High Density, Vertically-Aligned Carbon Nanotube Membranes
High Density, Vertically-Aligned Carbon Nanotube Membranes
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DOI：
10.1021/nl802816h
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发表时间：
2009-01-01
期刊：
影响因子：
10.8
通讯作者：
Noble, Richard D.
中科院分区：
文献类型：
--
作者：
Yu, Miao;Funke, Hans H.;Noble, Richard D.
提出了一种制备高密度垂直取向碳纳米管（VA CNT）膜的方法。碳纳米管阵列的制备通过化学气相沉积（CO），和阵列坍塌成致密的膜由于溶剂蒸发的毛细管力。收缩后CNT之间的平均间距近似于3 nm，这与CNT的孔径相当。因此，CNT之间的间隙孔未被密封，并且气体渗透通过CNT和间隙孔两者。金纳米粒子的纳滤和N-2吸附表明孔径约为3 nm。基于总膜面积的气体渗透率比文献中的VA-CNT膜高1-4个数量级，并且气体渗透率比文献值高4-7个数量级。气体渗透率约为努森扩散预测的450倍，理想的选择性类似于或高于努森选择性。这些膜将较大的分子（原甲酸三异丙酯（TIPO））与较小的分子（n-）分离。己烷），可能是由于优先吸附，这表明液体混合物的分离潜力。
A method is presented to prepare high-density, vertically aligned carbon nanotube (VA-CNT) membranes. The CNT arrays were prepared by chemical vapor deposition (CO), and the arrays were collapsed into dense membranes by capillary-forces due to solvent evaporation. The average space between the CNTs after shrinkage was similar to 3 nm, which is comparable to the pore size of the CNTs. Thus, the interstitial pores between CNTs were not sealed, and gas permeated through both CNTs and interstitial pores. Nanofiltration of gold nanoparticles and N-2 adsorption indicated the pore diameters were approximately 3 nm. Gas permeances, based on total membrane area, were 1-4 orders of magnitude higher than VA-CNT membranes in the literature, and gas permeabilities were 4-7 orders of magnitude higher than literature values. Gas permeances were approximately 450 times those predicted for Knudsen diffusion, and ideal selectivities were similar to or higher than Knudsen selectivities. These membranes separated a larger molecule (triisopropyl orthoformate (TIPO)) from a smaller molecule (n-. hexane) during pervaporation, possibly due to the preferential adsorption, which indicates separation potential for liquid mixtures.