Tag: automotive industry

Innovation in the production of composite materials: the use of graphene in pultrusion

Posted on | by Energeia Graphenemex

Innovation in the production of composite materials:

the use of graphene in pultrusion

Fiber-reinforced polymeric composites are widely used in the aerospace, automotive, naval, and wind power generation sectors due to their lightweight properties and high mechanical strength. These materials are a booming alternative to replace other materials such as metals.

At present there are different methods for the manufacture of fiber-reinforced composites, among which the pultrusion method stands out. A highly efficient and automated method that allows control of process parameters (greater precision and accuracy), reducing variability in the production of parts.

Pultrusion is a production process for reinforced materials where two components can be distinguished, the matrix or continuous phase and the reinforcement or discontinuous phase. The matrix acts as a bonding agent, in which the reinforcement is embedded. The function of the matrix is to transfer the load to the fibers, keep the fibers in their position, prevent the propagation of cracks, provide physical and chemical properties of the composite and also define the temperature range that the composite material can withstand. The matrix is thermosetting or thermosetting (unsaturated polyester, epoxy resins or vinyl-ester resins). On the other hand, the reinforcement has the purpose of adding some property that the matrix does not have, such as increasing mechanical resistance, rigidity, resistance to abrasion or improving its performance when exposed to high temperatures. The reinforcement efficiency is greater, the smaller the size of the particles or the diameter of the fiber and the more homogeneously they are distributed in the matrix. The most used fibers are glass, carbon and aramid due to their high tensile strength.

The pultrusion process (Figure 1) is continuous and is used to manufacture parts with a constant cross section, such as poles, rods, automotive moldings, etc. In the first feeding stage, the reinforcing fibers go through a perforated plate for alignment, then they go through a pre-molding where a fabric is added to reinforce the fiber. Later, in the second stage, the fibers are impregnated with liquid resin and go to a pre-forming stage where the fibers are oriented before entering the mold. In the third stage (molding), the cross section of the part is shaped, and the resin is hardened by applying heat. During the application of heat in the mold, there are three phases: pre-heating of the matrix and reinforcement, activation of the polymerization catalyst and curing of the material. The profile then exits the mold as a thermoset material and passes into a continuous traction mechanism that pulls the material at a constant speed (fourth stage)). Finally, in the fifth stage, a disk saw cuts the profile to the desired length. The profile of the reinforced composite obtained is a completely rigid material, which does not soften and is insoluble with the ability to withstand high temperatures.

Figure 1. General scheme of the pultrusion process: (1) Feeding, (2) Impregnation, (3) Molding, (4) Traction device and (5) Saw (Cutting).

Currently, the main applications of this process are focused on the manufacture of materials for construction, transport, and consumables, for example: vehicle construction, thermal insulation, cable ducts, covers and grids for water treatment plants, beam profiles, building facades, windows, bridges, stairs, among others.

However, there are still limitations in this technology, the low chemical interaction of the fiber with the matrix (resin) leads to a weak interface bond strength between both phases (low chemical adhesion), which makes the behavior of interlaminar shearing and performance of composite materials is not entirely satisfactory. In other words, if the matrix is brittle, spontaneous rupture can be generated. This behavior makes it possible to measure the resistance to interlaminar shearing. Depending on the type of break, the resistance of the matrix material or the quality of the fiber-matrix bond can be characterized.

In recent years, it has been reported that the introduction of functionalized graphene oxide (GO) on the surface of the fibers is an effective method to improve the interfacial properties of composite materials, since the large surface area of graphene oxide allows covering the surface of the fibers, increasing the strength of the chemical bond between the fiber and the matrix, thus improving the mechanical resistance of the reinforced composites. In addition, graphene oxide helps to improve the resistance to interlaminar fracture of the composite material, inhibiting the initiation and propagation of cracks.

The addition of graphene oxide to reinforced polymeric composites offers numerous advantages for the development of advanced materials in a wide variety of applications due to its large surface area, which has a strong impact on mechanical strength properties, greatly improving properties such as modulus, toughness, and fatigue. On the other hand, graphene oxide can provide compounds with greater resistance to fire. Its efficiency is associated with the fact that graphene oxide has a strong barrier effect, high thermal stability, and great surface absorption capacity, which are favorable for effectively reducing heat and mass transfer.

