Date: July 2, 2019
Source: University of Colorado at Boulder
Summary: Sand is a key ingredient in the recipe of modern life, and yet it is being extracted faster than it can be replaced.
What links the building you live in, the glass you drink from and the computer you work on? The answer is smaller than you think and is something we are rapidly running out of: sand.
In a commentary published today in the journal Nature, a group of scientists from the University of Colorado Boulder, the University of Illinois, the University of Hull and Arizona State University highlight the urgent need for a global agenda for sand.
Sand is a key ingredient in the recipe of modern life, and yet it might be our most overlooked natural resource, the authors argue. Sand and gravel are being extracted faster than they can be replaced. Rapid urbanization and global population growth have fueled the demand for sand and gravel, with between 32 and 50 billion tons extracted globally each year.
"From 2000-2100 it is projected there will be a 300 percent increase in sand demand and 400 percent increase in prices," said Mette Bendixen, a researcher at CU Boulder's Institute of Arctic and Alpine Research (INSTAAR). "We urgently require a monitoring program to address the current data and knowledge gap, and thus fully assess the magnitude of sand scarcity. It is up to the scientific community, governments and policy makers to take the steps needed to make this happen."
A lack of oversight and monitoring is leading to unsustainable exploitation, planning and trade. Removal of sand from rivers and beaches has far-reaching impacts on ecology, infrastructure, national economies and the livelihoods of the 3 billion people who live along the world's river corridors. Illegal sand mining has been documented in 70 countries across the globe, and battles over sand have reportedly killed hundreds in recent years, including local citizens, police officers and government officials.
"Politically and socially, we must ask: If we can send probes to the depths of the oceans or the furthest regions of the solar system, is it too much to expect that we possess a reliable understanding of sand mining in the world's great rivers, and on which so much of the world's human population, rely?" said Jim Best, a professor at the University of Illinois Department of Geology. "Now is the time to commit to gaining such knowledge by fully grasping and utilizing the new techniques that are at our disposal."
In order to move towards globally sustainable sand extraction, the authors argue that we must fully understand the occurrence of sustainable sources and reduce current extraction rates and sand needs, by recycling concrete and developing alternative to sand (such as crushed rocks or plastic waste materials). This will rely on a knowledge of the location and extent of sand mining, as well as the natural variations in sand flux in the world's rivers.
"The fact that sand is such a fundamental component of modern society, and yet we have no clear idea of how much sand we remove from our rivers every year, or even how much sand is naturally available, makes ensuring this industry is sustainable very, very difficult" said Chris Hackney, research fellow at the University of Hull's Energy and Environment Institute. "It's time that sand was given the same focus on the world stage as other global commodities such as oil, gas and precious metals."
"The issue of sand scarcity cannot be studied in geographical isolation as it has worldwide implications," said Lars L. Iversen, a research fellow at Arizona State University's Julie Ann Wrigley Global Institute of Sustainability. "The reality and size of the problem must be acknowledged -- and action must be taken -- on a global stage. In a rapidly changing world, we cannot afford blind spots."
The Carlsberg Foundation and the Danish National Research Foundation provided funding for the study.
Story Source: University of Colorado at Boulder. "The world needs a global agenda for sand." ScienceDaily. ScienceDaily, 2 July 2019. https://www.sciencedaily.com/releases/2019/07/190702112726.htm.
Showing posts with label Engineering and Construction. Show all posts
Showing posts with label Engineering and Construction. Show all posts
Wednesday, July 10, 2019
Monday, August 13, 2018
Rethinking Ketchup Packets: New Approach to Slippery Packaging Aims to Cut Food Waste
Benefits Also Include Consumer Safety and Comfort
Date: August 3, 2018
Source: Virginia Tech
Summary: New research aims to cut down on waste -- and consumer frustration -- with a novel approach to creating super slippery industrial packaging. The study establishes a method for wicking chemically compatible vegetable oils into the surfaces of common extruded plastics, like those used for ketchup packets and other condiments.
Virginia Tech doctoral student Ranit Mukherjee observes a dollop of ketchup as it moves on a super slippery plastic film. Mukherjee is the lead author on a study that yielded a novel approach to creating super slippery industrial packaging.
Credit: Virginia Tech
Almost everyone who eats fast food is familiar with the frustration of trying to squeeze every last drop of ketchup out of the small packets that accompany french fries.
What most consumers don't realize, however, is that food left behind in plastic packaging is not simply a nuisance. It also contributes to the millions of pounds of perfectly edible food that Americans throw out every year. These small, incremental amounts of sticky foods like condiments, dairy products, beverages, and some meat products that remain trapped in their packaging can add up to big numbers over time, even for a single household.
New research from Virginia Tech aims to cut down on that waste -- and consumer frustration -- with a novel approach to creating super slippery industrial packaging.
