According to an embodiment, an apparatus for applying hydroxyapatite to a nonwoven fabric includes a tank, a shower head, an ultrasonic wave generator, and a drying section. The tank stores suspension containing hydroxyapatite. The shower head jets the suspension against the nonwoven fabric in the suspension in the tank. The ultrasonic wave generator emits ultrasonic waves against the nonwoven fabric. The drying section dries the nonwoven fabric in a wet state removed from the suspension in the tank.

Described herein is an antiviral face mask and methods of use thereof to inactivate a virus in contact with the face mask. The face mask may include a fibrous material with silicon nitride powder impregnated therein and a layer surrounding the fibrous material. In some embodiments, silicon nitride is present in the fibrous material at a concentration of about 1 wt. % to about 15 wt. %.

Described herein is an antiviral face mask and methods of use thereof to inactivate a virus in contact with the face mask. The face mask may include a fibrous material with silicon nitride powder impregnated therein and a layer surrounding the fibrous material. In some embodiments, silicon nitride is present in the fibrous material at a concentration of about 1 wt. % to about 15 wt. %.