Connect with us

Material Science

Making the most of metals from cradle to grave


Position Senior Research Fellow

Institution School of Engineering, University of Limerick

URL www.ul.ie
www.bravoeip.eu
www.lcdval.eu
www.votechnik.com
www.revolvproject.eu

Lisa O'Donoghue, University of Limerick.
Lisa O'Donoghue, University of Limerick.
The EU's list of Critical Raw Materials (CRM) shows those that have high economic importance and are considered a supply risk with in the region (red dots represent CRMs).
The EU's list of Critical Raw Materials (CRM) shows those that have high economic importance and are considered a supply risk with in the region (red dots represent CRMs).
EC eco-innovation ReVolv project meeting.
EC eco-innovation ReVolv project meeting.
Launch event.
Launch event.
Algeopolymers project meeting.
Algeopolymers project meeting.

We live in a ‘throw away’ or ‘use once’ economy where growth (sell more) is pitted directly against the waste (reuse and recycle). Companies measure growth in sales, expansion, export of products, and competitive pricing, while consumers or end users have patterns of behavior interacting with products. While it will be difficult to drive the sustainable use of materials, Lisa O’Donoghue and her colleagues at the University of Limerick are making progress.

Lisa O’Donoghue talked to Materials Today/Metal Powder Reports about her current research and the future of sustainable approaches to metal processing and usage.

What are the major themes of your current research?

Our research is focused on the raw material needs and requirements of society and specifically on ‘critical raw materials’ (CRM), which are materials and metals essential to our economy and lifestyle (typically used in ICT products, transportation, and mobility sectors). Many of these materials have difficult-to-secure long-term supply and our focus is on recovering these materials from secondary or waste sources.

We develop technologies to capture CRM from waste and by-products arising from different industries including the alumina sector, mining industry, power plants, and electronics manufacturers. The goal is to obtain a high purity fraction of metal that can be re-inserted into the value chain and processed by smelters and traditional hydrometallurgy plants into raw material feedstock, turning waste into a source (a type of alchemy) according to the principles of circular economy. 

How and why did you come to work in these areas?

Our research has been directly influenced by the EU and national policy, which have highlighted the dependency we have as a society on particular metals and minerals and the need to secure sustainable resources. The EU has published a list of high economic importance CRMs that are considered a supply risk within the region (as shown in the figure where red dots represent CRMs). Metals such as indium, vanadium, gallium, scandium, and magnesium are among those listed. Indium, for example, is used as transparent electrode material in displays (TVs and monitors) and is predominantly supplied from China. The opportunity exists to recover and recycle indium from waste LCDs, providing an internal source of the metal in a closed loop system and reducing dependency on imports.

We are running research projects on key application areas including LCD recycling, indium recovery, alumina residue processing for CRMs, flyash reuse, novel geopolymers, and mine tailing metal recovery. These projects are funded by the Irish Environment Protection Agency to identify pressures and opportunities within the region for particular waste streams, potential solutions, and new technologies, using the results to inform policy as well as industrial applications.

What do you think has been your most influential work to date?

We have developed an automated recycling technology that is being deployed at full scale in an Irish facility recycling the country’s waste LCDs. The technology removes components from old or waste LCD TVs displays that contain hazardous substances including mercury tubes and liquid crystal panels. As TVs have a complex internal structure, disassembly is predominantly manual, which can expose workers to mercury and glass lacerations, as well as being a very slow process (only 3-6 LCDs can be disassembled per hour). Instead, our high-throughput approach has the capacity to process 80 LCDs per hour in a safe environment. The technology is patented and being brought to market by the spinout company Votechnik, which launched in Ireland under an EC eco-innovation €1.6m pilot project called ReVolv. The first-of-its-kind automated robotic recycling plant has a processing capacity of over 160,000 LCD per year, removing 38.5 tonnes of mercury-containing fluorescent tubes and 266 tonnes of liquid crystal panels, taking care of Ireland’s entire LCD recycling requirements. The technology has been granted patents in the USA, Japan, Korea, and multiple European applications are in process. Votechnik is now engaging with these key markets for multiple launches and deployments of the technology. 

In addition, the research team at Limerick has undertaken a follow-on project called LCDVAL on indium recovery from the liquid crystal glass panel component of LCDs. We are working on a solution that will fit with the Irish industrial landscape with a focus on pre-treatment of LCD panels to remove the indium in the form of a high purity concentrated powder that can be shipped abroad for smelting where economics of scale would render the process viable. We have developed a novel laser removal process that can be scaled to meet the requirements of indium recovery safely and efficiently. We are currently focusing on the scale-up opportunities with a variety of industry and innovation platforms, with a goal to launch the technology in Ireland.

