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Going with the flow for water purification

Posted By Graphene Council, Monday, September 21, 2020
Membrane separations have become critical to human existence, with no better example than water purification. As water scarcity becomes more common and communities start running out of cheap available water, they need to supplement their supplies with desalinated water from seawater and brackish water sources.

Lawrence Livermore National Laboratory (LLNL) researchers have created carbon nanotube (CNT) pores that are so efficient at removing salt from water that they are comparable to commercial desalination membranes. These tiny pores are just 0.8 nanometers (nm) in diameter. In comparison, a human hair is 60,000 nm across. The research appears on the cover of the Sept. 18 issue of the journal Science Advances.

The dominant technology for removing salt from water, reverse osmosis, uses thin-film composite (TFC) membranes to separate water from the ions present in saline feed streams. However, some fundamental performance issues remain. For example, TFC membranes are constrained by the permeability-selectivity trade-offs and often have insufficient rejection of some ions and trace micropollutants, requiring additional purification stages that increase the energy and cost.

Biological water channels, also known as aquaporins, provide a blueprint for the structures that could offer increased performance. They have an extremely narrow inner pore that squeezes water down to a single-file configuration that enables extremely high water permeability, with transport rates exceeding 1 billion water molecules per second through each pore.

“Carbon nanotubes represent some of the most promising scaffold structures for artificial water channels because of the low friction of water on their smooth inner surfaces, which mimic the biological water channels,” said Alex Noy, LLNL chemist and a lead co-author of the report.

The team developed CNT porins (CNTPs) — short segments of CNTs that self-insert into biomimetic membranes – which form artificial water channels that mimic aquaporin channel functionality and intrachannel single-file water arrangement. Researchers then measured water and chloride ion transport through 0.8-nm-diameter CNTPs using fluorescence-based assays. Computer simulations and experiments using CNT pores in lipid membranes demonstrated the mechanism for enhanced flow and strong ion rejection through inner channels of carbon nanotubes.

“This process allowed us to determine the accurate value of water-salt permselectivity in narrow CNT pores,” said LLNL materials scientist and lead co-author Tuan Anh Pham, who led the simulation efforts of the study. “Atomistic simulations provide a detailed molecular-scale view of water entering the CNTP channels and support the activation energy values.”

Other key contributors to the project included LLNL chemists Yuhao Li, Zhongwu Li and Fikret Aydin. Researchers from Southeast University in China and UC Merced also contributed.

The work was funded by the Department of Energy’s Office of Science and parts of it were performed as a part of the Center for Enhanced Nanofluidic Transport Energy Frontier Research Center.

Tags:  Alex Noy  carbon nanotube  Graphene  Lawrence Livermore National Laboratory  Tuan Anh Pham  water purification 

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New technology extracts potential to identify quality graphene cheaper and faster

Posted By Graphene Council, Wednesday, August 26, 2020
Engineers at Australia’s Monash University have developed world-first technology that can help industry identify and export high quality graphene cheaper, faster and more accurately than current methods.

Published in international journal Advanced Science ("A High Throughput and Unbiased Machine Learning Approach for Classification of Graphene Dispersions"), researchers used the data set of an optical microscope to develop a machine-learning algorithm that can characterise graphene properties and quality, without bias, within 14 minutes.

This technology is a game changer for hundreds of graphene or graphene oxide manufacturers globally. It will help them boost the quality and reliability of their graphene supply in quick time.

Currently, manufacturers can only detect the quality and properties of graphene used in a product after it has been manufactured.

Through this algorithm, which has the potential to be rolled out globally with commercial support, graphene producers can be assured of quality product and remove the time-intensive and costly process of a series of characterisation techniques to identify graphene properties, such as the thickness and size of the atomic layers.

Professor Mainak Majumder from Monash University’s Department of Mechanical and Aerospace Engineering and the Australian Research Council’s Hub on Graphene Enabled Industry Transformation led this breakthrough study.

“Graphene possesses extraordinary capacity for electric and thermal conductivity. It is widely used in the production of membranes for water purification, energy storage and in smart technology, such as weight loading sensors on traffic bridges,” Professor Majumder said.

“At the same time, graphene is rather expensive when it comes to usage in bulk quantities. One gram of high quality graphene could cost as much as $1,000 AUD ($720 USD) a large percentage of it is due to the costly quality control process.

“Therefore, manufacturers need to be assured that they’re sourcing the highest quality graphene on the market. Our technology can detect the properties of graphene in under 14 minutes for a single dataset of 1936 x 1216 resolution. This will save manufacturers vital time and money, and establish a competitive advantage in a growing marketplace.”

Discovered in 2004, graphene is touted as a wonder material for its outstanding lightweight, thin and ultra-flexible properties. Graphene is produced through the exfoliation of graphite. Graphite, a crystalline form of carbon with atoms arranged hexagonally, comprises many layers of graphene.

