What are composite materials?

Composite materials (also referred to as composition materials, or simply composites) are materials formed by combining two or more materials with different properties to produce an end material with unique characteristics. These materials do not blend or dissolve together but remain distinct within the final composite structure. Composite materials can be made to be stronger, lighter or more durable than traditional materials due to properties they gain from combining their different components.

Most composites are made up of two materials - the matrix (or binder) surrounds a cluster of fibers or fragments of a stronger material (reinforcement). A common example of this structure is fiberglass, which was developed in the 1940’s to be the first modern composite and is still in widespread use. In fiberglass, fine fibers of glass, which are woven into a cloth of sorts, act as the reinforcement in a plastic or resin matrix.

composite crossection image

While composite materials are not a new concept (for example, mud bricks, made from dried mud embedded with straw pieces, have been around for thousands of years), recent technologies have brought many new and exciting composites to existence. By careful selection of matrix and reinforcement (as well as the best manufacturing process to bring them together) it is possible to create significantly superior materials, with tailored properties for specific needs. Typical composite materials include composite building materials like cement and concrete, different metal composites, plastic composites and ceramic composites.

How are composite materials made?

The three main factors that help mold the end composite material are the matrix, reinforcement and manufacturing process. As matrix, many composites use resins, which are thermosetting or thermosoftening plastics (hence the name ‘reinforced plastics’ often given to them). These are polymers that hold the reinforcement together and help determine the physical properties of the end composite.

layers inside a composite image

Thermosetting plastics begin as liquid but then harden with heat. They do not return to liquid state and so they are durable, even in extreme exposure to chemicals and wear. Thermosoftening plastics are hard at low temperatures and but soften with heat. They are less commonly used but possess interesting advantages like long shelf life of raw material and capacity for recycling. There are other matrix materials such as ceramics, carbon and metals that are used for specific purposes.

Reinforcement materials grow more varied with time and technology, but the most commonly used ones are still glass fibers. Advanced composites tend to favor carbon fibers as reinforcement, which are much stronger than glass fibers, but are also more expensive. Carbon fiber composites are strong and light, and are used in aircraft structures and sports gear (golf clubs and various rackets). They are also increasingly used to replace metals that replace human bones. Some polymers make good reinforcement materials, and help make composites that are strong and light.

The manufacturing process usually involves a mould, in which the reinforcement is first placed and then the semi-liquid matrix is sprayed or poured in to form the object. Moulding processes are traditionally done by hand, though machine processing is becoming more common. One of the new methods is called ‘pultrusion’ and is ideal for making products that are straight and have a constant cross section, like different kinds of beams. Products that of thin or complex shape (like curved panels) are built up by applying sheets of woven fiber reinforcement, saturated with matrix material, over a mould. Advanced composites (like those which are used in aircraft) are usually made from a honeycomb of plastic held between two sheets of carbon-fiber reinforced composite material, which results in high strength, low weight and bending stiffness.

Where can composites be found?

Composite materials have many obvious advantages, as they can be made to be lightweight, strong, corrosion and heat resistant, flexible, transparent and more according to specific needs. Composites are already used in many industries, like boats, aerospace, sports equipment (golf shafts, tennis rackets, surfboards, hockey sticks and more), Automotive components, wind turbine blades, body armour, building materials, bridges, medical utilities and others. Composite materials’ merits and potential assures ample research in the field which is hoped to bring future developments and implementations in additional markets.

Modern aviation is a specific example of an industry with complex needs and requirements, which benefits greatly from composite materials’ advantages. This industry raises demands of light and strong materials, that are also durable to heat and corrosion. It is no surprise, then, that many aircraft have wing and tail sections, as well as propellers and rotor blades made of composites, along with much of the internal structure.

What is graphene?

Graphene is a two-dimensional matrix of carbon atoms, arranged in a honeycomb lattice. A single square-meter sheet of graphene would weigh just 0.0077 grams but could support up to four kilograms. That means it is thin and lightweight but also incredibly strong. It also has a large surface area, great heat and electricity conductivity and a variety of additional incredible traits. This is probably why scientists and researchers call it “a miracle material” and predict it will revolutionize just about every industry known to man.

