Researchers Find Microbes that Break-down Harmful Phthalates in Humid Conditions

The dust that settles throughout our homes and offices almost always contains bits of chemicals that can cause problems for the human endocrine system, scientists say. But a new study indicates that the microbes we track into buildings—the microscopic bacteria and other microorganisms that thrive on our skin and outdoors—can help break those chemicals down.

Starting Point to Deal With Harmful Indoor Chemicals

The study, published online in the journal Environmental Sciences: Process Impacts, is the first of its kind to show that microbes can break down these chemicals, called phthalates. Microbes grow rapidly in humid environments, breaking down harmful chemicals as they grow. But that humidity—and that microbial growth—could cause even more problems, including mold and musty air, the study found. Still, the study is a starting point to understanding how to deal with harmful chemicals indoors.

“Previously, people thought there really wasn’t a lot of microbial activity happening in the indoor environment,” said Karen Dannemiller, director of the Indoor Environmental Quality Laboratory at The Ohio State University and co-author of the study. “We knew microbes were shed from human skin or tracked in from outdoors, and we thought they sat there and didn’t do anything. This study shows that is not always the case.”

Microbes are Eating Away Harmful Chemicals

Instead, the researchers found, those microbes are eating away at potentially harmful chemicals in dust—chemicals that are part of everyday, modern life.

Phthalates are most commonly used to make plastics and vinyl. They are present in some fragrances, many adhesives and certain shampoos and other personal care products. The term covers an entire group of chemicals, and studies have shown that they can affect the human endocrine system, which includes human reproductive organs. One such chemical, di-ethylhexyl phthalate—DEHP—can cause cancer.

“We should care about these chemicals because they have public health implications,” said Ashleigh Bope, co-author of the study and a PhD student in environmental science at Ohio State. “And we know that these chemicals can be degraded in other systems—like aquatic systems and soils—but we have high exposure to them indoors, so it was important for us to see if biodegradation was actually occurring in the indoor environment.”

Carpet Samples Indicate Higher Levels of DEHP

All of that was on the researchers’ minds when they started looking into ways phthalates might break down indoors. They started by taking a piece of carpet—worn, medium-pile, made of nylon—from a family home in Massachusetts. They also collected pieces of carpet from three homes in Ohio, and took samples of dust from vacuum cleaner bags from those same homes.

In the lab, they examined the dust to see what existed in it. They found microbes, of course, and phthalates. One phthalate appeared in higher levels than the others: DEHP—the cancer-causing phthalate. Then, they stored the pieces of carpet at varying levels of humidity to see how the microbes and phthalates might interact.

Higher the Humidity, Greater the Microbes

They found that the higher the humidity, the more the microbes grew—and the more phthalates they destroyed. Moisture was necessary to jump-start the microbes, and though getting rid of the chemicals might be a good thing, it might also cause additional problems, said Sarah Haines, co-author of the study and a graduate student in environmental science in Dannemiller’s lab.

The researchers kept the carpet at relative humidity ranging from 50 to 100 percent—much higher than the humidity levels of a normal home. (The U.S. Environmental Protection Agency recommends homes stay between 30 and 50 percent relative humidity.) At higher humidity levels, microbial activity explodes. Mold grows. Other fungi form.

Creating Buildings without Phthalates or Microbes

“We could see that the phthalates were degrading, but the byproducts of that degradation could be even more harmful,” Haines said. “We really need to look at that more, especially at those elevated relative humidity conditions. It’s not recommended to maintain a high relative humidity in your home due to increased potential for microbial growth.”

Dannemiller, who is an assistant professor of civil, environmental and geodetic engineering at Ohio State, said this study sets the stage for creating better indoor environments in the future that can protect people from both chemicals and microbes.

“The big picture is that understanding these interactions can eventually lead to better building design to prevent exposure to some of these harmful compounds,” she said. “We know that both chemicals and microbes are there, so how can we create the healthiest buildings that we possibly can?”

Source: Ohio State University

DSM, Stratasys SLA 3D Printing Partnership to Facilitate Durable Parts Production

Royal DSM has entered into a partnership Stratasys. Stratasys, which aims to disrupt traditional 3D printing, enters the stereolithography segment with a new printer, the V650™ Flex. DSM backs this launch with its Somos® materials, relentlessly aiming to expand the offering available to its customer base and to accelerate the adoption of 3D printing. 