We also work on waste streams generated by the alumina and aluminum sector. Ireland is home to Europe’s largest alumina refinery, Aughinish Alumina, which produces 1 million tonnes of alumina a year from bauxite ore. The Bayer process on which the refinery relies generates 0.6-1 tonnes of bauxite residue annually. The Algeopolymers project focuses on using these wastes in novel materials, known as geopolymers, which have applications as new cements for the concrete sector. We have created a national stakeholder platform for the industry (including the concrete sector, alumina and flyash producers), along with government and policy organizations, to explore the potential for applications of geopolymers in Ireland. The real impact of this research has been on the development of an Irish roadmap for geopolymer applications. 

We are also a partner in REMOVAL, a large-scale EU multi-pilot project on valorization of bauxite residue, which is deploying cutting-edge technology to valorize bauxite residue including CRM recovery. These pilots represent close-to-market activities that are the forefront of development of breakthrough technologies. Our role is to undertake economic viability studies of the deployed pilots and assess their impact on the local ecosystem (both economic and legislative).

Lastly, we co-ordinate BRAVO, a European Innovation Partnership (EIP) on alumina and aluminum by-products valorization. BRAVO partners represent over 44% of the global aluminum market and the consortium provides a platform for a collaborative systemic approach to addressing common market challenges. The consortium is uniquely positioned to make an impact on the aluminum, steel, and construction sectors through technology and business innovations addressing these challenges. We are also a partner in the WEEE2020 EIP on waste electronics and EIT Raw Materials. 

I believe these EU-supported platforms are key to bringing together industrial sectors to address diverse challenges across complex value chains. These platforms create fertile grounds for innovation and it is from these that projects with the potential to have real impact emerge. 

What have been the most major developments in this field over the past decade?

The area of metal or CRM recovery has been around for a very long time – driven by industry where it is economically viable to recover metals. Platinum smelting facilities, for example, have procedures to capture platinum residues or particles in filters, which can be recycled back into the process. During indium deposition on PV or LCD panels, up to 80% of internal sections of the manufacturing setup get coated as well, so these are regularly stripped and the material recycled back to the process. These examples of closed loop recycling work well because impurities are not introduced into the system, but when it comes to recovery of individual metals from complex systems containing an array of materials bonded to each other it becomes much more difficult and cost ineffective.

Over the last decade in Europe, however, we have seen a large push for metal and CRM recovery, particularly regarding electronics. The EU’s WEEE directive requires that 85% weight of the product must be recycled or recovered. These policies have had a significant impact on value chains with manufacturers (under producer responsibilities), recyclers, and recovery plants now liaising and discussing ways to achieve the targets.

I believe these policies have been the key driver of the major developments seen over the last decade. These developments include cross-sector and value chain dialogue and engagement, consideration of recycling requirements during product design, industrial pilots testing new technologies, and market uptake activities.  

Europe 2020 and other flagship initiatives are now setting the direction for the future, promoting the principles of waste hierarchy such as material reuse, recycle, recovery, and energy recovery. There is still away to go toward CRM recovery and sustainable recycling practices compatible with current infrastructure and value chains in particular sectors. Continued activity pushing new technologies and practices into the market for materials recovery will be required.

What specific questions or problems do you hope to tackle in the future?               

The challenge of the future, I believe, is tackling the alignment of the value chain with the core principles of circular economy that foster both economics and sustainability. For this reason, I think industry and stakeholder platforms, where novel business models and local ecosystem approaches can be fostered, are key to the adoption of new technologies and sustainable recycling.

Specific sectors where there could be a high impact are ICT, where there is a high turnover of electronic products such as mobile phones, LCD displays, and laptops; and electric vehicles for which battery consumption, materials requirements, recycling and reducing use of non-recyclable plastic will be important. The development of technologies to meet these needs should run in tandem with improvements to business model and value chain practices.

Creating high-value CRM powders from multiple sources or sectors will require utilizing local ecosystems of materials inventories and finding relevant applications that add value. New processing routes such as 3D-printing or additive manufacturing could offer a key potential opportunity for these materials. 

Where do you see this area of research going in the future?

Within the next 5-10 years, I see technologies addressing key raw material needs within individual sectors continuing to be developed and tested with a stepwise and somewhat slow implementation and market uptake. 

The real impact, I believe, will come with a business model approach over 10-20 years, which will help technologies penetrate markets more readily. Support from the policy sector will foster new market uptake and adaption of the value chain for sustainable materials consumption.  

How do you believe research could impact on real-life applications in the future? 

Our work on LCD recycling shows how research can go from the lab to the market to solve a need at a national level. I believe that the future impact of such research around the world can have a positive effect reducing the amount of waste going to landfill, increasing recovery of CRM from secondary resources, and using waste from one sector as feedstock for another.

The changes or adaptions required in a complex value chain to adopt such technologies serve as a glass ceiling to implementing developed solutions, making the business model mechanism a key aspect of future developments. 

What factors do you believe will be key to the success of the field in the future?

At the research level, I believe funding technology development with market impact in mind and examining in parallel how technologies would fit with value chain infrastructure and market dynamics is key. Projects that engage key players across the value chain give the best chance of success. Researching business model approaches in tandem with technology development is vital.

