Today's KNOWLEDGE Share : Researchers Develop Cool Paint Using Recycled Plastics

Today's KNOWLEDGE Share

An NTU research team has successfully developed new methods to create a type of “cool paint” using recycled plastics – namely acrylic, old PVC pipes and polystyrene foam – and barium sulphate, offering a sustainable and efficient alternative to new plastics.

The NTU methods not only help in cooling temperatures in tropical environments, but also contribute to effective plastic waste management.

Can Reach 3°C Below the Ambient Temperature:

In the first method (sol-gel), the research team used recycled plastics and mixed them with barium sulphate (BaSO4), to create their cool paint.

A 24-hour test on the roof-top of a building in Singapore showed that the newly created coating can reach 1.2°C below the surrounding air temperature when exposed to direct sunlight. At night, the coating could reach 3°C below the ambient temperature. The coating can reflect about 97.7% of sunlight and emits 95% of its heat in the infra-red band.

Made Recycled Plastics Porous to Scatter Sunlight:

In a second method (phase inversion), the team also used recycled plastics and barium sulphate to make the cool paint but focused on making the recycled plastics porous by creating tiny air-filled holes in them during the production process. This is because air pores help to scatter sunlight across its spectrum.

Results showed that the surfaces coated with this version of the paint could almost match the surrounding air temperature at noon and achieve night temperature of 2.5°C below the ambient temperature.

The cool paint developed using both methods outperforms commercially available cool paints which typically are unable to bring surface temperatures below ambient. 

Reduces the Need of Sorting

Further investigations using a mix of unsorted plastic waste (mix of acrylic, PVC pipes and polystyrene foam) also showed that results were comparable to those from cool paints developed using only a single type of plastic waste. This suggests that the NTU team’s approaches reduce the need for sorting different types of plastic.

Source: NTU/omnexus.specialchem.com

Lummus Invests in RWDC Industries to Globally Commercialize PHA

Lummus Technology has taken a lead investor position in RWDC Industries' convertible bond round. This further strengthens the partnership between the two companies to bring polyhydroxyalkanoates (PHA) to the global market.

This strategic investment marks a significant milestone in commercialization of PHA. PHA is a biodegradable and environmentally safe alternative to petroleum-based plastics. It can help mitigate the accelerating health concerns associated with persistent plastics and microplastics in the environment and support the development of a circular economy.

First Commercial-scale PHA Facility to Open in 2025:

Since signing a binding Joint Development and Commercial Cooperation Agreement in September 2023, Lummus and RWDC have made substantial progress in their shared mission to accelerate worldwide adoption of PHA and prepare the technology for global licensing.

The engineering phase of RWDC’s first commercial-scale PHA facility is nearly complete. The detailed engineering and preconstruction activities are set to be finalized in the coming months. Lummus' lead investment in RWDC's convertible bond round will enable completion of these final stages, targeting groundbreaking of the facility in early 2025.

“Lummus’ investment in RWDC is a testament to our unwavering commitment to commercializing PHA and advancing the circular economy of the polymer industry,” said Leon de Bruyn, president and chief executive officer, Lummus Technology. “By combining our expertise in process technology with RWDC’s innovative PHA production capabilities, we are poised to make a significant impact on the world's transition to sustainable and more carbon neutral materials.”

“Lummus’ support as the lead investor in our convertible bond round is a major step forward for RWDC and the future of PHA,” said Dr. Daniel Carraway, chief executive officer, RWDC. “This investment not only accelerates our journey towards construction of our first commercial-scale PHA production facility but also validates the immense potential of our technology in addressing the global challenge of plastic pollution.”

Source: Lummus Technology/omnexus.specialchem.com

Today's KNOWLEDGE Share : Optical Plastic Vs Optical Glass

Today's KNOWLEDGE Share

Optical Plastic Vs Optical Glass

Optical plastics and optical glass are the two mainstream materials for optical devices, each with unique characteristics and application advantages. First of all, from the perspective of material properties, the refractive index of optical plastics usually ranges from 1.42 to 1.69, the Abbe number ranges from 18.8 to 65.3, and the relative density ranges from 0.83 to 1.46g/cm³. In contrast, optical glass has a wider range of refractive index and dispersion, but optical plastics come at the expense of relatively low heat resistance, high moisture absorption, and a large coefficient of thermal expansion.