Accelerating the Adoption of 3D Printing

As part of its alliance with DSM, Stratasys offers customers recipes for Somos® stereolithography resins, commercially available directly from the company. This choice is backed by Stratasys’ extensive utilization of Somos® verified resins in its service bureau, Stratasys Direct Manufacturing.

By entering into partnership with Stratasys, DSM wants to expand the choice for customers to increasingly meet application performance demands.

Hugo da Silva, VP of Additive Manufacturing at DSM: “From the high-performance demands of automotive and aerospace industries to the durability and flexibility requirements of consumer goods, customers worldwide rely on Somos materials to create the highest-performing additive manufacturing prototypes and tools,” said Hugo da Silva. “Stratasys’ entrance into the stereolithography segment is really a game-changer for the industry. Our collaboration allows customers to have greater access and flexibility for development of durable and reliable prototypes and tooling using stereolithography 3D printing.”

Greater Access to Develop to Meet Durability and Flexibility Needs

The open vat configuration of the V650 Flex stereolithography printer comes with recipes for DSM Somos resins commercially available directly from Stratasys – including:

• Somos® Element: The antimony-free stereolithography resin, specifically designed for producing strong, stable investment casting patterns with fine-feature detail and very low residual burnout ash.
• Somos® NeXt: The resin that provides the accuracy of stereolithography with the look, feel and performance of a thermoplastic.
• Somos® PerFORM: The material-of-choice for applications that require strong, stiff, high-temperature resistant parts, such as rapid tooling and wind tunnel testing.
• Somos® Watershed XC 11122: A clear solution for designers looking for ABS and PBT-like properties for stereolithography – producing highly detailed, dimensionally stable, optically-clear parts with water resistance.

Source:DSM

Ireland’s first biomethane bus starts passenger operations in Cork

Bus travelers in Cork were the first passengers to ride a ‘green bus’ in Ireland on March 25.  With zero carbon emissions, this biomethane vehicle is a viable alternative for Ireland’s public bus fleet, and the bus has been part of national trials looking at its performance, air quality impacts and CO2 emissions, among other criteria. “Energy Cork has been advocating the benefits of adopting CNG and biomethane for our public bus fleet in Cork for a number of years, so we are delighted to be making a journey on Ireland’s first zero carbon emissions bus,” said Michelle O’Sullivan, Energy Cork spokesperson and Cork Chamber Public Affairs Senior Executive.

“Never has the demand for public transport been greater in Cork with the city centre expecting an additional 10,000 jobs in the next 5 years. We have the opportunity now to shape how we grow and be proactive in adopting technologies that work for the city and which protect our environment and air quality. This technology is tried and tested with examples of biomethane bus fleets in Stockholm, Lille and Nottingham to name just a few cities. We are very keen to see this technology supported by the National Transport Authority and hope to see these buses rolled out in Cork in the not too distant future,” she added.

Faced with EU deadlines to reduce harmful greenhouse gases, and following Budget 2018, Ireland will no longer be able to purchase diesel buses for public transport as of July 1 2019. The Department of Transport, Tourism & Sport has been carrying out technology trials of hybrid diesel, fully electric, electric hybrid, CNG and biomethane buses in Cork and Dublin in recent months to review performance. The buses have been traveling key routes in the urban bus transport network, but have been weighted rather than carrying passengers so this recent operation represents a landmark in Ireland’s move to a greener public transport system.

The first passenger bus journey of its kind in Ireland picks up from Lapps Quay in Cork city and travels to the SFI (Science Foundation Ireland) funded Centre for Marine and Renewable Energy (MaREI) in Ringaskiddy where passengers have the opportunity to gain insights from leading gas and algal biofuels researcher Professor Jerry D. Murphy on the research and focus of the work ongoing.

Dónal Kissane, Commercial Manager, Gas Networks Ireland said, “We are delighted to welcome members of Cork Chamber, Energy Cork and MaREI/UCC to take part in Ireland’s first carbon neutral bus journey. Unlike the diesel buses currently in operation, this bus runs on renewable gas, and its journey will have a zero carbon emissions footprint.  We believe that the future of public transport in Ireland will be based on renewable gas, using waste from the agriculture and food industry.”