At company level, the drivers behind company investment strategy should be guided by principles of sustainable supply and usage of materials. Traditional investment strategies of growing a company quickly by saturating the local market and then exporting products are not always in line with the best life cycle approach. Investors could diversify their portfolios to include local ecosystem entrepreneurial activities and export models.

Last year, I spent five months with the EU’s EIT Raw Materials initiative at their Swedish division for mining and metallurgy sector, which gave me the opportunity to evaluate and work on core aspects at the heart of the sustainable supply of raw materials from ore to end product. Many technologies end in ‘the valley of death’ – the gap between seed funding and market – which I believe is often the result of the complexity of deploying a new technology in a value chain with competing drivers. 

Are there any developments that you would particularly like to see come to pass?

From my years of research in LCD and ICT product recycling – and seeing how many electronic products I own myself – I believe the circular economy concept could have a large impact on this sector. The base and exotic metals used to power and operate electronic devices are only ever needed in small amounts for next generation products. Being readily able to recycle these materials could, I believe, have a significant impact. At the end of the day, end user consumption drives our material needs.

Further information

http://votechnik.com/

http://revolvproject.eu/

Technology video: https://www.youtube.com/watch?v=s8GKB7JdFc8&t=4s

http://lcdval.eu/

http://bravoeip.eu/algeopolymers/

https://www.removal-project.com/

https://eitrawmaterials.eu/

Republished by Plato

Published

on


Position Senior Research Fellow

Institution School of Engineering, University of Limerick

URL www.ul.ie
www.bravoeip.eu
www.lcdval.eu
www.votechnik.com
www.revolvproject.eu

Lisa O'Donoghue, University of Limerick.
Lisa O’Donoghue, University of Limerick.
The EU's list of Critical Raw Materials (CRM) shows those that have high economic importance and are considered a supply risk with in the region (red dots represent CRMs).
The EU’s list of Critical Raw Materials (CRM) shows those that have high economic importance and are considered a supply risk with in the region (red dots represent CRMs).
EC eco-innovation ReVolv project meeting.
EC eco-innovation ReVolv project meeting.
Launch event.
Launch event.
Algeopolymers project meeting.
Algeopolymers project meeting.

We live in a ‘throw away’ or ‘use once’ economy where growth (sell more) is pitted directly against the waste (reuse and recycle). Companies measure growth in sales, expansion, export of products, and competitive pricing, while consumers or end users have patterns of behavior interacting with products. While it will be difficult to drive the sustainable use of materials, Lisa O’Donoghue and her colleagues at the University of Limerick are making progress.

Lisa O’Donoghue talked to Materials Today/Metal Powder Reports about her current research and the future of sustainable approaches to metal processing and usage.

What are the major themes of your current research?

Our research is focused on the raw material needs and requirements of society and specifically on ‘critical raw materials’ (CRM), which are materials and metals essential to our economy and lifestyle (typically used in ICT products, transportation, and mobility sectors). Many of these materials have difficult-to-secure long-term supply and our focus is on recovering these materials from secondary or waste sources.

We develop technologies to capture CRM from waste and by-products arising from different industries including the alumina sector, mining industry, power plants, and electronics manufacturers. The goal is to obtain a high purity fraction of metal that can be re-inserted into the value chain and processed by smelters and traditional hydrometallurgy plants into raw material feedstock, turning waste into a source (a type of alchemy) according to the principles of circular economy. 

How and why did you come to work in these areas?

Our research has been directly influenced by the EU and national policy, which have highlighted the dependency we have as a society on particular metals and minerals and the need to secure sustainable resources. The EU has published a list of high economic importance CRMs that are considered a supply risk within the region (as shown in the figure where red dots represent CRMs). Metals such as indium, vanadium, gallium, scandium, and magnesium are among those listed. Indium, for example, is used as transparent electrode material in displays (TVs and monitors) and is predominantly supplied from China. The opportunity exists to recover and recycle indium from waste LCDs, providing an internal source of the metal in a closed loop system and reducing dependency on imports.

We are running research projects on key application areas including LCD recycling, indium recovery, alumina residue processing for CRMs, flyash reuse, novel geopolymers, and mine tailing metal recovery. These projects are funded by the Irish Environment Protection Agency to identify pressures and opportunities within the region for particular waste streams, potential solutions, and new technologies, using the results to inform policy as well as industrial applications.

What do you think has been your most influential work to date?

We have developed an automated recycling technology that is being deployed at full scale in an Irish facility recycling the country’s waste LCDs. The technology removes components from old or waste LCD TVs displays that contain hazardous substances including mercury tubes and liquid crystal panels. As TVs have a complex internal structure, disassembly is predominantly manual, which can expose workers to mercury and glass lacerations, as well as being a very slow process (only 3-6 LCDs can be disassembled per hour). Instead, our high-throughput approach has the capacity to process 80 LCDs per hour in a safe environment. The technology is patented and being brought to market by the spinout company Votechnik, which launched in Ireland under an EC eco-innovation €1.6m pilot project called ReVolv. The first-of-its-kind automated robotic recycling plant has a processing capacity of over 160,000 LCD per year, removing 38.5 tonnes of mercury-containing fluorescent tubes and 266 tonnes of liquid crystal panels, taking care of Ireland’s entire LCD recycling requirements. The technology has been granted patents in the USA, Japan, Korea, and multiple European applications are in process. Votechnik is now engaging with these key markets for multiple launches and deployments of the technology. 

