Gold and platinum group metals such as palladium, platinum and iridium are in high demand for use in electronics. However, sourcing these metals from mining and current electronics recycling techniques is not sustainable and comes with a high carbon footprint. Gold used in electronics accounts for 8% of the metal’s overall demand, and 90% of the gold used in electronics ends up in U.S. landfills yearly, the study reports.&nbsp;The study, led by <a href="https://chbe.illinois.edu/" target="_blank">chemical and biomolecular engineering</a> professor <a href="https://chbe.illinois.edu/people/profile/x2su" target="_blank">Xiao Su</a>, describes the first precious metal extraction and separation process fully powered by the inherent energy of electrochemical liquid-liquid extraction, or e-LLE. The method uses a reduction-oxidation reaction to selectively extract gold and platinum group metal ions from a liquid containing dissolved electronic waste.&nbsp;In the lab, the team dissolved catalytic converters, electronic waste such as old circuit boards, and simulated mining ores containing gold and platinum group metals using an organic solvent. The system then streams the dissolved electronics or ores over specialized electrodes in three consecutive extraction columns: one for oxidation, one for leaching and one for reduction.&nbsp;“The metals are then converted to solids using electroplating, and the leftover liquid can be treated to capture the remaining metals and recycle the organic solvent,” Su said. “The stream containing the organic extractant is then pumped back to the first extraction column, closing the loop, which greatly minimizes waste.”<img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1712185056672-224788.jpg" style="width: 768px;" class="fr-fic fr-dib">This schematic diagram details the electrochemical extraction device used in Su’s laboratory. Graphic courtesy Xiao SuAn economic analysis of the new approach showed that the new method runs at a cost of two orders of magnitude lower than current industrial processes. “The social value of this work is really its ability to produce green gold quickly in a single step, greatly improving transparency and trust in conflict free recycled precious metals,” said postdoctoral researcher Stephen Cotty, the first author of the study.&nbsp;Su said one of the many advantages of this new method is that it can run continuously in a green fashion and is highly selective in terms of how it extracts precious metals. “We can pull gold and platinum group metals out of the stream, but we can also separate them from other metals like silver, nickel, copper and other less valuable metals to increase purity greatly – something other methods struggle with.”The team said that they are working to perfect this method by improving the engineering design and the solvent selection.Research scientist Johannes Elbert and graduate student Aderiyike Faniyan contributed to this study. Su also is affiliated with the <a href="https://beckman.illinois.edu/" target="_blank">Beckman Institute for Advanced Science and Technology</a> and a professor of <a href="https://cee.illinois.edu/" target="_blank">civil and environmental engineering</a> at Illinois. &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;&nbsp;The U.S. Department of Energy supported this study. The University of Illinois Urbana-Champaign has filed a provisional patent on the technology presented in this work. The authors declare no competing financial interest.&nbsp;

A new study from the University of Illinois Urbana-Champaign shows how electrochemistry can be used to extract precious metals from discarded electronics in an efficient and environmentally friendly manner. Photo by Fred Zwicky

A new method safely extracts valuable metals locked up in discarded electronics and low-grade ore using dramatically less energy and fewer chemical materials than current methods, report University of Illinois Urbana-Champaign researchers in the journal Nature Chemical Engineering. 

Electrochemistry helps clean up electronic waste recycling, precious metal mining

As flexible networks of polymer chains suffused by water, hydrogels possess excellent properties including softness, elasticity and biocompatibility. Accordingly, the squishy materials have already found widespread use as contact lenses and wound dressings. Hydrogels also hold great promise for drug delivery systems, agriculture and food packaging, among other applications.Unfortunately, conventional hydrogels pose environmental pollution problems because they cannot be effectively recycled or reprocessed. Hydrogels also degrade from long-term use. The researchers said these limitations derive from the materials’ structure. Conventional hydrogels rely on chemical bonds for their firmness and ability to soak up water and other solvents. On a chemical level, these bonds are cross-linked, meaning that bonds form among different polymer molecules within the hydrogel. This cross-linking, characteristic of resins undergoing curing or rubber vulcanization, gives hydrogels flexibility and strength. But it also makes them extremely difficult to separate into components for recycling.The study’s lead author, <a href="https://cbe.princeton.edu/people/xiaohui-xu" target="_blank">Xiaohui Xu</a>, a postdoctoral researcher, previously worked with hydrogels for use in water purification and wondered if she could create a more environmentally sustainable hydrogel. Xu and her colleagues took a new approach to building hydrogels. Rather than relying on chemical bonds to connect different polymers, the researchers decided to harness phase separation, a familiar phenomenon in which mixed liquids, such as oil and water, separate into components.<img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1703815390706-16X9-for-web-121323-Lab-Shoot-105-2048x1152.jpg" style="width: 300px;" class="fr-fic fr-dib">Researchers Néhémie Guillomaitre and Xiaohui Xu with samples of the material they developed as part of a team led by Professor Rodney Priestley.“Hydrogels offer tremendous societal benefit, but their lack of sustainability has loomed as a significant issue,” said Xu, a postdoctoral researcher in the lab of&nbsp;<a href="https://engineering.princeton.edu/faculty/rodney-priestley" target="_blank">Rodney Priestley</a>, the Pomeroy and Betty Perry Smith Professor of&nbsp;<a href="https://cbe.princeton.edu/" target="_blank">Chemical and Biological Engineering</a> at Princeton. “In this study, we have shown how taking advantage of phase separation can lead to new kinds of hydrogels that are durable and recyclable and still have good mechanical properties.”The researchers described the process in a&nbsp;<a href="https://pubs.acs.org/doi/10.1021/jacsau.3c00326" target="_blank">study</a> published in the Journal of the American Chemical Society Au in September.To make the new hydrogel, the researchers formulated polymers with a complex and varying relation to water. Polymer molecules are long chains of smaller molecules (called monomers). The researchers created polymers that are water-loving in some sections of the chain and water-repelling in other sections. When they added water to the polymer mix, parts of the polymers absorbed the water, while other parts repelled it. This tension gave the hydrogel its structural strength. Unlike conventional hydrogels, the strength is based on physical characteristics rather chemical bonds among the polymers. So, recycling the hydrogel into its component polymers is relatively easy, as is repeatedly dehydrating and rehydrating the material.What is more, Xu said, the process allows engineers to tailor the characteristics of a hydrogel by adjusting the components of the polymers. The research team took advantage of this to create a hydrogel that could be cut and molded into any desired shape. For the research, Xu made an octopus.“Xiaohui used phase separation as a way to control the morphology, and ultimately, the properties of these hydrogel materials,” said Priestley, the paper’s senior author and Dean of the Graduate School at Princeton. “This work demonstrates an environmentally friendly approach for making tough and reusable hydrogels.”The Princeton researchers put the new hydrogel through its paces, testing its stability in extreme acidic and alkaline conditions and in air and water. Across the board, the hydrogel held up and performed as expected.With additional testing and development, the novel material could make existing and emerging applications for hydrogels — such as artificial muscles and soft robots for safe operation around humans — more sustainable and environmentally friendly.“Our general approach for recyclable hydrogels could help expand their applications in all kinds of areas,” said Xu. “The benefits of hydrogels can now be better realized without the environmental costs.”Xu said in the long term, the research team is exploring whether hydrogels could eventually serve as a substitute for plastics in many applications. If that is the case, advanced hydrogels could become a recyclable solution to plastic pollution that threatens the oceans.<hr>The paper, “<a href="https://pubs.acs.org/doi/10.1021/jacsau.3c00326" target="_blank">Tough and Recyclable Phase-Separated Supramolecular Gels via a Dehydration–Hydration Cycle</a>,“ was published Sept. 21 in the Journal of the American Chemical Society Au. In addition to Xu and Priestley, other Princeton authors on the study were former graduate student Yannick Eatmon; former postdoctoral researcher Kofi Christie, now an assistant professor at Louisiana State University; postdoctoral fellow Allyson McGaughey; graduate student Néhémie Guillomaitre; Sujit Datta, an associate professor of chemical and biological engineering; Zhiyong Jason Ren, professor of civil and environmental engineering and the Andlinger Center for Energy and the Environment; and Craig Arnold, the Susan Dod Brown Professor of Mechanical and Aerospace Engineering. The work was supported by the National Science Foundation and a National GEM Consortium Fellowship.