The study, which was published in Scientific Reports and has yielded a provisional patent, establishes a method for wicking chemically compatible vegetable oils into the surfaces of common extruded plastics.
Not only will the technique help sticky foods release from their packaging much more easily, but for the first time, it can also be applied to inexpensive and readily available plastics such as polyethylene and polypropylene.
These hydrocarbon-based polymers make up 55 percent of the total demand for plastics in the world today, meaning potential applications for the research stretch far beyond just ketchup packets. They're also among the easiest plastics to recycle.
"Previous SLIPS, or slippery liquid-infused porous surfaces, have been made using silicon- or fluorine-based polymers, which are very expensive," said Ranit Mukherjee, a doctoral student in the Department of Biomedical Engineering and Mechanics within the College of Engineering and the study's lead author. "But we can make our SLIPS out of these hydrocarbon-based polymers, which are widely applicable to everyday packaged products."
First created by Harvard University researchers in 2011, SLIPS are porous surfaces or absorbent polymers that can hold a chemically compatible oil within their surfaces via the process of wicking. These surfaces are not only very slippery, but they're also self-cleaning, self-healing, and more durable than traditional superhydrophobic surfaces.
In order for SLIPS to hold these oils, the surfaces must have some sort of nano- or micro-roughness, which keeps the oil in place by way of surface tension. This roughness can be achieved two ways: the surface material is roughened with a type of applied coating, or the surface material consists of an absorbent polymer. In the latter case, the molecular structure of the material itself exhibits the necessary nano-roughness.
Both techniques have recently gained traction with startups and in limited commercial applications. But current SLIPS that use silicone- and fluorine-based absorbent polymers aren't attractive for industrial applications due to their high cost, while the method of adding roughness to surfaces can likewise be an expensive and complicated process.
"We had two big breakthroughs," said Jonathan Boreyko, an assistant professor of biomedical engineering and mechanics and a study co-author. "Not only are we using these hydrocarbon-based polymers that are cheap and in high demand, but we don't have to add any surface roughness, either. We actually found oils that are naturally compatible with the plastics, so these oils are wicking into the plastic itself, not into a roughness we have to apply."
In addition to minimizing food waste, Boreyko cited other benefits to the improved design, including consumer safety and comfort.
"We're not adding any mystery nanoparticles to the surfaces of these plastics that could make people uncomfortable," he said. "We use natural oils like cottonseed oil, so there are no health concerns whatsoever. There's no fancy recipe required."
While the method has obvious implications for industrial food and product packaging, it could also find widespread use in the pharmaceutical industry. The oil-infused plastic surfaces are naturally anti-fouling, meaning they resist bacterial adhesion and growth.
Although the technique may sound very high-tech, it actually finds its roots in the pitcher plant, a carnivorous plant that entices insects to the edge of a deep cavity filled with nectar and digestive enzymes. The leaves that form the plant's eponymous shape have a slippery ring, created by a secreted liquid, around the periphery of the cavity. When the insects move onto this slippery ring, they slide into the belly of the plants.
"This slippery periphery on the pitcher plant actually inspired our SLIPS product," said Mukherjee.
The pitcher plant's innovation -- which engineers are now copying with great success -- is the combination of a lubricant with some type of surface roughness that can lock that lubricant into place very stably with surface tension.
"We're taking that same concept, but the roughness we're using is just a common attribute of everyday plastics, which means maximal practicality," said Boreyko.
This research was funded through an industrial collaboration with Bemis North America. Additional co-authors of the study include Mohammad Habibi, a Virginia Tech mechanical engineering graduate student; Ziad Rashed, an engineering science and mechanics 2018 graduate from Virginia Tech's undergraduate program; and Otacilio Berbert and Xiangke Shi, both of Bemis North America.
Reprinted From:
Virginia Tech. "Rethinking ketchup packets: New approach to slippery packaging aims to cut food waste: Benefits also include consumer safety and comfort." ScienceDaily. ScienceDaily, 3 August 2018. https://www.sciencedaily.com/releases/2018/08/180803103302.htm
Date: August 3, 2018
Source: Virginia Tech
Summary: New research aims to cut down on waste -- and consumer frustration -- with a novel approach to creating super slippery industrial packaging. The study establishes a method for wicking chemically compatible vegetable oils into the surfaces of common extruded plastics, like those used for ketchup packets and other condiments.
Virginia Tech doctoral student Ranit Mukherjee observes a dollop of ketchup as it moves on a super slippery plastic film. Mukherjee is the lead author on a study that yielded a novel approach to creating super slippery industrial packaging.
Credit: Virginia Tech
Almost everyone who eats fast food is familiar with the frustration of trying to squeeze every last drop of ketchup out of the small packets that accompany french fries.