However, the translation of this potential to real-life and usable products has been slow. One of the reasons is the lack of reliability and consistency of what is commercially often available as graphene.

The most widely used method of producing graphene and graphene oxide sheets is through liquid phase exfoliation (LPE). In this process, the single layer sheets are stripped from its 3D counterpart such as graphite, graphite oxide film or expanded graphite by shear-forces.

But, this can only be imaged using a dry sample (i.e. once the graphene has been coated on a glass slide). “Although there has been a strong emphasis on standardisation guidelines of graphene materials, there is virtually no way to monitor the fundamental unit process of exfoliation, product quality varies from laboratory to laboratory and from one manufacturer to other,” Dr Shaibani said.

“As a result, discrepancies are often observed in the reported property-performance characteristics, even though the material is claimed to be graphene.

“Our work could be of importance to industries that are interested in delivering high quality graphene to their customers with reliable functionality and properties. There are a number of ASX listed companies attempting to enter this billion-dollar market, and this technology could accelerate this interest.”

Researchers applied the algorithm to an assortment of 18 graphene samples – eight of which were acquired from commercial sources and the rest produced in a laboratory under controlled processing conditions.

Using a quantitative polarised optical microscope, researchers identified a technique for detecting, classifying and quantifying exfoliated graphene in its natural form of a dispersion.

To maximise the information generated from hundreds of images and large numbers of samples in a fast and efficient manner, researchers developed an unsupervised machine-learning algorithm to identify data clusters of similar nature, and then use image analysis to quantify the proportions of each cluster.

Mr Abedin said this method has the potential to be used for the classification and quantification of other two-dimensional materials.

“The capability of our approach to classify stacking at sub-nanometer to micrometer scale and measure the size, thickness, and concentration of exfoliation in generic dispersions of graphene/graphene oxide is exciting and holds exceptional promise for the development of energy and thermally advanced products,” Mr Abedin said.

Professor Dusan Losic, Director of Australian Research Council’s Hub on Graphene Enabled Industry Transformation, said: “These outstanding outcomes from our ARC Research Hub will make significant impact on the emerging multibillion dollar graphene industry giving graphene manufacturers and end-users new a simple quality control tool to define the quality of their produced graphene materials which is currently missing.”

Tags:  2D materials  Australian Research Council  Dusan Losic  energy storage  Graphene  Mainak Majumder  Monash University  water purification 

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New Device Can Measure Toxic Lead Within Minutes

Posted By Graphene Council, Wednesday, August 26, 2020
Rutgers researchers have created a miniature device for measuring trace levels of toxic lead in sediments at the bottom of harbors, rivers and other waterways within minutes – far faster than currently available laboratory-based tests, which take days.

The affordable lab-on-a-chip device could also allow municipalities, water companies, universities, K-12 schools, daycares and homeowners to easily and swiftly test their water supplies. The research is published in the IEEE Sensors Journal.

“In addition to detecting lead contamination in environmental samples or water in pipes in homes or elementary schools, with a tool like this, someday you could go to a sushi bar and check whether the fish you ordered has lead or mercury in it,” said senior author Mehdi Javanmard, an associate professor in the Department of Electrical and Computer Engineering in the School of Engineering at Rutgers University–New Brunswick.

“Detecting toxic metals like lead, mercury and copper normally requires collecting samples and sending them to a lab for costly analysis, with results returned in days,” Javanmard said. “Our goal was to bypass this process and build a sensitive, inexpensive device that can easily be carried around and analyze samples on-site within minutes to rapidly identify hot spots of contamination.”

The research focused on analyzing lead in sediment samples.  Many river sediments in New Jersey and nationwide are contaminated by industrial and other waste dumped decades ago. Proper management of contaminated dredged materials from navigational channels is important to limit potential impacts on wildlife, agriculture, plants and food supplies. Quick identification of contaminated areas could enable timely and cost-effective programs to manage dredged materials.

The new device extracts lead from a sediment sample and purifies it, with a thin film of graphene oxide as a lead detector. Graphene is an atom thick layer of graphite, the writing material in pencils.

More research is needed to further validate the device’s performance and increase its durability so it can become a viable commercial product, possibly in two to four years.

This project was done in collaboration with the Department of Electrical and Computer Engineering and Rutgers’ Center for Advanced Infrastructure and Transportation (CAIT). It was funded by CAIT, the USDOT-University Transportation Research Center–Region II.

Tags:  Graphene  graphene oxide  Mehdi Javanmard  Rutgers University  Sensors  water purification 

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Manchester launches spin-out to bring innovative water-filtration technology to market

Posted By Graphene Council, Saturday, June 20, 2020
Scientists and innovation experts from The University of Manchester have worked together to successfully develop a new, market-ready technology using 2D materials that could be a game-changer for the water filtration sector.
ollowing an 18-month technical development and business planning programme - funded by the University - the team of innovators has launched a spin-out company called Molymem Limited to help take the new membrane product into the marketplace. The technology has applications in the pharmaceutical, wastewater management and food and beverage sectors.

