Dataset Information

Hierarchically Multifunctional Polyimide Composite Films with Strongly Enhanced Thermal Conductivity.

ABSTRACT: The development of lightweight and integration for electronics requires flexible films with high thermal conductivity and electromagnetic interference (EMI) shielding to overcome heat accumulation and electromagnetic radiation pollution. Herein, the hierarchical design and assembly strategy was adopted to fabricate hierarchically multifunctional polyimide composite films, with graphene oxide/expanded graphite (GO/EG) as the top thermally conductive and EMI shielding layer, Fe₃O₄/polyimide (Fe₃O₄/PI) as the middle EMI shielding enhancement layer and electrospun PI fibers as the substrate layer for mechanical improvement. PI composite films with 61.0 wt% of GO/EG and 23.8 wt% of Fe₃O₄/PI exhibits high in-plane thermal conductivity coefficient (95.40 W (m K)^-1), excellent EMI shielding effectiveness (34.0 dB), good tensile strength (93.6 MPa) and fast electric-heating response (5 s). The test in the central processing unit verifies PI composite films present broad application prospects in electronics fields.

SUBMITTER: Guo Y

PROVIDER: S-EPMC8664909 | biostudies-literature | 2021 Dec

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Hierarchically Multifunctional Polyimide Composite Films with Strongly Enhanced Thermal Conductivity.

Guo Yongqiang Y Qiu Hua H Ruan Kunpeng K Zhang Yali Y Gu Junwei J

Nano-micro letters 20211210 1

The development of lightweight and integration for electronics requires flexible films with high thermal conductivity and electromagnetic interference (EMI) shielding to overcome heat accumulation and electromagnetic radiation pollution. Herein, the hierarchical design and assembly strategy was adopted to fabricate hierarchically multifunctional polyimide composite films, with graphene oxide/expanded graphite (GO/EG) as the top thermally conductive and EMI shielding layer, Fe<sub>3</sub>O<sub>4< ...[more]

PMID: 34890012

Similar Datasets

Project description:Thermoplastic polyimides have garnered significant interest in the electronic and electrical industries owing to their performance characteristics. However, their relatively low thermal conductivity coefficients pose a challenge. To address this issue, this study focused on the properties of nanocomposites comprising two thermoplastic semicrystalline polyimides R-BAPB and BPDA-P3, one amorphous polyimide ULTEMTM, and hexagonal nanoparticles. Polyimide R-BAPB was synthesized based on 1,3-bis-(3',4-dicarboxyphenoxy)benzene (dianhydride R) and 4,4'-bis-(4'-aminophenoxy)biphenyl (BAPB diamine); polyimide BPDA-P3 was synthesized based on 3,3',4,4'-biphenyltetracarboxylic dianhydride (BPDA) and diamine 1,4-bis[4-(4-aminophenoxy)phenoxy]benzene (P3); and amorphous polyimide ULTEMTM was commercially produced by Sabic Innovative Plastics. Using microsecond-scale all-atom molecular dynamics simulations, the effects of incorporating hexagonal nanoparticles with enhanced thermal conductivity, such as graphene, graphene oxide, and boron nitride, on the structural and thermophysical characteristics of these materials were examined. The formation of stacked aggregates was found for graphene and hexagonal boron nitride nanoparticles. It was observed that graphene oxide nanoparticles exhibited a dispersion in polyimide binders that was higher than those in graphene and hexagonal boron nitride nanoparticles, leading to reduced translational mobility of polymer chains. Consequently, the decrease in polyimide chain mobility correlated with an increase in the glass transition temperature of the nanocomposites. Aggregates of nanoparticles formed a pathway for phonon transport, resulting in improved thermal conductivity in polyimide nanocomposites. An increase in the thermal conductivity coefficient of polyimide nanocomposites was observed when the concentration of graphene, graphene oxide, and hexagonal boron nitride nanofillers increased. The enhancement in thermal conductivity was found to be strongest when graphene nanoparticles were added.

Project description:Polyimide (PI) composite films with enhanced mechanical properties were prepared by incorporating modified fumed silica (FS) particles while preserving their optical and thermal characteristics. The PI matrix was synthesized using a fluorinated diamine, a fluorinated dianhydride, and a rigid biphenyl dianhydride via chemical imidization. Commercially available FS particles, including unmodified FS particles (0-FS) and particles modified with dimethyl (2-FS), trimethyl (3-FS), octyl (8-FS), octamethylcyclotetrasiloxane (D4-FS), and polydimethylsiloxane (PDMS-FS) were used. Scanning electron microscope images and nitrogen adsorption-desorption isotherms revealed well-defined porous structures in the FS particles. The water contact angles on the composite films increased compared to those of the pristine PI films, indicating improved water resistance. The PI/0-FS films exhibited a typical trade-off relationship between tensile modulus and elongation at break, as observed in conventional composites. Owing to the poor compatibility and agglomeration of the PDMS-FS particles, the PI/PDMS-FS composite films exhibited poor mechanical performance and diminished optical characteristics. Although the longer-chained FS particles (8- and D4-FS) improved the tensile modulus of the PI film by up to 12%, a reduction of more than 20% in toughness was observed. The PI composite films containing the methylated FS particles (2- and 3-FS) outperformed 8- and D4-FS in terms of mechanical properties, with PI/3-FS films showing an over 10% increased tensile modulus (from 4.07 to 4.42 GPa) and 15% improved toughness (from 6.97 to 8.04 MJ/m3) at 7 wt. % silica loading. Except for the PI/PDMS-FS composites, all composite film samples exhibited more than 86% transmittance at 550 nm. Regarding thermal properties, the glass transition temperature (Tg) and thermal stability remained stable for most composite films. In addition, PI/3-FS films demonstrated enhanced dimensional stability with lower coefficients of thermal expansion (from 47.3 to 34.5 ppm/°C). Overall, this study highlights the potential of incorporating specific modified FS particles to tailor the mechanical, optical, and thermal properties of PI composite films.

Dataset Information

Hierarchically Multifunctional Polyimide Composite Films with Strongly Enhanced Thermal Conductivity.

Publications

Hierarchically Multifunctional Polyimide Composite Films with Strongly Enhanced Thermal Conductivity.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets