Home Blog Page 109

Graphene Contact Lenses can Shield you from Dehydration and Electromagnetic radiation

0

 

Graphene Contact lenses can protect from EM radiation and Dehydration. Credit: ACS Nano

Graphene (a sheet of carbon just one atom thick) could be used to coat smart contact lenses and help protect eyes from electromagnetic radiation and dehydration, according to new work by researchers at Seoul National University, Graphene Square Inc and Interojo Inc. The contact lenses could be used in various healthcare and wearable technologies in the future.

Graphene not only has remarkable electrical, mechanical and chemical properties, scientists recently discovered that it is also a strong diamagnet that can absorb electromagnetic (EM) energy and dissipate this in the form of heat. Since it is only made of carbon atoms, it is much more lightweight than other EM-shielding materials such as metals, which can also suffer from corrosion. The material is also impermeable thanks to its densely packed hexagonal carbon networks that act as a barrier to water molecules.

In recent years, researchers have developed wearable contact lenses that can be used in applications like glucose monitoring of tears – to diagnose diabetes or glaucoma, for example. A lens that would shield the eye from EM radiation would be a further advance in the field as our exposure to this type of radiation looks set to increase in the coming years, with the advent of the Internet of Things (IoT) technologies. A lens that would protect the eyes from dehydration at the same would be even better since wearing contact lenses for a long time can sometimes cause dry-eye syndrome.

A team led by Byung Hee Hong of the Graphene Research Center at Seoul National University has now developed a graphene-based highly conducting contact lens coating that fits the bill here.

The process of Fabricating a Micro LED on a graphene contact lens. Credit ACS Nano

Graphene conforms to convex surface of the lens

The researchers began by synthesizing an atom-thick graphene layer using a technique called chemical vapour deposition (CVD) on a copper foil. They then transferred the carbon sheet onto the surface of a contact lens with the help of a polymer layer after etching the copper. “Thanks to its outstanding flexibility, graphene can be coated on the convex lens surface and conform to it,” explains Hong.

The team tested the EM wave-shielding properties of the coated lens by testing it out on egg whites exposed to strong EM waves inside a microwave oven. The results showed that the EM energy is absorbed by the graphene layer and dissipated as heat throughout it so that damage to the egg white is minimized.

“When the graphene is exposed to EM waves, the electrons in orbital motion induce oscillating magnetic moments in response to the external magnetic field, which efficiently absorbs the EM energy and disperses it as thermal energy,” explains Hong. “We can thus evaluate the material’s EM absorption efficiency by monitoring the heat produced in the graphene-coated contact lens. We did this by using an IR camera to obtain thermal infrared images after applying EM radiation (of 120 W) on the samples inside a microwave oven for 20 seconds and found that the temperature of the graphene-coated contact lens rapidly increased to more than 45 °C, while a normal lens hardly increased in temperature.

Targeting real-time wireless monitoring of glucose concentration

“We also demonstrated that the graphene layer can offer protection from dehydration by monitoring the change in water evaporation rate from water-filled vials capped with the contact lens,” says Hong. “30% less water evaporated from vials capped with the graphene-coated lens when compared with vials capped with a non-coated one.

“We believe that such a lens could make for a new healthcare and bionic platform for wearable technologies in the future,” he tells nanotechweb.org. “For diabetes diagnosis, for example, we are now planning to integrate an active circuit with graphene-based sensors and electrodes for real-time wireless monitoring of glucose concentration in tears in collaboration with a contact lens company (Interojo Inc.).”

Source:http://bit.ly/2l4Ag8Y

Publication Journal: “Smart Contact Lenses with Graphene Coating for Electromagnetic Interference Shielding and Dehydration Protection”, Sangkyu Lee et al., ACS Nano, February 15, 2017, DOI: 10.1021/acsnano.7b00370

 

 

Chilwee Black Gold Batteries use Graphene Technology

0
Simple demonstration of how a graphene battery is made. (Photo/CGTN)

Graphene is regarded as one of the best nano-materials currently available, due to its various properties such as its thinness, electrical and thermal conductivity and its strength.

Thanks to its extensive properties, it is nicknamed “black gold.” Research suggests that China’s graphene industry will form a market with a value exceeding hundreds of billions of yuan by 2020.