Princeton researchers have developed a new type of recyclable hydrogel that can be cut and molded into different forms. Photos by Dan Komoda

Princeton researchers have created a new type of hydrogel that is recyclable, yet still tough and stable enough for practical use (and reuse).

Reusable and recyclable, this new hydrogel squishes the old version's environmental impact

<h2 dir="ltr" id="isPasted">FREE REPORT: Reducing Human Driver Error and Setting Realistic Expectations with Advanced Driver Assistance Systems</h2>Thousands die or are injured each year in automobile crashes. Bringing automated driving systems technologies into the advanced driver assist systems (ADAS) and connected vehicle space will help humans drive more safely and better prepare us for automated vehicles (AVs).Learn more about ADAS and ADS implementation with the goal of reaching zero deaths and serious injuries by downloading this FREE report from SAE International (valued at $50).&nbsp;<img src="https://images.wevolver.com/eyJidWNrZXQiOiJ3ZXZvbHZlci1wcm9qZWN0LWltYWdlcyIsImtleSI6ImZyb2FsYS8xNzAwNzUzODIyNjYzLVJlZHVjaW5nIEh1bWFuIERyaXZlciBFcnJvciBhbmQgU2V0dGluZyBSZWFsaXN0aWMgRXhwZWN0YXRpb25zIHdpdGggQWR2YW5jZWQgRHJpdmVyIEFzc2lzdGFuY2UgU3lzdGVtcy5wbmciLCJlZGl0cyI6eyJyZXNpemUiOnsid2lkdGgiOjk1MCwiZml0IjoiY292ZXIifX19" style="width: 300px;" class="fr-fic fr-dib"><h2><iframe width="540" height="740" src="https://c8056756.sibforms.com/serve/MUIFAIm7QnvQQ9ZyzkX--H5jNS-TSb9GWr5SQBXi_SUjRPpt67CBveq_yevZYMSeiJ-O1dwYw05f2kl-Q7sfNDRem1Y-03GXYZV4qkTbJeR_K_VpJzgMk_8Ry8fjyfgJ7fAMrCmcRHc1KXsSTuhIU5p5pBa3F1-TGDgOdQgcF-pU8cSTrl8JF2j2b9gl6-5e66Ro-rltcIrGxsRG" frameborder="0" scrolling="auto" allowfullscreen="" style="display: block;margin-left: auto;margin-right: auto;max-width: 100%;" class="fr-draggable" data-lf-form-tracking-inspected-kn9eq4roawkarlvp="true" data-lf-yt-playback-inspected-kn9eq4roawkarlvp="true" data-lf-vimeo-playback-inspected-kn9eq4roawkarlvp="true"></iframe> </h2><h2>Battery Recycling Inevitable</h2>The efficient and economical recycling of EV batteries is not just possible, but inevitable, said a panel of battery-recycling experts at the 2023 Battery Show North America in Novi, Mich.&nbsp;Panelists indicated that although the business model is evolving – and is likely to remain comparatively fluid for the near term – the sector’s broad directionals are firming and at least a few aspects of the business have become certain – one being that EV batteries ending up in landfills “absolutely will not happen,” asserted Renata Arsenault, Technical Expert for Advanced Battery Recycling at Ford.Equally important, established recycling companies and startups understand that the EV battery recycling environment will be diverse and require a variety of players at various points and places in the recycling process, said Mike O’Kronley, CEO of Ascend Elements, a startup with a proprietary process focused on recycling material specifically for lithium-ion battery cathodes. He said there will be numerous companies with various specialties needed at different points – geographically and within the recycling process. Localization of both materials supply and operations will be vital as recycling matures, added Ford’s Arsenault.Initiating EV battery recycling will take time to reach the scale and efficiency of recycling entire vehicles, for example, because batteries are more complicated, said Ryan Melsert, CEO at American Battery Technology Company (ABTC), which has a system to recover the individual minerals in lithium-ion batteries. Melsert said the comparative newness of automotive lithium-ion batteries also means recycling processes have yet to reach the efficiencies and scale of established recycling, such as that for lead-acid batteries.Moreover, Melsert said, EV battery recycling must be much more “holistic” in its approach because it will be a requirement to recover more than the “token elements” sought by some systems. “As batteries get higher-performance and more complex, so will the recycling process,” he said.<img src="https://images.wevolver.com/eyJidWNrZXQiOiJ3ZXZvbHZlci1wcm9qZWN0LWltYWdlcyIsImtleSI6ImZyb2FsYS8xNzAwNjQzNTIzNTI1LTIwMjMtYmF0dGVyeS1zaG93LXJlY3ljbGluZy1hcmdvbm5lLWxpZmVjeWNsZS1jaGFydF9nYWxsZXJ5LmpwZyIsImVkaXRzIjp7InJlc2l6ZSI6eyJ3aWR0aCI6OTUwLCJmaXQiOiJjb3ZlciJ9fX0=" style="width: 766px;" class="fr-fic fr-dib">Progression of an end-of-life EV battery through various current recycling processes.<h2>Open- and closed-loop approaches</h2>How automakers and recyclers eventually collaborate remains a question as recycling progresses through early stages of startup, but most panelists agreed that that eventual result is likely to be a “closed loop” process in which automakers form close partnerships with recyclers in what becomes a model in which the automaker “controls materials almost indefinitely, said ABTC’s Melsert. He added that closed-loop arrangements also will help to provide “security of supply” to automakers and their closely-aligned battery-manufacturing partners.A closed-loop system also will be essential, panelists believed, because of eligibility requirements connected to incentives from the federal government’s Inflation Reduction Act. Retaining control of domestically produced materials, from mining through recycling and reuse, will ease the burden of complying with IRA dictates and also allow manufacturers to retain a steady flow of materials not necessarily subject to the economics of the commodities market.“If you’re an OEM, you don’t want to sell that [recycled] material to the highest bidder,” confirmed Ascend’s O’Kronley, saying the material is too important to release to an open market. He said that although the industry will see elements of both open- and closed-loop systems for some time, EV battery recycling is almost certain to evolve to a mostly closed-loop environment.Ford’s Arsenault agreed, saying, “In the early years, we’re going to be somewhat more transactional.” But “the Holy Grail for all of us is to have the fully-closed loop. It seems it would be much more efficient for our customers, too.”<h2>Not much life for second-life</h2>Meanwhile, the panelists had a dim view of the potential for so-called “second-life” use of entire EV batteries once those batteries become too depleted for effective use in a vehicles. Second-life applications – often cited as a viable competitor for recycling – just won’t be the best use of the valuable battery materials, most panelists asserted.Second-life usage “has a lot of barriers,” said Gerardo Ramos-Vivas, Battery Lifecycle senior manager, Toyota Motor North America. “Right now, we’re thinking that’s way out there [in the future].”Ascend’s O’Kronley agreed, adding, “I think the second-life market is going to be a lot smaller than we think about. I truly believe that batteries will be for the life of the vehicle,” and that once a battery has reached the end of its useful life, it will be more efficient and economical to recycle its elements rather than keep the entire battery for a secondary purpose.Second-life usage is “going to be a smaller market than a lot of people are thinking,” said ABTC’s Melsert. He said there’s been an overestimation, as one example, of the stationary-source market’s potential use of second-life automotive batteries. He said it is becoming clearer that stationary sources likely will converge on the desire to use premium-performance batteries rather than make use of repurposed batteries.