The breakthrough development of a high-performing membrane coating is based around a new class of 2D materials, pioneered by Manchester researchers Professor Rob Dryfe and Dr Mark Bissett (pictured right), working with Clive Rowland, team leader for the Molymem project and the University’s Associate Vice-President for Intellectual Property.

Clive explained that membranes are used globally for separation applications in a wide range of valuable markets. “But all of these applications can be expensive,” he added. “They consume high energy and are prone to fouling - and, as a result, require frequent deep cleaning with corrosive chemicals. This causes lost production time and, due to the harsh nature of chemicals being used, it also leads to a deterioration in membrane quality over time.”

Using chemically modified molybdenum disulphide (MoS2), which is widely available at low cost and easily processed, Molymem has developed an energy-efficient and highly versatile membrane coating.

Fast-track innovation
Much of the lab-to-market work was carried out at the Graphene Engineering Innovation Centre (GEIC), which is dedicated to the fast-tracking of pilot innovation around graphene and other 2D materials. Graphene is the world’s first man-made 2D material and offers a range of disruptive capabilities.

Molymem is now ideally placed to raise investment capital to embark on its commercial journey – and interest has already been shown by industrial partners.

James Baker, CEO Graphene@Manchester, said: “The Molymem project demonstrates how the Graphene Engineering Innovation Centre can help to accelerate a breakthrough development in materials science into a brand-new, market-ready product.

“Molymem will now be mentored within the Graphene@Manchester innovation ecosystem as part our portfolio of graphene-based spin-outs. This includes bespoke support such as fundraising for future business development and rapid market development.”

Clive Rowland added: “Over the summer, I will hand-over the team leadership to Ray Gibbs, who is managing the University's graphene and 2D materials spin-out portfolio. Ray will look to fundraise and help take Molymem to the next stage of its exciting innovation journey.”

Tags:  2D materials  Clive Rowland  Graphene  Graphene Engineering Innovation Centre  James Baker  Mark Bissett  Rob Dryfe  University of Manchester  water purification 

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Khalifa University Researchers Develop Hybrid Graphene-Sand Material to Remove Pollutants from Industrial Wastewater

Posted By Graphene Council, Thursday, June 18, 2020
Khalifa University of Science and Technology today announced a team of researchers has developed a graphene-sand hybrid material capable of absorbing pollutants from industrial wastewater, using two natural resources of great abundance in the UAE – sand and dates.

Safely and affordably removing pollutants from industrial wastewater is a primary focus area for governments worldwide. Conventional methods that are used for removing different harmful pollutants from wastewater suffer from drawbacks such as cost-effectiveness, efficiency, range of applicability, and reusability. Comparatively, adsorption method is a relatively mature, globally-acclaimed, economically feasible, and efficient technology for arresting environmental pollutants.

The Khalifa University research team has developed the graphene-sand hybrid material capable of adsorbing pollutants, which involves attaching pollutants onto small particles that are then easily removed.

While synthesizing graphene-sand adsorbents can be prohibitively expensive, the Khalifa University researchers have turned to a previously unused resource – date syrup – to provide the carbon needed to produce the graphene. The adsorbent can be used as an environmentally benign and scalable option for decontaminating wastewater, with the adsorption capacity far surpassing that of similar reported graphene-based adsorbents.

Led by Dr. Fawzi Banat, Professor, Chemical Engineering, the team includes Anjali Edathil, former Research Engineer, and Shaihroz Khan, visiting Research Assistant. The in-situ strategy used to produce the graphene-sand hybrid with date syrup is described in a paper published in Scientific Reports.

Dr. Banat’s team used pyrolysis – the process of chemically decomposing organic materials at high temperatures in the absence of oxygen – to decompose the date syrup. This triggers a change of chemical composition and the synthesis of a large volume of graphene material, that subsequently attaches to desert sand without the use of any external chemical agents. Moreover, graphene’s high surface area, combined with its versatile chemistry and highly water-repellent surface physical property, makes it an ideal adsorbent for removing pollutants.

Dr. Banat’s graphene-sand hybrid adsorbent was tested in the laboratory and showed remarkable efficiency in simultaneously removing both dye and heavy metals from multicomponent systems. The researchers concluded that their adsorbent had great potential as an exceptional material resource of water purification.

“This will undoubtedly open new avenues for the practicability of graphene to curb the existing water shortage,” said Dr. Banat. “We hope our material will help in increasing water resources in the UAE, reducing energy consumption in wastewater treatment processes and be used to convert oily wastewaters from waste-to-commodity that can be used in applications such as industrial recycling and agriculture.”