Currently, Energeia – Graphenemex®, a leading Mexican company in Latin America in the research and production of graphene materials for the development of applications at an industrial level, sells graphene and graphene oxide that can be incorporated or dispersed in any matrix (resin) during the pultrusion process and with them improve the mechanical properties of the profiles or products.

The incorporation of graphene materials (graphene, graphene oxide) in the pultrusion process, provide improvements in the characteristics of the final product, which include:

  • Greater tensile strength. Tensile strength can increase up to 30% compared to a standard profile without graphene.
  • Production of lighter weight profiles since graphene allows the weight of the product to be reduced without affecting its mechanical properties.
  • Profiles with higher modulus of elasticity.
  • Greater resistance to corrosion and fire-retardant properties.
  • Greater resistance to fractures or fissures.

References

  1. Yuxin He, Qiuyu Chen. Effect of multiscale reinforcement by fiber surface treatment with polyvinyl alcohol/graphene oxide/oxidized carbon nanotubes on the mechanical properties of reinforced hybrid fiber composites. Composites Science and Technology 204 (2021).108634.
  2. Jonas H. M. Stiller, Kristina Roder, David Lopitz. Combining Pultrusion with carbonization: Process Analysis and materials properties of CFRP. Ceramics 2023, 6. 330-341.
  3. Dittrich B, Wartig K-A, Hofmann D, Mu¨lhaupt R, Schartel B. Flame retardancy through carbon nanomaterials: carbon black, multiwall nanotubes, expanded graphite, multi-layer graphene and graphene in polypropylene. Polym Degrad Stab 98:1495.

Improve safety with flame retardant polymeric compounds with graphene oxide

Posted on | by Energeia Graphenemex

Improve safety with flame retardant polymeric compounds

with graphene oxide

Polymeric compounds (engineering plastics) are widely used in the automotive, construction, food, aerospace and other sectors. Its use is based on the weight/resistance ratio, physical stability, chemical resistance and corrosion resistance.

However, most polymers, due to their nature, are flammable and combustible. That is, they are materials that catch fire quickly when exposed to fire, undergoing degradation, Veo complicadoand releasing heat to later start the propagation of the flames. During the combustion of polymers, they release smoke (soot) and toxic gases that are a danger to the safety of human life and property.

Four key components are involved during the combustion of polymeric materials: heat, oxygen, fuel, and free radical reaction. Flame retardancy of polymeric composites can be achieved by inhibiting or perturbing one or more of these components.

In recent years, multiple investigations have been carried out to develop additives that help inhibit or reduce the flammability of polymers, these additives are known as flame retardants.

Conventional flame retardants can be classified into two main categories, based on their components: inorganic flame retardants and organic flame retardants. The first include hydroxide, metal oxide, phosphate, silicate among others. They have excellent thermal stability, are non-toxic, are low cost and do not produce pollution. However, inorganic flame retardants are limited by high loading, low compatibility, and aggregation. On the other hand, organic flame retardants include flame retardants containing halogens, phosphorous, phosphorous-nitrogen, etc. The latter have high efficiency and good compatibility with polymers. Their main disadvantage is that they are restricted because they can release toxic gases and be harmful during combustion, endangering the health of people and the environment.

Graphene oxide (GO) is currently the most novel nanomaterial for use as a flame retardant because it exhibits high efficiency as a retardant with low loads and is non-toxic. Its efficiency is associated with the fact that graphene oxide has a strong barrier effect, high thermal stability and great surface absorption capacity, which are favorable for reducing heat and mass transfer.

Graphene-based flame retardants can improve the flame resistance of polymers by inhibiting the two key terms: heat and fuel. More specifically, graphene oxide can function as a flame retardant in different synergistic ways.

  1. First of all, GO has a unique two-dimensional layer structure and can promote the formation of a continuous dense layer of carbon during the combustion process. Carbon can act as a physical barrier to prevent heat transfer from the heat source and delay the escape of products (pyrolysis) from the polymeric substrate.
  2. Second, GO has a large specific surface area and can effectively adsorb flammable volatile organic compounds or hinder their release and diffusion during combustion.
  3. Third, GO contains abundant reactive oxygen-containing groups (carboxyl group at the edges, as well as epoxy and hydroxyl groups at the basal planes in the sheets). For example, oxygen-containing groups can undergo decomposition and dehydration at low temperatures, thus absorbing heat and cooling the polymeric substrate during combustion. Meanwhile, the gases generated by dehydration can dilute the oxygen concentration around the ignition periphery, decreasing the risk of fire spread.
  4. It can also modify the rheological behavior of the polymer and prevent its dripping, thus hindering the release and diffusion of volatile decomposition products through the ”maze effect” and affecting the flame retardancy of compounds (for example, modifying the UL-94 classification, oxygen index (OI) and time to ignition (TTI).