Battery recycling experts at the 2023 Battery Show North America indicate a sustainable recycling business model is coming into focus.

EV Battery recycling still being defined

Concrete is the most widely used building material worldwide, providing the foundation of our modern society’s infrastructure. It is partially recyclable and can even absorb CO2 from the atmosphere during the curing process. However, the amount of CO2 released during the manufacturing process far exceeds the amount that can be reabsorbed later. This is why the concrete industry generates around eight percent of global CO2 emissions – more than the aviation and shipping industry combined. Franco Zunino, a senior scientist at the Institute for Building Materials at ETH Zurich, wants to alter the formulation of concrete by adopting an “ultra-green concrete” approach.<h2>The ideal concrete</h2>Concrete consists of a mixture of cement, aggregates and water. Traditional cement is composed of about 95 percent clinker and five percent gypsum. To produce cement, limestone and clay are burned into clinker in a kiln heated to 1,450°Celsius, which inevitably releases CO2 due to the chemical decomposition of limestone. The huge amount of energy required by the kiln further worsens cement’s carbon footprint.EPFL has already launched its Limestone Calcined Clay Cements (LC3) project, in which Zunino is actively involved and which has set a new standard in cement production. It has developed a cement formulation using 50 percent clinker and a combination of calcined clay and limestone that has cut CO2 emissions by around 40 percent. However, improving the formulation of concrete can bring about a significant increase in these environmental benefits. This is where Franco Zunino’s UGC project at the ETH-Department of Civil, Environmental and Geomatic Engineering (D-BAUG) comes in.<img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1699804179857-image.imageformat.1286.1895314494.png" style="width: 766px;" class="fr-fic fr-dib">Three LC3-based concretes with varying amounts of cement. As the cement content in the concrete mix decreases, the compressive strength increases. (Photograph: Franco Zunino)Franco Zunino pursues a two-fold strategy for the new green concrete: first, reducing the clinker content, i.e. the amount of clinker per unit of cement; second, lowering the ratio of cement in the concrete. This dual strategy offers flexibility in tailoring low-carbon concrete compositions to individual markets. “The ideal would be to implement both at the same time; but the individual components are independent of each other. In some markets, it may be difficult to implement both aspects of the dual strategy, as production capacity and infrastructure need to be put in place. However, it is possible to implement at least one of them and still save reduce CO2&nbsp;emissions,” Franco Zunino explains.Calculations by Zunino and his team have shown that the CO2 emissions of Ultra Green Concrete can be reduced from 300 kg per cubic metre to about 80–100 kg per cubic metre. Depending on the application, up to two-thirds of CO2 emissions could be consequently saved without compromising material performance. Although the researcher emphasises that there is no such thing as inherently climate-neutral or carbon-negative concrete, he believes there are no excuses for the industrialised world not to adopt this new and more sustainable building material right away.<h2>More cost-effective than traditional concrete</h2>One reason for the reluctance might be that the concrete industry is not particularly innovative. Concrete has proven to be highly successful due to being cost-effective, safe and user-friendly. According to Zunino, “green concrete” could be even cheaper than conventional concrete. The proportion of expensive components is lower, while the quality and thus price of the concrete remain the same. This creates financial incentives for using more environmentally friendly material.Safety aspects are also important, of course. Franco Zunino comments: “Anyone who builds a house wants to use a material that insures it will stand for a hundred years. But we have to ask ourselves whether this really makes sense in view of the enormous CO2 emissions involved. Could we instead use a material that meets the structure’s required life cycle but emits significantly less CO2? In a climate-crisis scenario, one tonne of CO2 saved today is more valuable than the same tonne saved in 50 years.”<img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1699804212720-image.imageformat.1286.1672952278.jpg" style="width: 300px;" class="fr-fic fr-dib">From lab test to prototype: test cylinders of LC3 cement. (Photograph: Franco Zunino)<img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1699804225507-image.imageformat.1286.1939789219.jpg" style="width: 300px;" class="fr-fic fr-dib"><figure id="isPasted"><figcaption>Typically, calcined clay cements are characterised by their reddish colour, although this is not always the case, as there are also white and black clays. (Photograph: Franco Zunino) &nbsp;&nbsp;</figcaption></figure><h2 id="isPasted">LC3 production is already under way</h2>Zunino stresses that low-carbon cement is even more durable than conventional cement. There are currently about seven large-scale cement plants worldwide producing cement using the LC3 approach. Franco Zunino expects that number to exceed 40 in the coming years. “Demand for concrete will increase in the future. We can offer assistance by developing improved concrete mixtures with a lower cement content and thus still achieve our environmental goals,” Zunino adds. He is convinced that LC3 will be the most widely used type of cement worldwide ten years from now.<hr><h2 id="isPasted">Reference</h2>F. Zunino, A two-fold strategy towards low-carbon concrete, RILEM Technical Letters, 8 (2023), doi: <a href="https://doi.org/10.21809/rilemtechlett.2023.179" target="_blank">external page10.21809/rilemtechlett.2023.179</a>

ETH researchers are developing a low-​carbon cement with a significantly lower embodied CO2 content than traditional cement. The Ultra Green Concrete project aims to make low-​carbon, high-​performance concrete widely accessible.

Green change in a grey industry

In this episode, we discuss how Penn state researchers accidentally discovered that heat treatment of paper bags could make them stronger - especially when wet - thereby increasing their reusability significantly.

Podcast: Burning Paper Bags For Sustainability

20230717-Podcast: Burning Paper Bags For Sustainability

Plastics are everywhere in our daily lives, but not all plastics are created equal &shy;&ndash; far from it.&nbsp;Take, for instance, polyethylene terephthalate, which is used to make plastic soda bottles and clothing fibers and is a key contributor to plastic pollution. Then there&rsquo;s high-density polyethylene, from which shampoo bottles, milk jugs, and cutting boards are derived. And don&rsquo;t forget polystyrene for packaging, or low-density polyethylene, which gives us cling wrap and grocery bags.All of these are plastics, which are the most widely used types of polymers &ndash; macromolecules made of repeating units of small molecules called monomers. Post-consumer plastics are almost always collected as a mixed stream of waste, and products are often manufactured from two or more types of plastics.The bad news about collecting them in this way &nbsp;is that these items, though all &ldquo;plastics,&rdquo; are chemically and physically incompatible, and there&rsquo;s no good industrial method for reusing or re-processing them into other, useful products. That&rsquo;s why most of those &ldquo;recyclables&rdquo; that many of us &nbsp;throw into recycle bins every week are going to a landfill. Even after careful sorting and separation into individual plastics, mechanical recycling usually yields inferior products, termed down-cycling.Polymer chemists at Columbia University and Colorado State University, have long been leaders in finding ways to tackle the environmental problems humans have created with plastics waste. Now, they&rsquo;ve come up with fundamental new chemistry that seeds a creative, chemistry-based solution to the challenge of recycling mixed-use plastics. &nbsp;Led by Columbia Professors <a href="https://www.chem.columbia.edu/content/tomislav-rovis" rel="nofollow" target="_blank">Tomislav Rovis</a> and <a href="https://www.engineering.columbia.edu/faculty/sanat-kumar" rel="nofollow" target="_blank">Sanat Kumar</a>, and collaborators at Colorado State University, the team has devised a new chemical strategy that delivers specifically designed small molecules called universal dynamic crosslinkers into mixed plastic streams. These crosslinkers transform a formerly immiscible muck into a viable new set of polymers, which can be turned into new, higher-value, re-processable materials, a process known as upcycling. Their work is published in the journal, Nature.When heated and processed together with the dynamic crosslinkers added in small amounts, the mixed plastics are made compatible with each other through in-situ formation of a new material, called a multiblock copolymer.&nbsp;Kumar, the Bykhovsky Professor of Chemical Engineering at <a href="https://www.engineering.columbia.edu/" rel="nofollow" target="_blank">Columbia Engineering</a> likened the block copolymers to soap molecules, which make water compatible with oily dirt molecules. &ldquo;In a similar way, these new types of dynamically formed &lsquo;soaps,&rsquo; i.e. the block copolymers, compatibilize mixed plastics and make them usable as a new kind of material with useful properties.&rdquo;This new method of upcycling, which does not involve deconstructing or reconstructing any of the original polymers, introduces a potential solution for recapturing materials and energy endowed in post-consumer mixed plastics that typically end up in landfills.<blockquote>These new types of dynamically formed &lsquo;soaps,&rsquo; i.e. the block copolymers, compatibilize mixed plastics and make them usable as a new kind of material with useful properties.&nbsp; - SANAT KUMAR,&nbsp;MICHAEL BYKHOVSKY AND CHARO GONZALEZ-BYKHOVSKY PROFESSOR OF CHEMICAL ENGINEERING</blockquote>The team designed their crosslinkers and tested them on a variety of plastics including samples of mixed polyethylene zip-lock bags and polylactide cups without prior purification or removal of additives or dyes, which are typically present in post-consumer plastic products. They combined their experiments with modeling studies to verify that the crosslinkers induce the formation of new multiblock copolymers.&ldquo;The system is so efficient, it compatibilizes three different polymers into a single new material,&rdquo; said Rovis, the Samuel Latham Mitchill Professor of Chemistry at Columbia.The researchers posit that their new strategy could help achieve the ultimate goal of reusing mixed plastic waste over multiple use cycles, Chen said. &ldquo;A key barrier is cost; we are talking about millions of tons of plastic waste, and you have to consider how many of these dynamic crosslinkers you need, although we currently need only less than 5% of the weight of the plastics in our upcycling process. Like many fundamental discoveries made in history, practical obstacles exist at the very beginning, but we are very excited about future potential.&rdquo;<hr><h2 id="isPasted">Learn more about Sanat Kumar and his research</h2><iframe width="640" height="360" src="https://www.youtube.com/embed/GWtJUYfuLQg?&wmode=opaque&rel=0&enablejsapi=1&origin=https://www.wevolver.com" frameborder="0" allowfullscreen="" class="fr-draggable" data-lf-form-tracking-inspected-kn9eq4roawkarlvp="true" data-lf-yt-playback-inspected-kn9eq4roawkarlvp="true" data-lf-vimeo-playback-inspected-kn9eq4roawkarlvp="true"></iframe>Sanat Kumar&#39;s work has reshaped the way researchers think about polymers, particularly in confined geometries. And, as both an engineer and an educator he&#39;s reshaping how to think about the problems we tackle and their impact on society.

Photo Credit: Josep Curto/Shutterstock.com

Polymer chemists at Columbia University and Colorado State University have developed a fundamental new chemistry that seeds a creative, chemistry-based solution to the challenge of recycling mixed-use plastics.

An Upcycling Solution to Mixed Plastics Rooted in New Chemistry

Engineers at Duke University have produced the world&rsquo;s first fully recyclable printed electronics that replace the use of chemicals with water in the fabrication process. By bypassing the need for hazardous chemicals, the demonstration points down a path industry could follow to reduce its environmental footprint and human health risks.The research appeared online Feb. 28 in the journal Nano Letters.<img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1681253766429-ezgif-2-aeab43ebbb.gif" style="width: 766px;" class="fr-fic fr-dib">An aerosol jet printer puts down layers of carbon-based electronic inks to create transistors that can be fully recycled using only water, rather than requiring harsh, toxic chemicals. Credit - Jason Arthurs Photography&nbsp;One of the dominant challenges facing any electronics manufacturer is successfully securing several layers of components on top of each other, which is crucial to making complex devices. Getting these layers to stick together can be a frustrating process, particularly for printed electronics.<blockquote>&quot;Putting layers on top of each other is not as easy as putting them down on their own &mdash; but that&rsquo;s what you have to do if you want to build electronic devices with printing.&rdquo;AARON FRANKLIN</blockquote>&ldquo;If you&rsquo;re making a peanut butter and jelly sandwich, one layer on either slice of bread is easy,&rdquo; explained <a href="https://ece.duke.edu/faculty/aaron-franklin" target="_blank">Aaron Franklin</a>, the Addy Professor of Electrical and Computer Engineering at Duke, who led the study. &ldquo;But if you put the jelly down first and then try to spread peanut butter on top of it, forget it, the jelly won&rsquo;t stay put and will intermix with the peanut butter. Putting layers on top of each other is not as easy as putting them down on their own &mdash; but that&rsquo;s what you have to do if you want to build electronic devices with printing.&rdquo;In previous work, Franklin and his group demonstrated the <a href="https://pratt.duke.edu/about/news/recyclable-printed-electronics" target="_blank">first fully recyclable printed electronics</a>. The devices used three carbon-based inks: semiconducting carbon nanotubes, conductive graphene and insulating nanocellulose. In trying to adapt the original process to only use water, the carbon nanotubes presented the largest challenge.To make a water-based ink in which the carbon nanotubes don&rsquo;t clump together and spread evenly on a surface, a surfactant similar to detergent is added. The resulting ink, however, does not create a layer of carbon nanotubes dense enough for a high current of electrons to travel across.<iframe width="640" height="360" src="https://www.youtube.com/embed/CCwVaUYbarc?&wmode=opaque&rel=0&enablejsapi=1&origin=https://www.wevolver.com" frameborder="0" allowfullscreen="" class="fr-draggable" data-lf-form-tracking-inspected-kn9eq4roawkarlvp="true" data-lf-yt-playback-inspected-kn9eq4roawkarlvp="true" data-lf-vimeo-playback-inspected-kn9eq4roawkarlvp="true"></iframe>&ldquo;You want the carbon nanotubes to look like al dente spaghetti strewn down on a flat surface,&rdquo; said Franklin. &ldquo;But with a water-based ink, they look more like they&rsquo;ve been taken one-by-one and tossed on a wall to check for doneness. If we were using chemicals, we could just print multiple passes again and again until there were enough nanotubes. But water doesn&rsquo;t work that way. We could do it 100 times and there&rsquo;d still be the same density as the first time.&rdquo;This is because the surfactant used to keep the carbon nanotubes from clumping also prevents additional layers from adhering to the first. In a traditional manufacturing process, these surfactants would be removed using either very high temperatures, which takes a lot of energy, or harsh chemicals, which can pose human and environmental health risks. Franklin and his group wanted to avoid both.In the paper, Franklin and his group develop a cyclical process in which the device is rinsed with water, dried in relatively low heat and printed on again. When the amount of surfactant used in the ink is also tuned down, the researchers show that their inks and processes can create fully functional, fully recyclable, fully water-based transistors.<blockquote>&quot;If we were using chemicals, we could just print multiple passes again and again until there were enough nanotubes. But water doesn&rsquo;t work that way. We could do it 100 times and there&rsquo;d still be the same density as the first time.&rdquo;AARON FRANKLIN</blockquote>Compared to a resistor or capacitor, a transistor is a relatively complex computer component used in devices such as power control or logic circuits and sensors. Franklin explains that, by demonstrating a transistor first, he hopes to signal to the rest of the field that there is a viable path toward making some electronics manufacturing processes much more environmentally friendly.Franklin has already proven that nearly 100% of the carbon nanotubes and graphene used in printing can be recovered and reused in the same process, losing very little of the substances or their performance viability. Because nanocellulose is made from wood, it can simply be recycled or biodegraded like paper. And while the process does use a lot of water, it&rsquo;s not nearly as much as what is required to deal with the toxic chemicals used in traditional fabrication methods.According to a United Nations estimate, less than a quarter of the millions of pounds of electronics thrown away each year is recycled. And the problem is only going to get worse as the world eventually upgrades to 6G devices and the Internet of Things (IoT) continues to expand. So any dent that could be made in this growing mountain of electronic trash is important to pursue.<blockquote>&ldquo;The performance of our thin-film transistors doesn&rsquo;t match the best currently being manufactured, but they&rsquo;re competitive enough to show the research community that we should all be doing more work to make these processes more environmentally friendly.&quot;AARON FRANKLIN</blockquote>While more work needs to be done, Franklin says the approach could be used in the manufacturing of other electronic components like the screens and displays that are now ubiquitous to society. Every electronic display has a backplane of thin-film transistors similar to what is demonstrated in the paper. The current fabrication technology is high-energy and relies on hazardous chemicals as well as toxic gasses. The entire industry has been&nbsp;<a href="https://www.epa.gov/climateleadership/sector-spotlight-electronics" target="_blank">flagged for immediate attention by the US Environmental Protection Agency</a>.&ldquo;The performance of our thin-film transistors doesn&rsquo;t match the best currently being manufactured, but they&rsquo;re competitive enough to show the research community that we should all be doing more work to make these processes more environmentally friendly,&rdquo; Franklin said.This work was supported by the National Institutes of Health (1R01HL146849), the Air Force Office of Scientific Research (FA9550-22-1-0466), and the National Science Foundation (ECCS-1542015, Graduate Research Fellowship 2139754).CITATION: &ldquo;All-Carbon Thin-Film Transistors Using Water-Only Printing,&rdquo; Shiheng Lu, Brittany N. Smith, Hope Meikle, Michael J. Therien, and Aaron D. Franklin. Nano Letters, Feb. 28, 2023. DOI: 10.1021/acs.nanolett.2c04196