Tags:  Fawzi Banat  Graphene  Khalifa University  Water Purification 

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UT Projects Win $23.6M in R&D Funds as Part of Portuguese Government Technology Program

Posted By Graphene Council, Wednesday, June 10, 2020
The UT Austin Portugal program, a 13-year-old innovation partnership between the university and the Portuguese government, received $23.6 million in funding to pursue 11 R&D projects as part of a major technology initiative from Portugal’s Ministry of Science, Technology and Higher Education.

The projects fall under four major categories: nanomaterials, earth-space interactions, medical physics and advanced computing. The teams will spend the next three years developing their projects, which could transform industries like automotive, space, health care and data science.

“Ranging from electromagnetic interference shielding nanomaterials, to in-beam time-of-flight positron emission tomography for proton radiation therapy, all the way to an ocean and climate change monitoring constellation based on radar altimeter data combined with gravity and ocean temperature and salinity measurements, the spread, number, and quality of the UT Austin Portugal joint strategic projects selected for funding within the recent competitive solicitation set forth by the Foundation for Science and Technology and National Innovation Agency are truly outstanding,” said Manuel Heitor, Portugal’s Minister of Science, Technology and Higher Education. “I look forward to witnessing the results of such collaborative research between Portuguese and UT researchers.”

The call for proposals included just three universities: The University of Texas at Austin, Carnegie Mellon University and the Massachusetts Institute of Technology. UT won the majority of the investment dollars, about 40% of the funding, and saw the most projects funded among the three engineering powerhouses.

“We had anticipated four to five projects would be selected for strategic grant awards and were astounded when we learned 11 had been selected by the evaluation panel in Portugal,” said John Ekerdt, Cockrell School associate dean for research and principal investigator for UT Austin Portugal. “This is a testament to the outstanding faculty and quality projects they proposed with collaborators in Portugal and to the close ties that have been forged between UT researchers and faculty and counterparts in Portugal.”

“The performance of the UT Austin Portugal program in the 2019 call for strategic projects has been remarkable,” said Marco Bravo, executive director of the UT Austin Portugal program. “Eleven of 14 project proposals submitted by the UT Austin Portugal research consortia were approved for funding through an independent assessment process. Overall, UT Austin Portugal saw 11 of its groundbreaking, industry-led proposals approved out of a total of 25 projects approved at this solicitation that included proposals from two other international partnerships, corresponding to nearly $24 million over three years. That’s 40% of total funding to UT Austin Portugal projects, the largest share of research dollars available. UT Austin researchers are to be congratulated on this effort.”

The UT Austin Portugal program dates back to 2007, and it is one of several partnerships between the Portuguese government and research institutions. The goal is to elevate science and technology in Portugal while fostering strong partnerships to help universities continue to innovate. The partnership with UT was extended in 2018, continuing the alliance until at least 2030.

“Of the three international partnerships with American universities sponsored by the Portuguese Foundation for Science and Technology in Portugal, the partnership with UT Austin had the best performance in this call, which was designed and launched on the Portuguese side,” said José Manuel Mendonça, national director of the program. “The 11 approved projects represent a proposal success rate of almost 80% for the UT Austin Portugal Program. The approved projects will, undoubtedly, contribute to promoting and strengthening collaborations with UT Austin in high-level R&D matters with immediate transposition to various sectors of economic activity, several of which are critical to Portugal's competitive position at an international level.”

About a third of the funds for UT’s projects come from the university, with the rest coming from a combination of public and private Portuguese entities. Each project team in Portugal is led by a Portuguese company. The UT side includes 21 faculty members and one from the MD Anderson Cancer Center.

Here is a look at the UT projects:

Shielding electronic devices from electromagnetic interference
This project proposes to use the “wonder material” graphene to improve on methods to combat electromagnetic interference, which can disrupt circuits and cause devices to fail. The team plans to create two composites with electromagnetic interference shielding capabilities and fabricate a solution to protect electric wires used in the automotive industry.

UT Austin Faculty: Deji Akinwande, Cockrell School of Engineering, Department of Electrical and Computer Engineering; Brian Korgel, Cockrell School of Engineering, McKetta Department of Chemical Engineering

New lasers for next-generation biomedical imaging
The use of multiphoton microscopy to examine cell behavior in live tissue over time has become an important research tool for learning more about brains and tumors. This project aims to increase the speed and depth of this form of imaging and diagnostics through the development and application of ultrashort laser pulses.

UT Austin Faculty: Andrew Dunn, Cockrell School of Engineering, Department of Biomedical Engineering; Adela Ben-Yakar, Cockrell School of Engineering, Walker Department of Mechanical Engineering

Nano-satellites for gravitational field assessment
Researchers propose to develop a nano-satellite prototype for studying gravitational fields. The project will also develop a platform for future nano-satellite capabilities, including Earth observation, communications and exploration missions.

