Researchers discovered a way to use centimeter-size graphene sheets as reinforcement in polymer composites with a nanolaminate architecture.
Graphene has been a research focus for the past few years due to its exceptional properties. Researchers across the globe are trying to use graphene materials at its full potential. But the use of graphene in the form of tiny flakes in polymer composites limits the full usage of its excellent properties. This requires high filler loadings for achieving satisfactory electrical and mechanical properties.
A team of researchers from the Foundation for Research and Technology – Hellas, led by Professor Costas Galiotis, have suggested using centimeter-size graphene sheets as reinforcement in polymer composites with a nanolaminate architecture. This approach overcomes the typical drawbacks of nanoparticle fillers due to its large lateral size, which ensures efficient stress transfer and uniform and controllable dispersion through the alternation of the polymer and graphene layers.
Large-size monolayer graphene was produced by chemical vapor deposition (CVD) technique. Then centimeter-scale CVD graphene/polymer nanolaminates were produced by a semi-automatic process that allows for the manipulation of ultra-thin film. The thin laminate material shows a very high electromagnetic interference (EMI) shielding effectiveness in the Terahertz range, reaching 60 dB for a small thickness of 33 μm.
Prof. Galiotis says that “in this paper, we have tried to exploit the excellent mechanical and electrical properties of monolayer graphene when used as a reinforcement of engineering polymers. So far, by the use of short graphene flakes, this was not possible, due to the small size of the inclusions. Recent developments in the production of continuous (large size) monolayer graphene membranes allowed us to fabricate nanolaminates that incorporated tens and even hundreds of graphene layers embedded into commercial polymers. This has led to graphene nanolaminates with stiffnesses approaching those of perfect graphene per volume fraction and effective EMI shielding performance. This work paves the way for the development of nanolaminates with exceptional properties for aerospace, automotive but also a number of electronic applications.”
The work appeared in the journal Nature Communications.