Chinese company, Zhejiang Chilwee Power,? is using the nanomaterial to develop lead-acid batteries with longer battery lives, power performances and load capacities. Chilwee unveiled its latest generation battery using graphene on Sunday, promising a much better performance than previous lead-acid

Chilwee BG (BLACK GOLD) Series high energy VRLA Battery is specially designed based on Graphene Technology, which has obviously improve the battery’s capacity, output power, cycle life and high/low temperature performance. The Chilwee BG (BLACK GOLD) Series provides longer range, largerer power and extremely long life for motive power applications, i.e. electric bicycles, electric tricycles, electric motocycles and other device require DC power source.

Image of the Chilwee Black Gold battery. Credit Chilwee

Read More about Black Gold here.

 

The development and application of graphene in battery technology is expected to play a key role in the next generation of high-performance electric vehicles, as consumers seek cars with longer lives and better performances.
Source: http://bit.ly/2mluTmd

Hi-Tech Machine Enables new Graphene Purification Technique

0
Hi-tech machine enables new graphene purification technique
Professor Colin Raston with his invention, the Vortex Fluidic Device. Credit: Flinders University

A revolutionary machine that can unboil an egg is being used to develop graphene purification technology.

Researchers from Flinders University in South Australia along with Western Australian company First Graphite Ltd will use the dynamic Vortex Fluidic Device (VFD) to produce high-quality graphene for industrial use.

Graphene is the building block of graphite and is one of the most sought after materials in the world because of its robust nature. More than a million metric tons of graphite is mined globally each year. It is 200 times stronger than steel but remains flexible and impermeable, making it ideal for the development of a range of modern technology such as lithium-ion batteries, sensors and transparent-conducting electrodes for flexible solar cells. Based on previous graphite research involving the VFD, First Graphite plan to scale up the process to a commercial level with the potential of delivering high-value carbon materials to global markets.

First Graphite Managing Director Craig McGuckin said graphene uses were applicable to a vast range of industries and he believed the material would eventually be used in most modern technology.

“What is required is creating high quality graphene from graphite, doing so quickly and efficiently and that is what we are trying to take up now,” he said.

Hi-tech machine enables new graphene purification technique
First Graphite Ltd’s graphene cell in production. Credit: Flinders University

“We see the VFD partnering with our own processes to assist greatly in creating different types of graphene for different uses.”

In 2015, Flinders University scientists were awarded an Ig Nobel Award for creating the Vortex Fluidic Device and using it to unboil an egg. The device has also been used to slice carbon nanotubes accurately to an average length of 170 nanometres using only water, a solvent and a laser. It is now being tested to prove its potential as a commercially viable graphene producer.

VFD creator and professor of clean technology at Flinders University Colin Raston said Graphite was made up of multiple crystalline layers of graphene that could be stripped off by his machine. He said conventional methods used harsh chemicals, which generated defects and changed the properties of the graphite.

“You can’t keep making graphene the same way any more, you need to make it better and address the waste issues as well,” Professor Raston said.

“Given the capabilities of the VFD we are going to explore the operating parameters of producing graphite.

Hi-tech machine enables new graphene purification technique
Credit: Flinders University

“An environmentally safe process of producing the graphene opens up more applications for it – it also makes it a cheaper option because you eliminate waste.”

The Vortex Fluidic Device that will be used to manufacture the graphene sheets is a suitcase-sized piece of equipment that applies very high sheer forces to liquids fed into the system through spinning a tube at high velocity.

“Graphite is a well known solid lubricant because the sheets slip relative to each other,” Professor Raston said. “The VFD (pictured below) would cut through the graphite with precision and could be scaled up by aligning a row of machines parallel to each other or creating a larger device.”

First Graphite aims to develop an underground mining operation in Sri Lanka to extract high-grade, crystalline vein graphite and plans to use the VFD to help extract high-value graphene. Graphite has seen a resurgence in price in recent times due to increased demand from applications such as lithium-ion battery technology for electric cars but could now see itself replaced by graphene.

