Original Article

Investigation of reflection shielding for electromagnetic interference (EMI) in graphene/CuO–silicone rubber nanocomposites across the Ku frequency band

¹ Cummins College of Engineering for Women, Pune - 411052, MH, India
² Department of Technology, Savitribai Phule Pune University, Pune - 411007, MH, India
³ Nowrosjee Wadia College, Pune – 411001, MH, India
⁴ Jaihind College of Engineering, Kuran, Junnar, Pune – 410511, India

^* Corresponding author: This email address is being protected from spambots. You need JavaScript enabled to view it.

Received: 28 March 2026
Accepted: 8 July 2026

Abstract

In automotive, aerospace, electronics, and various industrial sectors, there is a growing demand for lightweight elastomeric nanocomposites with effective electromagnetic interference (EMI) protection. The key factors governing EMI shielding performance are the material's complex permittivity (both real and imaginary components), its dielectric loss tangent, and the contribution of reflection losses. In this work, we investigate silicone rubber reinforced with graphene and copper oxide (CuO) nanofillers to improve its dielectric response and electromagnetic interference EMI shielding effectiveness (SE), without compromising mechanical integrity. Nanocomposite samples were fabricated by two-roll milling followed by compression moulding, then curing with a hot-air oven at 180 °C. Excluding neat silicone rubber control, all specimens contained 1 weight% CuO and graphene loadings of 0, 1, 2, 4, or 8 wt%. The dielectric loss tangent and reflection-based shielding effectiveness were characterized across the Ku-band (12–18 GHz). The results demonstrate that the reflection component of shielding effectiveness increases with frequency within the Ku-band. The highest reflection shielding effectiveness values were −30.12 dB for the nsRGC6 specimen and −28.12 dB for nsRGC5 at 18 GHz. Furthermore, the nsRGC6, nsRGC5, and nsRGC4 nanocomposites exhibited effective reflection shielding performance over the 16–18 GHz frequency range, demonstrating their potential as lightweight EMI shielding materials for high-frequency applications.