INFLUENCE OF SURFACE FUNCTIONAL GROUPS ON MOLECULAR ADSORPTION BY SINGLE WALLED CARBON NANOTUBES (SWNTs)

Experimental A stainless steel ultra high vacuum (UHV) chamber, pumped by a turbo molecular pump backed by a mechanical pump, providing a base pressure of 5X10 torr after bake out, was used for temperature programmed desorption (TPD) experiments with a typical heating rate of 2.5 K/s. Samples could be cooled below 100 K via a liquid nitrogen dewar and heated up to 1300 K via resistive heating. A detailed description was provided previously [7]. Infrared studied were preformed in another high vacuum chamber with base pressure of 2X10 torr. Samples could be cooled to 90 K via a liquid nitrogen dewar and heated up to 1400 K via resistive heating. Molecules were purified and dosed into both chambers through a leak valve. Exposure was reported in Langmuir units (1L = 10 torr·s).