Source: Gas Networks Ireland

Dow Uses Post-consumer Recycled Plastic to Improve Performance of PMA Roads

As part of Dow’s commitment to reducing plastic in the environment and delivering circular economy solutions through innovation, the company constructed two new polymer modified asphalt (PMA) roads by improving them with post-consumer recycled plastic (PCR) at its Freeport, Texas facility. Both private roads—Plastics Road and Gulfstream Road—are now open for traffic.

DuPont’s Technology Enabled Several Benefits for the Road

Enabled by DuPont™ Elvaloy® asphalt modification technology, these roads achieved the following:

• Used 1,686 pounds of recycled linear low-density polyethylene (LLDPE) plastic —the equivalent weight of 120,000 plastic grocery bags
• Covered a combined length of approximately 2,600 feet
• Saved PMA material cost
• Met Performance Grade 70-22 requirements

“We’re excited about the technological implications of this project, and it’s worth mentioning that PCR helped to reduce the material cost of PMA in road construction,” said Jennifer Li, global construction sustainability leader and ICT infrastructure & construction marketing manager at Dow. “For many, a circular economy can seem unrealistic. It becomes far more realistic when they see how sustainability efforts can be supported by improved performance and cost savings.”

Further Improving Roads for Different Climates and Conditions

As Dow researchers examine the results of this project—a collaboration with Martin Asphalt, American Materials and Vernor Material & Equipment—they plan to monitor the longevity and performance of the PMA roads to further improve them for a variety of climates and conditions. Dow is developing plans to use next-generation recycled plastic mixtures to improve parking lots at its Midland, Michigan headquarters.

“Our global sustainability team is dedicated to identifying new construction end-use projects with our value chain collaborators,” said Li. “Imagine the impact if one day recycled plastic or used packaging (that isn’t recycled today) could be used to improve several high-performance roads and parking lots across an entire city, highway system or corporate campus.”

100 Metric Tons of Waste Diverted from Landfills

In combination with PMA projects around the world, Dow has now laid more than 26 miles of PMA pavement. This has diverted 100 metric tons (more than 220,000 pounds) of waste from ending up in a landfill as litter.

Before this North America pilot, the company began improving roads with recycled plastic in Depok City, Indonesia in 2017 to help the Indonesian government reach its goal of reducing plastic waste in the ocean by 70 percent by 2025. Following that trial project’s success, Dow turned its attention to India, where it worked with KK Plastic Waste Management, Ltd., Rudra Environmental Solutions and two local governments to implement roads improved by plastic in the cities of Pune and Bangalore. Most recently, Dow began a collaboration with Siam Cement Group in Thailand to begin improving asphalt roads with plastic.

Source: Dow

Researchers Discover Unexpected QHE Effect in Thin Graphite Sheets

Researchers at The University of Manchester have discovered unexpected phenomena in graphite thanks to their previous research on its two-dimensional (2D) relative – graphene.

The Quantum Hall Effect in Bulk Graphite

The team led by Dr Artem Mishchenko, Prof Volodya Fal’ko and Prof Sir Andre Geim, discovered the quantum Hall effect (QHE) in bulk graphite – a layered crystal consisting of stacked graphene layers. This is an unexpected result because the quantum Hall effect is possible only in two-dimensional materials where the movement of electrons’ motion is restricted. 

They have also found that the material behaves differently depending on whether it contains odd or even number of graphene layers - even when the number of layers in the crystal exceeds hundreds. The work is an important step to the understanding of the fundamental properties of graphite, which have often been misunderstood.

Graphite Delivering Different Phenomenas

“For decades graphite was used by researchers as a kind of 'philosopher's stone' that can deliver all probable and improbable phenomena including room-temperature superconductivity,” Geim commented. “Our work shows what is, in principle, possible in this material, at least when it is in its purest form.”
In the work, published in Nature Physics, Mishchenko and colleagues studied devices made from cleaved graphite crystals, which essentially contain no defects. The researchers preserved the high quality of the material by encapsulating it in another high-quality 2D layered material – hexagonal boron nitride. This allowed nearly perfect samples of thin graphite to measure electron transport in this material.

