Design of Laser Photothermal Conversion Membranes Based on Fluorinated Graphene

Laser photothermal-conversion membranes have great potential applications in many different fields, including laser ignition. However, the demand for real-time, high heat output calls for an extra heat-releasing pattern other than the traditional luminous energy-thermal, energy-conversion mechanism. Herein, it was found that fluorinated graphene (FG) was a promising candidate for laser photothermal conversion due to the extra chemical energy-thermal, energy-conversion process, which originated from a self-redox reaction under laser irradiation. Moreover, an easy sonochemical, exfoliation-filtration protocol was provided for the preparation of the fluorinated, graphene-based, free-standing membranes. In brief, FG flakes were arranged into flower-like patterns and formed freestanding, carpet-like membranes with layered structures with the filtration of FG suspension, which was obtained from exfoliating fluorographite in N-methylpyrrolidone. Furthermore, this contribution also revealed that modifying the FG membranes with polytetrafluoroethylene (PTFE) was helpful for improving the photothermal-conversion properties. With the construction of the FG/PTFE composited structure, higher heat output could be achieved when a laser pulse is applied to the composite membranes. This work revealed the great potential of fluorinated graphene in laser photothermal conversion, and provided an alternative route of introducing a chemical energy-thermal, energy-conversion process for achieving high heat output under laser irradiation.