Graphene and Composites

Graphene and Composites The discovery of graphene in 2004 by Andrei Geim and Konstantin Novoselov from Manchester University brought them the Nobel Prize in Physics, and following this discovery, graphene began to be used in many fields as a promising material for new technologies. One of these fields is composites.

What is graphene?

Graphene refers to one of the honeycomb structures of carbon atoms. At the same time, graphene can also be defined as a single-atom-thick layer of carbon atoms arranged in a hexagonal lattice. Graphene, a carbon allotrope in the form of a plane of sp2-bonded atoms with a molecular bond length of 0.142 nanometres, is described as a miraculous material and is found in many products that are changing our lives.

Properties and Applications of Graphene

Graphene has superior electrical properties, but that is not its only property. Since it also has strong carbon bonds, graphene is one of the strongest known materials and at the same time it conducts heat very well, even better than diamond. Another superior property of graphene is that it can be easily stretched, and thus surfaces of materials in various forms can be easily coated with graphene. With all these properties, graphene is described as a revolutionary material in the world. Graphene, which also contributes to the development of new technological products, is found especially in important products used in the healthcare field. To mention some of the areas where it is used; graphene supports diabetes control, cancer treatment, and early diagnosis of cancer cells. Another application area in healthcare is the treatment of teeth and bones, and graphene can also be utilized in the treatment of genetic diseases. Research shows that in the future, graphene will continue to be used in many areas such as automotive, aviation sector, electrical-electronics sector, robot manufacturing, energy storage, telecommunications, biochemistry, medicine, and solar cells. Supercapacitors, one of the areas where graphene is particularly effective, are subjects that have been extensively researched in recent years. Supercapacitors, systems that can store energy in a manner similar to rechargeable batteries, utilize graphene. At the same time, graphene does not degrade in ionic liquids present in the human body, making it a material that could be preferred for bionic arm, eye and other organ technologies. Graphene is also used in electronic devices. For example, it serves as a battery in wearable electronic devices, and graphene is also used in solar cells. Graphene can also be used as a reinforcing material in composites and polymers.

Graphene-Reinforced Composites

Composites are formed by bringing together more than one material, and reinforcing materials are selected for composites according to desired properties. Graphene can be utilized in the development of composite materials with high strength. By reinforcing matrix materials such as polyester, aluminium, titanium, and magnesium with graphene, next-generation composites can be produced for the automotive, tramway, train, aircraft, space and aviation sectors that frequently utilize composites. In recent times, the use of nanoparticle composites is increasing. Nano graphene can also be used as a nanoparticle, and the most important property provided by the use of nano graphene as reinforcement is solving the static electricity problem. Static electricity can cause problems in many areas where composites are used. For example, static electricity generated in wind turbine blades can damage cables and generators. In epoxy flooring, static electricity tendency can also cause fires. By adding nano graphene, the static electricity problem can be solved. By adding nano graphene to polymers and polyester resins, anti-static composites and resins can be produced. Since graphene has very high thermal conductivity, adding graphene at a rate of 1% to polymers makes the polymers conductive.

Graphene-Reinforced Polyester Composites

Polyester is frequently used in composite manufacturing because it offers high mechanical properties. In studies conducted, graphene, graphite and graphene oxide reinforcement were added to produce polyester-matrix composite materials, and the properties of these materials were examined. As a result of the tests conducted, improvements were observed in mechanical properties such as hardness, tensile strength, and impact strength of graphene-reinforced polyester composites. In addition, as a result of studies conducted, it was observed that yield strength increased, thermal degradation temperatures increased in direct proportion to the amount of graphite, and thermal conductivity also increased in direct proportion to graphite. The polyester matrix formed a different chemical bond with graphene oxide and graphite, and through this chemical interaction, the overall composite performance was seen to improve. As a result of this study, it was observed that especially the thermal, electrical and mechanical properties of graphene impart high properties to polyester-matrix composites, and that high-property composites can be obtained by adding graphene to different polymer matrices in nanocomposite production. (2)

Graphene-Reinforced Aluminium Composites

Studies have been conducted on graphene reinforcement of aluminium composites, and the properties of this new material have been examined. Again, as a result of the studies conducted, it was determined that reinforcing the composite with graphene had a positive effect on the mechanical properties of the composite. However, this positive result was achieved when graphene reinforcement up to 0.5% was performed. When graphene reinforcement beyond this ratio was performed, graphene was seen to have a tendency to agglomerate, and mechanical properties were adversely affected. As long as the determined ratio is not exceeded, an increase in tensile strength of aluminium composites was observed, wear resistance increased, and the coefficient of friction decreased. At the same time, graphene together with ceramics is also used in the production of high wear-resistant composites within the aluminium matrix. (3) In conclusion, the discovery of this Nobel Prize-winning material is regarded by the composite sector as a positive development in the production of next-generation composites. In recent years, developments have been taking place in composite manufacturing with the influence of nanotechnology as well. It is anticipated that the use of nano graphite as reinforcement in composite materials will increase in the coming years and more sectors will benefit from these developments. Sources (1) Graphene-based Composite Materials - Mohammad Ali Rafiee (2) Investigation of Mechanical and Thermal Properties of Polyester/Graphene Composites - Azime SUBAŞI, Merve ZURNACI, Aliye KAHYAOĞLU, Elif DEMİR (3) Next-Generation Graphene-Reinforced Aluminium Matrix Composites – Mahmut Can Şenel, Mevlüt Gürbüz, Erdem Koç https://nanokar.com/blog/makale/Grafen-Takviyeli-Kompozitve-Polimer-Malzemeler-160.html https://tr.wikipedia.org/wiki/Grafen Compiled by: Nilsu Kotil