn't materialize as expected. Instead of coating the top of the liquid crystal, the links slipped into the fluid and connected with each other on the glass slide. The liquid crystal then guided the shapes of the nanofibers growing up from the bottom, creating nanoscale carpets.”
As Nicholas Abbott, co-author and a professor of chemical engineering notes, "The discovery reinforces my view that the best advances in science and engineering occur when things don't go as planned. You just have to be alert and view failed experiments as opportunities."
Nanotechnology involves a huge number of totally different areas of research. Their only common feature is that they focus on the world of microscopic dimensions. One nanometer corresponds to roughly 10 hydrogen atoms. From these dimensions starts a new world of nanomaterials that work in ways that are completely different from our macro-world.
The research has now been published in the peer-reviewed journal, Science, where the team explain how, “Extrusion, electrospinning, and microdrawing are widely used to create fibrous polymer mats, but these approaches offer limited access to oriented arrays of nanometer-scale fibers with controlled size, shape, and lateral organization.” However, the accidental breakthrough, now shows, “… that chemical vapor polymerization can be performed on surfaces coated with thin films of liquid crystals to synthesize organized assemblies of end-attached polymer nanofibers.
What is most exciting about this nanomaterial discovery is the wide-range of nanocoating designs now available to researchers.
As Lahann states, “We have a lot of control over the chemistry, the type of fibers, the architecture of the fibers and how we deposit them. This really adds a lot of complexity to the way we can engineer surfaces now; not just with thin two-dimensional films but in three dimensions."
While the scientific journal Phys.org reports that, “The researchers grew straight and curved fibers and tested how they stuck together like Velcro -- finding that clockwise and counter-clockwise twisted fibers knitted together more tightly than two arrays of straight fibers.” They also found that, “Depending on the liquid crystal, they could generate curved fibers, like microscopic bananas or staircases.” And have also, “Shown that their nanofibers can repel water like lotus leaves.”
In fact, the true beauty of the discovery is the world of possibilities that it has opened up. Allowing chemical engineers to design ultra-thin coatings that can provide extraordinary properties.
However, this breakthrough is very typical of what is happening throughout the nanomaterial industry. By focusing on the way materials function at a minute-scale, manufacturers are creating raw materials that are making better products.
For example, an ordinary tire can be made with the addition of single walled carbon nanotubes (SWCNT), giving it improved performance such as lower weight, increased durability (to over 200,000km), and greater air retention. Another example is the use of nanotechnology in domestic batteries making them capable of lasting for several years in normal use, or nano-filters that provide health benefits by capturing toxic particles in the air.
As a whole, the nanotechnology industry and the production of nano-sized raw materials is predicted to be worth $125 billion by 2024.
Small technology that is worth a big sum.