In studies carried out, it has been found that the incorporation of functionalized graphene oxide (5% by weight) in Polypropylene (PP) increased the Young’s modulus and the elastic limit of PP by 53% and 11%, respectively. While in the results of the flammability test (UL-94), it indicates that the presence of GO produces a change in the behavior of the melt and prevents the material from dripping.

On the other hand, the preparation of polymeric compounds in melt blending (extrusion) of Polystyrene/GO have been reported, where it was found that GO (5%) can promote carbonization on the polymer surface (layer of carbonized material). and inside, the presence of a load or filler that presents high resistance to heat and contributes to the formation of carbon residues, improving the flame resistance of polystyrene-based compounds.

Currently Energeia – Graphenemex®, a leading Mexican company in Latin America in research and production of graphene materials for the development of applications at an industrial level, through its Graphenergy Masterbatch line, has developed a wide range of masterbatches with graphene oxide, based on various polymers, such as PP, HDPE, LDPE, PET and PA6.

The incorporation of graphene and graphene derivatives (GO) to polymeric matrices has allowed the development of polymeric compounds with better mechanical properties, greater thermal stability, gas barrier capacity and reduced flammability of polymeric compounds.

References

  1. Han Y, Wu Y, Shen M, Huang X, Zhu J, Zhang X. Preparation and properties of polystyrene nanocomposites with graphite oxide and graphene as flame retardants. J Mater Sci 48:4214.
  2. Hofmann D, Wartig K-A, Thomann R, Dittrich B, Schartel B, Mu¨lhaupt R. Functionalized graphene and carbon materials as additives for melt-extruded flame retardant polypropylene. Macromol Mater Eng 298:1322.
  3. Dittrich B, Wartig K-A, Hofmann D, Mu¨lhaupt R, Schartel B. Flame retardancy through carbon nanomaterials: carbon black, multiwall nanotubes, expanded graphite, multi-layer graphene and graphene in polypropylene. Polym Degrad Stab 98:1495.

Innovation in the plastics industry: how graphene masterbatches are changing the game

Posted on | by Energeia Graphenemex

Innovation in the plastics industry:

how graphene masterbatches are changing the game

Graphene has extraordinary electrical, optical, thermal properties and high mechanical resistance. The properties of graphene are attributed to its structure in the form of two-dimensional (2D) sheets, formed by hexagonal bonded carbon atoms and a thickness of one carbon atom.

Today, graphene is the most promising nanotechnological additive in the plastics industry. The incorporation of graphene and its derivatives (graphene oxide, GO) in different polymer matrices (masterbatches), have great potential for a wide range of applications. The graphene masterbatch can act as a mechanical reinforcement or conductive additive for both thermoplastic and thermosetting materials. They can be used in the automotive, aerospace, electronics or packaging sectors.

Graphene-based polymeric compounds have shown significant improvements in properties such as elastic modulus, tensile strength, impact resistance, electrical conductivity, resistance to UV radiation, thermal stability, antimicrobial property, impermeability or barrier effect (it does not allow the diffusion of moisture or other molecules).

Currently Energeia – Graphenemex®, a leading Mexican company in Latin America in research and production of graphene materials for the development of applications at an industrial level, through its Graphenergy Masterbatch line, has developed and sells a wide range of masterbatches with graphene, based on various polymers, such as PP, HDPE, LDPE, PET and PA6.