What most consumers don't realize, however, is that food left behind in plastic packaging is not simply a nuisance. It also contributes to the millions of pounds of perfectly edible food that Americans throw out every year. These small, incremental amounts of sticky foods like condiments, dairy products, beverages, and some meat products that remain trapped in their packaging can add up to big numbers over time, even for a single household.
New research from Virginia Tech aims to cut down on that waste -- and consumer frustration -- with a novel approach to creating super slippery industrial packaging.
The study, which was published in Scientific Reports and has yielded a provisional patent, establishes a method for wicking chemically compatible vegetable oils into the surfaces of common extruded plastics.
Not only will the technique help sticky foods release from their packaging much more easily, but for the first time, it can also be applied to inexpensive and readily available plastics such as polyethylene and polypropylene.
These hydrocarbon-based polymers make up 55 percent of the total demand for plastics in the world today, meaning potential applications for the research stretch far beyond just ketchup packets. They're also among the easiest plastics to recycle.
"Previous SLIPS, or slippery liquid-infused porous surfaces, have been made using silicon- or fluorine-based polymers, which are very expensive," said Ranit Mukherjee, a doctoral student in the Department of Biomedical Engineering and Mechanics within the College of Engineering and the study's lead author. "But we can make our SLIPS out of these hydrocarbon-based polymers, which are widely applicable to everyday packaged products."
First created by Harvard University researchers in 2011, SLIPS are porous surfaces or absorbent polymers that can hold a chemically compatible oil within their surfaces via the process of wicking. These surfaces are not only very slippery, but they're also self-cleaning, self-healing, and more durable than traditional superhydrophobic surfaces.
In order for SLIPS to hold these oils, the surfaces must have some sort of nano- or micro-roughness, which keeps the oil in place by way of surface tension. This roughness can be achieved two ways: the surface material is roughened with a type of applied coating, or the surface material consists of an absorbent polymer. In the latter case, the molecular structure of the material itself exhibits the necessary nano-roughness.
Both techniques have recently gained traction with startups and in limited commercial applications. But current SLIPS that use silicone- and fluorine-based absorbent polymers aren't attractive for industrial applications due to their high cost, while the method of adding roughness to surfaces can likewise be an expensive and complicated process.
"We had two big breakthroughs," said Jonathan Boreyko, an assistant professor of biomedical engineering and mechanics and a study co-author. "Not only are we using these hydrocarbon-based polymers that are cheap and in high demand, but we don't have to add any surface roughness, either. We actually found oils that are naturally compatible with the plastics, so these oils are wicking into the plastic itself, not into a roughness we have to apply."
In addition to minimizing food waste, Boreyko cited other benefits to the improved design, including consumer safety and comfort.
"We're not adding any mystery nanoparticles to the surfaces of these plastics that could make people uncomfortable," he said. "We use natural oils like cottonseed oil, so there are no health concerns whatsoever. There's no fancy recipe required."
While the method has obvious implications for industrial food and product packaging, it could also find widespread use in the pharmaceutical industry. The oil-infused plastic surfaces are naturally anti-fouling, meaning they resist bacterial adhesion and growth.
Although the technique may sound very high-tech, it actually finds its roots in the pitcher plant, a carnivorous plant that entices insects to the edge of a deep cavity filled with nectar and digestive enzymes. The leaves that form the plant's eponymous shape have a slippery ring, created by a secreted liquid, around the periphery of the cavity. When the insects move onto this slippery ring, they slide into the belly of the plants.
"This slippery periphery on the pitcher plant actually inspired our SLIPS product," said Mukherjee.
The pitcher plant's innovation -- which engineers are now copying with great success -- is the combination of a lubricant with some type of surface roughness that can lock that lubricant into place very stably with surface tension.
"We're taking that same concept, but the roughness we're using is just a common attribute of everyday plastics, which means maximal practicality," said Boreyko.
This research was funded through an industrial collaboration with Bemis North America. Additional co-authors of the study include Mohammad Habibi, a Virginia Tech mechanical engineering graduate student; Ziad Rashed, an engineering science and mechanics 2018 graduate from Virginia Tech's undergraduate program; and Otacilio Berbert and Xiangke Shi, both of Bemis North America.
Reprinted From:
Virginia Tech. "Rethinking ketchup packets: New approach to slippery packaging aims to cut food waste: Benefits also include consumer safety and comfort." ScienceDaily. ScienceDaily, 3 August 2018. https://www.sciencedaily.com/releases/2018/08/180803103302.htm
Friday, July 13, 2018
Using Coal Waste to Create Sustainable Concrete
New Coal Concrete Reduces Energy Demand, Greenhouse Emissions
Date: July 12, 2018
Source: Washington State University
Summary: Researchers have created a sustainable alternative to traditional concrete using coal fly ash, a waste product of coal-based electricity generation.
Chemical engineering student Ka Fung Wong looks at the data log, which is used to gather data from sensors buried under the concrete test plot.
