3D Graphene-Infused Polyimide with Enhanced Electrothermal Performance for Long-Term Flexible Space Applications

Abstract

Polyimides (PIs) have been praised for their high thermal stability, high modulus of elasticity and tensile strength, ease of fabrication, and moldability. They are currently the standard choice for both substrates for flexible electronics and space shielding, as they render high temperature and UV stability and toughness. However, their poor thermal conductivity and completely electrically insulating characteristics have caused other limitations, such as thermal management challenges for flexible high-power electronics and spacecraft electrostatic charging. In order to target these issues, a hybrid of PI with 3D-graphene (3D-C), 3D-C/PI, is developed here. This composite renders extraordinary enhancements of thermal conductivity (one order of magnitude) and electrical conductivity (10 orders of magnitude). It withstands and keeps a stable performance throughout various bending and thermal cycles, as well as the oxidative and aggressive environment of ground-based, simulated space environments. This makes this new hybrid film a suitable material for flexible space applications.

Advances in Polyimide‐Based Materials for Space Applications

“…The maximum conductivity achieved was 0.96 S cm −1 at a filler content of 5 vol%. This value is three times lower than the conductivity achieved using 3D‐C with similar and lower loading fractions . Therefore, the 3D‐C interconnected graphene structure presents several advantages over other conductive nanofillers such as CNTs, metallic nanoparticles, and graphene flakes.…”

“…3D‐C‐infused PI films were found to retain the excellent electrical and thermal conductivity of the 3D‐C. This material passed the space environment qualification tests; thus, it can be used as an ESD shielding protection with proven long‐term stability . The incorporation of 3D‐C in PI matrix improves the PIs' electrical and thermal conductivities by up to 10 orders of magnitude, to roughly 3.5 Ω □ −1 and 1.7 W m −1 K −1 , respectively.…”

“…In our recent studies, highly conductive 3D‐C/PI (i.e., 3D graphene with PI) composite films were developed . This composite demonstrated stable long‐term reliability in ground‐based simulated space environment tests.…”

“…The incorporation of 3D‐C in PI matrix improves the PIs' electrical and thermal conductivities by up to 10 orders of magnitude, to roughly 3.5 Ω □ −1 and 1.7 W m −1 K −1 , respectively. The thermal conductivity of PI with various fillers is shown in Table 1 in comparison to the thermal conductivity of 3D‐C/PI . The fillers include graphene, CNTs, and metal particles …”

Harnessing Three Dimensional Anatomy of Graphene Foam to Induce Superior Damping in Hierarchical Polyimide Nanostructures

“…Contrary to this, the interconnected structure of 3D GrF provides pathways for effective transfer of stress, electrons, and phonons. So far, there is only one report on graphene foam–polyimide composite by Loeblein and co‐workers . Highly impressive 1033% enhancement of thermal conductivity and ten orders of magnitude jump in electrical conductivity was observed due to 3D graphene filler.…”