Our Masterbatches are granular materials that act as multifunctional additives. The incorporation of graphene in different polymer matrices has shown important effects on the properties and processing conditions of plastics, among which are:

  • Increased resistance to tension, deformation and impact
  • Increased resistance to ultraviolet rays
  • Excellent dispersion
  • Improves processing conditions (thermal stability)
  • Acts as a nucleating agent (modification of the crystallization temperature of the polymer)

In this sense, it has been found that the incorporation of graphene and its derivatives, as well as the concentration, can modify the physicomechanical properties of the polymer to be processed. The addition of masterbatch to different polymers has improved the final characteristics of the material to a lesser or greater extent, for example:

  • Additivation of Polypropylene (PP) with polypropylene-graphene masterbatch (MB-PP/GO), increases tensile strength (8%) and rupture percentage (29%).
  • Additivation of Polyethylene (PE) with polyethylene-graphene masterbatch (MB-PE/GO), improves tensile strength (17%), flexural strength and rupture strength (66%).
  • Additivation of Polyethylene terephthalate (PET) with polyethylene terephthalate-graphene masterbatch (MB-PET/GO), improves resistance to humidity, increases tensile strength (72.2%) and improves impact resistance.
  • Additivation of Polycarbonate (PC) with polycarbonate-graphene masterbatch (MB-PC/GO), improves resistance to humidity and improves resistance to rupture (276%).

On the other hand, graphene masterbatches can also be incorporated into recycled polymers. Currently, the reuse and recycling of plastic materials are of vital importance in the transition path towards a circular economy. In this regard, the constant washing, pelletizing and reprocessing can cause the loss of physicomechanical properties of recycled plastics, therefore, by adding graphene, these properties can be restored or improved. In agricultural applications, mulch films with increased resistance to ultraviolet radiation can be produced.

References

  1. Fang, M., et al., Covalent polymer functionalization of graphene nanosheets and mechanical properties of composites. Journal of Materials Chemistry. 19(38): p. 7098-7105.
  2. Kim, H., A.A. Abdala, and C.W. Macosko, Graphene/Polymer Nanocomposites. Macromolecules. 43(16): p. 6515-6530.
  3. Balandin, A.A., et al., Superior Thermal Conductivity of Sin gle-Layer Graphene. Nano Letters, 8(3): p. 902-907.
  4. Nabira Fatima, Umair Yaqub Qazi, Asim Mansha., Recent developments for antimicrobial applications of graphene-based polymeric composites: A review, https://doi.org/10.1016/j.jiec.2021.04.050

The graphene revolution in the automotive industry: innovation in vehicle care and protection

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The graphene revolution in the automotive industry:

innovation in vehicle care and protection

Just as continuous exposure to solar radiation is harmful to our skin, it also affects the appearance of cars, in particular it causes damage to paint, moldings, tires and other auto parts. In fact, the sun, acid rain and temperature changes are three of its main enemies, for that reason there are countless product options on the market for its care.

Graphene is the most interesting form in which Carbon can occur and consists of sheets of carbon atoms extracted mainly from Graphite or from some gases. The great scientific and technological relevance of this material is due to the particular organization of its atoms, which gives it surprising and numerous properties that have captured the attention of a large number of industries, including the automotive industry.

The potential uses attributed to Graphene for this industry are the manufacture of coatings for chassis and bodies, plastics for auto parts, either to improve their quality or to totally or partially replace metal parts, tires, textiles, greases, lubricants and products for car care.

Energeia- Graphenemex® dedicated to the research and production of graphene materials as well as the development of applications at an industrial level, in 2018 under the Nanocar® brand, placed on the market the first line of products with Graphene for automotive care.

Benefits:

Nanocar® products form a protective and nano-filling film for defects that allows the atomic sheets of Graphene to adhere to the surfaces of the bodywork, protecting against dust and moisture, delaying the effects of corrosion, as well as acting as a barrier against UV radiation and as a temperature dissipator to limit the long-term deterioration of the paint. In addition, the continuous use of Nanocar® products facilitates subsequent cleaning, without leaving a trace of drying, even when washing is carried out with hot surfaces.

Relationship of the properties of Graphene and its effects on Nanocar® products

Drafting: EF/DHS

Graphene and its impact on the packaging industry

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Graphene

and its impact on the packaging industry

According to data from the World Bank, every year in Mexico 24 million tons of food are wasted. This means that 34% of the country’s production is not only NOT consumed, but also generates an average expense of 491 billion pesos.

This impact is not only economic, but it is a problem that extends to the social sphere, due to the well-known food crisis and to the environment, due to the high water requirements for food production processes that will not be used and whose decomposition will contribute considerable CO2 emissions that contribute to global warming.