In addition, the research team at Limerick has undertaken a follow-on project called LCDVAL on indium recovery from the liquid crystal glass panel component of LCDs. We are working on a solution that will fit with the Irish industrial landscape with a focus on pre-treatment of LCD panels to remove the indium in the form of a high purity concentrated powder that can be shipped abroad for smelting where economics of scale would render the process viable. We have developed a novel laser removal process that can be scaled to meet the requirements of indium recovery safely and efficiently. We are currently focusing on the scale-up opportunities with a variety of industry and innovation platforms, with a goal to launch the technology in Ireland.

We also work on waste streams generated by the alumina and aluminum sector. Ireland is home to Europe’s largest alumina refinery, Aughinish Alumina, which produces 1 million tonnes of alumina a year from bauxite ore. The Bayer process on which the refinery relies generates 0.6-1 tonnes of bauxite residue annually. The Algeopolymers project focuses on using these wastes in novel materials, known as geopolymers, which have applications as new cements for the concrete sector. We have created a national stakeholder platform for the industry (including the concrete sector, alumina and flyash producers), along with government and policy organizations, to explore the potential for applications of geopolymers in Ireland. The real impact of this research has been on the development of an Irish roadmap for geopolymer applications. 

We are also a partner in REMOVAL, a large-scale EU multi-pilot project on valorization of bauxite residue, which is deploying cutting-edge technology to valorize bauxite residue including CRM recovery. These pilots represent close-to-market activities that are the forefront of development of breakthrough technologies. Our role is to undertake economic viability studies of the deployed pilots and assess their impact on the local ecosystem (both economic and legislative).

Lastly, we co-ordinate BRAVO, a European Innovation Partnership (EIP) on alumina and aluminum by-products valorization. BRAVO partners represent over 44% of the global aluminum market and the consortium provides a platform for a collaborative systemic approach to addressing common market challenges. The consortium is uniquely positioned to make an impact on the aluminum, steel, and construction sectors through technology and business innovations addressing these challenges. We are also a partner in the WEEE2020 EIP on waste electronics and EIT Raw Materials. 

I believe these EU-supported platforms are key to bringing together industrial sectors to address diverse challenges across complex value chains. These platforms create fertile grounds for innovation and it is from these that projects with the potential to have real impact emerge. 

What have been the most major developments in this field over the past decade?

The area of metal or CRM recovery has been around for a very long time – driven by industry where it is economically viable to recover metals. Platinum smelting facilities, for example, have procedures to capture platinum residues or particles in filters, which can be recycled back into the process. During indium deposition on PV or LCD panels, up to 80% of internal sections of the manufacturing setup get coated as well, so these are regularly stripped and the material recycled back to the process. These examples of closed loop recycling work well because impurities are not introduced into the system, but when it comes to recovery of individual metals from complex systems containing an array of materials bonded to each other it becomes much more difficult and cost ineffective.

Over the last decade in Europe, however, we have seen a large push for metal and CRM recovery, particularly regarding electronics. The EU’s WEEE directive requires that 85% weight of the product must be recycled or recovered. These policies have had a significant impact on value chains with manufacturers (under producer responsibilities), recyclers, and recovery plants now liaising and discussing ways to achieve the targets.

I believe these policies have been the key driver of the major developments seen over the last decade. These developments include cross-sector and value chain dialogue and engagement, consideration of recycling requirements during product design, industrial pilots testing new technologies, and market uptake activities.  

Europe 2020 and other flagship initiatives are now setting the direction for the future, promoting the principles of waste hierarchy such as material reuse, recycle, recovery, and energy recovery. There is still away to go toward CRM recovery and sustainable recycling practices compatible with current infrastructure and value chains in particular sectors. Continued activity pushing new technologies and practices into the market for materials recovery will be required.

What specific questions or problems do you hope to tackle in the future?               

The challenge of the future, I believe, is tackling the alignment of the value chain with the core principles of circular economy that foster both economics and sustainability. For this reason, I think industry and stakeholder platforms, where novel business models and local ecosystem approaches can be fostered, are key to the adoption of new technologies and sustainable recycling.

Specific sectors where there could be a high impact are ICT, where there is a high turnover of electronic products such as mobile phones, LCD displays, and laptops; and electric vehicles for which battery consumption, materials requirements, recycling and reducing use of non-recyclable plastic will be important. The development of technologies to meet these needs should run in tandem with improvements to business model and value chain practices.

