In order to improve the electromagnetic interference (EMI) shielding performance of poly(vinylidene fluoride) (PVDF), both carbon nanotubes (CNTs) and graphene nanoplatelets (GNPs) as functional fillers were chosen and employed in this work. The PVDF‐based composites were prepared through melt blending and the hybrid fillers exhibited fine interaction with PVDF matrix. CNTs and GNPs could act as heterogeneous nucleation agents for PVDF matrix, thus increased the crystallization peak temperature. The gradual formation of interconnected conductive network of hybrid fillers could improve the conductivity and rheological properties of PVDF effectively. Especially, in contrast to those of pure PVDF, about four orders of magnitude increment for their storage modulus and complex viscosity of PVDF/GNPs/CNTs composite as well as approximate 10 orders of magnitude improvement in their electrical conductivity were obtained. Adding 2 wt% CNTs in PVDF matrix could generate the conductive network and further GNPs addition was helpful to obtain higher EMI shielding effectiveness. The new PVDF samples would possess wide applications as electromagnetic shielding materials, on account of their simple processing, low‐cost and without use of organic solvent characteristics.

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In view of the exhaustion of nonrenewable oil-based resources and the concerns on the environmental issues triggered by nondegradable plastics, biobased and biodegradable polymers have aroused increasing interest in recent decades. In this paper, bionanocomposites composed of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) as a matrix and carbon nanotubes (CNTs) as nanofillers were fabricated via a facile, green, and efficient method. Interconnected CNT structures and CNT−CNT networks formed in PHBV/CNT nanocomposites were demonstrated by a scanning electron microscope and transmission electron microscope. Compared with those of neat PHBV, the crystallization temperature and crystallinity of PHBV/CNT nanocomposites increased remarkably; in addition, the storage modulus increased by 6 orders of magnitude. A low electrical percolation threshold of 0.66 wt % was achieved in the PHBV/CNT nanocomposite. Furthermore, the dielectric and electromagnetic interference (EMI) shielding properties of PHBV/CNT nanocomposites were significantly improved with the increase of CNT content. For a typical PHBV/CNT sample with a thickness of 3 mm, the EMI shielding effectiveness reached 43.5 dB. The environmentally friendly PHBV/CNT nanocomposites prepared in this study were not only endowed with multifunctionality by the inclusion of CNTs but also made full use of the biogenetic derivation and biodegradability of the matrix to replace petroleum-based plastics and alleviate environmental pollution.

Polymeric electromagnetic interference (EMI) shielding foaming materials are found and applied in many frontier fields such as aerospace, transportation, and portable electronics. In this paper, a foam based on a composite system of poly(vinylidene fluoride) (PVDF) filled with carbon nanotubes (CNTs) is prepared for EMI shielding properties by using a solid‐state supercritical CO2 foaming strategy. PVDF is chosen as the matrix because of its excellent chemical resistance, thermal stability, and flame retardancy. The inclusion of CNTs renders this composite system enhanced complex viscosity and storage modulus by about two orders of magnitude. The electrical conductivity and EMI specific shielding effectiveness of obtained foams can be adjusted and reached the optimum value of 0.024 S m−1 and 29.1 dB cm3 g−1, respectively, originating from the gradual development of interconnected CNTs and conductive CNTs network as well as the introduction of cell structure in PVDF matrix. Interestingly, the reorientation of CNTs caused by foaming process results in electrical conductivity percolation threshold of PVDF/CNTs foams markedly decreases, in comparison to their unfoamed samples. This study provides a facile, efficient, green, and economic route for the preparation of EMI shielding foams consisted of fluorinated polymers and carbonaceous fillers.