Author
S. Mahdi Hamidinejad
Bio: S. Mahdi Hamidinejad is an academic researcher from University of Toronto. The author has contributed to research in topics: Electromagnetic shielding & Composite number. The author has an hindex of 3, co-authored 3 publications receiving 366 citations.
Papers
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TL;DR: This study provides the groundwork for an effective way to design flexible, ultrathin conductive polymer composite film for application in miniaturized electronic devices.
Abstract: In this study, we fabricated conductive poly(vinylidene fluoride) (PVDF)/carbon composites simply by dispersing multiwalled carbon nanotubes (MWCNTs) and graphene nanoplatelets into a PVDF solution The electrical conductivity and the electromagnetic interference (EMI) shielding of the PVDF/carbon composites were increased by increasing the conductive carbon filler amounts Moreover, we also found that the EMI shielding properties of the PVDF/CNT/graphene composites were higher than those of PVDF/CNT and PVDF/graphene composites The mean EMI shielding values of PVDF/5 wt %-CNT, PVDF/10 wt %-graphene, and PVDF/CNT/graphene composite films with a thickness of 01 mm were 2241, 1870, and 2758 dB, respectively An analysis of the shielding mechanism showed that the main contribution to the EMI shielding came from the absorption mechanism, and that the EMI shielding could be tuned by controlling the films’ thickness The total shielding of the PVDF/CNT/graphene films increased from 2190 to 3646 dB as the
254 citations
TL;DR: In this paper, a polyvinylidene fluoride (PVDF)/carbon/Ni-chain composites were prepared by dispersing Ni chains, and either carbon nanotubes (CNTs) or graphene nanoplatelets (GNPs) into a PVDF solution.
167 citations
TL;DR: This technique provides a novel approach to the development of microscopically tailored structures for the production of lighter and more thermally conductive heat sinks for next generations of miniaturized electronic devices.
Abstract: As electronic devices become increasingly miniaturized, their thermal management becomes critical. Efficient heat dissipation guarantees their optimal performance and service life. Graphene nanoplatelets (GnPs) have excellent thermal properties that show promise for use in fabricating commercial polymer nanocomposites with high thermal conductivity. Herein, an industrially viable technique for manufacturing a new class of lightweight GnP-polymer nanocomposites with high thermal conductivity is presented. Using this method, GnP-high-density polyethylene (HDPE) nanocomposites with a microcellular structure are fabricated by melt mixing, which is followed by supercritical fluid (SCF) treatment and injection molding foaming, which adds an extra layer of design flexibility. Thus, the microstructure is tailored within the nanocomposites and this improves their thermal conductivity. Therefore, the SCF-treated HDPE 17.6 vol % GnP microcellular nanocomposites have a solid-phase thermal conductivity of 4.13 ± 0.12 W m-1 K-1. This value far exceeds that of their regular injection-molded counterparts (2.09 ± 0.03 W m-1 K-1) and those reported in the literature. This dramatic improvement results from in situ GnPs' exfoliation and dispersion, and from an elevated level of random orientation and interconnectivity. Thus, this technique provides a novel approach to the development of microscopically tailored structures for the production of lighter and more thermally conductive heat sinks for next generations of miniaturized electronic devices.
114 citations
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TL;DR: In this article, the authors used ICP and conductive fillers incorporated in conductive polymer-based composites (CPC) to facilitate the research in electromagnetic interference (EMI) s...
Abstract: Intrinsically conducting polymers (ICP) and conductive fillers incorporated conductive polymer-based composites (CPC) greatly facilitate the research in electromagnetic interference (EMI) s...
457 citations
TL;DR: In this paper, a multilayered polyvinyl alcohol/transition metal carbide (PVA/MXene) film with alternating multilayer structure was fabricated through multi-layered casting and the continuous MXene layer provided a compact network for conducting heat and electron.
376 citations
TL;DR: In this paper, spin spray layer-by-layer (SSLbL) is used to rapidly assemble Ti3C2Tx MXene-carbon nanotube (CNT) composite films and their potential for EMI shielding is demonstrated.
Abstract: Lightweight, flexible, and electrically conductive thin films with high electromagnetic interference (EMI) shielding effectiveness are highly desirable for next-generation portable and wearable electronic devices. Here, spin spray layer-by-layer (SSLbL) to rapidly assemble Ti3C2Tx MXene-carbon nanotube (CNT) composite films is shown and their potential for EMI shielding is demonstrated. The SSLbL technique allows strategic combinations of nanostructured materials and polymers providing a rich platform for developing hierarchical architectures with desirable cross-functionalities including controllable transparency, thickness, and conductivity, as well as high stability and flexibility. These semi-transparent LbL MXene-CNT composite films show high conductivities up to 130 S cm−1 and high specific shielding effectiveness up to 58 187 dB cm2 g−1, which is attributed to both the excellent electrical conductivity of the conductive fillers (i.e., MXene and CNT) and the enhanced absorption with the LbL architecture of the films. Remarkably, these values are among the highest reported values for flexible and semi-transparent composite thin films. This work could offer new solutions for next-generation EMI shielding challenges.
375 citations
TL;DR: The brightest and most cutting‐edge smart EM devices constructed by 3D nano–micro architectures are reported as highlights, and the device principles are deeply dissected.
Abstract: Smart devices, nowadays, are inspiring the infinite vitality and possibilities of intelligent life, such as self-power electromagnetic (EM) nanogenerator and microsensor, smart window, thermally-driven EM absorber, interstellar energy deliverer, and so on. Herein, the latest and most impressive works of 3D nano-micro architectures and their smart EM devices are highly focused on. The most key information, including assembly strategy and mechanism, EM response, and approach-structure-function relationship, is extracted and well-organized with profundity and easy-to-understand approach. The merit and demerit are revealed by comparison. What's more, the brightest and most cutting-edge smart EM devices constructed by 3D nano-micro architectures are reported as highlights, and the device principles are deeply dissected. Finally, a profound and top comment on the fast-growing field as well as challenges are proposed, and the future directions are predicted intelligently.
282 citations
TL;DR: In this article, covalently bonded polyaniline (PANI)/graphene aerogel (GA) was synthesized using hydrothermal and in-situ polymerization techniques.
Abstract: In this paper, covalently bonded polyaniline (PANI)/graphene aerogel (GA) was synthesized using hydrothermal and in-situ polymerization techniques. The chemical bonding between PANI and GA and the micromorphological features of the aerogel were investigated employing several characterization methods, which included Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), Brunauer-Emmett-Teller (BET) analysis, field emission scanning electron microscopy (FESEM), and transmission electron microscopy (TEM). Due to combination of appropriate impedance match, synergistic effects, and hierarchical nanostructures of PANI and GA, the hybrids exhibited obviously improved microwave absorption performances, compared to GA. The PANI/GA showed the strongest reflection loss (RL) of −42.3 dB at 11.2 GHz with a matching thickness of 3 mm, and the corresponding absorption bandwidth (RL
268 citations