Polymers reinforced with ultra-fine strands of carbon fibers epitomize composite materials that are “light as a feather and strong as steel,” earning them versatile applications across several industries. Adding materials called carbon nanotubes can further enhance the composites’ functionality. But the chemical processes used for incorporating carbon nanotube end up spreading them unevenly on the composites, limiting the strength and other useful qualities that can be ultimately achieved.
In a new study, Texas A&M University researchers have used a natural plant product, called cellulose nanocrystals, to pin and coat carbon nanotubes uniformly onto the carbon-fiber composites. The researchers said their prescribed method is quicker than conventional methods and also allows the designing of carbon-fiber composites from the nanoscale.
The results of the study are published online in the journal American Chemical Society (ACS) Applied Nano Materials. Composites are built in layers. For example, polymer composites are made of layers of fiber, like carbon fibers or Kevlar, and a polymer matrix. This layered structure is the source of the composites’ weakness. Any damage to the layers causes fractures, a process technically known as delamination.
To increase strength and give carbon-fiber composites other desirable qualities, such as electrical and thermal conductivity, carbon nanotubes are often added. However, the chemical processes used for incorporating the carbon nanotubes into these composites often cause the nanoparticles to clump up, reducing the overall benefit of adding these particles.