According to the Food and Agriculture Organization of the United Nations, the loss and food waste exceeds 1,300 million tons per year.

Within this multifactorial problem, the container and packaging industry, also known as “packing”, is a crucial actor considering that there are unavoidable conditions such as temperature, humidity, lighting, oxygen and numerous handling practices throughout the entire supply chain. production of food, which affect its quality, shelf life and acceptability by consumers.

In the search for solutions to improve the quality of packing products and, consequently, their content, nanotechnology has been a great ally. For example, to avoid microbial contamination, nanoparticles of silver, titanium dioxide, copper oxide, carbon nanotubes or magnesium oxide are used; to improve the mechanical or barrier properties, it is common to use nanoparticles of silicate, clay, polyamide, iron or iron oxides, cellulose nanofibers and for other needs there are nanoparticles of tungsten, molybdenum, barium sulfate, barium titanate , chitosan, zeolites, activated carbon, etc.

Graphene nanoparticles are mainly made up of carbon, like graphite and diamond, but with multifunctional characteristics. This means that they do not have a single function, but rather, unlike other nanoparticles, Graphene, due to its extraordinary physical and chemical properties, can be used for different purposes, for example, to design lighter and more resistant products, with greater impermeability against liquids and gases, in addition to protecting against microbial contamination and against UV radiation, among other properties that substantially improve the performance of the compounds with which it is combined.

“Graphene has crossed the limits of laboratories to reach commercial applications to combat the main enemies of food”, these are some examples of what is being developed for the Packing industry:

Tetra Pak
The Swedish company Tetra Pak, leader in research and development in the packaging sector, through the European Graphene Flagship project, studies the use of Graphene for the manufacture of products with low environmental impact to reduce the carbon footprint, improve the performance of materials, add properties and optimize recyclability.

Applynano
The Spanish company Applynano uses nanomaterials, including graphene oxide, to promote the durability and recyclability of plastics, as well as to improve antimicrobial, thermal, and electrical properties, among others.

Plastic Technology Center (Andaltec)
The Technological Center of Plastic (Andaltec) within the European project Grafood, had the initiative to use derivatives of Graphene for the development of active packaging to increase the shelf life of food and reduce food waste.

Energeia – Graphenemex®
The Mexican company Energeia – Graphenemex®, through the polymer division Graphenergy Advanced Graphenic Solutions, promotes the use of Graphene and its derivatives as nano-reinforcement of plastic for different industries. Among the benefits it offers for the packing industry are mechanical resistance and resistance to degradation by UV radiation, greater barrier effect and interesting antimicrobial properties, highly promising for prolonging the life of products and their contents. Likewise, in addition to adding value to its developments with the multifunctional properties of Graphene and its derivatives, the company also aims to support other innovation projects with graphene nanotechnology, while seeking to collaborate with the circular economy to improve the quality of new and recycled plastic materials, to reduce the consumption of single-use products.

Polymeric nanocomposites with graphene: the future of the industry

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Polymeric nanocomposites with graphene:

the future of the industry

Mexico City – Thanks to the extraordinary properties, innumerable investigations and business promises around Graphene in the world, in 2021 its market was valued at 127.12 million dollars, forecasting an annual growth rate of more than 70% in the period from 2022 to 2027. However, 18 years after its isolation and despite the enormous competition from companies to develop applications with this nanomaterial, there are still relatively few products available on the market that contain it and take advantage of its benefits. This is mainly due to the investment and complexity for the transformation of graphite into graphene or in any of its variants (graphene oxide and reduced graphene oxide), the difficulty of producing it on an industrial scale to have it available as the fundamental raw material in the transformation of new compounds, as well as the need for scientific-industrial knowledge for the creation of efficient and economically viable applications.

The Mexican company Energeia Fusion S.A. de C.V., has focused on solving the most representative obstacles that Graphene has faced to reach the market, working hard on the creation and standardization of its own methods and processes that today allow it to optimize resources for product development. quality in a short time.

Polymeric nanocomposites with graphene oxide

The polymer division of the Graphenergy Advanced Graphenic Solutions line is part of a new line of highly effective nanotechnological additives for the plastics industry that, in addition to the added value represented by the multifunctional properties that graphene provides to polymers (mechanical strength, impermeability, resistance to UV radiation and/or antimicrobial activity), it also adds value for the circular economy, since it allows the use, reuse and recycling of plastic products, reducing the exploitation of natural resources and reducing the generation of waste, resulting in significant social, economic and environmental impacts.

