Electromagnetic interference shielding of thermally exfoliated graphene/polyurethane composite foams

Thermally exfoliated graphene (TEG)/polyurethane (PU) expanded composite samples were synthesized for application in electromagnetic interference shielding (EMIS) in the 8-12 GHz frequency range. The effect of TEG concentration on both the shielding efficiency (SE) and mechanical characteristics of the resultant composite foam was investigated in detail, with the goal of determining the optimal TEG concentration that delivers the best performance in terms of SE and mechanical properties. The TEG filler was characterized using x-ray diffraction (XRD), Raman spectroscopy, and scanning electron microscopy (SEM). Whereas the prepared composite foam samples were examined by Fourier Transform Infrared (FTIR), SEM, Thermogravimetric analysis (TGA) and mechanical testing. The experimental results revealed that the composite foam sample with 5 wt% TEG content exhibits the highest SE to be -25.6 dB (-430.3 dB cm(3) g(-1)). It was also found that the optimal loading of TEG is 3 wt%, resulting in a compromise between SE (-20.4 dB; -345.68 dB cm(3) g(-1)) and mechanical characteristics (compressive strength of 15.5 MPa and compressive modulus of 5.06 MPa). These findings highlight the potential applicability of the synthesized composite foam to a variety of EMIS applications.