Carbon nanotube sheet for air or water purification

1. A filter for removing contaminants from a liquid or gaseous medium comprising a nonwoven sheet of entangled carbon nanotubes having a length of between 1-10 mm, wherein the entangled carbon nanotubes are further characterized as having two or more of the following characteristics: (i) a diameter of between about 2-20 nm, (ii) a density of between about 0.7-1.9 g/cm 3 , (iii) an aspect ratio of at least about 250,000, (iv) a strain to failure of between about 1.8-7%, and (v) a surface area from about 100-300 m 2 /g and wherein the nonwoven sheet further comprises an input configured for receiving energy from a power source.

2. A method of purifying a liquid or gaseous medium containing one or more contaminants by contacting the liquid or gaseous medium with filter of claim 1 , wherein the carbon nanotubes are present in the nonwoven sheet in an amount sufficient to reduce the concentration of at least one contaminant in the liquid or gaseous medium that comes into contact with the nonwoven sheet.

3. A cabin air filter comprising a housing having an inlet, an outlet, a cavity positioned between the inlet and outlet and a nonwoven sheet of entangled carbon nanotubes having a length of between 1-10 mm, wherein the entangled carbon nanotubes are further characterized as having two or more of the following characteristics: (i) a diameter of between about 2-20 nm, (ii) a density of between about 0.7-1.9 g/cm 3 , (iii) an aspect ratio of at least about 250,000, (iv) a strain to failure of between about 1.8-7%, and (v) a surface area from about 100-300 m 2 /g disposed within the cavity and wherein the nonwoven sheet further includes an input configured to receive electrical energy from a power source.

4. The cabin air filter of claim 3 , wherein the nonwoven sheet is disposed within the cavity in a pleated configuration.

5. The cabin air filter of claim 4 further comprising a particulate filter disposed within the cavity.