Graphene has the largest volume to surface area ratio of any material, weighing in at about 0.77 milligrams per square metre and capable of stretching up to 20 per cent of its initial length. It is an isotropic heat conductor. It also has the highest recorded electrical current density, about one million times that of copper. South Australia is home to more than 75 per cent of Australia’s Joint Ore Reserve Committee (JORC) graphite resources, largely on Eyre Peninsula.Published by http://bit.ly/2lzHa50

This story was previously covered in the following article: “Flinders Uni, First Graphite create new graphene purification technique” (Read More)

Saint Jean Carbon Announces Graphene Battery Preliminary Results

0
 

 Saint Jean Carbon Inc. (“Saint Jean” or the “Company”) (TSX-V:SJL) (OTCQB:TORVF), a carbon science company engaged in the design and build of green energy storage, green energy creation and green re-creation through the use of carbon materials. The Company is pleased to announce that it has set the preliminary numbers for the graphene battery project announced on January 18th, 2017. The preliminary performance markers will be used to judge performance for and against the three prototype graphene batteries in production.

Graphene based batteries have a number of very strong possibilities to outperform any other known energy storage device.  The key lies in the difference in how the lithium intercalates with the anode material, basically the rate of absorption. In contrast to graphite; graphene, the unique two-dimensional atom-thick honey-comb structured carbon, has revealed various novel properties. Graphene has the highest intrinsic mechanical strength (1060 Gpa) and thermal conductivity (3000Wm-1k-1), in addition to a high surface area (2630 m2g-1) and electronic mobility (10000 cm2V-1s). Due to this the carbon material is transformed from graphite to graphene with a capacity that is expected to increase up to 500–1100 mAhg?1.

It has been proposed that lithium ions can be adsorbed on both sides of the graphene sheets which are arranged like a ‘‘house of cards’’ in hard carbons, leading to two layers of lithium for each graphene sheet, with a theoretical capacity of 744 mAhg-1 through the formation of Li2C6. Recently, large reversible Li storage (540 mAhg-1 in the first cycle) in graphene Nano-sheets has been reported.

Paul Ogilvie, CEO, commented: “As the world of engineering, studies and works to perfect the lithium-ion battery, new and wonderful materials like graphene will get their shot at making a game changing contribution. With the final lab prototype batteries, our goal is to achieve; the fastest recharge, highest density and greatest capacity within a very small size. If we achieve this, we will have set a new high watermark for performance.”

The Company hopes to have the final batteries results ready within three weeks. The Company is continuing with the recycled battery project. Further, the final spherical carbon coated graphite specifications and performance results are expected very shortly.

About Saint Jean Carbon

Saint Jean is a publicly traded carbon science company, with specific interests in energy storage and green energy creation and green re-creation, with holdings in graphite mining and lithium claims in the province of Quebec in Canada.  For the latest information on Saint Jean’s properties and news please refer to the website: http://bit.ly/2ldeagx

Published by http://bit.ly/2lJV8ll

Revealing a Hidden Spin Polarization in MoS2

0

 

Synopsis figure

Elia Razzoli/University of Fribourg

Photoemission spectroscopy has detected two different populations of spin-polarized electrons that are “hidden” within a layered, graphene-like material.

The layers inside certain materials can carry spin-polarized electrons, but this polarization is hidden to measurements that aren’t sufficiently localized. A new study using photoemission spectroscopy has detected the hidden spin polarization in a graphene-like material called molybdenum disulfide (MoS2). Unique to this work is the ability to target specific populations of spin-polarized electrons with circularly polarized light.

Polarized spins, which can be programmed to carry information, are traditionally produced with magnetic fields. However, researchers are actively exploring nonmagnetic methods that could prove faster and more versatile for processing spin information. So-called transition-metal dichalcogenides (TMDCs), which include MoS2, are nonmagnetic materials whose layers exhibit a crystal asymmetry that produces spin polarization. But the polarization is hidden because the polarization direction is opposite for adjacent layers, resulting in a net polarization of zero.