Credit: WSU
Washington State University researchers have created a sustainable alternative to traditional concrete using coal fly ash, a waste product of coal-based electricity generation.
The advance tackles two major environmental problems at once by making use of coal production waste and by significantly reducing the environmental impact of concrete production.
Xianming Shi, associate professor in WSU's Department of Civil and Environmental Engineering, and graduate student Gang Xu, have developed a strong, durable concrete that uses fly ash as a binder and eliminates the use of environmentally intensive cement. They report on their work in the August issue of the journal, Fuel.
Reduces Energy Demand, Greenhouse Emissions
Production of traditional concrete, which is made by combining cement with sand and gravel, contributes between five and eight percent of greenhouse gas emissions worldwide. That's because cement, the key ingredient in concrete, requires high temperatures and a tremendous amount of energy to produce.
Fly ash, the material that remains after coal dust is burned, meanwhile has become a significant waste management issue in the United States. More than 50 percent of fly ash ends up in landfills, where it can easily leach into the nearby environment.
While some researchers have used fly ash in concrete, they haven't been able to eliminate the intense heating methods that are traditionally needed to make a strong material.
"Our production method does not require heating or the use of any cement," said Xu.
Molecular Engineering
This work is also significant because the researchers are using nano-sized materials to engineer concrete at the molecular level.
"To sustainably advance the construction industry, we need to utilize the 'bottom-up' capability of nanomaterials," said Shi.
The team used graphene oxide, a recently discovered nanomaterial, to manipulate the reaction of fly ash with water and turn the activated fly ash into a strong cement-like material. The graphene oxide rearranges atoms and molecules in a solution of fly ash and chemical activators like sodium silicate and calcium oxide. The process creates a calcium-aluminate-silicate-hydrate molecule chain with strongly bonded atoms that form an inorganic polymer network more durable than (hydrated) cement.
Aids Groundwater, Mitigates Flooding
The team designed the fly ash concrete to be pervious, which means water can pass through it to replenish groundwater and to mitigate flooding potential.
Researchers have demonstrated the strength and behavior of the material in test plots on the WSU campus under a variety of load and temperature conditions. They are still conducting infiltration tests and gathering data using sensors buried under the concrete. They eventually hope to commercialize the patented technology.
"After further testing, we would like to build some structures with this concrete to serve as a proof of concept," said Xu.
The research was funded by the U.S. Department of Transportation's University Transportation Centers and the WSU Office of Commercialization.
Story Source: Washington State University. "Using coal waste to create sustainable concrete: New coal concrete reduces energy demand, greenhouse emissions." ScienceDaily. ScienceDaily, 12 July 2018. https://www.sciencedaily.com/releases/2018/07/180712100513.htm.
Date: July 12, 2018
Source: Washington State University
Summary: Researchers have created a sustainable alternative to traditional concrete using coal fly ash, a waste product of coal-based electricity generation.
Chemical engineering student Ka Fung Wong looks at the data log, which is used to gather data from sensors buried under the concrete test plot.
Credit: WSU
Washington State University researchers have created a sustainable alternative to traditional concrete using coal fly ash, a waste product of coal-based electricity generation.
The advance tackles two major environmental problems at once by making use of coal production waste and by significantly reducing the environmental impact of concrete production.
Xianming Shi, associate professor in WSU's Department of Civil and Environmental Engineering, and graduate student Gang Xu, have developed a strong, durable concrete that uses fly ash as a binder and eliminates the use of environmentally intensive cement. They report on their work in the August issue of the journal, Fuel.
Reduces Energy Demand, Greenhouse Emissions
Production of traditional concrete, which is made by combining cement with sand and gravel, contributes between five and eight percent of greenhouse gas emissions worldwide. That's because cement, the key ingredient in concrete, requires high temperatures and a tremendous amount of energy to produce.
Fly ash, the material that remains after coal dust is burned, meanwhile has become a significant waste management issue in the United States. More than 50 percent of fly ash ends up in landfills, where it can easily leach into the nearby environment.
While some researchers have used fly ash in concrete, they haven't been able to eliminate the intense heating methods that are traditionally needed to make a strong material.
"Our production method does not require heating or the use of any cement," said Xu.
Molecular Engineering
This work is also significant because the researchers are using nano-sized materials to engineer concrete at the molecular level.
"To sustainably advance the construction industry, we need to utilize the 'bottom-up' capability of nanomaterials," said Shi.
The team used graphene oxide, a recently discovered nanomaterial, to manipulate the reaction of fly ash with water and turn the activated fly ash into a strong cement-like material. The graphene oxide rearranges atoms and molecules in a solution of fly ash and chemical activators like sodium silicate and calcium oxide. The process creates a calcium-aluminate-silicate-hydrate molecule chain with strongly bonded atoms that form an inorganic polymer network more durable than (hydrated) cement.
