Significant Reduction of Interfacial Thermal Resistance and Phonon Scattering in Graphene/Polyimide Thermally Conductive Composite Films for Thermal Management

Abstract

The developing flexible electronic equipment are greatly affected by the rapid accumulation of heat, which is urgent to be solved by thermally conductive polymer composite films. However, the interfacial thermal resistance (ITR) and the phonon scattering at the interfaces are the main bottlenecks limiting the rapid and efficient improvement of thermal conductivity coefficients (λ) of the polymer composite films. Moreover, few researches were focused on characterizing ITR and phonon scattering in thermally conductive polymer composite films. In this paper, graphene oxide (GO) was aminated (NH2-GO) and reduced (NH2-rGO), then NH2-rGO/polyimide (NH2-rGO/PI) thermally conductive composite films were fabricated. Raman spectroscopy was utilized to innovatively characterize phonon scattering and ITR at the interfaces in NH2-rGO/PI thermally conductive composite films, revealing the interfacial thermal conduction mechanism, proving that the amination optimized the interfaces between NH2-rGO and PI, reduced phonon scattering and ITR, and ultimately improved the interfacial thermal conduction. The in-plane λ (λ∥) and through-plane λ (λ⊥) of 15 wt% NH2-rGO/PI thermally conductive composite films at room temperature were, respectively, 7.13 W/mK and 0.74 W/mK, 8.2 times λ∥ (0.87 W/mK) and 3.5 times λ⊥ (0.21 W/mK) of pure PI film, also significantly higher than λ∥ (5.50 W/mK) and λ⊥ (0.62 W/mK) of 15 wt% rGO/PI thermally conductive composite films. Calculation based on the effective medium theory model proved that ITR was reduced via the amination of rGO. Infrared thermal imaging and finite element simulation showed that NH2-rGO/PI thermally conductive composite films obtained excellent heat dissipation and efficient thermal management capabilities on the light-emitting diodes bulbs, 5G high-power chips, and other electronic equipment, which are easy to generate heat severely.

Hierarchically Multifunctional Polyimide Composite Films with Strongly Enhanced Thermal Conductivity

“…The λ ∥ and EMI SE of the rGO/CNF composite films with 50 wt% rGO were 7.30 W (m K) −1 and 26.2 dB, respectively [ 20 ]. However, directly mixing the fillers and polymer has obvious disadvantages, which is difficult to form efficient fillers thermal conduction pathways and networks because the fillers are easily separated or coated by the polymer matrix [ 21 ]. Moreover, high interfacial thermal resistance between the fillers and polymer matrix results in low thermal conductivity for the prepared composites.…”

Breaking Through Bottlenecks for Thermally Conductive Polymer Composites: A Perspective for Intrinsic Thermal Conductivity, Interfacial Thermal Resistance and Theoretics

“…Calculation based on the improved Hashin-Shtrikman model [18] showed that the surface functionalization of BNNS could effectively reduce the inplane and through-plane ITR F-M values from 0.1644 and 0.1696 to 0.1590 and 0.1587, respectively. In addition, Gu et al [19] prepared thermally conductive aminated reduced graphene oxide (NH 2 -rGO)/PI composite films. When the amount of NH 2 -rGO was 15 wt%, the λ ⊥ and λ ∥ of thermally conductive NH 2 -rGO/PI composite films reached 0.74 and 7.13 W m −1 K −1 , respectively, higher than pure PI film (λ ⊥ = 0.21 W m −1 K −1 , λ ∥ = 0.87 W m −1 K −1 ) and thermally conductive pristine rGO/PI composite films (λ ⊥ = 0.62 W m −1 K −1 , λ ∥ = 5.50 W m −1 K −1 ).…”

“…In addition, Gu et al . [ 19 ] prepared thermally conductive aminated reduced graphene oxide (NH 2 -rGO)/PI composite films. When the amount of NH 2 -rGO was 15 wt%, the λ ⊥ and λ ∥ of thermally conductive NH 2 -rGO/PI composite films reached 0.74 and 7.13 W m −1 K −1 , respectively, higher than pure PI film ( λ ⊥ = 0.21 W m −1 K −1 , λ ∥ = 0.87 W m −1 K −1 ) and thermally conductive pristine rGO/PI composite films ( λ ⊥ = 0.62 W m −1 K −1 , λ ∥ = 5.50 W m −1 K −1 ).…”

Enhanced interfacial interactions of carbon fiber/epoxy resincomposites by regulatingPEG‐E51and graphene oxide complex sizing at the interface

“…On the other hand, GO, which can exhibit some functional properties 20–22 and improve the wettability of CF/EP to enhance the interfacial adhesion performance of the composite, is usually used to construct multiscale interfacial reinforced structure . 23–28 Zhang et al 15 used the sizing agent method to introduce GO at the interface region between CF and matrix.…”