Scalable synthesis of high-quality, reduced graphene oxide with a large C/O ratio and its dispersion in a chemically modified polyimide matrix for electromagnetic interference shielding applications

Mehmood, Zahid; Shah, Syed Aizaz Ali; Omer, Saeed; Idrees, Ramsha; Saeed, Shaukat

doi:10.1039/d4ra00329b

Cited by 4 publications

(1 citation statement)

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“…R. K. Biswas et al, have thermally converted polyimide to graphene by writing with a pulsed CO 2 laser on a copper substrate [ 26 ]. However, the composites of graphene and polyimide are not ideally dispersed, often requiring dispersants or modification of the graphene to improve its dispersion and binding in the polyimide matrix [ 27 , 28 ]. C. Lim and his colleagues prepared graphene/polyimide films via the electrostatic discharge method and found that the thermal conductivity of the graphene/polyimide films increased exponentially with an increasing graphene content; however, when the graphene content was more than 40 wt%, the graphene/polyimide films could not maintain their shape [ 29 ].…”

Section: Introductionmentioning

confidence: 99%

Changes in Current Transport and Regulation of the Microstructure of Graphene/Polyimide Films under Joule Heating Treatment

Yu,

Ding,

Chen

et al. 2024

Materials

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The excellent electrical properties of graphene have received widespread attention. However, the difficulty of electron transfer between layers still restricts the application of graphene composite materials to a large extent. Therefore, in this study, graphene/polyimide films were subjected to a Joule heating treatment to improve the electrical conductivity of the film by ~76.85%. After multiple Joule thermal cycle treatments, the conductivity of the graphene/polyimide film still gradually increased, but the increase in amplitude tended to slow down. Finally, after eight Joule heat treatments, the conductivity of the graphene/polyimide film was improved by ~93.94%. The Joule heating treatment caused the polyimide to undergo atomic rearrangement near the interface bonded to the graphene, forming a new crystalline phase favourable for electron transport with graphene as a template. Accordingly, a model of the bilayer capacitive microstructure of graphene/polyimide was proposed. The experiment suggests that the Joule heating treatment can effectively reduce the distance between graphene electrode plates in the bilayer capacitive micro-nanostructures of graphene/polyimide and greatly increases the number of charge carriers on the electrode plates. The TEM and WAXS characterisation results imply atomic structure changes at the graphene/polyimide bonding interface.

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Section: Introductionmentioning

confidence: 99%

Changes in Current Transport and Regulation of the Microstructure of Graphene/Polyimide Films under Joule Heating Treatment

Yu,

Ding,

Chen

et al. 2024

Materials

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Fabrication of Robust Forward Osmosis Membrane by Assembling FeO_xCl_y Nanoparticles

Roy,

Deka,

Gogoi

et al. 2024

Adv Funct Materials

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Owing to its inherent advantages like low‐energy consumption, low‐fouling propensity, and high recovering ability over high‐pressure‐driven membrane processes, the future of membrane technology is shifting toward forward osmosis (FO). However, the utility of FO in challenging areas is hindered by the lack of suitable FO membranes. Here, the development of innovative FO membranes by depositing weakly magnetic and positively charged FeOxCly nanoparticles on a negatively charged nylon membrane (FeOx‐Nyl) is reported. Remarkably, the FeOx‐Nyl membrane possesses outstanding stability in an aqueous medium and survived in both acidic (pH = 3.3) and basic (pH = 12.2) solutions. Upon varying the loading amount of FeOxCly, the water flux of the FeOx‐Nyl membrane varies from 27.8 to 61.3 LMH (from 5 to 30 mg). Due to its hydrophilic nature, the FeOx‐Nyl membrane exhibits excellent flux recovery rates (FRR), up to ≈70%. The outstanding robustness and high flux of FeOx‐Nyl are exploited in challenging applications like recovering reactive chemical wastes and dehydration of acetic acid.

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Guar gum assisted synthesis of high‐quality silver nanoplates and their polyimide matrix nanocomposites for electromagnetic interference shielding applications

Mehmood,

Shah,

Omer

et al. 2024

J of Applied Polymer Sci

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Two‐dimensional (2D) silver nanoplates are chemically synthesized in the presence of guar gum – a naturally occurring biopolymer. The polymer directs anisotropic growth of silver nuclei into high aspect ratio nanoplates spanning 4500 ± 500 nm lateral length with thickness as small as 40 ± 10 nm. After a thorough investigation of the reaction parameters (temperature, precursor to reductant ratio, and polymer quantity) on the morphology of the product, a scalable synthetic protocol to achieve good yields (95%–98%) of highly pure (~100%) 2D silver nanoplates (AgNPls) in a facile, inexpensive, room temperature, aqueous phase chemical reaction of only about 5 min is devised. The optimized AgNPls induce appreciable conductivity of 5.5 ± 0.38 S/cm in polyimide at only 12 wt% loading. Consequently, the resulting polymer nanocomposite (containing 12 wt% AgNPls), at only 130 ± 15 μm thickness and 0.45 g/cm3 density, effectively blocks electromagnetic radiation in X‐band with a total shield effectiveness of about 10 dB resulting in substantially high specific shielding effectiveness and absolute shielding effectiveness of 22.48 and 1729.23 dB cm3 g−1, respectively. Additionally, the nanocomposites remain thermally stable up to 500°C in oxidative environment and possess an appreciably high storage modulus of 3.113 GPa at 50°C. These low‐density conductive polyimide films, therefore, present great prospects in shielding against electromagnetic interference under extreme conditions.

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Scalable synthesis of high-quality, reduced graphene oxide with a large C/O ratio and its dispersion in a chemically modified polyimide matrix for electromagnetic interference shielding applications

Abstract: High-quality, conductive filler-grade RGO is synthesized and uniformly dispersed in a polyimide matrix to form a high-performance EMI shielding composite material for advanced applications.

Cited by 4 publications

References 54 publications

Changes in Current Transport and Regulation of the Microstructure of Graphene/Polyimide Films under Joule Heating Treatment

Changes in Current Transport and Regulation of the Microstructure of Graphene/Polyimide Films under Joule Heating Treatment

Fabrication of Robust Forward Osmosis Membrane by Assembling FeO_xCl_y Nanoparticles

Guar gum assisted synthesis of high‐quality silver nanoplates and their polyimide matrix nanocomposites for electromagnetic interference shielding applications

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Scalable synthesis of high-quality, reduced graphene oxide with a large C/O ratio and its dispersion in a chemically modified polyimide matrix for electromagnetic interference shielding applications

Abstract: High-quality, conductive filler-grade RGO is synthesized and uniformly dispersed in a polyimide matrix to form a high-performance EMI shielding composite material for advanced applications.

Cited by 4 publications

References 54 publications

Changes in Current Transport and Regulation of the Microstructure of Graphene/Polyimide Films under Joule Heating Treatment

Changes in Current Transport and Regulation of the Microstructure of Graphene/Polyimide Films under Joule Heating Treatment

Fabrication of Robust Forward Osmosis Membrane by Assembling FeOxCly Nanoparticles

Guar gum assisted synthesis of high‐quality silver nanoplates and their polyimide matrix nanocomposites for electromagnetic interference shielding applications

Contact Info

Product

Resources

About

Fabrication of Robust Forward Osmosis Membrane by Assembling FeO_xCl_y Nanoparticles