Aids Groundwater, Mitigates Flooding
The team designed the fly ash concrete to be pervious, which means water can pass through it to replenish groundwater and to mitigate flooding potential.
Researchers have demonstrated the strength and behavior of the material in test plots on the WSU campus under a variety of load and temperature conditions. They are still conducting infiltration tests and gathering data using sensors buried under the concrete. They eventually hope to commercialize the patented technology.
"After further testing, we would like to build some structures with this concrete to serve as a proof of concept," said Xu.
The research was funded by the U.S. Department of Transportation's University Transportation Centers and the WSU Office of Commercialization.
Story Source: Washington State University. "Using coal waste to create sustainable concrete: New coal concrete reduces energy demand, greenhouse emissions." ScienceDaily. ScienceDaily, 12 July 2018. https://www.sciencedaily.com/releases/2018/07/180712100513.htm.
Thursday, February 16, 2017
Eco-Friendly Concrete Created
Date: February 13, 2017
Source: Rutgers University
Summary: In the future, wide-ranging composite materials are expected to be stronger, lighter, cheaper and greener for our planet, thanks to a new invention. Nine years ago, an American researcher invented an energy-efficient technology that harnesses largely low-temperature, water-based reactions.
In the future, wide-ranging composite materials are expected to be stronger, lighter, cheaper and greener for our planet, thanks to an invention by Rutgers' Richard E. Riman.
Nine years ago, Riman, a distinguished professor in the Department of Materials Science and Engineering in the School of Engineering, invented an energy-efficient technology that harnesses largely low-temperature, water-based reactions. As a result, he and his team can make things in water that previously were made at temperatures well above those required to thermally decompose plastics.
So far, the revolutionary technology has been used to make more than 30 different materials, including concrete that stores carbon dioxide, the prime greenhouse gas linked to climate change. Other materials include multiple families of composites that incorporate a wide range of metals, polymers and ceramics whose behavior can be processed to resemble wood, bone, seashells and even steel.
A promising option is creating materials for lightweight automobiles, said Riman, who holds dozens of patents and was recently named a fellow of the National Academy of Inventors. The materials could be used for engine, interior and exterior applications. Other materials could perform advanced electronic, optical and magnetic functions that replace mechanical ones.
"Ultimately, what we'd like to be able to do is create a 'Materials Valley' here, where this technology can start one company after another, small, medium and large businesses," Riman said. "It's a foundational or platform technology for solidifying materials that contain ceramics, among other things. They can be pure ceramics, ceramics and metals, ceramics and polymers -- a really wide range of composites."
Riman, who has taught for 30 years in the Department of Materials Science and Engineering, focuses on making ceramic materials under sustainable conditions. That means low energy with a low carbon dioxide footprint.
His patented technology creates bonds between materials at low temperatures. It's called reactive hydrothermal liquid-phase densification (rHLPD), also known as low-temperature solidification. And it's been used to make a wide range of ceramic composite materials at Rutgers, according to an article published last summer in the Journal of the American Ceramic Society.
"Typically, we don't go any higher than 240 degrees centigrade (464 degrees Fahrenheit) to make the composite materials," Riman said. "A lot of these processes are done even at room temperature."
Riman, who earned a bachelor's degree in ceramic engineering at Rutgers and a doctorate in materials science and engineering at the Massachusetts Institute of Technology, invented the technology after studying how engineers densified Alaskan fields of snow and ice to create airplane landing strips.
"I looked at how shellfish make ceramics at low-temperature, like carbonate crystals, and then looked at what people can do with water to make landing strips in Alaska and I said we should be able to do this with ceramics, but use a low-temperature chemical process that involves water," he said.
Riman came up with the idea decades ago but didn't launch the technology until climate change became a bigger issue. "When it became important to investors to see green technology developed to address carbon emissions in the world, I decided it was time to take this technology commercial," he said.
So he founded Solidia Technologies Inc. in Piscataway, New Jersey, in 2008. It's a startup company marketing improved, eco-friendly cement and concrete for construction and infrastructure. Concrete is a $1 trillion market, Riman noted.
"The first thing we did was show that we could make a material that costs the same as conventional Portland cement," he said. "We developed processing technology that allows you to drop the technology right into the conventional world of concrete and cement without having to make major capital expenditures typically encountered when a technology is disruptive to the marketplace. We plan to do the same thing in the advanced materials business."
Solidia Concrete products have superior strength and durability. They, combined with Solidia Cement, can reduce the carbon footprint of cement and concrete by up to 70 percent and can save as much as 528.3 billion gallons a year, according to Solidia Technologies.
The company's concrete-based products include roofing tiles, cinder blocks and hollow core building slabs. The company approaches concrete product manufacturers to see if they're interested in licensing its products.
"When you can develop technologies that are safe and easy to use, it's a game changer -- and that's just one of the many areas that we're interested in pursuing," Riman said.
