Technology

November 15, 2018

Epoxy Graphene Composite

Epoxy compound gets a graphene bump

Scientists combine graphene foam, epoxy into tough, conductive composite

Date:
November 14, 2018
Source:
Rice University
Summary:
Researchers combine epoxy with a tough graphene foam and carbon nanotube scaffold to build a resilient composite that’s tougher and as conductive as other compounds but as light as pure epoxy.
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Led by scientists at Rice University, researchers have created an epoxy-graphene foam compound that is tough and conductive without adding significant weight. The material is suitable for applications like electromagnetic shielding.
Credit: Rouzbeh Shahsavari Group/Rice University

Rice University scientists have built a better epoxy for electronic applications.

Epoxy combined with “ultrastiff” graphene foam invented in the Rice lab of chemist James Tour is substantially tougher than pure epoxy and far more conductive than other epoxy composites while retaining the material’s low density. It could improve upon epoxies in current use that weaken the material’s structure with the addition of conductive fillers.

The new material is detailed in the American Chemical Society journal ACS Nano.

By itself, epoxy is an insulator, and is commonly used in coatings, adhesives, electronics, industrial tooling and structural composites. Metal or carbon fillers are often added for applications where conductivity is desired, like electromagnetic shielding.

But there’s a trade-off: More filler brings better conductivity at the cost of weight and compressive strength, and the composite becomes harder to process.

The Rice solution replaces metal or carbon powders with a three-dimensional foam made of nanoscale sheets of graphene, the atom-thick form of carbon.

The Tour lab, in collaboration with Rice materials scientists Pulickel Ajayan, Rouzbeh Shahsavari and Jun Lou and Yan Zhao of Beihang University in Beijing, took their inspiration from projects to inject epoxy into 3D scaffolds including graphene aerogels, foams and skeletons from various processes.

The new scheme makes much stronger scaffolds from polyacrylonitrile (PAN), a powdered polymer resin they use as a source of carbon, mixed with nickel powder. In the four-step process, they cold-press the materials to make them dense, heat them in a furnace to turn the PAN into graphene, chemically treat the resulting material to remove the nickel and use a vacuum to pull the epoxy into the now-porous material.

“The graphene foam is a single piece of few-layer graphene,” Tour said. “Therefore, in reality, the entire foam is one large molecule. When the epoxy infiltrates the foam and then hardens, any bending in the epoxy in one place will stress the monolith at many other locations due to the embedded graphene scaffolding. This ultimately stiffens the entire structure.”

The puck-shaped composites with 32 percent foam were marginally denser, but had an electrical conductivity of about 14 Siemens (a measure of conductivity, or inverse ohms) per centimeter, according to the researchers. The foam did not add significant weight to the compound, but gave it seven times the compressive strength of pure epoxy.

Easy interlocking between the graphene and epoxy helped stabilize the structure of the graphene as well. “When the epoxy infiltrates the graphene foam and then hardens, the epoxy is captured in micron-sized domains of the graphene foam,” Tour said.

The lab upped the ante by mixing multiwalled carbon nanotubes into the graphene foam. The nanotubes acted as reinforcement bars that bonded with the graphene and made the composite 1,732 percent stiffer than pure epoxy and nearly three times as conductive, at about 41 Siemens per centimeter, far greater than nearly all of the scaffold-based epoxy composites reported to date, according to the researchers.

Tour expects the process will scale for industry. “One just needs a furnace large enough to produce the ultimate part,” he said. “But that is done all the time to make large metal parts by cold-pressing and then heating them.”

He said the material could initially replace the carbon-composite resins used to pre-impregnate and reinforce fabric used in materials from aerospace structures to tennis rackets.

https://www.sciencedaily.com/releases/2018/11/181114120308.htm

November 14, 2018

New Memory Foam Application

Hari Mari Gets Patent For Memory Foam Toe Post

Hari Mari announced today the issuance to it by the US Patent Office of a patent that covers its Memory Foam Toe Post, ™an enhanced toe post that eliminates break in periods.

Hari Mari focuses on using premium materials, infusing color in a stagnant market of black and brown, and helping kids battle pediatric cancer.  In addition, comfort is a large part of the brand’s DNA and this patent further speaks to Hari Mari’s commitment to innovation, design, and producing a comfortable product.

Prior to launching in 2012, Hari Mari’s Founder, Jeremy Stewart, hosted focus groups, speaking to all ages about what they did, and didn’t like, about flip flops. The main factor keeping most from purchasing and wearing flip flops, was a common loathing of uncomfortable toe posts between the first and second toe. Hari Mari’s patented toe piece was the brand’s solution to this industry wide complaint.

“You never truly understand the impact toe posts have in flip flops until you speak with customers who have experienced the difference first hand. The small amount of memory foam between the toes adds new levels of comfort customers do not realize they’re looking for,” said Hari Mari Customer Service Director, Anne Cadenhead.