UT Austin Faculty: Byron Tapley, Cockrell School of Engineering, Department of Aerospace Engineering and Engineering Mechanics, and the Center for Space Research; Brandon Jones, Cockrell School of Engineering, Department of Aerospace Engineering and Engineering Mechanics, and the Texas Spacecraft Laboratory

Software to match big data with high-performance computing
The advancement of technology has generated huge troves of data, which requires stronger computing power to process and analyze all that information. This project aims to create a software bundle to help companies pair their big data operations with high-performance computing, which includes tools for managing challenges such as computing and research storage.

UT Austin Faculty: Vijay Chidambaram, College of Nature Sciences, Department of Computer Science; Todd Evans, Texas Advanced Computing Center

Sensors for monitoring cancer patients
This project will develop a biosensor that can be injected into prostate cancer patients after surgery. The minimally invasive sensor would allow medical personnel to monitor high-risk patients remotely and look for the development of early tumors, with the potential to increase the predictive value of cancer screenings.

UT Austin Faculty: Thomas Milner, Cockrell School of Engineering, Department of Biomedical Engineering; James Tunnell, Cockrell School of Engineering, Department of Biomedical Engineering

Wearable rehabilitation devices
Researchers will develop a series of nano-sensors embedded into clothing that administer electrostimulation to people suffering from a lack of mobility and motor deficiency. The sensors could be monitored remotely by health professionals, creating a mobile rehabilitation option for people who have trouble getting to a doctor’s office consistently or want greater freedom to complete treatment anywhere. The team envisions its project as a tool mostly for elderly people, but it has applications for training high-level athletes as well.

UT Austin Faculty: George Biros, Cockrell School of Engineering, Walker Department of Mechanical Engineering, and the Oden Institute for Computational Engineering and Sciences; Michael Cullinan, Cockrell School of Engineering, Walker Department of Mechanical Engineering

Software for gathering better data on manufacturing
Getting reliable data on manufacturing processes proves challenging due to issues with placing sensors in the right spots and retaining strong connectivity. Thin films loaded with small sensors that can be applied directly to the equipment represent a promising solution; however, installation has proved difficult. This project proposes a new set of software to make it easier to layer these films on top of equipment by providing necessary data to avoid mechanical problems during installation.

UT Austin Faculty: Rui Huang, Cockrell School of Engineering, Department of Aerospace Engineering and Engineering Mechanics, Center for Mechanics of Solids, Structures and Materials; Kenneth M. Liechti, Cockrell School of Engineering, Department of Aerospace Engineering and Engineering Mechanics, Center for Mechanics of Solids, Structures and Materials

A new way to measure next-generation cancer therapy
Proton radiation therapy, the use of protons rather than X-rays to treat cancer patients, is on the rise, but measuring the distance protons travel proves problematic. Typically, it takes a ring of detectors surrounding the patient to get accurate measurements, but that poses geometric challenges. This project proposes to develop a new type of Positron Emission Tomography scan, which shows how tissues and organs are functioning to better understand the range of protons and whether they are traveling to the right spots to attack the cancer.

UT Faculty: Karol Lang, College of Natural Sciences, Department of Physics; Narayan Sahoo, University of Texas MD Anderson Cancer Center, Department of Radiation Physics

Satellite constellations for monitoring climate change
This project aims to develop the next generation of radar altimeter instruments — which measure the distance between an aircraft and the terrain below it — and a series of small satellites that can understand long-term variability in local, regional and global climate created by changes in sea levels due to water temperature. The project also includes a data processing and visualization system using advanced modeling, estimation techniques, statistical and scientific machine learning methods and error analysis.

UT Austin Faculty: Byron Tapley, Cockrell School of Engineering, Department of Aerospace Engineering and Engineering Mechanics Department, and the Center for Space Research; Patrick Heimbach, Jackson School of Geosciences, Department of Geological Sciences, and the Oden Institute for Computational Engineering and Sciences

Improving cutting tools for airline and automotive components
Fabricating parts of cars and planes is hard on cutting tools and tends to ware them down. This project aims to develop coatings that better protect and extend the lifespan of these crucial pieces of equipment. The team also plans to develop simulation programs to improve cutting tools’ performance.

UT Austin Faculty: Gregory J. Rodin, Cockrell School of Engineering, Department of Aerospace Engineering and Engineering Mechanics, and the Oden Institute for Computational Engineering and Sciences; Filippo Mangolini, Cockrell School of Engineering, Walker Department of Mechanical Engineering

An alternative to traditional water treatment options
Traditional water treatment tech struggles to efficiently remove high amounts of pollutants from some types of surface and groundwater. This team is looking to use metallic nanoparticles to clean water by improving a process called catalytic hydrogenation, which involves adding hydrogen via a metallic catalyst.

