Enhanced Mechanical and Multifunctional Properties of GNPs/CNTs Hybridized PLA Nanocomposites by Implementing Dual-Processing of Pickering Emulsion-Melt Blending Methods

Polylactic acid (PLA) composites with multifunctional properties and minimal filler content are increasingly in demand across various industries. However, achieving a balance between high mechanical strength, electrical conductivity, thermal conductivity, and electromagnetic interference (EMI) shielding remains challenging. In this study, a dual-processing strategy combining Pickering emulsion templating and melt blending is presented to hybridize 1D carbon nanotubes (CNTs) and 2D graphene nanoplatelets (GNPs) within a PLA matrix. This approach successfully forms a stable dual-filler network, ensuring uniform dispersion of the fillers. The results show that this method significantly enhances the performance of the resulting PM-PG_xC_y composites (P: Pickering emulsion; M: melt blending; x and y: mass fractions of GNPs and CNTs, respectively). Specifically, the PM-PG_1.43C_1.43 composite exhibits remarkable improvements in mechanical strength (56.2 MPa), electrical conductivity (43.5 S m⁻¹), EMI shielding effectiveness (20.1 dB), and thermal conductivity (0.34 W m·K⁻¹), outperforming composites prepared using either method alone. These findings indicate that the dual-processing strategy effectively combines 1D and 2D fillers, facilitating superior interfacial interactions and enhancing the multifunctional properties of PLA-based composites. This study offers a new approach to achieving high-performance PLA composites with low filler content, offering significant potential for applications in electronics, packaging, and EMI shielding technologies.