Tailoring the internal structure of porous copper film via size-controlled copper nanosheets for electromagnetic interference shielding

We studied the effects that internal porous structures tailored using size-controlled copper nanosheets (Cu NSs) had on the electromagnetic interference (EMI) shielding performance of the resulting Cu NS films. Cu NSs were carefully synthesized as two-dimensional (2D) conductive fillers, and their size was controlled by adjusting the concentrations of the shape modifier (iodine), stabilizer (hexadecylamine) and reductant (glucose). Three kinds of Cu NSs had the size of 3.8 mu m (Max. 10.0 mu m), 8.9 mu m (Max. 28.0 mu m), and 12.2 mu m (Max. 33.7 mu m) and used as a conductive filler for shielding film by spray printing. The films had different surface coverages, film thicknesses, and EMI shielding effectiveness (SE) at a fixed loading weight of 0.6 mg/cm2. The smallest to largest Cu NSs exhibited EMI shielding performances of 6.3 dB, 43.6 dB, and 69.7 dB, respectively, so performance was directly proportional to size.

Automated summary

This study investigated the effects of internally tailored porous structures using size-controlled copper nanosheets on the electromagnetic interference (EMI) shielding performance. The results showed that the shielding performance increased as the size of the copper nanosheets increased.