First-of-its-kind demonstration suggests a more environmentally friendly future for the electronics industry is possible

Fully Recyclable Printed Electronics Ditch Toxic Chemicals for Water

This article was discussed in our&nbsp;<a data-saferedirecturl="https://www.google.com/url?q=https://www.wevolver.com/profile/the.next.byte&source=gmail&ust=1672821999265000&usg=AOvVaw3lLKdHdEN0YvCEsaHI7hx9" href="https://www.wevolver.com/profile/the.next.byte" rel="noopener noreferrer" target="_blank">Next Byte podcast</a>.&nbsp;<iframe height="200px" width="100%" frameborder="no" scrolling="no" seamless="" src="https://player.simplecast.com/63f10d22-cd2f-4c1e-8609-6ae7d0af5a2e?dark=false" class="fr-draggable" data-lf-form-tracking-inspected-kn9eq4roawkarlvp="true" data-lf-yt-playback-inspected-kn9eq4roawkarlvp="true" data-lf-vimeo-playback-inspected-kn9eq4roawkarlvp="true"></iframe> The full article will continue below.<hr>The study suggests a process for creating paper bags durable enough to be used multiple times and then broken down chemically by an alkaline treatment to be used as a source for biofuel production, according to researcher <a href="https://abe.psu.edu/directory/dec109" target="_blank">Daniel Ciolkosz</a>, associate research professor of agricultural and biological engineering.&ldquo;When the primary use of these paper products ends, using them for secondary purposes makes them more sustainable,&rdquo; he said. &ldquo;Recycling and reducing paper waste also helps in reducing total solid waste destined for landfills. This is a concept we think society should consider.&rdquo;<img src="https://images.wevolver.com/eyJidWNrZXQiOiJ3ZXZvbHZlci1wcm9qZWN0LWltYWdlcyIsImtleSI6ImZyb2FsYS8xNjgxMjUzMTMxOTI4LXBhcGVyLWJhZy1wZXhlbHMtbGlzYS1mb3Rpb3MuanBnIiwiZWRpdHMiOnsicmVzaXplIjp7IndpZHRoIjo5NTAsImZpdCI6ImNvdmVyIn19fQ==" style="width: 766px;" class="fr-fic fr-dib">Paper bags are a popular alternative to plastic bags to reduce the environmental impacts caused by using plastics, but paper bags have short lifespans due to their low durability, particularly when wet. Credit:&nbsp;Lisa Fotios/Pexals.&nbsp;All Rights Reserved.&nbsp;Lead researcher <a href="https://abe.psu.edu/directory/jxt380" target="_blank">Jaya Tripathi</a>, who will graduate from Penn State this spring with a doctoral degree in biorenewable systems and has accepted a position at the Joint BioEnergy Institute in California, devised an innovative process in which cellulose in paper is torrefied, or roasted in an oxygen-deprived environment, to greatly increase its tensile strength when wet.Paper bags are a popular alternative to plastic bags to reduce the environmental impacts caused by using plastics, she explained, but paper bags have short lifespans due to their low durability, particularly when wet. And a paper bag must be reused several times to reduce its global-warming potential to below that of the conventional high-density polyethylene bag, Tripathi added.&ldquo;Reuse is mainly governed by bag strength, and it is unlikely that a typical paper bag can be reused the required number of times due to its low durability upon wetting,&rdquo; she said. &ldquo;Using expensive chemical processes to enhance wet strength diminishes paper&#39;s ecofriendly and cost-efficient features for commercial application, so there is a need to explore non-chemical techniques to increase the wet strength of paper bags. Torrefaction could be the answer.&rdquo;<img src="https://images.wevolver.com/eyJidWNrZXQiOiJ3ZXZvbHZlci1wcm9qZWN0LWltYWdlcyIsImtleSI6ImZyb2FsYS8xNjgxMjUzMTU3NTU0LWJhZy12ZWdnaWVzLW1hcmNvLXZlcmNoLWZsaWNrci1maXhlZC5qcGciLCJlZGl0cyI6eyJyZXNpemUiOnsid2lkdGgiOjk1MCwiZml0IjoiY292ZXIifX19" style="width: 766px;" class="fr-fic fr-dib">By switching to stronger, reusable paper shopping bags, a large volume of plastic waste could be eliminated, the researchers suggest..&nbsp;Credit:&nbsp;Marco Verch/Flickr.&nbsp;All Rights Reserved.&nbsp;Because torrefaction decreased the glucose yield in the paper, she then treated the paper with a solution of sodium hydroxide, also known as lye or caustic soda, that increased its glucose yield, making it a better source for biofuel production.In&nbsp;<a href="https://www.sciencedirect.com/science/article/abs/pii/S0921344923000198" target="_blank">findings recently published in Resources, Conservation and Recycling</a>, using filter paper as the medium, the researchers reported that the wet-tensile strength of the paper increased by 1,533%, 2,233%, 1,567% and 557% after torrefaction for 40 minutes at 392 degrees Fahrenheit, 428 F, 464 F and 500 F, respectively.Glucose yield decreased with increased torrefaction severity, but after treating torrefied paper samples with an alkaline sodium hydroxide solution, glucose yield increased, the researchers noted. For instance, the glucose yield of raw filter paper was 955 mg/g of substrate, whereas it was 690 mg/g of substrate for the same paper sample torrefied at 392 F. The glucose yield increased to 808 and 933 mg/g of substrate with 1% and 10% alkaline treatment, respectively.The need for a concept like the one demonstrated by the researchers to replace plastic bags is obvious, Tripathi pointed out. According to the U.N. Environment Programme,&nbsp;<a href="https://www.unep.org/interactives/beat-plastic-pollution/" target="_blank">5 trillion plastic bags are produced worldwide annually</a>. It can take up to 1,000 years for these bags to disintegrate completely. Americans throw away 100 billion bags annually &mdash; the equivalent to dumping nearly 12 million barrels of crude oil.&ldquo;By switching to stronger, reusable paper shopping bags, we could eliminate much of that waste,&rdquo; Tripathi said. &ldquo;The implications of a technology like the one we demonstrated in this research &mdash; if it can be perfected &mdash; including using the worn-out bags as a substrate for biofuel production, would be huge.&rdquo;Like many scientific discoveries, Tripathi learned about the synergy of torrefaction and alkaline treatment for increased paper capabilities by accident.&ldquo;I was looking into something else, studying how torrefaction impacts cellulose for glucose yield for use as a biofuel substrate,&rdquo; she said. &ldquo;But I noticed that the paper&rsquo;s strength was increasing as we torrefied the cellulose. That made me think that it probably would be good for packaging, an entirely different application.&rdquo;Contributing to the research was Daniel Sykes, teaching professor of chemistry.This research was supported by the U.S. Department of Agriculture&rsquo;s National Institute for Food and Agriculture.