Although optical plastics are relatively disadvantaged in some aspects, such as poor heat resistance and chemical stability, they have clear advantages. Optical plastics are lightweight and have strong impact resistance. Their relative density is only half that of glass, and their manufacturing and processing costs are far lower than 1/10 to 1/30 of optical glass. The impact resistance of optical plastic lenses is about 10 times that of glass, making it an ideal choice for scenarios that require high device weight and safety. In addition, optical plastics have good shape adaptability and can flexibly prepare complex shapes such as aspheric lenses, providing more possibilities for optical system design.

However, optical plastics also have some limitations. It has relatively low heat resistance and may soften or deform in high temperature environments. The surface has relatively poor abrasion and chemical resistance and may require additional protective measures. In contrast, optical glass has higher heat resistance, better wear resistance and chemical stability.

In practical applications, optical system designers need to choose optical plastics or optical glasses according to specific needs, or use them in clever combinations to achieve the best performance balance. For high-demand application scenarios, optical glass may be preferred, while in applications that emphasize lightweight and cost, optical plastics appear to be more competitive.

source:nonicustomoptics.com

Trillium to Establish Bio-acrylonitrile Plant at INEOS Nitriles’ Texas Facility

Trillium Renewable Chemicals (Trillium) announces the selection of INEOS Nitriles’ Green Lake facility in Port Lavaca, Texas to establish the world’s first demonstration plant for converting plant-based glycerol into acrylonitrile. The demonstration plant is named “Project Falcon.”

Offering Lower Carbon Footprint than Standard Acrylonitrile:

Trillium Renewable Chemicals has developed a groundbreaking technology for producing sustainable acrylonitrile, a key raw material in numerous industries, including toys, auto parts, aerospace components, medical supplies, and apparel. Selecting INEOS underscores Trillium's ambition to scale up its technology in an industrial environment to accelerate progress.

“Trillium is thrilled that INEOS Nitriles Green Lake, home to America’s largest acrylonitrile production plant, will serve as the home for Project Falcon,” said Corey Tyree, CEO of Trillium Renewable Chemicals. “This milestone is a significant step forwards in bringing our technology to market and producing sustainable bio-based acrylonitrile at scale.”

Following a $10.6M Series A financing round in December 2022 and $2.5 million award from the Department of Energy’s Advanced Manufacturing Office in June 2022, Trillium constructed a pilot plant that successfully produced acrylonitrile from glycerol. Trillium’s sustainable acrylonitrile offers a lower carbon footprint than standard acrylonitrile based on the Sohio propylene process. The company’s innovative approach addresses growing customer demand for greener bio based raw materials.

Project Falcon Operations to Begin in Early 2025

The ongoing operation of Trillium’s pilot plant progresses product sampling and customer validation, contributing valuable insights for the design of the Falcon plant, which is to operate at the INEOS Nitriles Green Lake site.

Hans Casier, CEO of INEOS Nitriles, highlighted the significance of Trillium’s decision, “INEOS Nitriles is very pleased to be working with Trillium to advance technology for the production of sustainable bio-based acrylonitrile. Our support for this project, which is part of our wider sustainability strategy, emphasizes our commitment as the world’s largest producer of acrylonitrile, to reducing the carbon footprint of the industry. We look forward to working closely with Trillium to help achieve this objective.”

The operation of Project Falcon will help to validate commercial-scale economics and product carbon footprint at scale. Emphasis will be placed on achieving process performance criteria such as plant uptime, demonstrating key equipment in its final form, and securing qualification as a supplier of bio-based acrylonitrile. Set to commence operations in early 2025, the project will run through early 2026.

Source: INEOS/polymer-additives.specialchem.com

 

Today's KNOWLEDGE Share : Brain Stimulation

 Today's KNOWLEDGE Share

Ultrasound offers a new way to perform deep brain stimulation

MIT engineers’ implantable ImPULS device could become an alternative to the electrodes now used to treat Parkinson’s and other diseases.

Deep brain stimulation, by implanted electrodes that deliver electrical pulses to the brain, is often used to treat Parkinson’s disease and other neurological disorders. However, the electrodes used for this treatment can eventually corrode and accumulate scar tissue, requiring them to be removed.