Graphene and composite materials

As was stated before, graphene has a myriad of unprecedented attributes, any number of which could potentially be used to make extraordinary composites. The presence of graphene can enhance the conductivity and strength of bulk materials and help create composites with superior qualities. Graphene can also be added to metals, polymers and ceramics to create composites that are conductive and resistant to heat and pressure.

graphene and tin layered composite image

Graphene composites have many potential applications, with much research going on to create unique and innovative materials. The applications seem endless, as one graphene-polymer proves to be light, flexible and an excellent electrical conductor, while another dioxide-graphene composite was found to be of interesting photocatalytic efficiencies, with many other possible coupling of materials to someday make all kinds of composites. The potential of graphene composites includes medical implants, engineering materials for aerospace and renewables and much more.

Further reading

Latest Graphene Composite news

Zenyatta Ventures to collaborate with Western University in a graphene-enhanced plastics project

Nov 10, 2017

Zenyatta Ventures has announced the commencement of a collaborative research project with Dr. Takashi Kuboki at Western University to develop an advanced plastic (polymer composite) using Zenyatta graphene (or graphene-oxide) derived from Albany high-purity graphite deposit.

Zenyatta sees a potential for such enhanced polymer composite materials to be attractive to the automotive, aerospace and construction industries that seek lightweight materials with added strength, electrical and thermal properties. This new project may expand Zenyatta's business opportunities as a graphene nanomaterial supplier for the polymer composite markets.

Two projects demonstrate how metal-oxide coatings influence graphene

Nov 07, 2017

Two interesting projects focused on coating single-layer graphene with metal-oxide nanolayers were presented at the latest Thin Films and Coating Technologies for Science and Industry event in the UK. Researchers from Cranfield University, UK, together with collaborators from University of Cambridge and the Centre for Process Innovation (CPI), applied alumina to form a composite barrier layer, while a team from Imperial College London, UK, used the unique properties of strontium titanate to fabricate a tuneable capacitor.

The researchers of the first project explained that in theory, graphene should represent an ideal ultrathin barrier layer, as the pores between carbon atoms are smaller even than the radius of a helium atom. In practice, however, crystal boundaries and missing atoms allow vapor to permeate through the material, and the weak van der Waals bonds between planes mean that even stacks of multiple graphene layers can be penetrated. The solution reported by the team is to take a graphene monolayer formed by CVD, and to then use atomic layer deposition (ALD) to coat it with a 25–50 nm thick layer of alumina. Achieving conformal coatings on single-layer graphene is known to be difficult due to the material’s strong hydrophobicity.

Graphene Batteries Market Report

Versarien reports on potential collaborations to further Nanene development and gets set to raise £1.2 Million

Nov 05, 2017

Versarien LogoAdvanced material solutions company Versarien updated that it is currently in advanced negotiations with two of the world's "largest consumer groups" and expects to receive a first purchase order "imminently". The collaboration with these companies would involve research and development and testing of the company's Nanene few layer graphene nano-platelets in polymer structures.

Versarien also reported "record levels of interest in its graphene products" and also, said that it is set to raise £1.2 million before expenses by issuing new shares in the company. Proceeds will be used to purchase capital equipment and provide working capital to enable current graphene collaborations to continue.

Thomas Swan develops prototype of graphene-reinforced carbon fiber composite

Nov 05, 2017

Chemicals manufacturer Thomas Swan has announced an expansion of its range of formulated Elicarb Graphene materials with a prototype product focusing on the manufacture of a carbon fiber composite prototype.

Thomas Swan's graphene composite prototype image

Initial independent testing with unidirectional carbon fibers reportedly gave very encouraging results. Adding 1% wt Elicarb Materials Grade Graphene in the epoxy resin in the manufacturing of a carbon fiber laminate improved flexural strength and modulus. This gave the company motivation to move the development one step further and manufacture a commercially relevant carbon fiber prepreg (a woven cloth of carbon fibre pre-impregnated with resin). This prototype was prepared by working collaboratively with an established and experienced third party.

IIT and FADEL unveil graphene-enhanced shoes

Nov 02, 2017

Graphene Flagship partners Istituto Italiano di Tecnologia, Italy, in collaboration with FADEL, a leading Italian shoe company, have developed graphene-enhanced shoes. The new GET technology, patented by FADEL, reportedly gives the footwear better thermoregulation and freshness.

IIT and Fadel develop graphene-enhanced shoes image

In this innovative shoe, when flakes consisting of several graphene layers are added to polyurethane, (the material of which the soles of FADEL shoes are made), laboratory tests show an augmented heat dispersion, a greater resistivity to water and enhanced antibacterial properties. Combining these effects with a ventilation system developed for this particular type of shoe yielded a better user experience. This prototype shoe was presented at the International Footwear Exhibition in Milan.

Versarien - Think you know graphene? Think again!Versarien - Think you know graphene? Think again!