Creating high-value CRM powders from multiple sources or sectors will require utilizing local ecosystems of materials inventories and finding relevant applications that add value. New processing routes such as 3D-printing or additive manufacturing could offer a key potential opportunity for these materials. 

Where do you see this area of research going in the future?

Within the next 5-10 years, I see technologies addressing key raw material needs within individual sectors continuing to be developed and tested with a stepwise and somewhat slow implementation and market uptake. 

The real impact, I believe, will come with a business model approach over 10-20 years, which will help technologies penetrate markets more readily. Support from the policy sector will foster new market uptake and adaption of the value chain for sustainable materials consumption.  

How do you believe research could impact on real-life applications in the future? 

Our work on LCD recycling shows how research can go from the lab to the market to solve a need at a national level. I believe that the future impact of such research around the world can have a positive effect reducing the amount of waste going to landfill, increasing recovery of CRM from secondary resources, and using waste from one sector as feedstock for another.

The changes or adaptions required in a complex value chain to adopt such technologies serve as a glass ceiling to implementing developed solutions, making the business model mechanism a key aspect of future developments. 

What factors do you believe will be key to the success of the field in the future?

At the research level, I believe funding technology development with market impact in mind and examining in parallel how technologies would fit with value chain infrastructure and market dynamics is key. Projects that engage key players across the value chain give the best chance of success. Researching business model approaches in tandem with technology development is vital.

At company level, the drivers behind company investment strategy should be guided by principles of sustainable supply and usage of materials. Traditional investment strategies of growing a company quickly by saturating the local market and then exporting products are not always in line with the best life cycle approach. Investors could diversify their portfolios to include local ecosystem entrepreneurial activities and export models.

Last year, I spent five months with the EU’s EIT Raw Materials initiative at their Swedish division for mining and metallurgy sector, which gave me the opportunity to evaluate and work on core aspects at the heart of the sustainable supply of raw materials from ore to end product. Many technologies end in ‘the valley of death’ – the gap between seed funding and market – which I believe is often the result of the complexity of deploying a new technology in a value chain with competing drivers. 

Are there any developments that you would particularly like to see come to pass?

From my years of research in LCD and ICT product recycling – and seeing how many electronic products I own myself – I believe the circular economy concept could have a large impact on this sector. The base and exotic metals used to power and operate electronic devices are only ever needed in small amounts for next generation products. Being readily able to recycle these materials could, I believe, have a significant impact. At the end of the day, end user consumption drives our material needs.

Further information

http://votechnik.com/

http://revolvproject.eu/

Technology video: https://www.youtube.com/watch?v=s8GKB7JdFc8&t=4s

http://lcdval.eu/

http://bravoeip.eu/algeopolymers/

https://www.removal-project.com/

https://eitrawmaterials.eu/

Source: https://www.materialstoday.com/metals-alloys/features/making-the-most-of-metals-from-cradle-to-grave/

Material Science

Weak force has strong impact on metal nanosheets


A transmission electron microscope image by Rice University scientists shows a silver nanosheet deformed by a particle, which forms flower-shaped stress contours in the nanosheet that indicate a bump. Image: The Jones Lab/Rice University.
A transmission electron microscope image by Rice University scientists shows a silver nanosheet deformed by a particle, which forms flower-shaped stress contours in the nanosheet that indicate a bump. Image: The Jones Lab/Rice University.

New research has revealed that the hills are alive with the force of van der Walls. Researchers at Rice University have found that nature's ubiquitous 'weak' force is sufficient to indent rigid nanosheets, extending their potential for use in nanoscale optics or catalytic systems.

Changing the shape of nanoscale particles changes their electromagnetic properties, said Matt Jones, an assistant professor of chemistry and an assistant professor of materials science and nanoengineering at Rice University. That makes the phenomenon worth further study.

"People care about particle shape, because the shape changes its optical properties," Jones said. "This is a totally novel way of changing the shape of a particle." He and his colleagues report their work in a paper in Nano Letters.

Van der Waals is a weak force that allows neutral molecules to attract one another through randomly fluctuating dipoles, or separated opposite charges, depending on distance. Though small, its effects can be seen in the macro world, like when geckos walk up walls.

"Van der Waals forces are everywhere and, essentially, at the nanoscale everything is sticky," Jones said. "When you put a large, flat particle on a large, flat surface, there's a lot of contact, and it's enough to permanently deform a particle that's really thin and flexible."

In the new study, the Rice team decided to see if this force could be used to manipulate 8nm-thick sheets of ductile silver. After a mathematical model suggested it was possible, the researchers placed 15nm-wide iron oxide nanospheres on a surface and then sprinkled prism-shaped nanosheets over them.

Without applying any other force, they saw through a transmission electron microscope that the nanosheets acquired permanent bumps where none existed before, right on top of the spheres. As measured, the distortions were about 10 times larger than the width of the spheres.

These hills weren't very high, but simulations confirmed that van der Waals attraction between the sheet and the substrate surrounding the spheres was sufficient to influence the plasticity of the silver sheet's crystalline atomic lattice. The researchers also showed that the same effect would occur in silicon dioxide and cadmium selenide nanosheets, and perhaps other compounds.