His second investor-funded start-up company is RRTC Inc., which is developing advanced composite materials for myriad uses. They include electronic, optical, magnetic, biomedical, biotechnology, pharmaceutical, agricultural, electrochemical, energy storage, energy generation, aerospace, automotive, body and vehicle armor, textile, and abrasive and cutting applications.
Story Source: Rutgers University. "Eco-friendly concrete created." ScienceDaily. ScienceDaily, 13 February 2017.
Original written by Todd B. Bates.
Journal Reference:
Cekdar Vakifahmetoglu, Jean Francois Anger, Vahit Atakan, Sean Quinn, Surojit Gupta, Qinghua Li, Ling Tang, Richard E. Riman. Reactive Hydrothermal Liquid-Phase Densification (rHLPD) of Ceramics - A Study of the BaTiO3[TiO2] Composite System. Journal of the American Ceramic Society, 2016; 99 (12): 3893 DOI: 10.1111/jace.14468
Source: Rutgers University
Summary: In the future, wide-ranging composite materials are expected to be stronger, lighter, cheaper and greener for our planet, thanks to a new invention. Nine years ago, an American researcher invented an energy-efficient technology that harnesses largely low-temperature, water-based reactions.
In the future, wide-ranging composite materials are expected to be stronger, lighter, cheaper and greener for our planet, thanks to an invention by Rutgers' Richard E. Riman.
Nine years ago, Riman, a distinguished professor in the Department of Materials Science and Engineering in the School of Engineering, invented an energy-efficient technology that harnesses largely low-temperature, water-based reactions. As a result, he and his team can make things in water that previously were made at temperatures well above those required to thermally decompose plastics.
So far, the revolutionary technology has been used to make more than 30 different materials, including concrete that stores carbon dioxide, the prime greenhouse gas linked to climate change. Other materials include multiple families of composites that incorporate a wide range of metals, polymers and ceramics whose behavior can be processed to resemble wood, bone, seashells and even steel.
A promising option is creating materials for lightweight automobiles, said Riman, who holds dozens of patents and was recently named a fellow of the National Academy of Inventors. The materials could be used for engine, interior and exterior applications. Other materials could perform advanced electronic, optical and magnetic functions that replace mechanical ones.
"Ultimately, what we'd like to be able to do is create a 'Materials Valley' here, where this technology can start one company after another, small, medium and large businesses," Riman said. "It's a foundational or platform technology for solidifying materials that contain ceramics, among other things. They can be pure ceramics, ceramics and metals, ceramics and polymers -- a really wide range of composites."
Riman, who has taught for 30 years in the Department of Materials Science and Engineering, focuses on making ceramic materials under sustainable conditions. That means low energy with a low carbon dioxide footprint.
His patented technology creates bonds between materials at low temperatures. It's called reactive hydrothermal liquid-phase densification (rHLPD), also known as low-temperature solidification. And it's been used to make a wide range of ceramic composite materials at Rutgers, according to an article published last summer in the Journal of the American Ceramic Society.
"Typically, we don't go any higher than 240 degrees centigrade (464 degrees Fahrenheit) to make the composite materials," Riman said. "A lot of these processes are done even at room temperature."
Riman, who earned a bachelor's degree in ceramic engineering at Rutgers and a doctorate in materials science and engineering at the Massachusetts Institute of Technology, invented the technology after studying how engineers densified Alaskan fields of snow and ice to create airplane landing strips.
"I looked at how shellfish make ceramics at low-temperature, like carbonate crystals, and then looked at what people can do with water to make landing strips in Alaska and I said we should be able to do this with ceramics, but use a low-temperature chemical process that involves water," he said.
Riman came up with the idea decades ago but didn't launch the technology until climate change became a bigger issue. "When it became important to investors to see green technology developed to address carbon emissions in the world, I decided it was time to take this technology commercial," he said.
So he founded Solidia Technologies Inc. in Piscataway, New Jersey, in 2008. It's a startup company marketing improved, eco-friendly cement and concrete for construction and infrastructure. Concrete is a $1 trillion market, Riman noted.
"The first thing we did was show that we could make a material that costs the same as conventional Portland cement," he said. "We developed processing technology that allows you to drop the technology right into the conventional world of concrete and cement without having to make major capital expenditures typically encountered when a technology is disruptive to the marketplace. We plan to do the same thing in the advanced materials business."
Solidia Concrete products have superior strength and durability. They, combined with Solidia Cement, can reduce the carbon footprint of cement and concrete by up to 70 percent and can save as much as 528.3 billion gallons a year, according to Solidia Technologies.
The company's concrete-based products include roofing tiles, cinder blocks and hollow core building slabs. The company approaches concrete product manufacturers to see if they're interested in licensing its products.
"When you can develop technologies that are safe and easy to use, it's a game changer -- and that's just one of the many areas that we're interested in pursuing," Riman said.