As the world searches for ways to reduce the use of plastics such as single-use plastic bags, a novel study by Penn State researchers demonstrates a process to make paper bags stronger — especially when they get wet — to make them a more viable alternative.

Stronger paper bags, reused repeatedly then recycled for biofuel could be future

Recovering up to 70 percent of the lithium from battery waste without the need for corrosive chemicals, high temperatures or prior sorting of the materials: This is made possible by a recycling process developed at the Karlsruhe Institute of Technology (KIT) that combines mechanical processes and chemical reactions. The method allows a wide variety of lithium-ion batteries to be recycled in a cost-effective, energy-efficient and environmentally friendly manner. The researchers report in the journal Nature Communications Chemistry ( <a href="https://doi.org/10.1038/s42004-023-00844-2" target="_blank">DOI: 10.1038/s42004-023-00844-2</a> )&nbsp;Lithium-ion batteries permeate our everyday life: They not only supply notebooks and smartphones, toys, remote controls and other small devices with wireless power, but also act as the most important energy storage medium for the rapidly growing electromobility. The increasing use of these batteries calls for economically and ecologically sustainable recycling methods. Today, mainly nickel and cobalt, copper and aluminum as well as steel are recovered and recycled from battery waste. The recovery of lithium is currently still expensive and not very profitable. The available, mostly metallurgical processes consume a lot of energy and/or leave behind harmful by-products. In contrast, approaches in mechanochemistry, which use mechanical processes to bring about chemical reactions, promise&nbsp;<h2>Suitable for different cathode materials</h2>Such a method has now been developed by the Institute for Applied Materials - Energy Storage Systems (IAM-ESS) of KIT together with the Helmholtz Institute Ulm for Electrochemical Energy Storage (HIU) founded by KIT in cooperation with the University of Ulm and EnBW Energie Baden-W&uuml;rttemberg AG . In the journal Nature Communications Chemistrythe researchers present their method.&nbsp;You can achieve a recovery rate of up to 70 percent for the lithium without the need for corrosive chemicals, high temperatures or prior sorting of the materials.&nbsp;&quot;The process is suitable for recovering lithium from cathode materials with different chemical compositions and is therefore suitable for many different commercially available lithium-ion batteries,&quot; explains Dr.&nbsp;Oleksandr Dolotko from the IAM-ESS of the KIT and from the HIU, main author of the publication.&nbsp;&quot;It allows for cost-effective, energy-efficient and environmentally friendly recycling.&quot;<h2>Reaction takes place at room temperature&nbsp;</h2>For their process, the researchers use aluminum as a reducing agent in the mechanochemical reaction. Since aluminum is already contained in the cathode, the process does not require any additional substances. How it works: The battery waste is first ground up. Then they are used in a reaction with aluminum to create metallic composites with water-soluble lithium compounds. The lithium is then recovered by dissolving the water-soluble compounds in water and then heating to remove the water through evaporation. Since the mechanochemical reaction takes place at ambient temperature and pressure, the process is particularly energy-efficient. Another advantage is the simple process, which will facilitate use on an industrial scale.<img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1680261956042-2023_015_Batterierecycling+70+Prozent+des+Lithiums+zurueckgewonnen_2_72dpi.jpg" style="width: 766px;" class="fr-fic fr-dib">The more batteries there are for recycling, the more important sustainable recycling processes for the recyclable materials they contain become. (Photo: Amadeus Bramsiepe, KIT)&nbsp;<hr>Original publication (Open Access)&nbsp;Oleksandr Dolotko, Niclas Gehrke, Triantafillia Malliaridou, Raphael Sieweck, Laura Herrmann, Bettina Hunzinger, Michael Knapp &amp; Helmut Ehrenberg: Universal and efficient extraction of lithium for lithium-ion battery recycling using mechanochemistry. Communications Chemistry, 2023. DOI: 10.1038/s42004-023-00844-2&nbsp;

dr Oleksandr Dolotko, lead author of the publication, conducts research at the IAM-ESS Institute and the HIU. (Photo: Amadeus Bramsiepe, KIT)

KIT researchers develop inexpensive and environmentally friendly mechanochemical recycling process - publication in Nature Communications Chemistry

