12-08 – High Temperature-Resistant Ceramic-Carbon Nanotube Composite with Very High Laser-Damage Threshold

Thermal absorber coatings that can absorb as much energy as possible from high-powered lasers are essential for a variety of devices, including optical power detectors that measure the output energy of the lasers. Currently, such coatings struggle to meet industry needs for increased ability to resist high levels of laser irradiation. Additionally, current processes to make these products are often difficult, time-consuming, and require the use of corrosive chemicals. Researchers at Kansas State University have developed a spray-on mixture of polymer-derived carbon nanotubes and ceramic that has unprecedented ability to resist damage while absorbing laser light. The new material improves upon recent advances in which optical detectors have been coated with nanotubes (because of their unique ability to tolerate high levels of laser light). The new composition combines multiwall carbon nanotubes with a ceramic made of silicon, boron, carbon, and nitrogen. Upon exposure to a far-infrared laser beam at a wavelength of 10.6µm, the coating has been demonstrated to absorb 97.5 percent of laser light and tolerate 15 kilowatts of laser power per square centimeter for 10 seconds. This is roughly 10 and 100 times higher damage tolerance than found in similar coatings, such as nanotubes alone and carbon paint, respectively. The spray-on material absorbs light uniformly, transmits heat well, and adheres easily to copper surfaces. With the ability to carry out the production process at atmospheric pressure and without the use of corrosive chemicals, the coating can be produced easily and quickly in large qualities. Aarushi Gupta-Sheth aarushi@ksu.edu 785-532-3907