Cellulose-containing filtration materials and methods of making the same

A method comprising:

• preparing a slurry comprising cellulose nanofibers in a liquid;
• depositing the slurry onto a first surface of a woven cotton fabric having a thickness, resulting in a coating of the slurry on the first surface of the woven cotton fabric;
• and
• removing at least a portion of the liquid, resulting in the depositing of the cellulose nanofibers on the first surface, wherein:
• the cellulose nanofibers penetrate into at least a portion of the thickness of the woven cotton fabric.

A filter media comprising:

• a composite comprising:
• a woven cotton fabric having an outer surface and a thickness;
• and
• a plurality of cellulose nanofibers in physical contact with the outer surface, wherein:
• the cellulose nanofibers penetrate into at least a portion of the thickness of the woven cotton fabric,
• the cellulose nanofibers are present on the woven cotton fabric at a loading between 0.01 mg and 1 mg per square centimeter of woven cotton fabric,
• the woven cotton fabric comprises a plurality of hydroxyl groups bonded to the outer surface,
• the cellulose nanofibers are at least partially bonded to the woven cotton fabric by hydrogen bonding between the hydroxyl groups and the cellulose nanofibers,
• the composite has an average filtration efficiency of less than or equal to 90% for particles having a characteristic length between about 50 nm and about 100 μm, and
• the composite is characterized by an average inhalation resistance of less than or equal to 35 mm H2O as measured across the thickness and the material.