Battery recycling: 70 percent of the lithium recovered

Plastic is everywhere. Our society cannot do without it: plastics have numerous advantages, are extremely versatile, and are also cost effective. Today, plastics are mainly produced from crude oil. When the products reach the end of their life, they often end up in a waste incineration plant. The energy-intensive production of plastics and their incineration release large amounts of CO2 into the atmosphere, making plastic products a major contributor to climate change.One way out would be to rely on sustainable production methods, such as the circular economy, in which as much plastic as possible is recycled. Then the main raw material for plastic products would no longer be crude oil but shredded plastic waste. But is it even possible to tweak the plastics economy to absolute sustainability? Yes, it is, shows a new study led by Andr&eacute; Bardow, Professor of Energy and Process Systems Engineering at ETH Zurich. Gonzalo Guill&eacute;n Gos&aacute;lbez, Professor of Chemical Systems Engineering at ETH Zurich, and researchers from RWTH Aachen University and the University of California, Santa Barbara collaborated on the study.<h2>Massively increased recycling rate needed</h2>The scientists looked at the complete value chains of the 14 most common types of plastics, including polyethylene, polypropylene and polyvinyl chloride. These 14 bulk plastics account for 90 percent of the plastic products manufactured worldwide. In their study, the researchers investigated for the first time whether it is possible for the plastics industry to respect planetary boundaries. These are a measure of comprehensive sustainability. They go beyond energy and climate issues to include, for example, impacts on land and water resources, ecosystems and biodiversity. In short: processes that adhere to planetary boundaries can be sustained over the long term without depleting the Earth&rsquo;s resources.The study finds that circular plastics are feasible within planetary boundaries. This would require at least 74 percent of the plastic to be recycled. By way of comparison, only around 15 percent is recycled in Europe today, and the rate is likely to be much lower in other regions of the world. In addition, the study finds that recycling processes would have to be improved. Specifically, plastics recycling would have to become as efficient as other chemical processes already are today. As things currently stand, not all plastics can be recycled. In the case of polyurethanes used as foams, for example, recycling has yet to be established &ndash; a question Professor Bardow is also addressing.For the remaining maximum 26 percent of plastics, the carbon needed for production could be sourced using two other technologies, according to the study: on the one hand, CO2 captured from combustion processes or from the atmosphere (known as carbon capture and utilisation or CCU), and on the other hand, from biomass. &ldquo;Recycling alone won&rsquo;t do it; we need all three pillars,&rdquo; Bardow says.<blockquote>&#39;Recycling efforts should be intensified wherever possible. More recycling of plastic always leads to more sustainability.&#39; -&nbsp;<cite>Andr&eacute; Bardow</cite>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;</blockquote>&ldquo;Increasing the recycling rate to 74 percent worldwide is a very ambitious goal,&rdquo; Bardow admits. As such, it is unlikely to be achieved by 2030, but 2050 is more realistic. Another challenge, however, is that more plastic products are currently being manufactured year after year. If the current trend continues until 2050, it won&rsquo;t be enough to simply improve recycling processes, as planetary boundaries would still be exceeded in 2050.That is why the study&rsquo;s authors suggest also addressing demand as well as assigning a different value to plastic. &ldquo;Plastic is considered cheap, which for a long time was a blessing but has now become a curse,&rdquo; Bardow says. &ldquo;Given its outstanding properties, we should view plastic as the high-quality material it truly is. That way, it would be okay for it to cost a little more, and its recycling, too.&rdquo;<h2>Fuller understanding of product stewardship</h2>In the study, the scientists point out that plastic products must be better aligned with the circular economy in future. To this end, manufacturers should work more closely with recyclers. According to the study&rsquo;s authors, it would be desirable if plastics manufacturers had a wider understanding of the responsibility they hold: Today, responsibility often ends where the product leaves the factory gates. The scientists therefore call for product stewardship to encompass the entire life cycle &ndash; including disposal and recycling &ndash; as the basis for optimising the design of sustainable processes.In any case, pushing recycling is the right way to go: given that it has no serious disadvantages, it should be treated as a special case in the transformation of the economy toward sustainability. In many other areas, conflicting goals arise. Take, for example, the production of synthetic fuels, which is extremely energy-intensive, or the use of biomass, which competes with food production. Recycling plastic, on the other hand, does not lead to such a conflict of goals. &ldquo;Recycling efforts should be intensified wherever possible,&rdquo; Bardow says. &ldquo;As a good rule of thumb: More recycling of plastic always leads to more sustainability.&rdquo;ETH Zurich&#39;s part in this study was conducted under the auspices of the National Centre of Competence in Research <a href="https://www.nccr-catalysis.ch/" target="_blank">external page(NCCR) Catalysiscall_made</a>.

Recyled PET from drinks bottles can be used to make shoes and clothing. (Photograph: Adobe Stock)

A new study shows what it will take for the plastics industry to become completely sustainable: lots of recycling combined with the use of CO2 from the air and biomass. It is also the image of plastics that need to change.

A wholly sustainable plastics economy is feasible

Less than 15% of the 92 million tons of clothing and other textiles discarded annually are recycled&mdash;in part because they are so difficult to sort. Woven-in labels made with inexpensive photonic fibers, developed by a University of Michigan-led team, could change that.&ldquo;It&rsquo;s like a barcode that&rsquo;s woven directly into the fabric of a garment,&rdquo; said <a href="https://mse.engin.umich.edu/people/mshtein" target="_blank">Max Shtein</a>, U-M professor of materials science and engineering and corresponding author of the study in Advanced Materials Technologies. &ldquo;We can customize the photonic properties of the fibers to make them visible to the naked eye, readable only under near-infrared light or any combination.&rdquo;Ordinary tags often don&rsquo;t make it to the end of a garment&rsquo;s life&mdash;they may be cut away or washed until illegible, and tagless information can wear off. Recycling could be more effective if a tag was woven into the fabric, invisible until it needs to be read. This is what the new fiber could do.<img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1676377902069-PhotonicFibers1.jpg" style="width: 766px;" class="fr-fic fr-dib">Brian Iezzi scans and measures the photonic fibers in the fabric he developed. The laptop screen reflects the information he gathered. Photo: Marcin Szczepanski/Michigan Engineering&nbsp;Recyclers already use near-infrared sorting systems that identify different materials according to their naturally occurring optical signatures&mdash;the PET plastic in a water bottle, for example, looks different under near-infrared light than the HDPE plastic in a milk jug. Different fabrics also have different optical signatures, but <a href="https://shteinlab.engin.umich.edu/profile/brian-iezzi/" target="_blank">Brian Iezzi</a>, a postdoctoral researcher in Shtein&rsquo;s lab and lead author of the study, explains that those signatures are of limited use to recyclers because of the prevalence of blended fabrics.&ldquo;For a truly circular recycling system to work, it&rsquo;s important to know the precise composition of a fabric&mdash;a cotton recycler doesn&rsquo;t want to pay for a garment that&rsquo;s made of 70% polyester,&rdquo; Iezzi said. &ldquo;Natural optical signatures can&rsquo;t provide that level of precision, but our photonic fibers can.&rdquo;The team developed the technology by combining Iezzi and Shtein&rsquo;s photonic expertise&mdash;usually applied to products like displays, solar cells and optical filters&mdash;with the advanced textile capabilities at MIT&rsquo;s Lincoln Lab. The lab worked to incorporate the photonic properties into a process that would be compatible with large-scale production.<img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1676377925678-PhotonicFibers2.jpg" style="width: 766px;" class="fr-fic fr-dib">Brian Iezzi use his phone to simulate the scanning of the photonic fibers fabric he developed. In the future, one will be able to use their phone to read the clothing woven-in labels made with inexpensive photonic fibers. Photo: Marcin Szczepanski/Michigan Engineering&nbsp;They accomplished the task by starting with a preform&mdash;a plastic feedstock that comprises dozens of alternating layers. In this case, they used acrylic and polycarbonate. While each individual layer is clear, the combination of two materials bends and refracts light to create optical effects that can look like color. It&rsquo;s the same basic phenomenon that gives butterfly wings their shimmer.The preform is heated and then mechanically pulled&mdash;a bit like taffy&mdash;into a hair-thin strand of fiber. While the manufacturing process method differs from the extrusion technique used to make conventional synthetic fibers like polyester, it can produce the same miles-long strands of fiber. Those strands can then be processed with the same equipment already used by textile makers.By adjusting the mix of materials and the speed at which the preform is pulled, the researchers tuned the fiber to create the desired optical properties and ensure recyclability. While the photonic fiber is more expensive than traditional textiles, the researchers estimate that it will only result in a small increase in the cost of finished goods.&ldquo;The photonic fibers only need to make up a small percentage&mdash;as little as 1% of a finished garment,&rdquo; Iezzi said. &ldquo;That might increase the cost of the finished product by around 25 cents&mdash;similar to the cost of those use-and-care tags we&rsquo;re all familiar with.&rdquo;<img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1676377988942-PhotonicFibers3.jpg" style="width: 766px;" class="fr-fic fr-dib">Max Stein and Brian Iezzi analyze the fabric with photonic fibers woven into it. Photo: Marcin Szczepanski/Michigan Engineering&nbsp;Shtein says that in addition to making recycling easier, the photonic labeling could be used to tell consumers where and how goods are made, and even to verify the authenticity of brand-name products. It could be a way to add important value for customers.&ldquo;As electronic devices like cell phones become more sophisticated, they could potentially have the ability to read this kind of photonic labeling,&rdquo; Shtein said. &ldquo;So I could imagine a future where woven-in labels are a useful feature for consumers as well as recyclers.&rdquo;Iezzi worked closely with Lincoln Lab researchers Austin Coon, Lauren Cantley, Bradford Perkins, Erin Doran, Tairan Wang and Mordechai Rothschild to adapt the technology to a scalable, low-cost textile manufacturing process.<img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1676378024473-PhotonicFibers4.jpg" style="width: 766px;" class="fr-fic fr-dib">Brian Iezzi scans and measures the photonic fibers in the fabric he developed. Photo: Marcin Szczepanski/Michigan Engineering&nbsp;The team has applied for patent protection with the assistance of Innovation Partnerships at the University of Michigan and is evaluating ways to move forward with the commercialization of the technology.The research was supported by the United States National Science Foundation INTERN program (no. 1727894) and the Under Secretary of Defense for Research and Engineering under Air Force (no. FA8702-15-D-0001).