What is the science of Graphene for reinforcing materials?

  1. Las fuertes interacciones entre la región interfacial de la matriz polimérica y las partículas nanométricas del grafeno son decisivas para mejorar las propiedades de los materiales,
  2. La correcta integración del grafeno con los materiales poliméricos mejora la organización en su estructura, haciendola más densa y compacta y por lo tanto mejora las propiedades mecánicas.
  3. Mejora las propiedades de barrera contra líquidos y gases, aumenta el tiempo de vida útil del producto y permite tener diversas propiedades en un solo material, como: conductividad, resistencia a la radiación ultravioleta, impermeabilidad, flexibilidad, ligereza, actividad antimicrobiana, etc.

“Las propiedades del Grafeno son tan numerosas como las variables asociadas, por eso es difícil definir una fórmula estándar que satisfaga todas sus expectativas. El reto está en encontrar el equilibrio entre sus propiedades”.

A continuación, se describen algunos de los innumerables efectos y potenciales usos de los materiales grafénicos sobre distintas matrices poliméricas:

Mechanical strength

Graphene materials cause changes in the viscoelastic behavior of polymers, showing greater resistance to elongation, an interesting property for the design of products that are more resistant to deformation, such as sealing products, cushioning, transport or tires, footwear, sports, etc. In addition to increasing the elastic modulus, it also improves the impact resistance of polymers in the range of 20 to 200%, with weight reductions of up to 35%, this property is of interest for the manufacture of lighter products with equal or greater resistance than conventional plastics, opening the possibility of reducing or substituting the use of metal parts for plastic parts for the automotive, construction, and security industries, among others.

Resistance to degradation

On the other hand, this nanomaterial has also shown other interesting contributions, for example, in accelerated weathering tests carried out on plastics reinforced with graphene and/or derivatives, it has been identified that the use of low concentrations can increase its resistance to extreme conditions up to 7 times. of humidity, temperature and ultraviolet radiation. Furthermore, if we consider that when plastic is exposed to UV radiation, it emits greenhouse gases (methane and ethylene). Therefore, by increasing the resistance to degradation, we could also favor the reduction of these emissions, without affecting the ability of PET to be reused or recycled, but, on the contrary, using graphene offers it more opportunities to be recycled.

Fire resistance

Another recognized property of graphene is that it is an excellent thermal conductor. In tests carried out on different polymers, those modified with graphene oxide, in addition to improving their mechanical properties, also improved flame retardancy. Being the polypropylene the most benefited when identifying a self-extinguishing behavior. This contribution is attractive for its application in electrical cable and wire coatings or plastic materials in general that require thermal resistance.

These are just some of the multiple properties that graphene and its derivatives can offer the plastics industry and all those who benefit from it and that, despite efforts to reduce the circulation of plastic due to environmental impacts, the advantages offered by graphene can be well focused to make the use, reuse and recycling of plastic more efficient.

Some of the plastic products with graphene that have been commercialized are described below:

  1. Energeia Fusion-Graphenemex through its polymer division develops Masterbatches with graphene oxide for the production of personal protection equipment such as face shields and non-woven fabrics for face masks. Likewise, it has developed modified polymers for hydraulic concrete and asphalt concrete, in addition to the Graphenergy line of coatings for anticorrosive and antimicrobial protection (Mexico),
  2. Directa Plus designed a face mask with graphene for the fight against the pandemic caused by SARS-COV2 (United Kingdom),
  3. The international wheel producer Vittoria developed the bicycle wheels called Qurano (Italy),
  4. Progress, with its Progress Atom LTD model, provides better performance in terms of wear resistance, greater grip, greater impermeability, more efficient heat dissipation and greater lateral rigidity, with less weight (Spain),
  5. Dassi Bikes built the world’s first bicycle made from graphene (UK),
  6. FiiO Electronics launched headphones with a graphene-enhanced diaphragm driver (China),
  7. NanoCase created smartphone cases for better heat dissipation (China),
  8. Catlike uses graphene to produce cycling helmets (Spain).

References