His second investor-funded start-up company is RRTC Inc., which is developing advanced composite materials for myriad uses. They include electronic, optical, magnetic, biomedical, biotechnology, pharmaceutical, agricultural, electrochemical, energy storage, energy generation, aerospace, automotive, body and vehicle armor, textile, and abrasive and cutting applications.
Story Source: Rutgers University. "Eco-friendly concrete created." ScienceDaily. ScienceDaily, 13 February 2017.
Original written by Todd B. Bates.
Journal Reference:
Cekdar Vakifahmetoglu, Jean Francois Anger, Vahit Atakan, Sean Quinn, Surojit Gupta, Qinghua Li, Ling Tang, Richard E. Riman. Reactive Hydrothermal Liquid-Phase Densification (rHLPD) of Ceramics - A Study of the BaTiO3[TiO2] Composite System. Journal of the American Ceramic Society, 2016; 99 (12): 3893 DOI: 10.1111/jace.14468
Wednesday, January 6, 2016
More Environmentally-Friendly Concrete Made Using Sugar Cane Residue
Date: January 4, 2016
Source: Asociación RUVID
Summary: A new type of concrete has been developed that is cheaper and much less polluting to the environment. Researchers have swapped in sugar cane straw ash, a crop residue typically discarded as waste, as a substitute for Portland cement.
Researchers from the Universitat Politècnica de València (Polytechnic University of Valencia, UPV) and San Paolo State University (Unesp) have developed a new type of concrete that is cheaper and much less polluting to the environment. They have done so by swapping in sugar cane straw ash, a crop residue typically discarded as waste, as a substitute for Portland cement.
Currently pursued at laboratory scale only, the results of this work have been published in the Construction and Building Materials journal. They also form part of Brazilian student João Cláudio Bassan de Moraes's master's dissertation, directed by lecturer Mauro Tashima, who completed his PhD at the UPV and is currently lecturing at Unesp.
Talking to us about the project, Jordi Payá, researcher at the Concrete Science and Technology Institute (ICITECH) at the UPV, explains: "The harvester strips the cane, discarding the tops and leaves as waste. This is the raw material we work with, sugar cane straw." In total around 650 million tonnes of sugar cane are harvested in Brazil every year. Of this, between 15 and 20% corresponds to sugar straw, which is left on the field and either burned or left to decay naturally.
So far, the international research team has been able to obtain concrete using 30% less Portland cement, substituting it with the ashes obtained from burning the sugar cane straw.
"The cement itself is the most expensive and most polluting ingredient of concrete, which makes the benefits [of this new method] as much economic as environmental. We are also making use of a by-product that is currently unexploited, with all the benefits that this entails" (Payá).
Process
To burn the waste, UPV and Unesp researchers have designed a bespoke combustion burner, into which the raw material must be fed following a strict procedure. "Through this process we obtain ashes that are very reactive to the cement, a quality that is very important to the mechanical performance of the resulting concrete, to its resistance to compression, for instance" (Payá).
Work has focused primarily on the microstructural analysis of the concrete. "In the lab we analyse the chemical compounds of the ashes and of the compounds produced during the reaction with the cement, in order to assess their performance in the final product," explains Payá. Future work would include studying indicators related to the durability of mass and reinforced concrete.
The ICITECH research team also studies the use of other agricultural waste as a cement substitute, including the bamboo leaf.
Story Source: The above post is reprinted from materials provided by Asociación RUVID.
Source: Asociación RUVID
Summary: A new type of concrete has been developed that is cheaper and much less polluting to the environment. Researchers have swapped in sugar cane straw ash, a crop residue typically discarded as waste, as a substitute for Portland cement.
Researchers from the Universitat Politècnica de València (Polytechnic University of Valencia, UPV) and San Paolo State University (Unesp) have developed a new type of concrete that is cheaper and much less polluting to the environment. They have done so by swapping in sugar cane straw ash, a crop residue typically discarded as waste, as a substitute for Portland cement.
Currently pursued at laboratory scale only, the results of this work have been published in the Construction and Building Materials journal. They also form part of Brazilian student João Cláudio Bassan de Moraes's master's dissertation, directed by lecturer Mauro Tashima, who completed his PhD at the UPV and is currently lecturing at Unesp.
Talking to us about the project, Jordi Payá, researcher at the Concrete Science and Technology Institute (ICITECH) at the UPV, explains: "The harvester strips the cane, discarding the tops and leaves as waste. This is the raw material we work with, sugar cane straw." In total around 650 million tonnes of sugar cane are harvested in Brazil every year. Of this, between 15 and 20% corresponds to sugar straw, which is left on the field and either burned or left to decay naturally.
So far, the international research team has been able to obtain concrete using 30% less Portland cement, substituting it with the ashes obtained from burning the sugar cane straw.
