Adding graphene to low-emissive paint

The ability to camouflage an object in different wavelength regions is essential in order to avoid detection by sensors. As sensor technologies constantly develop, the need for efficient military camouflage techniques increases. Painting vehicles and aircrafts with low-emissive paint decreases the amount of emitted electromagnetic energy radiating in the infrared (IR) range from the surfaces, making the surfaces appear cooler and thus less detectable by IR sensors. However, paint may be rather soft and require protective coating when applied to surfaces, which are subject to weathering and rain erosion. A protective coating such as a clear coat might interfere with the IR properties of a low-emissive paint, making it less efficient. We have investigated the possibility to add graphene to the paint formulation in order to increase the mechanical durability. Low-emissive paints doped with either graphene or graphene oxide (GO) of lower quality (nano-graphite) and of higher quality were tested with regard to IR reflectance and mechanical durability. IR reflectance was measured by FTIR spectroscopy and the mechanical durability by sclerometer hardness and cross cut adhesion tests. Graphene and GO of lower quality appeared to increase the mechanical durability of the paint while increasing the IR emissivity. Graphene and GO of higher quality also appeared to increase the mechanical durability of the paint. While some of the samples of higher quality increased the IR emissivity, a few samples showed potential to decrease the emissivity.