"We were trying to make really thin, large silver nanoplates and when we started taking images, we saw these strange, six-fold strain patterns, like flowers," said Jones, who earned a multiyear Packard Fellowship in 2018 to develop advanced microscopy techniques.

"It didn't make any sense, but we eventually figured out that it was a little ball of gunk that the plate was draped over, creating the strain," he said. "We didn't think anyone had investigated that, so we decided to have a look.

"What it comes down to is that when you make a particle really thin, it becomes really flexible, even if it's a rigid metal."

In further experiments, the researchers discovered that the nanospheres could be used to control the shape of the deformation, ranging from single ridges when two spheres are close together to saddle shapes or isolated bumps when the spheres are farther apart. They determined that sheets less than about 10nm thick and with aspect ratios of about 100 are most amenable to deformation.

In the paper, the researchers noted their technique creates "a new class of curvilinear structures based on substrate topography" that "would be difficult to generate lithographically". That opens up new possibilities for electromagnetic devices that are especially relevant to nanophotonic research. Straining the silver lattice could also turn the inert metal into a possible catalyst, by creating defects where chemical reactions can happen.

"This gets exciting because now most people make these kinds of metamaterials through lithography," Jones said. "That's a really powerful tool, but once you've used that to pattern your metal, you can never change it.

"Now we have the option, perhaps someday, to build a material that has one set of properties and then change it by deforming it. Because the forces required to do so are so small, we hope to find a way to toggle between the two."

This story is adapted from material from Rice University, with editorial changes made by Materials Today. The views expressed in this article do not necessarily represent those of Elsevier. Link to original source.

Republished by Plato

Published

on


A transmission electron microscope image by Rice University scientists shows a silver nanosheet deformed by a particle, which forms flower-shaped stress contours in the nanosheet that indicate a bump. Image: The Jones Lab/Rice University.
A transmission electron microscope image by Rice University scientists shows a silver nanosheet deformed by a particle, which forms flower-shaped stress contours in the nanosheet that indicate a bump. Image: The Jones Lab/Rice University.

New research has revealed that the hills are alive with the force of van der Walls. Researchers at Rice University have found that nature’s ubiquitous ‘weak’ force is sufficient to indent rigid nanosheets, extending their potential for use in nanoscale optics or catalytic systems.

Changing the shape of nanoscale particles changes their electromagnetic properties, said Matt Jones, an assistant professor of chemistry and an assistant professor of materials science and nanoengineering at Rice University. That makes the phenomenon worth further study.

“People care about particle shape, because the shape changes its optical properties,” Jones said. “This is a totally novel way of changing the shape of a particle.” He and his colleagues report their work in a paper in Nano Letters.

Van der Waals is a weak force that allows neutral molecules to attract one another through randomly fluctuating dipoles, or separated opposite charges, depending on distance. Though small, its effects can be seen in the macro world, like when geckos walk up walls.

“Van der Waals forces are everywhere and, essentially, at the nanoscale everything is sticky,” Jones said. “When you put a large, flat particle on a large, flat surface, there’s a lot of contact, and it’s enough to permanently deform a particle that’s really thin and flexible.”

In the new study, the Rice team decided to see if this force could be used to manipulate 8nm-thick sheets of ductile silver. After a mathematical model suggested it was possible, the researchers placed 15nm-wide iron oxide nanospheres on a surface and then sprinkled prism-shaped nanosheets over them.

Without applying any other force, they saw through a transmission electron microscope that the nanosheets acquired permanent bumps where none existed before, right on top of the spheres. As measured, the distortions were about 10 times larger than the width of the spheres.

These hills weren’t very high, but simulations confirmed that van der Waals attraction between the sheet and the substrate surrounding the spheres was sufficient to influence the plasticity of the silver sheet’s crystalline atomic lattice. The researchers also showed that the same effect would occur in silicon dioxide and cadmium selenide nanosheets, and perhaps other compounds.

“We were trying to make really thin, large silver nanoplates and when we started taking images, we saw these strange, six-fold strain patterns, like flowers,” said Jones, who earned a multiyear Packard Fellowship in 2018 to develop advanced microscopy techniques.

“It didn’t make any sense, but we eventually figured out that it was a little ball of gunk that the plate was draped over, creating the strain,” he said. “We didn’t think anyone had investigated that, so we decided to have a look.

“What it comes down to is that when you make a particle really thin, it becomes really flexible, even if it’s a rigid metal.”

In further experiments, the researchers discovered that the nanospheres could be used to control the shape of the deformation, ranging from single ridges when two spheres are close together to saddle shapes or isolated bumps when the spheres are farther apart. They determined that sheets less than about 10nm thick and with aspect ratios of about 100 are most amenable to deformation.

