Clancy A J, Melbourne J, Shaffer M S P
London Centre for Nanotechnology , Department of Chemistry , Imperial College London , South Kensington , SW7 2AZ , UK . Email:
J Mater Chem A Mater. 2015 Aug 28;3(32):16708-16715. doi: 10.1039/c5ta03561a. Epub 2015 Jul 23.
Reductive dissolution is a promising processing route for single walled carbon nanotubes (SWCNTs) that avoids the damage caused by ultrasonication and aggressive oxidation whilst simultaneously allowing access to a wealth of SWCNT functionalisation reactions. Here, reductive dissolution has been simplified to a single one-pot reaction through the use of sodium naphthalide in dimethylacetamide allowing direct synthesis of SWCNT Na solutions. Gram quantities of SWCNTs can be dissolved at concentrations over 2 mg mL. These reduced SWCNT solutions can easily be functionalised through the addition of alkyl halides; reducing steric bulk of the grafting moiety and increasing polarisability of the leaving group increases the extent of functionalisation. An optimised absolute sodium concentration of 25 mM is shown to be more important than carbon to metal ratio in determining the maximum degree of functionalisation. This novel dissolution system can be modified for use as a non-destructive purification route for raw SWCNT powder by adjusting the degree of charging to dissolve carbonaceous impurities, catalyst particles and defective material, before processing the remaining SWCNTs.
还原溶解是一种很有前景的单壁碳纳米管（SWCNT）处理方法，它避免了超声处理和剧烈氧化造成的损伤，同时还能进行大量的SWCNT功能化反应。在此，通过在二甲基乙酰胺中使用萘钠，将还原溶解简化为单一的一锅法反应，从而直接合成SWCNT钠溶液。数克的SWCNT可以以超过2 mg/mL的浓度溶解。通过添加卤代烃，这些还原的SWCNT溶液可以很容易地实现功能化；减小接枝部分的空间位阻并增加离去基团的极化率会提高功能化程度。结果表明，在确定最大功能化程度时，25 mM的优化绝对钠浓度比碳与金属的比例更为重要。通过调整电荷程度以溶解含碳杂质、催化剂颗粒和有缺陷的材料，这种新型溶解系统可以在处理剩余的SWCNT之前用作原始SWCNT粉末的无损纯化途径。
