Adsorbability of Single-Wall Carbon Nanotubes onto Agarose Gels Affects the Quality of the Metal/Semiconductor Separation
Adsorbability of Single-Wall Carbon Nanotubes onto Agarose Gels Affects the Quality of the Metal/Semiconductor Separation
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DOI：
10.1021/jp207786g
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发表时间：
2011-11-10
影响因子：
3.7
通讯作者：
Kataura, Hiromichi
中科院分区：
文献类型：
--
作者：
Hirano, Atsushi;Tanaka, Takeshi;Kataura, Hiromichi
尽管使用琼脂糖凝胶柱分离单壁碳纳米管（SWCNT）的金属/半导体已成功开发，但对分离机制知之甚少。在这项研究中，我们研究了琼脂糖浓度依赖性的分离使用该柱。从琼脂糖凝胶中获得的单壁碳纳米管的量随着琼脂糖浓度的增加而减少，表明在较高浓度下，较少量的单壁碳纳米管被吸附到琼脂糖凝胶上。为了阐明单壁碳纳米管的吸附能力和琼脂糖浓度之间的关系，各种浓度的单壁碳纳米管吸附到2，4，和6%的琼脂糖凝胶在准平衡状态。结果表明，未吸附的单壁碳纳米管的浓度随着琼脂糖浓度的增加而增加。通过假设吸附遵循Langmuir等温线，发现用于吸附的有效凝胶体积与琼脂糖浓度呈负相关;具体地，吸附能力与有效凝胶体积相关。最后，考虑了吸附能力对使用琼脂糖凝胶柱的分离的影响。随着单壁碳纳米管在琼脂糖上吸附能力的降低，吸附在柱顶部的单壁碳纳米管的量减少，单壁碳纳米管沿柱的分布沿着变宽。因此，分离质量的琼脂糖浓度依赖性归因于SWCNT在琼脂糖凝胶上的吸附性。
Although the metal/semiconductor separation of single-wall carbon nanotubes (SWCNTs) using an agarose gel column has been successfully developed, little is known about the mechanism of the separation. In this study, we examined the agarose concentration dependence of the separation using this column. The amount of SWCNTs obtained from the eluate decreased with increasing agarose concentration, indicating that a smaller amount of SWCNTs was adsorbed onto the agarose gels at higher concentrations. To clarify the relation between the adsorbability of SWCNTs and the agarose concentration, various concentrations of SWCNTs were adsorbed onto 2, 4, and 6% agarose gels in a quasi equilibrium state. The results showed that the concentration of the unadsorbed SWCNTs increased with increasing agarose concentration. By assuming that the adsorption follows the Langmuir isotherm, it was found that the effective gel volume for the adsorption was negatively correlated with the agarose concentration; specifically, the adsorbability was associated with the effective gel volume Finally, an effect of the adsorbability on the separation using the agarose gel columns was considered. With decreasing adsorbability of SWCNTs onto agarose, the amount of SWCNTs adsorbed onto the top of the column decreased and the distribution of the SWNCNTs became broadened along the column. Thus, the agarose concentration dependence of the separation quality is attributable to the adsorbability of SWCNTs onto the agarose gels.