Porous MXene-polymer composites have gained attention due to their lightweight properties, large surface area, and high electrical conductivity, which can be used in applications such as electromagnetic interference (EMI) shielding, sensing, energy storage, and catalysis. Polymerization from templated high internal phase emulsions (HIPEs) can produce porous structure with controllable pore sizes, and when solid particles are used as the interfacial agent, composites with pores lined with the particles can be realized. Here, we report a simple method to prepare conductive porous MXene/polyacrylamide structures via polymerization of the continuous phase in oil/water HIPEs. Ti₃C₂T_x nanosheets are used as particle surfactants to stabilize HIPEs, without the use of a co-surfactant. By polymerizing the continuous phase of HIPEs and then removing the inner phase, the polyHIPE structure are formed, consisting of porous polymer struts and pores lined with Ti₃C₂T_x nanosheets, as confirmed by scanning electron microscopy, energy dispersive X-ray spectroscopy, and X-ray photoelectron spectroscopy. The pore size can be tuned by varying the Ti₃C₂T_x concentration, and the interconnected Ti₃C₂T_x network allows for electrical percolation at low Ti₃C₂T_x loading; further, the electrical conductivity is stable for months indicating that in these composites, the nanosheets are stable to oxidation at ambient conditions. The Ti₃C₂T_x polyHIPEs also exhibit rapid heating in response to radio frequency fields, even at low power (10 °C/s at 1W). This work demonstrates a simple approach to accessing electrically conductive porous MXene/polymer composites with tunable pore morphology and good oxidation stability of the nanosheets.

Kai-Wei Liu

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