“The measurements were quite simple.” explains Dr Jun Yin, the first author of the paper. “We passed a small current along the device, applied strong magnetic field and then measured voltages generated along and across the device to extract longitudinal resistivity and Hall resistance.

Samples with QHE Accompanied by Zero Longitudinal Resistivity

Prof Fal’ko who led the theory exploration said: “We were quite surprised when we saw the quantum Hall effect accompanied by zero longitudinal resistivity in our samples. These are thick enough to behave just as a normal bulk semimetal in which QHE should be strictly forbidden.”

The researchers say that the QHE comes from the fact that the applied magnetic field forces the electrons in graphite to move ‘in a reduced dimension’, with conductivity only allowed in one direction. Then, in thin enough samples, this one-dimensional motion can become quantized thanks to the formation of standing electron waves. The material goes from being a 3D electron system to a 0D one, with discrete energy levels in a magnetic field.

QHE Sensitive to Even & Odd Graphene Layers

Another big surprise is that this QHE is very sensitive to even/odd number of graphene layers. The electrons in graphite are similar to those in graphene and come in two “flavors” (called valleys). The standing waves formed from electrons of two different flavors sit on either even - or odd - numbered layers in graphite. In films with even number of layers, the number of even and odd layers is the same, so the energies of the standing waves of different flavors coincide.

The situation is different in films with odd numbers of layers, however, because the number of even and odd layers is different as there is always an extra odd layer. This results in the energy levels of the standing waves of different flavours shifting with respect to each other and means that these samples have reduced QHE energy gaps. The phenomenon even persists for graphite hundreds of layers thick.

Fractional QHE in Thin Graphite at Low Temperatures

The unexpected discoveries did not end there: the researchers also observed the fractional QHE in thin graphite at temperatures below 0.5 K. The fractional QHE is a result of strong interactions between electrons. These interactions, which can often lead to important collective phenomena such as superconductivity, magnetism and superfluidity, make the charge carriers behave as particles with a charge that is a fraction of that of an electron.

“Most of the results we have observed can be explained using a simple single-electron model but seeing the fractional QHE tells us that the picture is not so simple,” says Mishchenko. “There are plenty of electron-electron interactions in our graphite samples at high magnetic fields and low temperatures, which shows that many-body physics is important in this material.”

New Stepping Stone for Further Studies on Graphite

Graphene has been in the limelight these last 15 years, due to its many superlative properties, and graphite was pushed back a little by its one-layer-thick offspring. Mishchenko adds: “We have now come back to this old material. Knowledge gained from graphene research, improved experimental techniques (such as van der Waals assembly technology) and a better theoretical understanding (again from graphene physics), has already allowed us to discover this novel type of the QHE in graphite devices we made.

“Our work is a new stepping stone to further studies on this material, including many-body physics, like density waves, excitonic condensation or Wigner crystallization.”

The Manchester researchers say they now plan to explore all those phenomena and theoretical predictions using the fact that their thin graphite samples are as perfect as materials can be.

Source: The University of Manchester

Nouryon has unveiled a new version of its Butanox M-50 Vanishing Red peroxide at JEC World, a leading trade event for the composites market. The new version contains a less-hazardous dye solvent that makes it safer for customers to handle and reduces its environmental impact while maintaining its industry-leading performance.

Safer for Customers and Reduces Environmental Impact

Vanishing Red is widely used by customers in the composites market as part of the curing process for unsaturated resins. Its red color gradually vanishes as resins cure, allowing customers to better monitor the dosing, mixing, and curing progress. Vanishing Red is especially useful for automated processes used to make products such as wind turbine blades and boats.

Prevent Failures without Leaving a Trace

“Customers using automated dosing equipment may face problems if peroxide doesn’t properly flow through the dosing line, leading to under-cured or uncured end products,” said Raymond ten Broeke, Polymer Chemistry Customer Support Engineer at Nouryon. “This can be very costly to manufacturers if molds need to be cleaned. Using Vanishing Red peroxides helps prevent such failures without leaving a trace that any indicator was used.”

