Assembly of Carbon Nanotubes on Polymer Particles: Towards Rapid Shape Change by Near-Infrared Light

A study was conducted to propose a strategy to photothermally modulate shape change of sub-micrometer biodegradable particles in the near-infrared (IR) spectral range. Single-wall carbon nanotubes (SWCNTs) were coated onto a thermal-responsive polymer via a Pickering emulsion-based process as a proof-of-concept. Heat generated by SWCNTs under near-IR irradiation rapidly melted the elongated particles, switching the shape from prolate to spherical due to the minimization of the interfacial energy. A Pickering emulsion was formed between polycaprolactone (PCL) dissolved in dichloride methane and SWCNTs dispersed in water in which polycaprolactone solution was the dispersed phase and the SWCNT solution was the continuous phase. SWCNTs acted as the emulsifier to stabilize the oil droplets in water instead of traditional small molecular surfactants.