Facile preparation of asymmetric Ni/PVC film with controlled structure: Application as a high‐performance EMI shielding material

Abstract

Controlling the spatial configuration of conductive fillers in thin composites by a facile strategy is critical to widely commercial use these materials for electromagnetic interference (EMI) shielding applications. In this work, a series of free-standing thin Ni/polyvinyl chloride (PVC) films with the same composition just systematically varied Ni particles dispersion states was prepared by solution casting method. The relationships between the structure and properties were also investigated. Ni particles motion was governed by evaporation and sedimentation during solvent evaporation with the presence of soluble PVC influencing the casting solution viscosity. The experimental results fit the 1D model. In dilute casting system, the effective concentration of Ni particles in the lower part of the film was significantly enhanced and a dense, closed packed conductive network was formed. This special distribution of Ni particles was found to play a key role in the corresponding properties. Compared to the uniform film, the film which was fabricated from the casting solution containing 0.03 g/mL PVC, exhibited much better electrical conductivity and EMI shielding performance. Furthermore, the detailed study shows that the obtained thin film exhibited excellent EMI SE values per unit film thickness of 200 dB/mm. Meanwhile, the resultant films possessed thermal conductivity of 0.32$0.59 W/(mÁK) depended on whether a Ni continuous network formation throughout the whole film in the temperature range of 30$608C. Our study results pave thus the way for scalable fabrication of substrate-free systems that have advantages in multifunctional complex devices.

Electromagnetic interference properties of carbon nanofiber–reinforced acrylonitrile–styrene–acrylate/natural graphite composites

“…The enhancement in SE is ascribed to the following factors. Carbon nanofibers not only have low electrical resistivity, but also have a high aspect ratio. These traits make carbon nanofibers connect with each other easily and form good conductive networks in the composites .…”

“…Electromagnetic irradiation, emitted by alternating‐current motors, televisions, computers, microwave ovens, cellular phones, and other electronic equipment, has been regarded as one of the main pollutants by the United Nations. It can leak out important information and disturb the normal operation of adjacent equipment; what's more, it can endanger human health . A serious incident was reported on the USS Forrestal in 1967 at Vietnam.…”

An Ingenious Strategy to Construct Helical Structure with Excellent Electromagnetic Shielding Performance

“…Great effort has been devoted to developing the high‐performance EMI shielding materials . High‐efficiency microwave attenuation ability and light weight are two key factors that drive practical applications of EMI shielding materials . Furthermore, strong absorption ability and thin thickness are also required intensively for a wide range of aerospace, military, and civil applications.…”

Tunable Electromagnetic Interference Shielding Ability in a One-Dimensional Bagasse Fiber/Polyaniline Heterostructure

“…EMI not only reduces the reliability and lifetime of electronic equipment but also adversely affects human health. Thus, proper EMI protection is a basic requirement to solve the above problems. − As lightweight, high EMI shielding properties, and easy processing are essential considerations, especially for military and aerospace applications, tremendous efforts are currently underway to develop suitable EMI shielding materials on an industrial scale. − Compared with traditional metal-based shields, intrinsically conductive polymers (ICPs) are a new alternative due to the low cost, lightweight, and versatility. − …”