In the paper, the researchers noted their technique creates “a new class of curvilinear structures based on substrate topography” that “would be difficult to generate lithographically”. That opens up new possibilities for electromagnetic devices that are especially relevant to nanophotonic research. Straining the silver lattice could also turn the inert metal into a possible catalyst, by creating defects where chemical reactions can happen.

“This gets exciting because now most people make these kinds of metamaterials through lithography,” Jones said. “That’s a really powerful tool, but once you’ve used that to pattern your metal, you can never change it.

“Now we have the option, perhaps someday, to build a material that has one set of properties and then change it by deforming it. Because the forces required to do so are so small, we hope to find a way to toggle between the two.”

This story is adapted from material from Rice University, with editorial changes made by Materials Today. The views expressed in this article do not necessarily represent those of Elsevier. Link to original source.

Source: https://www.materialstoday.com/nanomaterials/news/weak-force-impact-metal-nanosheets/

Continue Reading

Material Science

Glass forming by metallic mixtures becomes clearer


Researchers at the University of Tokyo used computer simulations to model the effects of elemental composition on the glass-forming ability of metallic mixtures. Image: Institute of Industrial Science, the University of Tokyo.
Researchers at the University of Tokyo used computer simulations to model the effects of elemental composition on the glass-forming ability of metallic mixtures. Image: Institute of Industrial Science, the University of Tokyo.

Researchers from the Institute of Industrial Science at the University of Tokyo in Japan have used molecular dynamics calculations to simulate the glass-forming ability of metallic mixtures. They show that even small changes in composition can strongly influence the likelihood that a material will assume a crystalline versus a glassy state upon cooling. This work, reported in a paper in Science Advances, may lead to a universal theory of glass formation and cheaper, more resilient, electroconductive glasses.

Although a table might be set with expensive 'crystal' glasses, crystal and glass are actually two very different states that liquids, including liquid metals, can assume as they cool. A crystal has a defined three-dimensional lattice structure that repeats indefinitely, while glass is an amorphous solid that lacks long-range ordering.

Current theories of glass formation cannot accurately predict which metallic mixtures will 'vitrify' to form a glass and which will crystallize. A better, more comprehensive understanding of glass formation would be a great help when designing new recipes for mechanically tough, electrically conductive materials.

Now, researchers at the University of Tokyo have used computer simulations of three prototypical metallic systems to study the process of glass formation. "We found that the ability for a multi-component system to form a crystal, as opposed to a glass, can be disrupted by slight modifications to the composition," says first author Yuan-Chao Hu.

Stated simply, glass formation is the consequence of a material avoiding crystallization as it cools. This locks the atoms into a 'frozen' state before they can organize themselves into their energy-minimizing pattern. The researchers' simulations showed that a critical factor determining the rate of crystallization was the liquid-crystal interface energy.

The researchers also found that changes in elemental composition can lead to local atomic orderings that frustrate the process of crystallization, because these orderings are incompatible with the crystal's usual form. Specifically, these structures can prevent tiny crystals from acting as 'seeds' that nucleate the growth of ordered regions in the sample. In contrast with previous explanations, the scientists determined that the chemical potential difference between the liquid and crystal phases has only a small effect on glass formation.

"This work represents a significant advancement in our understanding of the fundamental physical mechanism of vitrification," says senior author Hajime Tanaka. "The results of this project may also help glass manufacturers design new multi-component systems that have certain desired properties, such as resilience, toughness and electroconductivity."

This story is adapted from material from the University of Tokyo, with editorial changes made by Materials Today. The views expressed in this article do not necessarily represent those of Elsevier. Link to original source.

Republished by Plato

Published

on


Researchers at the University of Tokyo used computer simulations to model the effects of elemental composition on the glass-forming ability of metallic mixtures. Image: Institute of Industrial Science, the University of Tokyo.
Researchers at the University of Tokyo used computer simulations to model the effects of elemental composition on the glass-forming ability of metallic mixtures. Image: Institute of Industrial Science, the University of Tokyo.

Researchers from the Institute of Industrial Science at the University of Tokyo in Japan have used molecular dynamics calculations to simulate the glass-forming ability of metallic mixtures. They show that even small changes in composition can strongly influence the likelihood that a material will assume a crystalline versus a glassy state upon cooling. This work, reported in a paper in Science Advances, may lead to a universal theory of glass formation and cheaper, more resilient, electroconductive glasses.

Although a table might be set with expensive ‘crystal’ glasses, crystal and glass are actually two very different states that liquids, including liquid metals, can assume as they cool. A crystal has a defined three-dimensional lattice structure that repeats indefinitely, while glass is an amorphous solid that lacks long-range ordering.

Current theories of glass formation cannot accurately predict which metallic mixtures will ‘vitrify’ to form a glass and which will crystallize. A better, more comprehensive understanding of glass formation would be a great help when designing new recipes for mechanically tough, electrically conductive materials.

Now, researchers at the University of Tokyo have used computer simulations of three prototypical metallic systems to study the process of glass formation. “We found that the ability for a multi-component system to form a crystal, as opposed to a glass, can be disrupted by slight modifications to the composition,” says first author Yuan-Chao Hu.

