PEDOT:PSS/MXene/PEG composites with remarkable thermal management performance and excellent HF-band & X-band electromagnetic interference shielding efficiency for electronic packaging

Recently, the miniaturization of microelectronics has proposed a more urgent demand for the multi-functionalization of packaging materials. Here, a PEDOT:PSS/MXene/PEG composite, which is prepared by vertical directional freezing and vacuum infiltrating, integrates the function of heat management & EMI shielding into single packaging material. The melting & cooling enthalpy (237.6 & 236.1 J g−1) and the phase transition temperature of composite are enhanced synchronously for the first time. The zigzag modification of polyethylene glycol (PEG) crystal is induced by poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS). The rest of crystal with (7/2) helix conformation packs preferentially along the (1 2 0) plane. The stability of the melting composite is enhanced. The PEG leakage is less than 0.66 %, and over 80 % dimension is maintained under the pressure of 1.88 kPa. The composite shows excellent photo-thermal (η = 94.9 %) and electro-thermal (tη = 7.86) conversion performances. The EMI shielding mechanism is reflection-dominated and the total EMI shielding effectiveness (SET) of composite is 29.8 dB at the framework content as low as 1.22 wt%, which is the relatively low filler content and the highest enthalpy efficiency among the reported composites with the equivalent SET. The HF-band shielding capability of composite is verified by the Tesla kit. The assembled heterogeneous asynchrony photo-thermal-electric conversion system identifies its potential application on photo-thermal converters and heat buff. The HF-band & X-band (Sub-6G) EM waves shielding and heat management in microelectronics can be achieved simultaneously by applying this composite.