Johan Landfors, Managing Director Polymer Chemistry at Nouryon, added:

“We are proud that Vanishing Red offers our customers in the composites market a safer and more sustainable solution for curing unsaturated polyester resins. This is the latest in a series of products we have introduced to better serve and grow with our customers in this important market.”

Nouryon recently expanded its peroxides offering in North America with the launch of its Butanox-branded product line of methyl ethyl ketone peroxide (MEKP) and the launch of emulsion-based organic peroxides. The company has also expanded capacity in Mexico and the United States. Another expansion project in Mexico is due to be completed this year and additional capacity is also scheduled to come online in Brazil, China, and India.

Source: Nouryon

BASF Ultramid® GF-reinforced PA Use in Fuel Cells Pushes Electric Drive Concepts Ahead

In close cooperation with Joma-Polytec and Mercedes-Benz Fuel Cell, a subsidiary of Daimler AG, the engineering plastic Ultramid from BASF has successfully been used to manufacture a number of fuel cell system components. This innovative solution is being used as standard in the new Mercedes GLC F-CELL, which combines a fuel cell with a rechargeable lithium-ion battery. 

Plastics increase efficiency – not only in hybrid, plug-in and electric vehicles but also in internal combustion engines. 

Andreas Stockheim, Segment Manager Powertrain and Chassis at BASF explains, “Our extensive plastics portfolio offers all sorts of advantages which help us to satisfy specific customer requirements, depending on the drive concept and the specific component,” 

“By continually developing new products in close collaboration with our customers, we are also able to adapt our portfolio to trends and changes in the market.”

Meeting Quality & Safety Requirements in Automotive Industry

The high quality and safety requirements in the automotive industry place huge demands on materials. BASF is able to keep pace with car manufacturers’ latest developments, while also setting innovative trends with versatile and sophisticated polymers such as:

• Polyamides (Ultramid®)
• Polybutylene terephthalates (Ultradur®)
• Polyphthalamides (PPA)
• Polyoxymethylene (Ultraform®)
• Polyethersulfone (Ultrason®)

Technical properties and high functionality are key here. For the Mercedes GLC F-Cell, it is the all-round excellence of Ultramid’s properties that counts: 

• Good thermal and chemical resistance
• Dynamic stiffness
• Impact strength, and
• Good long-term performance

“Earlier tests with other materials revealed mechanical problems, so Daimler had very specific requirements for the material,” explains Stefan Milimonka, Key Account Manager in BASF’s Performance Materials division.

“Our expertise with plastic automotive components and the extensive choice of existing products meant that we were able to work out possible solutions with our partners and identify the right material. It shows that with specialist knowledge and good cooperation between everyone involved, a complex project like this can be brought to a successful conclusion.”

Three Partners – One Tailor-made Solution

In conjunction with Joma-Polytec GmbH and Mercedes-Benz Fuel Cell GmbH, a subsidiary of Daimler AG, a development project was initiated. Its aim: to find an optimal solution satisfying the extensive range of requirements including thermal stability, media resistance, and durability.

In view of the unique material structure, and on the basis of intensive material analyses of the chemical and mechanical resistance, the partners ultimately decided on the tailor-made Ultramid grades:

• Ultramid® A3WG10 CR
• Ultramid® A3EG7 A3EG7 EQ

Glass Fiber-reinforced Polyamides for Sensitive Applications

Following successful testing of all components, the two-glass fiber-reinforced Ultramid polyamide grades are now being used as standard to manufacture the anode- and cathode-end plate in fuel cells. 

Ultramid A3EG7 EQ is an ideal material, given the exceptional purity requirements associated with sensitive applications in the electronics industry. In the case of the media distribution plate and the water separator unit, which is exposed to a wide variety of media through the cooling water, air and hydrogen channel, this Ultramid grade offers excellent resistance, while at the same time meeting all requirements regarding the purity of the material.

“Thanks to BASF’s extensive product portfolio and the specialist knowledge of all the parties involved, we have taken an important step forward in the serial development of fuel cells,” is how Stefan Heinz, deputy head of plastics technology development at Joma-Polytec GmbH, sums up the project. “We worked together to analyze the stringent requirements and were able to put in place a highly efficient solution.”
 

Source: BASF

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