The Hari Mari Toe Post™ is chemically affixed to the flip-flop’s sole and comprised of memory foam, which is distributed throughout the tubular sheath structure of the toe piece. This feature not only adds comfort to the customer, but also removes the chance that the post might rip out of the flop’s sole, another common complaint about flip flops.

“In a highly competitive footwear marketplace, it is important as a brand to have a unique story that people can relate to. At Hari Mari, we have created a comfort story with our memory foam toe post as a key component to that story,” said Trisha Hegg VP of Design. “When you can put your sandals (footwear) on , and wear them 24/7, with no break-in period, its a game changer.”

For more information on Hari Mari’s patented toe piece, click here.

https://www.shop-eat-surf.com/2018/11/hari-mari-gets-patent-for-memory-foam-toe-post/

November 14, 2018

New Memory Foam Application

Hari Mari Gets Patent For Memory Foam Toe Post

Hari Mari announced today the issuance to it by the US Patent Office of a patent that covers its Memory Foam Toe Post, ™an enhanced toe post that eliminates break in periods.

Hari Mari focuses on using premium materials, infusing color in a stagnant market of black and brown, and helping kids battle pediatric cancer.  In addition, comfort is a large part of the brand’s DNA and this patent further speaks to Hari Mari’s commitment to innovation, design, and producing a comfortable product.

Prior to launching in 2012, Hari Mari’s Founder, Jeremy Stewart, hosted focus groups, speaking to all ages about what they did, and didn’t like, about flip flops. The main factor keeping most from purchasing and wearing flip flops, was a common loathing of uncomfortable toe posts between the first and second toe. Hari Mari’s patented toe piece was the brand’s solution to this industry wide complaint.

“You never truly understand the impact toe posts have in flip flops until you speak with customers who have experienced the difference first hand. The small amount of memory foam between the toes adds new levels of comfort customers do not realize they’re looking for,” said Hari Mari Customer Service Director, Anne Cadenhead.

The Hari Mari Toe Post™ is chemically affixed to the flip-flop’s sole and comprised of memory foam, which is distributed throughout the tubular sheath structure of the toe piece. This feature not only adds comfort to the customer, but also removes the chance that the post might rip out of the flop’s sole, another common complaint about flip flops.

“In a highly competitive footwear marketplace, it is important as a brand to have a unique story that people can relate to. At Hari Mari, we have created a comfort story with our memory foam toe post as a key component to that story,” said Trisha Hegg VP of Design. “When you can put your sandals (footwear) on , and wear them 24/7, with no break-in period, its a game changer.”

For more information on Hari Mari’s patented toe piece, click here.

https://www.shop-eat-surf.com/2018/11/hari-mari-gets-patent-for-memory-foam-toe-post/

October 29, 2018

Urethane Pothole Repair

Where does your recycled plastic go? Perhaps into future highways.


TechniSoil Industrial says its roads are eight to 16 times more durable than traditional pavement. (TechniSoil Industrial)

October 28 at 5:15 PM

Until about a year ago, few people had reason to wonder where the plastic they tossed into the recycling bin ended up. It was being made into new bottles, bags, straws and beach balls, right?

Wrong: Almost half of it was shipped to China. Then, China announced last year that it didn’t want to buy the stuff anymore.

So, what should we do with all that plastic choking the world’s landfills? Why not recycle it and use it to build roads?

Bound together with plastic polymers, the asphalt will be cheaper and last longer than conventional pavement, according to independent experts.

One European firm already is combining plastic pellets with hot-mix asphalt to resurface roadways. A U.S. company says that once it finds financial backing, its product “could be deployed within six months” with a process that combines asphalt milled from the road’s surface with plastic urethane.

Mixing recycled plastic into asphalt is more common in India and Pakistan than in the United States.


These samples show a product using recycled asphalt and G5 polymer from TechniSoil Industrial, a plastic-roadway company. (TechniSoil Industrial)

“Every country is going to come up with ways to reuse this recycled plastic,” said Sahadat Hossain, an engineering professor at the University of Texas at Arlington. “I work with Africa and developing countries. Everywhere you go, they’re building new roads — hundreds of miles of them. We could put a lot of this [plastic] material to use.”

And an ambitious Dutch company envisions 100-percent-recycled plastic roads built in sectional panels that can be popped into place like Lego blocks. So far, though, its biggest project has been the test of a 30-meter bike path in a city about 60 miles west of Amsterdam.

No one knows how many tons of plastic waste might be put to use in building roads, bike paths or sidewalks. But the plastic problem became prodigious the minute China stopped taking all but a tiny fraction of what the world produces.