Stated simply, glass formation is the consequence of a material avoiding crystallization as it cools. This locks the atoms into a ‘frozen’ state before they can organize themselves into their energy-minimizing pattern. The researchers’ simulations showed that a critical factor determining the rate of crystallization was the liquid-crystal interface energy.

The researchers also found that changes in elemental composition can lead to local atomic orderings that frustrate the process of crystallization, because these orderings are incompatible with the crystal’s usual form. Specifically, these structures can prevent tiny crystals from acting as ‘seeds’ that nucleate the growth of ordered regions in the sample. In contrast with previous explanations, the scientists determined that the chemical potential difference between the liquid and crystal phases has only a small effect on glass formation.

“This work represents a significant advancement in our understanding of the fundamental physical mechanism of vitrification,” says senior author Hajime Tanaka. “The results of this project may also help glass manufacturers design new multi-component systems that have certain desired properties, such as resilience, toughness and electroconductivity.”

This story is adapted from material from the University of Tokyo, with editorial changes made by Materials Today. The views expressed in this article do not necessarily represent those of Elsevier. Link to original source.

Source: https://www.materialstoday.com/amorphous/news/glass-forming-by-metallic-mixtures-becomes-clearer/

Continue Reading

Material Science

Material Science News | Materials Research

Scintacor: An Overview of Its Products and Capabilities

In this interview, AZoM talks to Ed Bullard and Martin Lewis, CEO and Principal Engineer at Scintacor respectively, about Scintacor, the companies products, capabilities, and vision for the future.

Republished by Plato

Published

on

Scintacor: An Overview of Its Products and Capabilities

In this interview, AZoM talks to Ed Bullard and Martin Lewis, CEO and Principal Engineer at Scintacor respectively, about Scintacor, the companies products, capabilities, and vision for the future.

Source: https://www.azom.com/materials-news-index.aspx

Continue Reading
News5 days ago

Jay-Z Announces Launch of Investment Fund To Aid Minority Cannabis Entrepreneurs

News22 hours ago

Cansortium Inc. Appoints CEO Robert Beasley to Board of Directors

Heartland3 days ago

Looking for something similar to FEALS but less pricey.

Heartland4 days ago

A Permanent solution to the import impasse on children’s CBD-based medication has emerged with the Dutch manufacturer set to see the medicines made in the UK

Heartland10 hours ago

is it possible for accidental thc product in my cbd cigarettes?

Heartland5 days ago

New Wave Welcomes Iman Nevab, Homeopathic Research Expert to the Scientific Advisory Board

News4 days ago

Florida Lawmakers Pushing For Cannabis Law Changes And Reform

Heartland4 days ago

Topical CBD feels amazing

Heartland5 days ago

Anybody ever bought from highkind? Review?

Heartland5 days ago

Psyched Wellness Submits an Application to Register a Trademark for the Company’s Unique Extraction

Heartland4 days ago

My new ‘Up in Smoke’ 40th Anniversary Rolling Tray! 🌱🎱😎 Love it! High Quality and Much Larger than Anticipated!

Heartland5 days ago

Cannabis Antibiotics: Answer to Disease-Resistant Bacteria

Heartland5 days ago

Never been a “flavored” CBD person but the hint of mint in this product is not bad.

Heartland3 days ago

Anyone had issues ordering from the US to the uk

Heartland4 days ago

Cannabis for Eating Disorders Like Anorexia

Heartland4 days ago

Quitting Nicotine

Heartland4 days ago

Anyone heard of or have tried this brand? Location near Dallas Texas

Heartland3 days ago

CBD oil causing issues with heart

Heartland4 days ago

Update – bought some of this 33% Moonbarguy hash instead of the HempHash. Hope it’s better

Heartland3 days ago

1 dropper CBD VS 2 droppers CBD = dramatic contrast in effect

Heartland4 days ago

How CBD changed a young boy’s life

Heartland3 days ago

Newbie questions regarding cbd & anxiety

Heartland5 days ago

Minty taste when vaping CBD isolate?

Heartland4 days ago

Horizons ETFs to Launch World’s First Psychedelics-Focused ETF

Uncategorized4 days ago

USDA Final Rule on Hemp

Heartland4 days ago

Even Bernie is a fan of The Green Claw

Heartland4 days ago

Mendo x Royal Kush

Heartland3 days ago

What Is Kief And How To Use It | Honest Marijuana

Heartland3 days ago

CBG is so amazing for me! I guess it’s different for everyone but it has way more health benefits than CBD! I’ve been ordering by the case from centurioncbg, this is the best pain relief lotion I’ve ever had. Anyone try them yet? Or any CBG?

Heartland2 days ago

Can someone tell me what type of CBD liquid I’m supposed to put in a vape pen refillable cartridge?

Trending

A Cloud Nine Capital Entity Copyright © 2020 – All Rights Reserved Proudly Made in America