Previous work observed hidden spin polarization in a TMDC called tungsten diselenide by targeting the surface layer of the material (where the spin polarization points “up” out of the surface). Now, Elia Razzoli of the University of Fribourg, Switzerland, and his colleagues have demonstrated a way to probe the spin polarization of deeper layers. In their spin- and angle-resolved photoemission spectroscopy experiments with MoS2, circularly polarized photons with energy around 50 eV penetrated into the material, causing electrons to be ejected. The spins of these electrons depended on the polarization of the light. In agreement with this observation, the team’s calculations showed that left-handed (right-handed) light preferentially excites spin-up (spin-down) electrons in different layers of MoS2. The results suggest the possibility of devices in which polarized light selects and manipulates different spin populations within a bulk material.

This research is published in Physical Review Letters.

Publication Journal: “Selective Probing of Hidden Spin-Polarized States in Inversion-Symmetric Bulk MoS2” ,E. Razzoli, T. Jaouen, M.-L. Mottas, B. Hildebrand, G. Monney, A. Pisoni, S. Muff, M. Fanciulli, N.?C. Plumb, V.?A. Rogalev, V.?N. Strocov, J. Mesot, M. Shi, J.?H. Dil, H. Beck, and P. Aebi, Phys. Rev. Lett. 118, 086402 – Published 22 February 2017

Elcora, a Graphene Company Appoints CTO for Anode Development

0

 

ELCORA ADVANCED MATERIALS CORP. (TSX-V:ERA / Frankfurt: ELM / OTCQB: ECORF) (the “Company” or “Elcora”) is pleased to announce the appointment of Dr. Shane Beattie as the CTO of anode development with responsibilities in the technology, testing, manufacturing, and technical support of the Company’s anode powder.

Dr. Shane Beattie

Dr. Beattie has more than 15 years of experience in energy storage and anode development. He earned his Ph.D. working with Jeff Dahn at Dalhousie University. His Post Doctoral fellowship was with Dr. Jean-Marie Tarascon at the LRCS, UPJV, Amiens, France. More recently, he was the Technical Director at Warwick University’s Battery Pilot Scale-up line.

Dr. Beattie will be responsible for expanding the Company’s existing capabilities to include testing of pouch cells, evaluating different graphite sources, supervision of the anode facility construction and related personnel, and interfacing with clients. He brings valuable experience working with several automotive companies using Li-ion technology and with cell manufacturers.

“The appointment of Dr. Beattie facilitates the development of the anode powder aspect of Elcora’s vertically integrated structure and brings battery anode manufacturing and testing knowledge into the Company,” said Troy Grant, Elcora’s President and CEO. In addition, “His experiences and knowledge of the industry will be key to help commercialize and sell the Elcora anode products.”

Elcora is pleased to report that they received $500,000 in non-repayable grants and $1,300,000 in Government Loans to assist with continued Lithium-Ion battery testing and development.

In addition to the $1,800,000 amount, the Company announces that it has closed the second and final tranche of the non-brokered private placement financing (the “Private Placement”) announced on January 31, 2017. The Private Placement closed at a total of $2,645,823 or 9,799,343 Units.

The first tranche involved the issuance of 9,326,093 units (“Units”) of the Company at a price of $0.27 per Unit for gross proceeds of $2,518,045. The final tranche involved the issuance of 473,250 Units of the Company at a price of $0.27 per Unit for gross proceeds of $127,778.

Each Unit will be comprised of one common share and one common share purchase warrant. Each full warrant gives the holder the right to purchase one additional common share of Elcora at an exercise price of $0.34 for two years following the closing of the Private Placement. The term of the warrants may be accelerated in the event that the issuer’s shares trade at or above a price of $0.60 cents per share for a period of 20 consecutive days. In such case of accelerated warrants, the issuer may give notice, in writing or by way of news release, to the subscribers that the warrants will expire 45 days from the date of providing such notice.

In connection with the closing of both tranches of the Private Placement, the Company paid cash finders’ fees equal to 6% of the proceeds and issued finders’ shares equal to 6% of the number of Units sold. All securities issued pursuant to the Private Placement will be subject to a statutory four-month hold period.

About Elcora Advanced Materials

Elcora was founded in 2011 and has been structured to become a vertically integrated graphite and graphene company that mines, refines, and processes graphite, and produces graphene. The Company’s products are then used to manufacture battery grade anode graphite and to develop future graphene based and/or enriched high tech products, such as graphene enhanced silicon anodes for lithium ion batteries. As part of this vertical integration strategy, Elcora has secured high-grade graphite and graphene precursor graphite from its interest in the operation of the Ragedara mine in Sri Lanka, which is already in production. Elcora has developed a unique low cost effective ecological processes to make high quality battery grade and battery form graphite and graphene at commercial scale. This combination means that Elcora has vertically integrated the tools and resources required to produce graphite, micro-graphite, and graphene.

