Single-Walled Carbon Nanotubes Used as Stationary Phase in GC

Abstract

Single-walled carbon nanotubes (SWNTs) have high surface area, high adsorption ability, and nanoscale interactions. In this study, capillary columns including SWNTs, ionic liquid (IL), and IL + SWNTs for GC were prepared. The separation results showed that SWNTs possessed a wide selectivity toward alkanes, alcohols, aromatic compounds, and ketones, and a SWNT capillary column was a very useful GC column for the separation of gas samples. Coating the IL stationary phase on the SWNT capillary column, the SWNTs were able to improve chromatographic characteristic of ionic liquid. Comparing the IL coated on three graphite carbon black capillary columns, which were prepared by dynamic coating, static coating, and chemical bonding the Carbopack C with on SWNTs capillary column, the capacity factors were much higher on the SWNT column. The SEM showed that SWNTs could be bonded to the inner surface of capillary tubing, and most of them were linked end-to-end to form a layer of network structure of skeletons resulting in a high surface area, which increased the interactions between stationary phase and analytes. This is the first single-wall carbon nanotubes bonded to the fused-silica capillary tubing. In the first approach, SWNTs assist ionic liquid with enhanced chromatographic characteristic in GC. This work indicates that SWNTs make it possible to extend the application range on the newly prepared chromatographic stationary phases for GC.

Synthesis of novel functional liquid and its application as a modifier in SBR/silica composites

“…Ionic liquid (IL), a kind of fascinating molten salt with nearly zero vapor pressure and high thermal stability [5][6][7], has demonstrated high affinity toward various kinds of solid, such as carbon nanotubes [8][9][10][11][12][13][14], silica [15][16][17] and clays [18]. Various interactions, including cation-π interaction [8][9][10][11]19], van der Waal forces [13], delocalized electron interaction [14] and hydrogen bonding [16,18] have been well acknowledged and therefore subjected to a plenty of applications [14,[16][17][18][20][21][22][23][24][25][26]. Thanks to these interactions, ILs with specific structure can be employed as possible interfacial modifiers for various filled polymer composites.…”

Homochiral metal-organic framework [Zn2(d-Cam)2(4,4′-bpy)]nfor high-resolution gas chromatographic separations

“…The McReynolds constants [45][46][47] were usually used as the evaluation standard of stationary phase polarity. In this study, we chose benzene, 1-butanol, 2-pentanone, 1-nitropropane, and pyridine as the analytes for describing the polarity of [Zn 2 (D-Cam) 2 (4,4′-bpy)] n .…”

Carbon Nanotube Stationary Phase in a Microfabricated Column for High-Performance Gas Chromatography

“…Carbon nanotubes (CNTs) are attractive materials for the chromatographic stationary phase, and previous studies have demonstrated that CNTs have good separation ability due to chemical and thermal stability and a high surface-to-volume ratio [9][10][11][12]. These studies used a conventional steel, glass, or fused-silica column.…”

“…However, the previously reported use of CNTs as a GC stationary phase resulted in relatively low separation efficiency [5,[9][10][11][12]. Moreover, gas separation columns with a CNT stationary phase suffer from poor separation of high-boiling-point compounds [5,11,12].…”

“…Moreover, gas separation columns with a CNT stationary phase suffer from poor separation of high-boiling-point compounds [5,11,12]. These problems are attributed to the thickness of the CNT layer.…”