Novel Water-Based Paints for Composite Materials Used in Electromagnetic Shielding Applications

Abstract

The development of materials offering electromagnetic interference (EMI) shielding is of significant consideration, since this can help in expanding the lifetime of devices, electromagnetic compatibility, as well as the protection of biological systems. Conductive paints used widely today in electromagnetic interference (EMI) shielding applications are often based on organic solvents that can create safety issues due to the subsequent environment problems. This paper concerned the development of eco-friendly conductive water-based paints for use in EMI-shielding applications. Graphene nanoplatelets, polyaniline emeraldine (PANI) doped with poly(styrene sulfonic acid) (PSS) or HCl or HBr and poly(3,4-ethylenedioxythiophene) poly(styrene sulfonic acid) (PEDOT:PSS) in various ratios were employed in a water base for developing the paints. The target was to develop homogeneous water-based paint-like fluid mixtures easily applied onto surfaces using a paint brush, leading in homogeneous, uniform, opaque layers, draying fast in air at room temperature, and having quite good electrical conductivity that can offer efficient EMI-shielding performance. The results of this parametric trial indicated the optimum compositions leading in paints with optimized properties that can result in uniform, homogeneous, and conductive layers up to a thickness of over 500 μm without deformation and cracking, offering attenuation of up to 60 dBs of incoming GHz electromagnetic radiation. In addition, the structural and morphological characteristics of these paints were studied in detail.

Carbon Allotropes-Based Paints and Their Composite Coatings for Electromagnetic Shielding Applications

“…The shielding performance of the developed materials was examined and presented in our previous study [ 13 ], in terms of shielding effectiveness, a parameter that depends on several factors related to both the material and the design used; this parameter can be expressed as: where P i is the incident and P t the transmitted wave, E i and E t are incident and transmitted electric fields, respectively.…”

“…In very recent and extensive reviews on this subject [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 ], many nanomaterial-based potential solutions have been developed and tested for specific electromagnetic-shielding applications. Among these, different forms of carbon, such as graphene, carbon nanotubes, carbon fiber, carbon aerogels, carbon black, activated carbon, and carbon nanoparticles, as well as their hybrid composites, have been widely advanced and considered for EMI shielding in the GHz range [ 4 , 5 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 ]. The electrical and dielectric properties, as well as the shielding effectiveness of various polymer/graphene nanoplatelets (GNP) polymer/carbon black (CB) nanocomposites, were investigated recently [ 5 , 7 , 8 , 9 , 10 , 11 , 12 , 13 ], but multiple component formulations that can result in hybrid composites based on carbon-allotrope conductive fillers are not so frequent.…”

“…Among these, different forms of carbon, such as graphene, carbon nanotubes, carbon fiber, carbon aerogels, carbon black, activated carbon, and carbon nanoparticles, as well as their hybrid composites, have been widely advanced and considered for EMI shielding in the GHz range [ 4 , 5 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 ]. The electrical and dielectric properties, as well as the shielding effectiveness of various polymer/graphene nanoplatelets (GNP) polymer/carbon black (CB) nanocomposites, were investigated recently [ 5 , 7 , 8 , 9 , 10 , 11 , 12 , 13 ], but multiple component formulations that can result in hybrid composites based on carbon-allotrope conductive fillers are not so frequent. Hybrid composites based on carbon-allotrope conductive fillers are very important for the current developments due to the new 5G technology that requires improved EM-shielding properties, particularly in the highest bands of frequencies needed for wireless applications.…”

“…Hybrid composites based on carbon-allotrope conductive fillers are very important for the current developments due to the new 5G technology that requires improved EM-shielding properties, particularly in the highest bands of frequencies needed for wireless applications. The combination of the microstructures of these carbon materials as building blocks of the shielding layers, as well as the inclusion of magnetic and dielectric materials in the shield, proved to be helpful for EMI-shielding effectiveness [ 2 , 13 ].…”

“…The present paper reports the most recent achievements in a larger research trial that is dedicated to the development of efficient and environmentally friendlier multicomponent paints for EMI-shielding purposes. Previously, we reported the successful fabrication of water-based formulations of EMI-shielding effective paints [ 13 ] for use on hydrophilic surfaces and the compositional optimization of the CB-based solid-state composites formulations for further integration in the EMI-shielding paints [ 18 ].…”