Drywall coated with biochar as electromagnetic interference shielding material

Biochar, a carbon based material derived from biomass, emerges as a sustainable, renewable, environmentally friendly and inexpensive material. Biochar is characterized by high carbon content and it can be used in composites instead of more expensive or less environmentally friendly carbon fillers. Transmission through a common building materials such as drywall coated with a biochar based paste is measured in the frequency band 1-12 GHz for normal incidence in a compact anechoic chamber.