"The cement itself is the most expensive and most polluting ingredient of concrete, which makes the benefits [of this new method] as much economic as environmental. We are also making use of a by-product that is currently unexploited, with all the benefits that this entails" (Payá).
Process
To burn the waste, UPV and Unesp researchers have designed a bespoke combustion burner, into which the raw material must be fed following a strict procedure. "Through this process we obtain ashes that are very reactive to the cement, a quality that is very important to the mechanical performance of the resulting concrete, to its resistance to compression, for instance" (Payá).
Work has focused primarily on the microstructural analysis of the concrete. "In the lab we analyse the chemical compounds of the ashes and of the compounds produced during the reaction with the cement, in order to assess their performance in the final product," explains Payá. Future work would include studying indicators related to the durability of mass and reinforced concrete.
The ICITECH research team also studies the use of other agricultural waste as a cement substitute, including the bamboo leaf.
Story Source: The above post is reprinted from materials provided by Asociación RUVID.
Monday, November 9, 2015
Structure of 'Concrete Disease' Solved
Previously undocumented sheet-silicate crystal structure
Date: November 5, 2015
Source: Swiss Federal Laboratories for Materials Science and Technology (EMPA)
Summary: When bridges, dam walls and other structures made of concrete are streaked with dark cracks after a few decades, the culprit is AAR: the alkali-aggregate reaction. AAR damages concrete structures all over the world and makes complex renovations or reconstructions necessary. Researchers have now solved the structure of the material produced in the course of AAR at atomic Level.
Researchers from the Paul Scherrer Institute (PSI) teamed up with colleagues from the Swiss Materials Science Lab Empa to study a degenerative sign of ageing in concrete: the so-called alkali-aggregate reaction (AAR). In the course of AAR, a material forms that takes up more space than the original concrete and thus gradually cracks the concrete from within as the decades go by.
The researchers have now explored the exact structure of this material. They managed to demonstrate that its atoms are arranged extremely regularly, making it a crystal. They also showed that the structure of this crystal is a so-called sheet-silicate structure. This specific structure had never been observed before. The researchers made their discovery thanks to measurements at the Swiss Light Source SLS at PSI. The research results could help towards the development of more durable concrete in future.
A Global Problem
AAR is a chemical reaction that affects outdoor concrete structures all over the world. It happens when concrete is exposed to water or moisture. For instance, numerous bridges and up to twenty per cent of the dam walls in Switzerland are affected by AAR. With AAR, the basic ingredients in the concrete are actually the problem: cement -- the main component of concrete -- contains alkali metals such as sodium and potassium. Any moisture infiltrating the concrete -- stemming for example from rainwater -- reacts with these alkali metals, leading to an alkaline solution.
The second main ingredient in concrete is sand and gravel, which in turn are composed of minerals, such as quartz or feldspar. Chemically speaking, these minerals are so-called silicates. The alkaline water reacts with these silicates and forms a so-called alkali calcium silicate hydrate. This is itself able to absorb more moisture, which causes it to expand and gradually crack the concrete from within. This entire process is referred to as AAR.
AAR takes place extremely slowly, so that the cracks are initially only tiny and invisible to the naked eye. Over the course of three or four decades, however, the cracks widen significantly and eventually jeopardise the durability of the entire concrete structure.
A New Crystal
Even if the chemical processes involved in AAR have long been known, nobody had identified the physical structure of the alkali calcium silicate hydrate formed in the course of AAR. The researchers at PSI and Empa have now managed to fill this knowledge gap. They studied the substance of a Swiss bridge constructed in 1969, which has been affected heavily by AAR. Researchers from Empa cut out a material sample from the bridge and ground down a small piece of it until they were left with a wafer-thin sample that was merely 0.02 millimetres thick. The sample was then taken to the Swiss Light Source SLS and irradiated with an extremely narrow x-ray beam, fifty times thinner than a human hair. Performing so-called diffraction measurements and a complex data analysis, the PSI researchers were eventually able to determine the crystal structure of the material with pinpoint precision.
They found that the alkali calcium silicate hydrate has a previously undocumented sheet-silicate crystal structure. "Normally, discovering an uncatalogued crystal structure means you get to name it," explains Rainer Dähn, the first author of the study. "But it has to be a crystal found in nature, therefore we didn't get that honour," says the researcher with a smile. Andreas Leemann, Head of the Concrete Technology Group at Empa, had the idea for the current study. The researchers from PSI then brought their knowledge of the x-ray beam method to the table. "In principle, it's possible to add organic materials to the concrete that are able to reduce the build-up of tension," explains materials scientist Leemann. "Our new results provide a scientific basis for these considerations and could pave the way for the development of new materials.
Story Source: Swiss Federal Laboratories for Materials Science and Technology (EMPA). "Structure of 'concrete disease' solved: Previously undocumented sheet-silicate crystal structure." ScienceDaily. ScienceDaily, 5 November 2015.
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