Wong Gwendeline K S, Webster Richard D
Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University 21 Nanyang Link Singapore 637371 Singapore
NEWRI-ECMG, Nanyang Environment & Water Research Institute 1 Cleantech Loop, CleanTech One, #06-08 Singapore 637141 Singapore.
RSC Adv. 2021 Sep 7;11(48):29913-29919. doi: 10.1039/d1ra05585b. eCollection 2021 Sep 6.
Carbon nanotubes (CNTs) of varying sizes and CNTs functionalised with carboxylic acids were examined by thermal desorption gas chromatography mass spectrometry (TD-GCMS) to determine the degree of surface contamination of atmospheric volatile organic compounds (VOCs). The CNTs could be purged of physisorbed VOCs by heating to 380 °C under a stream of purified nitrogen gas. As soon as the cleaned CNTs were exposed to atmospheric air they spontaneously adsorbed trace VOCs. As well as passive adsorption of VOCs, active sampling was carried out by pumping atmospheric air through the CNTs and comparing the results with the standard multisorbent materials Carbopack X and Tenax that are used widely for VOC trapping and analysis. The CNTs were found to trap many VOCs at a comparable level to the standard sorbent materials. Therefore, to maintain the CNTs in a pristine condition, it is recommended that they are first heated under vacuum to remove residual physisorbed VOCs, and then stored under vacuum or in a purified inert gas atmosphere.
通过热脱附气相色谱-质谱联用仪（TD-GCMS）对不同尺寸的碳纳米管（CNT）以及用羧酸官能化的碳纳米管进行了检测，以确定大气挥发性有机化合物（VOC）的表面污染程度。通过在纯净氮气气流下加热至380°C，可去除碳纳米管上物理吸附的挥发性有机化合物。一旦清洁后的碳纳米管暴露于大气中，它们会自发吸附痕量挥发性有机化合物。除了挥发性有机化合物的被动吸附外，还通过将大气空气泵入碳纳米管进行主动采样，并将结果与广泛用于挥发性有机化合物捕集和分析的标准多吸附剂材料Carbopack X和Tenax进行比较。发现碳纳米管对许多挥发性有机化合物的捕集能力与标准吸附剂材料相当。因此，为了使碳纳米管保持原始状态，建议首先在真空中加热以去除残留的物理吸附挥发性有机化合物，然后在真空或纯净惰性气体气氛中储存。
