Rice University's high-density graphene nanoribbon film are fabricated in a multistep process. CREDIT: J.M. Tour/Rice University
Scientists at Rice University lab have modified graphene nanoribbon deicing film designed for radar domes to now suit applications on glass. This technology may help keep glass surfaces of automobile windshields, large buildings and other similar applications, free from ice formation, while remaining transparent to radio frequencies.
The Rice research group had last year developed overlapping films of graphene nanoribbons and polyurethane paint for military radar domes, which had to be kept free from ice formation. Ice would affect the performance of the radar. Metal oxide framework material, which not only consumes large amounts of energy, but is also very big, has been replaced by the nanoribbon films.
The study carried out by James Tour, a Rice chemist, along with his colleagues, has been reported in Applied Materials and Interfaces, an American Chemical Society journal.
Tour’s lab had earlier invented a process for splitting nanotubes to create graphene nanoribbons. These nanoribbons, which were used for making the material, could be sprayed, spin-coated and painted. They can conduct electricity and heat, whilst also being transparent. When exposed to extremely high radio signals, the graphene nanoribbon paint would break at the locations that were thickest. These locations would burn up due to the heat and also affect the film.
The researchers have developed new transparent films with consistent thickness between 50-200nm. When a voltage was applied, their ability to become hot was not affected. The newly developed films could be used for coating plastics, glass, antennas and radar domes, and also for deicing applications.
The research team had mixed polyurethane and nanoribbons in the earlier process. However, when graphene nanoribbons were applied to a surface they shaped themselves into an active network and hence, a polyurethane coating was then applied over the nanoribbons for protection.
During testing in a -20°C enviroment, the material was applied on glass slides and it was iced. Voltage was applied and it made the ice to melt within a very short time.
Long-range Wi-Fi signals cannot penetrate anything metallic, hence it may also benefit from nanoribbon films in the future.