Rice University - Page 6

Israel-based graphene quantum-dots (GQD) developer Dotz Nano has successfully concluded its IPO and is now listed in the Australian stock exchange under the ticker ASX:DTZ.

The IPO was very successful - Dotz Nano raised $6 million AUD and the shares doubled in the first day of trading. Following the IPO, Dotz Nano signed a memorandum of understanding with Nanyang Technological University, Singapore (NTU Singapore) to establish a graphene quantum dots application research center.

Researchers at Rice University have found that layers of graphene, separated by nanotube pillars of boron nitride, may be a suitable material to store hydrogen fuel in cars. The boron nitride pillars are situated between graphene layers to make space for hydrogen atoms, similarly to spaces between floors in a building. The actual challenge is to make the atoms enter and stay in sufficient numbers and exit upon demand.

In their latest molecular dynamics simulations, the researchers found that either pillared graphene or pillared boron nitride graphene would offer abundant surface area (about 2,547 square meters per gram) with good recyclable properties under ambient conditions. Their models showed adding oxygen or lithium to the materials would make them even better at binding hydrogen.

Researchers at Rice University have shown that combining graphene nanoribbons, made with a process developed at Rice University, and a common polymer to create a material called Texas-PEG could have potential of aiding in treating damaged spinal cords in people.

The customized GNRs are highly soluble in polyethylene glycol (PEG), a biocompatible polymer gel used in surgeries, pharmaceutical products and in other biological applications. When the biocompatible nanoribbons have their edges functionalized with PEG chains and are then further mixed with PEG, they form an electrically active network that can help the severed ends of a spinal cord reconnect (neurons tend to grow on graphene because it’s a conductive surface).

Researchers at Rice University, along with colleagues in Texas, Brazil and India, have found that flakes of graphene oxide, welded together into a solid material, could be advantageous for bone implants. The team used used spark plasma sintering to weld flakes of graphene oxide into porous solids that compare favorably with the mechanical properties and biocompatibility of titanium, a standard bone-replacement material.

A focused ion beam microscope image shows 3-D graphene layers welded together in a block

The researchers stated that their technique will give them the ability to create highly complex shapes out of graphene in minutes using graphite molds, which they believe would be easier to process than specialty metals. They also said that spark plasma sintering is being used in industry to make complex parts, generally with ceramics. "The technique uses a high pulse current that welds the flakes together instantly. You only need high voltage, not high pressure or temperatures". The material they made is nearly 50% porous, with a density half that of graphite and a quarter of titanium metal. But it has enough compressive strength—40 megapascals—to qualify it for bone implants. The strength of the bonds between sheets keeps it from disintegrating in water.

Researchers from Moscow Institute of Physics and Technology (MIPT), in collaboration with researchers from other Russian institutions, have designed a way to acquire 2D graphene-like layers of various rock salts. Thanks to the unique properties of atomically thin materials, this opens up fascinating prospects for nanoelectronics. Based on the computer simulation, they derived the equation for the number of layers in a crystal that will produce ultrathin films with potential applications in nanoelectronics.

Previous theoretical studies suggested that under certain conditions, films with a cubic structure and ionic bonding could spontaneously convert to a layered hexagonal graphitic structure in what is known as graphitisation. However, there was very little experimental data to make any practical use of this proposal.

Researchers at Rice University have created rivet graphene, 2D carbon that incorporates carbon nanotubes for strength and carbon spheres that encase iron nanoparticles, which enhance both the material’s portability and its electronic properties.

Transferring graphene grown via CVD is usually done with a polymer layer to keep it from wrinkling or ripping, but the polymer tends to leave contaminants behind and degrade graphene’s abilities to carry a current. According to the Rice team, rivet graphene proved tough enough to eliminate the intermediate polymer step, and the rivets also make interfacing with electrodes far better compared with normal graphene’s interface, since the junctions are more electrically efficient. Finally, the nanotubes give the graphene an overall higher conductivity. So for using graphene in electronic devices, this is said to be an all-around superior material.

Researchers at Rice University have shown that adding modified graphene nanoribbons to a polymer and then microwaving the mixture appears to reinforce wellbores drilled to extract oil and natural gas, which can make wells more stable and reduce production costs.

The team combined a small amount of the nanoribbons with an oil-based thermoset polymer. The combination then was cured in place with low-power microwaves emanating from the drill assembly, resulting in the composite plugging microscopic fractures. The combination allowed drilling fluid to seep through and destabilize the walls.

Researchers at Rice University have created a thin coating of graphene nanoribbons in epoxy, that has proven effective at melting ice on a helicopter blade. This coating may be an effective real-time de-icing mechanism for aircraft, wind turbines, transmission lines and other surfaces exposed to cold weather. In addition, the coating may also help protect aircraft from lightning strikes and provide an extra layer of electromagnetic shielding.

The scientists performed tests in which they melted centimeter-thick ice from a static helicopter rotor blade in a -4 degree Fahrenheit environment. When a small voltage was applied, the coating delivered electrothermal heat - called Joule heating - to the surface, which melted the ice.

Researchers at Rice University and the State University of Campinas in Brazil have found that random molecules scattered within layers of otherwise pristine graphene affect how the layers interact with each other under strain. The researchers, with flexible electronics in mind, decided to see how graphene oxide paper would handle shear strain, in which the sheets are pulled by the ends. Such knowledge is important for applications involving novel advanced materials, especially for making 3D structures from 2D materials, and some applications may include sensors, electronics and biomedical devices. 

Rice University researchers have configured their previous invention of Laser Induced Graphene (LIG) into flexible, solid-state microsupercapacitors that rival current leading ones for energy storage and delivery.

The LIG microsupercapacitors reportedly charge 50 times faster than batteries, discharge more slowly than traditional capacitors and match commercial supercapacitors for both the amount of energy stored and power delivered. The devices are made by burning electrode patterns with a commercial laser into plastic sheets in room-temperature air, eliminating the complex fabrication conditions that have limited the widespread application of microsupercapacitors.