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Speculated temperature has induced/reversed the oxidation of SDS-dispersed SWCNTs in water, in which the oxidation triggers the reorganization of SDS structure on SWCNTs to afford selective adsorption in gel chromatography. Molecular dynamics simulations are performed to elucidate how the oxidation affects the assembly of SDS structure on a SWCNT. We found the formation of higher-density SDS coatings over oxidized SWCNT than unoxidized SWCNT, which implies the temperature-dependent oxidation enables the metal/semiconductor (M/S) separation of SWCNTs.It is speculated temperature has induced/reversed the oxidation of SDS-dispersed SWCNTs in water, in which the oxidation triggers the reorganization of the SDS structure on SWCNTs to afford selective adsorption in gel chromatography. Molecular dynamics simulations are performed to elucidate how the oxidation affects the assembly of SDS structure on a SWCNT.

A comparative analysis of sorted semiconducting (sc‐) single‐walled carbon nanotubes (SWCNTs) films, metallic (m‐) SWCNTs films, pristine SWCNTs films, and graphene‐based simple two‐terminal sensors for the applications of ammonia gas sensing is presented. The comparison of the sensing response of different devices by separately measuring the SWCNTs film resistance and the contact resistance between SWCNTs and the electrodes reveals that the performance mainly relies on the modification of tube conductivity under exposure to gas. Moreover, the measurements show that the highest sensitivity of the devices is achieved by use of sc‐SWCNTs as the conducting channels. Sensor coated with surfactant‐free sc‐SWCNTs shows a sensitivity of 0.78% ppm at 5–100 ppm ammonia (NH3) concentrations that happened to be ≈28, ≈22, and ≈173 times more sensitive than pristine‐SWCNTs, m‐SWCNTs, and graphene‐based sensors, respectively, at 50 ppm and ≈4.5 times the previously reported sc‐SWCNTs‐based sensor at 5 ppm. Notably, all the experiments values are achieved at room temperature without any extra heating treatment for the recovery process. These results show that surfactant‐free sc‐SWCNTs provide a promising way of creating sensors with improved selectivity and sensitivity, which predicts the auspicious prospects in the development of future applications. The measurements of a simple two‐terminal sensors coated with four different materials (pristine SWCNTs, m‐SWCNTs, sc‐SWCNTs, graphene) show that excellent sensitivity under exposure to ammonia gas can be achieved by the use of surfactant‐free sorted sc‐SWCNTs as the conducting channels compared to the other materials.