Three-Dimensional Graphene Foam-Filled Elastomer Composites with High Thermal and Mechanical Properties

Abstract

To meet the increasing demands for effective heat management of electronic devices, a graphene-based polymeric composite is considered to be one of the candidate materials owing to the ultrahigh thermal conductivity (TC) of graphene. However, poor graphene dispersion, low quality of exfoliated graphene, and strong phonon scattering at the graphene/matrix interface restrict the heat dissipation ability of graphene-filled composites. Here, a facile and versatile approach to bond graphene foam (GF) with polydimethylsiloxane (PDMS) is proposed, and the corresponding composite with considerable improvement in TC and insulativity is fabricated. First, three-dimensional GF was coated with polydopamine (PDA) via π-π stack and functional groups from PDA reacted with 3-aminopropyltriethoxysilane (APTS). Then, the modified GF was compressed (c-GF) to enhance density and infiltrated with PDMS to get the c-GF/PDA/APTS/PDMS composite. As a result, these processes endow the composite with high TC of in-plane 28.77 W m K and out-of-plane 1.62 W m K at 11.62 wt % GF loading. Besides, the composite manifests obvious improvement in mechanical properties, thermal stability, and insulativity compared to neat PDMS and GF/PDMS composite. An attempt to use the composite for cooling a ceramic heater is found to be successful. Above results open a way for such composites to be applied for the heat management of electronic devices.

Surface Modification Design for Improving the Strength and Water Vapor Permeability of Waterborne Polymer/SiO2 Composites: Molecular Simulation and Experimental Analyses

“…A number of studies have shown that most properties of composite materials depend on the nanoparticles dispersion in polymer matrix and their interfacial interaction [13][14][15]. Therefore, there are numerous examples have been proposed for improving the dispersion of nanoparticles in polymer matrix thus improving the interfacial interactions by grafting or surface modified materials on the surface of nanoparticles for functionalization [16][17][18]. Meanwhile, effects of surface structure of nanomaterials on the properties of composites are still the focus of research [19][20][21].…”

Highly Conductive PDMS Composite Mechanically Enhanced with 3D-Graphene Network for High-Performance EMI Shielding Application

“…Lots of energy can be absorbed by GN when the strain occurred, leading to the improvement of Young's modulus and tensile strength [34]; (3) graphene tube has smaller elongation at break compared with PDMS. Once the fracture of GNs happened, the graphene tube propagated either along the interface, or into the PDMS matrix to cause final failure, resulting in the decrease of elongation at break of PDMS [37].…”

“…Lots of energy can be absorbed by GN when the strain occurred, leading to the improvement of Young's modulus and tensile strength [34]; (3) graphene tube has smaller elongation at break compared with PDMS. Once the fracture of GNs happened, the graphene tube propagated either along the interface, or into the PDMS matrix to cause final failure, resulting in the decrease of elongation at break of PDMS [37]. We have also conducted 100 stretching and release cycles to 100% tensile strain on the composite, and the composite shows a moderate decrease (<13%) in the stress required to deform it to this strain level at the 100th cycle (Figure 6b), indicating that the composite is intact for up to 100 stretching and release cycles.…”

“…The EMI SE is an evaluation criterion of material's ability to attenuate the power of electromagnetic waves during the electromagnetic waves transmitted through. The EMI SE of PDMS/GN composites and pristine PDMS in X-band (8-12 GHz) can be extracted from the measured the S-parameter of the composite according the following equation [32][33][34][35][36][37][38][39]:…”

Multifunctional 3D Hybrid Nanomaterials for Clean Energy Technologies

“…The mechanical properties of composites and their corresponding PDA/APTS modification were analyzed via tensile tests by Bai et al (Fang et al 2017). The typical stress-strain curves are shown in Fig.…”