| Autor: |
Yang DC; Mechanical and Aerospace Engineering, Rutgers University, Piscataway, New Jersey 08854, United States., Castellano RJ; Applications Development Center, Chasm Advanced Materials, Canton, Massachusetts 02021, United States., Silvy RP; Applications Development Center, Chasm Advanced Materials, Canton, Massachusetts 02021, United States., Lageshetty SK; Applications Development Center, Chasm Advanced Materials, Canton, Massachusetts 02021, United States., Praino RF; Applications Development Center, Chasm Advanced Materials, Canton, Massachusetts 02021, United States., Fornasiero F; Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, California 94550, United States., Shan JW; Mechanical and Aerospace Engineering, Rutgers University, Piscataway, New Jersey 08854, United States. |
| Abstrakt: |
Small-diameter carbon nanotubes (CNTs) have outstanding mass-transport properties, especially enhanced water flow. Here, we report on water transport through the first macroscopic membranes with vertically oriented, subnanometer (0.8 nm) CNT pores, made by a scalable, solution-based method with electric-field alignment of bulk-grown single-wall CNTs (SWCNTs). After plasma etching to open pores, vertically aligned CNTs served as the primary pathway for liquid-water transport. The CNT membranes showed fast pressure-driven water transport, with up to 10 5 -fold enhancement compared to no-slip Hagen-Poiseuille flow. Comparing 0.8 and 3 nm CNTs, we found that the hydrodynamic slip lengths increased with decreasing nanotube diameter, reaching 8.5 μm for the smaller-diameter CNTs. The results suggest that pressure-driven water transport in small-diameter CNTs is increasingly dominated by entrance resistance, thus becoming independent of nanotube length. Scalably fabricated membranes incorporating vertically aligned subnanometer CNT pores could have applications in water filtration, desalination, and energy harvesting. |
