Cold plasma treatment on starch foam reinforced with wood fiber for its surface hydrophobicity

► Starch foam is reinforced with wood fiber for better properties. ► The foam samples are treated by cold plasma of CF4 and SF6 for hydrophobicity. ► The treatments create fluorine-rich layers on starch foam in nano-depth. ► Each plasma gas shows different dependence on the plasma parameters. ► Treated surfaces are hydrophobic leading to low water/moisture absorption.