Single‐Walled Carbon Nanotubes in Highly Viscous Media: A Comparison between the Dispersive Agents [BMIM][BF4], L121, and Triton X‐1001. Issue 2 (23rd October 2015) - Gasbarri, Carla
Abstract: Dispersions of single‐walled carbon nanotubes (SWNTs) have been prepared by using the room‐temperature ionic liquid [BMIM][BF4 ] (1‐butyl‐3‐methylimidazolium tetrafluoroborate), the triblock copolymer Pluronic L121 [poly(ethylene oxide)5 ‐poly(propylene oxide)68 ‐poly(ethylene oxide)5 ] and the non‐ionic surfactant Triton X‐100 (TX100) in the pure state. The size of the SWNTs aggregates and the dispersion degree in the three viscous systems depend on the sonication time, as highlighted by UV/Vis/NIR spectroscopy and optical microscopy analysis. A nonlinear increase in conductivity can be observed as a function of the SWNTs loading, as suggested by electrochemical impedance spectroscopy. The generation of a three‐dimensional network of SWNTs showing a viscoelastic gel‐like behavior above a critical percolation concentration has been found at 25 °C in all the investigated systems by oscillatory rheology measurements. Abstract : How to disperse nanotubes : Homogeneous and stable dispersions can be obtained from single‐walled nanotube (SWNT) powders at room temperature by using an ionic liquid ([BMIM][BF4 ]), a triblock copolymer (L121), and a non‐ionic surfactant (TX100) in the pure state, without the addition of any solvent. Rheological and electrochemical measurements suggest a similar viscoelastic gel‐like behavior above a critical concentration threshold for the three systems.