More than 583 billion plastic bottles alone will be produced worldwide three years from now, according to the market research firm Euromonitor International. Bottles take close to 500 years to decompose in landfills, and some plastic items last almost twice as long.

By 2050, plastic floating in the oceans will outweigh the fish, according to a 2016 report by the Ellen MacArthur Foundation.

Without China paying to host the world’s biggest garbage dump, the rest of the world will have no place for an estimated 111 million metric tons of plastic waste that will accumulate in the next dozen years, according to University of Georgia researchers. Since 1992, China has accepted 45 percent of the world’s plastic recycling, they said.

Infusing plastic into highways is in its nascent hour, but the urgency of having no outlet for almost half the world’s plastic suggests traditional recycling may dry up, leaving landfills as the only other option.

“If you recycle plastic and you don’t have a market for it, what is the point?” said Hossain, who heads a test project that uses recycled plastic to shore up raised highway roadbeds in Texas. “So now, we are recycling the plastic, we have a tremendous market. You make this plastic from bottles into small pellets, then mix them with the [asphalt] aggregate material and they become a kind of cement-type material for the pavement.”

So far, companies in the United States and abroad have embraced research into three types of roadway plastics: adding refined plastic pellets to hot-mix asphalt, grinding off the top surface of roads and adding urethane, and roads that essentially are nothing but recycled plastic.

There are several reasons that roads infused with plastic last longer. One company, TechniSoil Industrial, says its roads are eight to 16 times more durable. A key reason has to do with something the industry calls “flow,” a term that translates best to “flexibility.” When the weight of a vehicle presses down as it passes over the asphalt, that pavement doesn’t spring back to 100 percent.

“It flexes back only a percentage” of what it once was, said Sean Weaver, founder of TechniSoil. “Well, that’s why you get potholes and roads start to fall apart. What we’ve found with using plastic [in the recycled asphalt mix] was that we had zero flow.”

Weaver said his California-based company does pothole work for about 100 West Coast cities, using a plastic-mix process called TrowelPave.

“The cities are just amazed they can fix a pothole and never go back to that pothole,” said Weaver, who needs to get more funding for his small firm before it can engage in full-fledged road paving. “The road will fail around it before the pothole fails.”

Weaver’s paving process, which combines recycled asphalt with MDI (methylene diphenyl diisocyanate) urethane, was tested for five years by the University of Nevada at Reno.

“It’s 100 percent RAP — recycled asphalt pavement,” said Elie Y. Hajj, an assistant professor of engineering at the university, who specializes in paving research. “You pulverize it, you add the liquid plastic, and it will come out with a cold mix that they can use as a surface layer” on the roadway.

A Scottish company, MacRebur, says it’s beginning to develop contracts worldwide for its product that puts recycled plastic pellets — a dozen or more could fit in the palm of a hand — into hot-mix asphalt. It’s CEO, Toby McCartney, in a video on the firm’s website, recalled first seeing the plastic-infusion process in India.

“Surely, everyone is doing this already, or people have thought about this?” he said he thought at the time. “But we just hit upon it [ourselves] and came up with the right mix.”

Another entrant in the plastic-road market is a coalition of three Dutch corporations who formed PlasticRoad, a company which says it ultimately intends to build roads made from 100-percent-recycled plastic.

One of its challenges is that plastic alone is a slippery surface.

“We have created a special coating — with proven safety — to make sure the plastic has a rough surface and wouldn’t be slippery,” Anne Koudstaal, an inventor of the PlasticRoad, said in an email. “We’re trying to make the complete road from waste plastics.”

https://www.washingtonpost.com/local/trafficandcommuting/where-does-your-recycled-plastic-go-perhaps-into-future-highways/2018/10/28/2aa3f5c4-d157-11e8-8c22-fa2ef74bd6d6_story.html?noredirect=on&utm_term=.b7b20a6610f2

October 29, 2018

Urethane Pothole Repair

Where does your recycled plastic go? Perhaps into future highways.


TechniSoil Industrial says its roads are eight to 16 times more durable than traditional pavement. (TechniSoil Industrial)

October 28 at 5:15 PM

Until about a year ago, few people had reason to wonder where the plastic they tossed into the recycling bin ended up. It was being made into new bottles, bags, straws and beach balls, right?

Wrong: Almost half of it was shipped to China. Then, China announced last year that it didn’t want to buy the stuff anymore.

So, what should we do with all that plastic choking the world’s landfills? Why not recycle it and use it to build roads?

Bound together with plastic polymers, the asphalt will be cheaper and last longer than conventional pavement, according to independent experts.

One European firm already is combining plastic pellets with hot-mix asphalt to resurface roadways. A U.S. company says that once it finds financial backing, its product “could be deployed within six months” with a process that combines asphalt milled from the road’s surface with plastic urethane.

