Home About Us Resources Products Services Contact Us COOH functionalized doublewall carbon nanotubes produced by CVD method, then functionalized via sulfuric/nitric acid reflux. Purity >95% Outside Diameter:4 ± 1nm Length 5-20 microns SSA 200 - 400 m2/g [back] D4L5-20-COOH-5g$1,650.00 updated: 03/29/2017