UT Austin Faculty: Charles J. Werth, Cockrell School of Engineering, Department of Civil, Architectural, and Environmental Engineering; Simon M. Humphrey, College of Natural Sciences, Department of Chemistry

Tags:  Biomedical  Carnegie Mellon University  Electronics  Environment  Graphene  Healthcare  John Ekerdt  Marco Bravo  Massachusetts Institute of Technology  nanomaterials  Sensors  The University of Texas at Austin  Water Purification 

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IIT Guwahati research team develops hierarchically structured graphene oxide nanosheets that can selectively separate oily or aqueous contaminates from respective emulsions

Posted By Graphene Council, Thursday, April 23, 2020
Researchers of Indian Institute of Technology Guwahati have developed a graphene-based superhydrophobic materials that can separate oil and water from both oil-in-water and water-in-oil emulsions, respectively.

Their work has recently been published in the Royal Society’s journal, Chemical Science. The research paper has been authored by Dr. Uttam Manna, Associate Professor, Department of Chemistry, IIT Guwahati, along with his research scholars Mr. Avijit Das, Mr. Kousik Maji, and Mr. Sarajit Naska.

Oil–water separation techniques have a number of industrial and environmental applications. Various porous and bulk substrates such as sponge that are made superhydrophobic, have been used to absorb oil from oil-water emulsions. The IIT Guwahati team has shown the efficacy of hierarchically structured graphene oxide nanosheets in removing oil or aqueous contaminates from respective emulsions, thereby effecting separation of oil and water.
 
Superhydrophobic materials – materials with extreme water repellence – are considered the best materials for removing oil from water, and they are being extensively studied for applications such as water purification and self-cleaning surfaces. The problem with superhydrophobic materials is that they are generally not scalable, or use environmentally toxic products such as fluorinated polymers/small molecules, or have poor mechanical and chemical stability. Moreover, the conventional spongy superhydrophobic materials are inherently less appropriate for separating oil-in-water emulsion due to poor accessibility of the dispersed oil droplets to the oil absorbing superhydrophobic interface.

“The hydrophobicity of materials is largely governed by the physical architecture and the chemical composition, and so such materials can be rationally created by combining low-surface-energy materials with hierarchical roughness”, explains Dr. Manna. This is exactly what the group has done in its quest for oil-water separating materials. They have manipulated graphene, a form of carbon, to have superhydrophobic properties suitable for separation of oil from water in emulsions.

The study of graphene for such applications is not unprecedented. Since the award of the Nobel prize to its creators in 2010, graphene – two dimensional structures of carbon – has been extensively studied for a variety of applications. Composed of pure carbon, graphene is similar to graphite but with characteristics that make it extraordinarily light and strong, giving it a moniker of “wonder material” in present day materials science research. Research all over the world have attempted to engineer the structure and composition of graphene to get surface roughness and low surface energy, suitable for use in applications that require superhydrophobicity. Such engineering is challenging and complicated.

The IIT Guwahati team has developed a facile method to produce graphene oxide-polymer composite with hierarchical topography and low surface energy chemistry in the confined space. Such graphene oxide species showed ‘confined-super- water-repellence’. They further deposited iron oxide nanoparticles on the two dimensional nanosheets, which made the entire material magnetically active.

“Our graphene oxide composites were able to separate oil from water in emulsions with high efficiency” says Dr. Manna. The uniqueness was that the separation could be brought about even under extremes of pH, salinity, surfactant contaminations etc., as is seen in real life scenarios. The IIT Guwahati’s graphene oxide species was capable of selectively soaking up tiny crude-oil droplets in oil-to-water emulsions with high absorption capacity (above 1000 wt%), as well as coalescing larger oil droplets of emulsions from water-in-oil emulsions.

“Further functionalization of this chemically/magnetically active 2D-nano-interface could help in the development of functional interfaces for various applications related to energy, catalysis and healthcare”, says Dr. Manna.

Tags:  2D materials  Graphene  graphene oxide nanosheets  Indian Institute of Technology Guwahati  nanoparticles  Uttam Manna  water purification 

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Graphene-iron filters a promising gas separation tool: research

Posted By Graphene Council, Tuesday, March 31, 2020
UNSW researchers have shown how a new class of low-cost graphene-based membranes – a type of filter used in industry sectors that generate enormous mixed waste gases, such as solid plastic waste, biowaste or wastewater – can be selectively tuned to separate different gases from gaseous mixtures. 

The team, led by Dr Rakesh Joshi in UNSW Science, hopes that down the track, they’ll be able to use these filters to separate and capture gases that have been considered waste, and therefore improve the way we use waste gas resources. 

The paper - published this month in high-impact journal Advanced Materials - outlines findings made in the lab, on a prototype. Now the researchers want to develop the filter further to make it available to industry. 

Specifically, the team studied graphene oxide filters that – unlike any other current filter – contained iron. 

“Graphene, a thin sheet of carbon atoms that forms in a honeycomb pattern, is considered a wonder material which is stronger than steel. In this piece of work, we essentially incorporated iron into graphene oxide filters, taking advantage of the fact that these membranes are ultra-thin,” says lead researcher Dr Rakesh Joshi. 

