Single‐Walled Carbon Nanotubes in Highly Viscous Media: A Comparison between the Dispersive Agents [BMIM][BF4], L121, and Triton X‐100

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.     

Gold Nanoparticles Grown on Ionic Liquid‐Functionalized Single‐Walled Carbon Nanotubes: New Materials for Photothermal Therapy

Gold nanoparticles were grown on single‐walled carbon nanotubes (SWNTs) coated with a thiol‐functionalized ionic liquid resulting in the formation of core‐shell structures referred to as SWNT‐IL‐Au nanohybrid materials. The nanohybrid materials were characterized by high‐resolution transmission electron microscopy (HR‐TEM), Raman‐, and UV/Vis absorption spectroscopy. The nanohybrid materials were found to enter lysosomes in HeLa cells and show negligible cytotoxicity. Interestingly, they have an enhanced NIR absorption that is effectively transferred into heat to cause localized hyperthermia, resulting in rapid cell death; overall, the material appears to have excellent properties for photothermal therapeutic applications.