Company’s website at http://bit.ly/2eJJK2O.
Published by http://bit.ly/2lJM6oo

Huawei’s R&D investment and Graphene-Assisted Li-ion batteries, major breakthrough for warm climates

0

Huawei was ranked as the world’s eighth-largest company in terms of research and development spending in 2016, according to EU Industrial R&D Investment Scoreboard, an annual ranking of the world’s top 2,500 R&D investors. The global technology manufacturer’s significant investment in research and development has led to major breakthroughs in the industry including the first long-lifespan graphene-assisted Li-ion battery able to withstand high temperatures.

According to the rankings compiled by European Commission’s Economics of Industrial Research and Innovation, R&D spending by Chinese companies increased 24.7% from previous year, boosting its share of the global total from 5.9% to 7.2%. Furthermore, the scoreboard shows that the largest groups of companies in the world top 2,500 companies are drawn from the ICT, health care and automotive industries.

Huawei’s investment into the Huawei Central Research Institute has led to developments in a number of technological advancements including their latest breakthrough – Li-ion batteries. The Watt Laboratory, an organization under Huawei’s Central Research Institute Huawei announced at the 57th Battery Symposium held in Japan that Huawei plans to unveil Li-ion batteries featuring new graphene-assisted heat-resistant technologies. These technologies allow Li-ion batteries to remain functional in a 60°C environment, a temperature 10°C higher than the existing upper limit. The lifespan of the graphene-assisted Li-ion batteries will also be twice as long as ordinary Li-ion batteries, allowing for an unprecedented long battery life.

Huawei’s research results will reshape the storage systems of communications base stations. In high-temperature regions and countries like the United Arab Emirates, outdoor base stations powered by the graphene-assisted high-temperature Li-ion batteries can have working lifespans longer than four years. These batteries ensure a high mileage for electric vehicles per charge in high temperatures. They can also guarantee the safe operation of drones, which often generate a significant amount of heat.

The URL of Huawei’s graphene-assisted high-temperature Li-ion battery demo video: https://youtu.be/OceA8Wye71M
Published by http://bit.ly/2lBCCew

Top Record High Frequency RF Graphene Transistors on Flexible Substrates

0

 

Figure: Flexible graphene RF transistor (reproduced from Nanoscale 2016, 8, 14097-14103 with permission from The Royal Society of Chemistry).

Graphene has long been regarded as an ideal candidate channel material for radio frequency (RF) flexible electronics. Scientists from IEMN-CNRS, Graphenea, and Nokia have now demonstrated flexible graphene transistors with a record high cut-off frequency of 39 GHz. The graphene devices, made on flexible polymer substrates, are stable against bending and fatigue of repeated flexing.

Flexible electronics has become a very active research and application field, driven by a potentially enormous market for smart devices and wearables. It is expected that in the near future people will be wearing medical, recreation, and entertainment devices on their clothes, a goal which requires sensors to be placed on a large variety of flexible supports. These sensors and devices will communicate to each other, which will require an extra layer of flexible RF electronics.

Transistors form the main building blocks of RF electronic components such as amplifiers and mixers, thus a new generation of flexible RF transistors is key to enabling the smart devices and wearables markets. Graphene, a flexible, strong, thin material with outstandingly high carrier mobility is a perfect candidate channel material for such transistors. Flexible graphene transistors are an active research direction but this most recent work, published in the journal Nanoscale, demonstrates a record high frequency by bringing device fabrication to a new level.

The graphene field effect transistor (GFET) is made from high quality CVD grown graphene with a carrier mobility of ~2500 cm2 V-1 s-1 on a flexible Kapton substrate with a thin alumina dielectric spacer in the channel region. The use of such sophisticated and optimized materials leads to the record high frequency performance as well as stability against bending. The GFET continues to operate even after 1,000 bending cycles and can be flexed to a radius of 12 mm with a cutoff frequency shift of up to 10%.