Mixing recycled plastic into asphalt is more common in India and Pakistan than in the United States.


These samples show a product using recycled asphalt and G5 polymer from TechniSoil Industrial, a plastic-roadway company. (TechniSoil Industrial)

“Every country is going to come up with ways to reuse this recycled plastic,” said Sahadat Hossain, an engineering professor at the University of Texas at Arlington. “I work with Africa and developing countries. Everywhere you go, they’re building new roads — hundreds of miles of them. We could put a lot of this [plastic] material to use.”

And an ambitious Dutch company envisions 100-percent-recycled plastic roads built in sectional panels that can be popped into place like Lego blocks. So far, though, its biggest project has been the test of a 30-meter bike path in a city about 60 miles west of Amsterdam.

No one knows how many tons of plastic waste might be put to use in building roads, bike paths or sidewalks. But the plastic problem became prodigious the minute China stopped taking all but a tiny fraction of what the world produces.

More than 583 billion plastic bottles alone will be produced worldwide three years from now, according to the market research firm Euromonitor International. Bottles take close to 500 years to decompose in landfills, and some plastic items last almost twice as long.

By 2050, plastic floating in the oceans will outweigh the fish, according to a 2016 report by the Ellen MacArthur Foundation.

Without China paying to host the world’s biggest garbage dump, the rest of the world will have no place for an estimated 111 million metric tons of plastic waste that will accumulate in the next dozen years, according to University of Georgia researchers. Since 1992, China has accepted 45 percent of the world’s plastic recycling, they said.

Infusing plastic into highways is in its nascent hour, but the urgency of having no outlet for almost half the world’s plastic suggests traditional recycling may dry up, leaving landfills as the only other option.

“If you recycle plastic and you don’t have a market for it, what is the point?” said Hossain, who heads a test project that uses recycled plastic to shore up raised highway roadbeds in Texas. “So now, we are recycling the plastic, we have a tremendous market. You make this plastic from bottles into small pellets, then mix them with the [asphalt] aggregate material and they become a kind of cement-type material for the pavement.”

So far, companies in the United States and abroad have embraced research into three types of roadway plastics: adding refined plastic pellets to hot-mix asphalt, grinding off the top surface of roads and adding urethane, and roads that essentially are nothing but recycled plastic.

There are several reasons that roads infused with plastic last longer. One company, TechniSoil Industrial, says its roads are eight to 16 times more durable. A key reason has to do with something the industry calls “flow,” a term that translates best to “flexibility.” When the weight of a vehicle presses down as it passes over the asphalt, that pavement doesn’t spring back to 100 percent.

“It flexes back only a percentage” of what it once was, said Sean Weaver, founder of TechniSoil. “Well, that’s why you get potholes and roads start to fall apart. What we’ve found with using plastic [in the recycled asphalt mix] was that we had zero flow.”

Weaver said his California-based company does pothole work for about 100 West Coast cities, using a plastic-mix process called TrowelPave.

“The cities are just amazed they can fix a pothole and never go back to that pothole,” said Weaver, who needs to get more funding for his small firm before it can engage in full-fledged road paving. “The road will fail around it before the pothole fails.”

Weaver’s paving process, which combines recycled asphalt with MDI (methylene diphenyl diisocyanate) urethane, was tested for five years by the University of Nevada at Reno.

“It’s 100 percent RAP — recycled asphalt pavement,” said Elie Y. Hajj, an assistant professor of engineering at the university, who specializes in paving research. “You pulverize it, you add the liquid plastic, and it will come out with a cold mix that they can use as a surface layer” on the roadway.

A Scottish company, MacRebur, says it’s beginning to develop contracts worldwide for its product that puts recycled plastic pellets — a dozen or more could fit in the palm of a hand — into hot-mix asphalt. It’s CEO, Toby McCartney, in a video on the firm’s website, recalled first seeing the plastic-infusion process in India.

“Surely, everyone is doing this already, or people have thought about this?” he said he thought at the time. “But we just hit upon it [ourselves] and came up with the right mix.”

Another entrant in the plastic-road market is a coalition of three Dutch corporations who formed PlasticRoad, a company which says it ultimately intends to build roads made from 100-percent-recycled plastic.

One of its challenges is that plastic alone is a slippery surface.

“We have created a special coating — with proven safety — to make sure the plastic has a rough surface and wouldn’t be slippery,” Anne Koudstaal, an inventor of the PlasticRoad, said in an email. “We’re trying to make the complete road from waste plastics.”

https://www.washingtonpost.com/local/trafficandcommuting/where-does-your-recycled-plastic-go-perhaps-into-future-highways/2018/10/28/2aa3f5c4-d157-11e8-8c22-fa2ef74bd6d6_story.html?noredirect=on&utm_term=.b7b20a6610f2