MIT researchers have now developed an alternative approach that uses ultrasound instead of electricity to perform deep brain stimulation, delivered by a fiber about the thickness of a human hair. In a study of mice, they showed that this stimulation can trigger neurons to release dopamine, in a part of the brain that is often targeted in patients with Parkinson’s disease.

“By using ultrasonography, we can create a new way of stimulating neurons to fire in the deep brain,” says Canan Dagdeviren, an associate professor in the MIT Media Lab and the senior author of the new study. “This device is thinner than a hair fiber, so there will be negligible tissue damage, and it is easy for us to navigate this device in the deep brain.

In addition to offering a potentially safer way to deliver deep brain stimulation, this approach could also become a valuable tool for researchers seeking to learn more about how the brain works.

MIT graduate student Jason Hou and MIT postdoc Md Osman Goni Nayeem are the lead authors of the paper, along with collaborators from MIT’s McGovern Institute for Brain Research, Boston University, and Caltech. The study appears today in Nature Communications.

Deep in the brain

Dagdeviren’s lab has previously developed wearable ultrasound devices that can be used to deliver drugs through the skin or perform diagnostic imaging on various organs. However, ultrasound cannot penetrate deeply into the brain from a device attached to the head or skull.

“If we want to go into the deep brain, then it cannot be just wearable or attachable anymore. It has to be implantable,” Dagdeviren says. “We carefully customize the device so that it will be minimally invasive and avoid major blood vessels in the deep brain.”

Deep brain stimulation with electrical impulses is FDA-approved to treat symptoms of Parkinson’s disease. This approach uses millimeter-thick electrodes to activate dopamine-producing cells in a brain region called the substantia nigra. However, once implanted in the brain, the devices eventually begin to corrode, and scar tissue that builds up surrounding the implant can interfere with the electrical impulses.

The MIT team set out to see if they could overcome some of those drawbacks by replacing electrical stimulation with ultrasound. Most neurons have ion channels that are responsive to mechanical stimulation, such as the vibrations from sound waves, so ultrasound can be used to elicit activity in those cells. However, existing technologies for delivering ultrasound to the brain through the skull can’t reach deep into the brain with high precision because the skull itself can interfere with the ultrasound waves and cause off-target stimulation.

“To precisely modulate neurons, we must go deeper, leading us to design a new kind of ultrasound-based implant that produces localized ultrasound fields,” Nayeem says. To safely reach those deep brain regions, the researchers designed a hair-thin fiber made from a flexible polymer. The tip of the fiber contains a drum-like ultrasound transducer with a vibrating membrane. When this membrane, which encapsulates a thin piezoelectric film, is driven by a small electrical voltage, it generates ultrasonic waves that can be detected by nearby cells.

“It’s tissue-safe, there’s no exposed electrode surface, and it’s very low-power, which bodes well for translation to patient use,” Hou says.

In tests in mice, the researchers showed that this ultrasound device, which they call ImPULS (Implantable Piezoelectric Ultrasound Stimulator), can provoke activity in neurons of the hippocampus. Then, they implanted the fibers into the dopamine-producing substantia nigra and showed that they could stimulate neurons in the dorsal striatum to produce dopamine.

“Brain stimulation has been one of the most effective, yet least understood, methods used to restore health to the brain. ImPULS gives us the ability to stimulate brain cells with exquisite spatial-temporal resolution and in a manner that doesn’t produce the kind of damage or inflammation as other methods. Seeing its effectiveness in areas like the hippocampus opened an entirely new way for us to deliver precise stimulation to targeted circuits in the brain,” says Steve Ramirez, an assistant professor of psychological and brain sciences at Boston University, and a faculty member at B.U.’s Center for Systems Neuroscience, who is also an author of the study.

A customizable device

All of the components of the device are biocompatible, including the piezoelectric layer, which is made of a novel ceramic called potassium sodium niobate, or KNN. The current version of the implant is powered by an external power source, but the researchers envision that future versions could be powered a small implantable battery and electronics unit.

The researchers developed a microfabrication process that enables them to easily alter the length and thickness of the fiber, as well as the frequency of the sound waves produced by the piezoelectric transducer. This could allow the devices to be customized for different brain regions.