“We found that doing this enhanced graphene oxide’s ability to transport gas. It turns out adding the iron – which is what we call a transitional metal – to graphene oxide membranes allowed us to separate different gases more effectively than with other types of filters.

“In particular, the material was great at enhancing permeance – that is, how fast a gas molecule transports through the filter – and selectivity, which represents how efficiently the gas is separated from the mixture during the transportation. In fact, our filter has unpreceded selectivity.”

Separating carbon dioxide from nitrogen
The researchers say the filter described in this paper also allowed them to recover valuable resources by selectively separating carbon dioxide from nitrogen.

“Highly purified nitrogen is widely used in materials processing – for example, in semiconductors manufacturing – as well as in electronic, synthetic, and medical industries,” says Xioheng Jin, the first author of the article. 

“Carbon dioxide is one of the most conventional impurities in gas products. Most current methods to remove CO2 often produce hazardous chemicals, and the separation of CO2 from nitrogen has significant industrial value, especially for greenhouse mitigation of flue gases – e.g., the combustion exhaust gas produced at power plants – that has been a challenge using existing technologies.”

Given the promising results, the researchers hope their findings will lead to new avenues for efficiently separating carbon dioxide from nitrogen and other gases and help them develop new solutions for industry that use this new class of filters for all sorts of applications.

“This finding provides a new opportunity for the application of graphene-based materials in the gas purification industry, for example, in instances where waste solids or waste liquids generate toxic gas mixtures,” says Tobias Foller, co-author of the article .

“We think the filter has the potential to revolutionise the gas separation industry. Ultimately, we hope that our findings help Australia achieve a greener society and a more liveable environment.”

What about other metals?
The team now wants to test the same principle using other types of metals. 

“There are enormous possibilities for all the other transition metals that have not been studied that could be implanted in graphene-based structures and provide exciting gas separation properties,” Xioheng Jin says. 

In 2018, Dr Joshi’s team also successfully demonstrated a graphene-based, laboratory-scale filter that can remove more than 99% of the ubiquitous natural organic matter left behind during conventional treatment of drinking water.

Tags:  Graphene  Rakesh Joshi  Tobias Foller  University of New South Wales  water purification  Xioheng Jin 

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​Graphene cleans water more effectively

Posted By Graphene Council, Friday, March 27, 2020

Billions of cubic meters of water are consumed each year. However, lots of the water resources such as rivers, lakes and groundwater are continuously contaminated by discharges of chemicals from industries and urban area. It’s an expensive and demanding process to remove all the increasingly present contaminants, pesticides, pharmaceuticals, perfluorinated compounds, heavy metals and pathogens. Graphil is a project that aims to create a market prototype for a new and improved way to purify water, using graphene.

Graphene enhanced filters for water purification (GRAPHIL) is one of eleven selected spearhead projects funded by The Graphene Flagship, Europe’s biggest initiative on graphene research, involving more than 140 universities and industries located in 21 countries. Chalmers is the coordinator of the Graphene Flagship.

The purpose of the spearhead projects which will start in April 2020, building on previous scientific work, is to take graphene-enabled prototypes to commercial applications. Planned to end in 2023, the project aims to produce a compact filter that can be connected directly onto a household sink or used as a portable water purifying device, to ensure all households have access to safe drinking water.

"This is a brand-new research line for Chalmers in the Graphene flagship, and it will be a strategic one. The purification of water is a key societal challenge for both rich and poor countries and will become more and more important in the next future. In Graphil, hopefully we will use our knowledge of graphene chemistry to produce a new generation of water purification system via interface engineering of graphene-polysulfone nanocomposites," says Vincenzo Palermo, professor at the Department of industrial and materials science.
 
Graphene enhanced filters outperforms other water purification techniques
Most of the water purification processes today are based on several different techniques. These are adsorption on granular activated carbon that removes organic contaminants, membrane filtration that removes for example, bacteria or large pollutants, and reverse osmosis. Reverse osmosis is the only technique today that can remove organic or inorganic emerging concern contaminants with high efficiency. Reverse osmosis has however high electrical and chemical costs both from the operation and the maintenance of the system.
 
Many existing contaminants present in Europe’s water sources, including pharmaceuticals, personal care products, pesticides and surfactants, are also resistant to conventional purification technologies. Consequently, the number of cases of contamination of ground and even drinking water is rapidly increasing throughout the world, and it is matter of great environmental concern due to their potential effect on the human health and ecosystem.
 
Graphil is instead proposing to use graphene related material polymer composites. Thanks to the unique properties of graphene, the composite material favours the absorption of organic molecules. Its properties also allow the material to bind ions and metals, thus reducing the number of inorganic contaminants in water. Furthermore, unlike typical reverse osmosis, granular activated carbon and microfiltration train systems, the graphene system will provide a much simpler set up for users.