Finally, the device is tested for thermal stability. Thermal stability is an important issue in flexible electronics, due to the poor thermal conductivity of the polymer substrates generally used in such devices. The researchers show that at high voltage bias, the device heats up and performance degrades irreversibly.

This new research on flexible GFETs not only sets a new record for the bandwidth but also proves that degradation commonly seen in these devices at high bias comes from thermal deformation of the substrate. As research in this direction advances, it is becoming obvious that flexible GFETs are here to stay as important building blocks of future wearable technology.

Published by http://bit.ly/2m4RiUE

Strem Chemicals and Dotz Nano Ltd. Sign Distribution Agreement for Graphene Quantum Dots

0

Strem Chemicals, Inc., a manufacturer of specialty chemicals for research and development, and Dotz Nano Ltd., an exciting new company aimed at capitalizing on the technological innovation in the Graphene Quantum Dots (GQD) market, are proud to announce the signing of a licensing agreement. 

Newburyport, MA | Posted on February 21st, 2017

With this agreement in place, Strem Chemicals will become a global distributor of Graphene Quantum Dots. Dotz Nano Ltd. uses low-cost, raw material to make high-quality and cost-effective products. These products can be used in various applications, such as medical imaging, sensing, consumer electronics, energy storage, solar cells, and computer storage.

“Strem is excited to introduce this unique line of products, especially at a time when the graphene market is growing steadily. Graphene Quantum Dots can be used for a wide variety of applications and partnering with Dotz Nano Ltd. will allow us to offer this new technology to our customers.” said Dr. Ephraim S. Honig, Chief Executive Officer at Strem.

Commenting on the new agreement, Dotz Nano’s CEO, Dr. Moti Gross, stated “The marketing and sales agreement which Dotz Nano has signed with Strem Chemicals will allow Dotz, through Strem, to supply and service a large group of valuable consumers that usually are either in research, pilot production phase or other types of activities. This agreement will allow Dotz Nano to take advantage of Strem’s marketing and logistics systems.”

##

About Strem Chemicals, Inc.
Strem Chemicals, Inc., established in 1964, is a privately held manufacturer and marketer of specialty chemicals of high purity. Strem’s key products include catalysts, ligands, organometallics, metal carbonyls, CVD/ALD precursors and nanomaterials. Its products are used for research and development and commercial scale applications, especially in the pharmaceutical, microelectronics, chemicals and petrochemicals industries. Strem Chemicals also provides custom synthesis, process development and cGMP manufacturing services. Strem is an ISO 9001 certified company. For more information, visit www.strem.com.

About Dotz Nano Ltd.

Dotz Nano Limited (ASX: DTZ) is a technology company focusing on the development, manufacture and commercialization of graphene quantum dots (GQDs). Its vision is to be the premier producer of GQDs by producing and supplying high quality GQDs for use in various applications including medical imaging, sensing, consumer electronics, energy storage, solar cells and computer storage. To learn more about Dotz Nano please view the website and our corporate video via the following link: www.dotznano.com

More stories on Dotz Nano :

  • Dotz Nano showed use of Graphene Quantum Dots in Flash Memories in Collaboration with Kyung Hee University (Read more)


Published by http://bit.ly/2kVdbk9

Directa Plus receives €1M to Research Smart Fabrics

0

 

The graphene specialist Directa Plus Plc (LON:DCTA) has been awarded €1mln European grant by the regional government in Lombardy, Italy, to help fund its research into smart fabrics.

Directa will be project leader of a team that includes local firms Novaresin and Soliani along with the Politecnico of Milan University.

The project will focus on the development of G+ membranes to enhance the thermal and electrical performance of textiles for fashion applications, the AIM-listed company said.

“Over the last six months we have made tremendous progress in the textiles segment, which has seen the launch of several customers’ end-products as well as an increasing pipeline of near- and medium-term commercial opportunities,” said chief executive Giulio Cesareo.

“With the award of this grant, we have a great opportunity to further develop our range of textile products to meet the demands of the textile industry for technological innovation in smart fabrics.”

Directa is one of the largest producers and suppliers of graphene-based products for use in consumer and industrial markets.

Published by http://bit.ly/2lZPZ9G