Graphene & New Materials Tech Digest - June 2017

Graphene fibre clothing

Clothing integrating graphene has been released on the Chinese market. The clothing – sportswear, dailywear and underwear – is made of graphene fibre: a mix of graphene and high polymer materials. It is claimed that the fibre lends garments resistance against ultraviolet light, effectiveness at preserving heat, antibacterial and anti-static properties. The graphene fibre is made by Shanghai Kyorene New Material Technology Co. which has an international patent on the technology.

Hackmanite for light

Scientists at the University of Turku, Finland, have developed a synthetic hackmanite material that exhibits luminescence comparable to sunlight. Hackmanite is non-toxic and abundant, offering an alternative to the expensive lanthanides currently used in lighting (LEDs and fluorescent lights) and diagnostics equipment. The researchers say that the material exhibits persistent luminescence (afterglow) meaning it could be used for glow-in-the-dark applications such as exit signs and watch-dials. They also say the light emitted by hackmanite is closer to natural white light than that produced by lanthanides. They tested the material to show that it also had uses in authenticating spices and foodstuffs as the afterglow properties could be used to detect real produce.

New method for water splitting

University of New South Wales scientists have invented a catalyst for splitting water with electric current to produce hydrogen, which they claim is cheap and efficient. The technology uses ultrathin slices of a porous nickel-iron metal-organic complex material coated on a foam electrode. Usually splitting water involves two different catalysts but this catalyst can split water into oxygen and hydrogen with no help. The scientists now intend to adapt their approach to enable the production of ultrathin nanosheet arrays made of these metal-organic materials.

New material could help smartphones become more resistant

Researchers at Queens University, UK, have discovered a new material which could make electronic device screens more resistant to cracking and breaking. The material consists of semiconducting molecules C60 and layered materials such as graphene and hBN. According to the team, hBN provides stability, electronic compatibility and isolation charge to graphene, while C60 can act as a solar cell – converting sunlight into electricity. The scientists say that the new material has similar physical properties to silicon but shows improved chemical stability, lightness and flexibility that could mean less propensity of breakage and damage when used in devices. A problem with the material that must be overcome, though, is the material’s lack of a band gap which is crucial to applications within current electronics. The scientists are investigating a potential solution – transition metal dichalcogenides (TMDs).

Ruthenium/graphene material could be used in fuel cells

Scientists at Rice University, USA, have developed a catalyst with potential for use in fuel cells by attaching single ruthenium atoms to a graphene sheet. To create the catalyst the scientists dispersed graphene oxide in a solution, to which was added a small amount of ruthenium. The solution was then freeze-dried, turning it into a foam. This was subsequently baked with nitrogen and hydrogen to reduce the graphene, which locked nitrogen atoms to the surface. The ruthenium could then bond to the nitrogen. The material showed high tolerance to degradation by methanol crossover and carbon monoxide poisoning in acidic conditions similar to those it would face in a fuel cell. This degradation is problem faced by the platinum catalysts which are currently used in fuel cells.

Metamaterial for the workplace

Acoustic Metamaterials Group (AMG), a Hong Kong-based company, is using metamaterials (synthetic composite materials with unusual structures that exhibit non-naturally occuring properties) in real-world spaces to provide soundproofing. AMG analyse the noise profile in a client’s space – i.e. a factory or office – and then design a material to target specific noise frequencies. The company claims that its metamaterial is a more effective sound dampener of low frequencies than alternative solutions currently available. Metamaterials rely more on structure than on composition, enabling metal to be used for example. This allows AMG to design and install soundproofing in environments where traditional materials would degrade.

Metasurface improves MRI scanning

Scientists from Leiden University, Netherlands, and ITMO University, Russia, have designed and tested a metasurface-based technology to enhance MRI (magnetic resonance imaging) scanners’ local sensitivity, resulting in higher quality images of brain regions. The metasurface is a periodic structure of conducting copper strips. According to the team, the results of the test on a human subject, with the metasurface placed on the MRI’s headrest, show that it can reduce image acquisition time by half, make the procedure more comfortable for the patient, and allow for the taking of higher resolution images which could mean earlier diagnoses.

Tuneable wettability nanoparticle

Researchers at Swansea University, Wales, UK, have developed a nontoxic waterproofing and antifouling material. The material comes from a set of novel aluminium oxide nanoparticles that exhibit tuneable wettability – by changing chains that the nanoparticles form it is possible to alter the roughness, wettability and surface energy of the material. The material can be applied to surfaces through spray- or spin-coating and provides the surface a texture and functionality that can be tuned to either absorb or repel water. The team is working to improve the durability of the material on various substrates, as well as potential application to large-scale surfaces.

Graphene headphones

Ora Graphene Audio is seeking funding on Kickstarter for its ORA GQ headphones that have the company’s GrapheneQ membrane technology incorporated into the loudspeaker design. GrapheneQ is a material that is 95 percent graphene. The graphene is shaped into cones and domes. The company says that graphene increases the sound quality of the speakers, increases battery life by up to 70 percent, enables speakers to provide more volume, and a wider 3D soundscape.

Graphene for dialysis

Scientists at MIT (Massachusetts Institute of Technology) have developed a graphene-based dialysis membrane that can filter 10 to 100 times faster than commercial membranes. The speed of the separation through graphene is so quick owning to the thinness of the material compared to current materials used for dialysis – particles have less physical distance to travel to get to the other side. The potential for graphene acting as a filter in haemodialysis and lab scale separation processes excites the scientists.

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