Va Cnt Synthesis And Va Cnt Membrane Fabrication Procedures

VA CNT synthesis and VA CNT membrane fabrication procedures were followed from the protocols of our previous study [28]. VA CNT synthesis was based on the water vapor assisted chemical vapor deposition (CVD) process. VA CNTs were grown on a Fe (1.5 nm)/Al (15 nm)/Si wafer. After the coating, the Si wafer was cut into rectangular chips, with the dimension of 9 mm width and 9 mm length, and the chopped chips were inserted in a cylindrical electric furnace of a CVD machine. Carbon source was high-purity ethylene gas (99.99%) at a flow rate of 100 sccm (standard cubic centimeters per minute indicating cc/min at a standard temperature and pressure). Argon (99.999%) was used as the carrier gas at a flow rate of 300 sccm. Hydrogen gas (99.999%, 200 sccm) and water vapor (50 sccm) by argon purging were added to the gases stream. Reaction was performed at 750 Â °C for 40 min. The interstitial space between the synthesized VA CNTs was filled in a mold with CRP 7005B urethane monomer (TL, Yongin, Korea) and ethanol in a volume ratio of 3:7. Ethanol was used as the densification agent and inducer for urethane monomer filling the interstitial space between CNTs. After infiltration, CRP 7005B monomer was crosslinked in the interstitial space of CNTs at 40 Â °C for 12 h. After the crosslinking, the top and bottom of the CNT membrane were cut by a microtome to open the CNT’s caps, and the membrane edge was extended by additional crosslinking by different urethane monomers (UC-40 A, B, Cytec,