Multifunctional starch/carbon nanotube composites with segregated structure: Electrical conductivity, electromagnetic interference shielding effectiveness, thermal conductivity, and electro‐thermal conversion

Abstract

Conductive polymer composites with segregated structure (s‐CPCs) are widely used in the electronics industry. Achieving selective distribution of the conductive fillers in the polymer matrix is an effective way to construct s‐CPCs. In this work, the starch was used as the matrix and the carbon nanotube (CNT) was used as the conductive fillers to fabricate multifunctional s‐CPCs, via simple mechanical mixing and compression molding. During the processing, the starch underwent partial gelatinization, which was conducive to the fusion of the starch granules and the selective distribution of the CNT. Scanning electron microscope and atomic force microscope images showed that the CNT was attached to the surface of the starch granules to form a segregated structure. The starch/CNT composites exhibited a significant percolation, with a percolation threshold of 0.24 vol%. When the CNT content was 3.05 vol%, the starch/CNT composites exhibited a high electromagnetic interference (EMI) shielding effectiveness of 33.12 dB, which was commercially applicable in EMI shielding devices. The starch/CNT composites also possess good thermal management properties and can be used as thermal conductors and electro‐thermal conversion devices. This work manifests the application prospect in the field of the electronics industry and broadens the application potential of starch.

Vertical Graphene on Graphene Composite Film for Heat Dissipation and Electromagnetic Shielding

“…According to the calculated results, the absorption efficiencies of the composite films all exceeded 99.9%, which clarified that the composite films can efficiently absorb the electromagnetic waves entering their interior. The skin depth, defined as the distance at which the incident electromagnetic wave intensity decays to 1/ e of the initial value, was determined for the composite film using equation : δ = 1 / π f μσ …”

Review of Polymer-Based Composites for Electromagnetic Shielding Application

“…Consequently, even at low filler content, the composite material exhibits strong electrical conductivity and EMI shielding capability [143][144][145]. Research by numerous investigators has demonstrated that the generation of a segregated structure is advantageous for reducing the percolation threshold of the composite, while synergistic filler interactions enhance the material's shielding ability and mechanical properties [39,40,[146][147][148][149]. The recent studies of segregated-structured electromagnetic shielding materials are summarized in Table 3.…”