“We cannot say that the device will give the same effect on every region in the brain, but we can easily and very confidently say that the technology is scalable, and not only for mice. We can also make it bigger for eventual use in humans,” Dagdeviren says.

The researchers now plan to investigate how ultrasound stimulation might affect different regions of the brain, and if the devices can remain functional when implanted for year-long timescales. They are also interested in the possibility of incorporating a microfluidic channel, which could allow the device to deliver drugs as well as ultrasound.

In addition to holding promise as a potential therapeutic for Parkinson’s or other diseases, this type of ultrasound device could also be a valuable tool to help researchers learn more about the brain, the researchers say.

“Our goal to provide this as a research tool for the neuroscience community, because we believe that we don’t have enough effective tools to understand the brain,” Dagdeviren says. “As device engineers, we are trying to provide new tools so that we can learn more about different regions of the brain.”

The research was funded by the MIT Media Lab Consortium and the Brain and Behavior Foundation Research (BBRF) NARSAD Young Investigator Award.

source:news.mit.edu

Covestro and Partners Launch Research Project to Recycle End-of-Life PU Mattress Foams

Material efficiency is the key objective when creating a new material cycle for flexible polyurethane (PU) foam from used mattresses. The French company Ecomaison has been working with Covestro for a few years to utilize its chemical recycling technology for this purpose. With this advanced process, both raw materials originally used can be recovered – the polyol as well as the precursor to the isocyanate TDI.

The aim of the partners is to recycle the sorted polyurethane foams as efficiently as possible. They will do this by combining mechanical and chemical technologies after careful sorting by foam type in the mattress cutting plants.

To Explore All Possibilities in A Future-oriented Foam Recycling Ecosystem:

Collaborations leveraging own expertise with like-minded partners are key. In addition to Ecomaison and Covestro, the French dismantling company Secondly and Federal Eco Foam, a Belgian specialist in the mechanical recycling of flexible foams, are involved as partners in the project. The project is planned to run for a maximum of 24 months. The project is called Foam Recycling Ecosystem Evolution (FREE) and coordinated by Covestro and half-funded by Ecomaison.

For the FREE consortium, the motivation lies in the added value of the material that can be recovered from the used foams and the opportunity to enter a more sustainable circular economy. The partners want to explore all possibilities in a future-oriented foam recycling ecosystem. They are convinced that chemical and mechanical recycling will complement each other in a meaningful way. As dismantler and sorting actor, Secondly is interested in empowering its sorting processes to be able to supply to recyclers a specified quality of foam.

At the same time, the project will provide a good picture of how the foam recycling market in the coming years may look like. The partners truly believe that chemical and mechanical recycling can be complementary given different specifications of inlet materials being sorted already at dismantlers. To provide added value to the PU foam material, the consortium will investigate all possibilities in a future oriented eco-system of foam recycling.

To Compare the Recycling Processes for Sorted Foams for Economic Feasibility

The research and development project includes the foam sorting at the dismantling step. It also includes a comparative feasibility study for two recycling processes for the sorted foams covering economic and ecologic value co-creation.

A few years ago, Covestro and its partners developed a chemical recycling process that is the only one of its kind capable of ultimately recovering both main raw materials of flexible PU foams in high purity.

source: Covestro/omnexus.specialchem.com

Today's KNOWLEDGE Share : Researchers Innovate Adhesive Smart Skin for Advanced Health Monitoring

Today's KNOWLEDGE Share

Skin can send certain health-related signals, such as dry skin feeling tighter to indicate the need for moisture. But what if skin could be smarter, capable of monitoring and sharing specific health information, such as the concentration of glucose in sweat or heart rate?

That was the question driving a team led by Penn State researchers that recently developed an adhesive sensing device that seamlessly attaches to human skin to detect and monitor the wearer’s health.

Multifunctional Adhesive Device Patch:

Co-corresponding author Huanyu “Larry” Cheng, the James L. Henderson, Jr. Memorial associate professor of engineering science and mechanics in the Penn State College of Engineering explained that conventional fabrication techniques for flexible electronics can be complicated and costly, especially as sensors built on flexible substrates, or foundational layers, are not necessarily flexible themselves.