Graphil will not just replace all the old techniques, but significantly out-perform them both in efficiency and cost. The filter works as a simple microfiltration membrane, and this simplicity requires lower operation pressures, amounting in reduced water loss and lower maintenance costs for end users.
 
Upscaling the technique for industrial use
Chalmers has, in collaboration with other partners of the Graphene Flagship, investigated during the last years the fundamental structure-property relationships of graphene related material and polysulfones composition in water purification. A filter has then been successfully developed and validated in an industrial environment by the National Research Council of Italy (CNR) and the water filtration supplier Medica.

Now the task is to integrate the results and prove that the production can be upscaled in a complete system for commercial use.

Prof. Vincenzo Palermo and Dr. Zhenyuan Xia from the department of Industrial and Materials Science, Chalmers will support Graphil with advanced facilities for chemical, structural and mechanical characterization and processing of graphene oriented-polymer composite on the Kg scale. Chalmers’ role in the project will be to perform chemical functionalization of the graphene oxide and of the polymer fibers used in the filters, to enhance their compatibility and their performance in capturing organic contaminants.

"We are very excited to begin this new activity in collaboration with partners from United Kingdom, France and Italy, and I hope that my previous ten years’ international working experience in Italy and Sweden will help us to better fulfil this project," says Zhenyuan Xia, researcher at the Department of industrial and materials science.
 
 
Partners
Graphil is a multidisciplinary project that consists of both academic and industry partners. The academic partners include Chalmers, the National Research Council of Italy (CNR) and the University of Manchester. The industrial partners are Icon Lifesaver, Medica SpA and Polymem S.A – all European industry leaders in the water purification sector. The aim is to have a working filter prototype that can be commercialized by the industry for household water treatment and portable water purification.
 
Funding
The Graphene Flagship is one of the largest research projects funded by the European Commission. With a budget of €1 billion over 10 years, it represents a new form of joint, coordinated research, forming Europe's biggest ever research initiative. The Flagship is tasked with bringing together academic and industrial researchers to take graphene from academic laboratories into European society, thus generating economic growth, new jobs and new opportunities.
 
The total budget of the spearhead project GRAPHIL will be 4.88 million EURO and it will start from April 2020 with a total period of 3 years.

Tags:  Chalmers University of Technology  Graphene  Graphene Flagship  GRAPHIL  nanocomposites  Vincenzo Palermo  water purification  Zhenyuan Xia 

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INST Mohali moving towards a globally competitive institution in Nano Science & Technology

Posted By Graphene Council, The Graphene Council, Monday, January 27, 2020
A cost-efficient and scalable method for graphene-based integrated on-chip micro supercapacitor, which is a miniaturized electrochemical storage device. A 'Nano-Spray Gel' that could be administered on-site for treatment of frostbite injuries and heal the wound; a novel low cost topical hemostatic device to address uncontrolled bleeding, purification devices for water and air respectively.

These are only some of the technologies rolled out by the Institute of Nanoscience and Technology (INST), one of the youngest autonomous institutions of the Department of Science and Technology. INST encourages all aspects of nanoscience and nanotechnology with major thrust in the areas of healthcare, agriculture, medical environment and energy with the ultimate goal to make a difference to society through nanoscience and technology.

INST brings together biologists, chemists, physicists, materials scientists, and engineers having an interest in nanoscience and technology. The scientists, having strengths in basic science together with more application-oriented minds from different backgrounds, work together by joining hands as a cohesive unit, under a congenial work environment, on a common platform apart from carrying out their individual research.

INST offers Ph.D. and Postdoctoral fellowships to students as part of its human resource development objective. Through its various activities, INST is committed to contribute significantly to the National Societal Programs like Swachh Bharat Abhiyan, Swasth Bharat, Smart Cities, Smart Villages, supporting the Strategic Sector, Make in India and Clean & Renewable Energy through scientific means and by generating processes, technologies and devices.

The institute encourages its scientists to publish their research in peer-reviewed international high impact journals which is reflected in their recent publication record in reputed journals like Energy and Environment, Nature Communication, JACS etc.INST supports industry’s through joint collaborations to address some of their needs like effluent management.

In addition, the institute imparts advanced training courses and laboratory techniques in the area of nanoscience, organizes important national and international level seminars and conferences, and supports the industry through joint industrial projects.INST is also promoting science amongst the young generation of the nation through its outreach program, especially for rural, remote and under-served schools by delivering talks to motivate the students to explore the world of science.

INST Mohali aims to emerge as India’s foremost research institution in Nano Science and Technology, which is globally competitive and contributes to the society through the application of nanoscience and nanotechnology in the field of healthcare, agriculture, energy and environment.

Tags:  Graphene  Institute of Nanoscience and Technology  nanotechnology  supercapacitor  water purification 

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