“Despite significant efforts on wearable sensors for health monitoring, there haven’t been multifunctional skin-interfaced electronics with intrinsic adhesion on a single material platform prepared by low-cost, efficient fabrication methods. This work, however, introduces a skin-attachable, reprogrammable, multifunctional, adhesive device patch fabricated by simple and low-cost laser scribing,” said Cheng.

The sensor’s rigidity can limit the flexibility of the entire device. Cheng’s team previously developed biomarker sensors using laser-induced graphene (LIG), which involves using a laser to pattern 3D networks on a porous, flexible substrate. The interactions between the laser and the materials contained in the substrate produce conductive graphene.

“However, the LIG-based sensors and devices on flexible substrates are not intrinsically stretchable and can’t conform to interface with human skin for bio-sensing,” Cheng said, noting that human skin is changeable in shape, temperature and moisture levels, especially during physical exertion when monitoring heart rate, nerve performance or sweat glucose levels might be necessary. “Although LIG can be transferred to stretchable elastomers, the process can greatly reduce its quality.”

Innovative Solution with Adhesive Composite:

As a result, Cheng said, it’s more difficult to program a sensor device to monitor specific biological or electrophysical signals. Even when the device can be appropriately programmed, its sensing performance is often degraded.

“To address these challenges, it is highly desirable to prepare porous 3D LIG directly on the stretchable substrate,” said co-author Jia Zhu, who graduated with a doctorate in engineering science and mechanics from Penn State in 2020 and is now an associate professor at the University of Electronic Science and Technology of China.

The researchers achieved this goal by making an adhesive composite with molecules called polyimide powders that add strength and heat resistance and amine-based ethoxylated polyethylenimine — a type of polymer that can modify conductive materials — dispersed in a silicone elastomer, or rubber. The stretchable composite not only accommodates direct 3D LIG preparation, but also its adhesive nature means it can conform and stick to non-uniform, changeable shapes — like humans.

The researchers experimentally confirmed that the device can monitor the pH value, glucose and lactate concentrations in sweat as well as can be detected via finger prick blood draws. It can also be reprogrammed to monitor heart rate, nerve performance and sweat glucose concentrations in real time.

Reprogramming is as simple as applying clear tape over the LIG networks and peeling them off. The substrate can then be re-lasered to new specifications, up to four times before it becomes too thin. Once it becomes too thin, the entire device can be recycled.

Future Potential and Applications:

Critically, according to Cheng, the device remains adhesive and capable of monitoring even when the skin is made slick with sweat or water. Currently powered by batteries or near-field communication nodules, like a wireless charger, the device could potentially harvest energy and communicate over radio frequencies, which researchers said would result in a standalone, stretchable adhesive platform capable of sensing desired biomarkers and monitoring electrophysical signals.

The team said they plan to work toward this goal, in collaboration with physicians, to eventually apply the platform to manage various diseases such as diabetes and monitor acute issues like infections or wounds.

“We would like to create the next generation of smart skin with integrated sensors for health monitoring — along with evaluating how various treatments impact health — and drug delivery modules for in-time treatment,” Cheng said.

Cheng is also affiliated with the departments of biomedical engineering, of mechanical engineering, of architectural engineering and of industrial and manufacturing engineering, as well as the materials research institute and the institute for computational and data sciences.

Other collaborators affiliated with the Department of Engineering Science and Mechanics at Penn State include Xianzhe Zhang, Chenghao Xing and Shangbin Liu, all graduate students; and Farnaz Lorestani, associate research fellow. Co-authors from outside of Penn State include Yang Xiao, Jiaying Li, Ke Meng, Min Gao, Taisong Pan and Yuan Lin, all with the University of Electronic Science and Technology of China; and Yao Tong, Yingying Zhang, Senhao Zhang, Benkun Bao and Hongbo Yang with the Suzhou Institute of Biomedical Engineering and Technology, Chinese Academy of Sciences. Li is also affiliated with the institute.

The U.S. National Institutes of Health, the U.S. National Science Foundation, Penn State, the University of Electronics Science and Technology China and the National Natural Science Foundation of China funded this research.

Source: Pennsylvania State University/adhesives.specialchem.com