Max Stein and Brian Iezzi analyze the fabric with photonic fibers woven into it. Photo: Marcin Szczepanski/Michigan Engineering

Photonic fibers borrow from butterfly wings to enable invisible, indelible sorting labels.

A "game changer" for clothing recycling?

DTU Campus Service at Ris&oslash; operates a server park with supercomputers covering 3,500 square metres. However, the energy does not simply vanish into thin air, but is converted into heat by means of a heat pump at Ris&oslash; Campus. &ldquo;It&rsquo;s possible to channel up to 600 kilowatts of waste heat from the IT equipment into the district heating network at Ris&oslash; Campus. This means that we are self-sufficient with heating four months of the year,&rdquo; says Esben H&oslash;jrup, Technical Project Manager at DTU Campus Service (CAS). For the rest of the year, the surplus energy contributes to a district heating corresponding to 19 percent of Ris&oslash; campus&#39; energy consumption in the same period.<h2>Low carbon footprint</h2>Despite rising electricity prices, it is still worthwhile to run the heat pump that recovers the surplus energy. This is shown by figures from DTU&rsquo;s latest green accounts. &ldquo;We get close to six times as much heat into the district heating network than the electricity consumed by the heat pump. This ratio&mdash;which is called the COP value&mdash;is really impressive,&rdquo; says Bjarke Nonb&oslash;l, Engineer at DTU Campus Service (CAS). Electricity emits more CO2 than district heating&mdash;approximately 2.7 times more per megawatt hour&mdash;but as the heat pump generates about six times more heat, the heat pump is the solution with the lowest carbon emission. &quot;The carbon emission is only 45 per cent of what it would have been with district heating from a utility company,&rdquo; says Bjarke Nonb&oslash;l.<h2>Intelligent control</h2>If electricity prices continue to skyrocket&mdash;or if we have periods of power shortages&mdash;it may be necessary to turn off the heat pump to save power. &ldquo;You can&rsquo;t say that the price of electricity must reach as much as, for example, ten Danish kroner on average before it&rsquo;s worthwhile to buy district heating from outside. The ratio between the electricity price and the district heating price determines whether it&rsquo;s still worthwhile to run the heat pump,&rdquo; says Bjarke Nonb&oslash;l. Therefore, CAS Ris&oslash; is working to develop a system that can monitor in real time whether operation of the heat pump is worthwhile. &ldquo;We regulate our heat production by using PLC&mdash;which is a programmable device&mdash;a small computer specially developed for automation and control of a process, also called &lsquo;process control&rsquo;. For example, opening and closing a valve, controlling temperatures, or controlling flow and pressure,&quot; says Esben H&oslash;jrup and continues:&quot;What we still need to do is to program the fluctuating electricity prices into the PLC environment.&nbsp;In this way, we can completely automatically control whether the heat pump is to supply heat to the campus, or whether we are to get the heat from the district heating company.&rdquo;<h2>Critical look</h2>CAS Ris&oslash; has long been working to reduce its carbon emissions by reducing its energy consumption. At a time when power has become expensive and will remain expensive for a long time to come, however, it raises the question of whether it is a luxury to choose to use power for heating.&ldquo;We have to consider the current prices and our power consumption. Power can be used for most purposes, while heat can primarily be used for heating in buildings. Therefore, we also need to take a critical look at how we can optimize our current heat recovery model using intelligent control,&rdquo; concludes Esben H&oslash;jrup.<img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1667560575661-Serverrum.jpg" style="width: 766px;" class="fr-fic fr-dib">In 2021, the server park contributed 2,525.5 [MWh] to DTU Ris&oslash; Campus&#39; district heating network, which makes a contribution of 19% of the total heat consumption.&nbsp;<img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1667560610087-Varmeroer-Risoe.jpg" style="width: 766px;" class="fr-fic fr-dib">DTU Ris&oslash; Campus is supplied with heat from the server park during the summer months.&nbsp;

With a heat pump connected to DTU's data center, engineers Esben Højrup and Bjarke Nonbøl from DTU Campus Service utilize waste heat from the cooling servers. The heat pump supplies heat to the district heating network on Risø Campus.

A project at DTU Risø Campus shows that heat recovery is the most sustainable and economical choice—even at a time of rising electricity prices.

Heat from supercomputers recycled at DTU

When electronic devices stop working, our immediate reaction tends to be to bin them and buy something new. But this throwaway culture is not good for the planet, and we need to think differently. If devices lasted longer and were easier to fix, they could provide many years of good service before recycling. That saves precious materials and the energy needed to manufacture new products.The problem is that most consumer products are not designed with long life or repair in mind. Consider the smartphones in our pockets. These have been designed to be feature-packed, sleek, and aesthetically pleasing, things that don&rsquo;t make for easy repair. Instead, consumers are encouraged to upgrade to new versions every few years. So what&rsquo;s the point of making them last longer?<h2>Making products repairable</h2>The good news is that change is afoot. For one, global tech giant Apple has indicated a desire to make its products more repairable. The company announced last year it would&nbsp;allow users to repair some iPhones, and in April, it released iPhone repair kits for several of its latest models.Samsung has also started allowing users to self-repair their devices with kits available for select models. Other major tech companies, including Google, are anticipating the release of self-repair services. And the <a href="https://www.ifixit.com/" rel="noopener" target="_blank">iFixit website</a>, among others, provides free user-submitted instructions on how to repair thousands of consumer electronics devices.Beyond consumer electronics, there are already billions of IoT devices across the globe that would also benefit from being &lsquo;designed for repair.&rsquo; And tomorrow, there will be billions more. Robust design, upgradable software, and very long life from batteries are already helping IoT products based on Nordic technology last for a very long time. Making those same devices easy to repair when they finally do fail would see them remain in service for even longer.<h2>Time for a rethink</h2>Both consumer electronics and IoT devices need semiconductors to support on-device processing and wireless connectivity. And before the pandemic, it was assumed there would be an unlimited number of chips to satisfy this demand (and the demand from all the other places silicon chips are used). This made production planning relatively simple for manufacturers. But a skyrocketing appetite for electronics coupled with production constraints during the pandemic has resulted in a squeeze on supply.At the same time, extraction of lithium, nickel, cobalt, and graphite&mdash;the raw materials at the heart of the batteries powering most portable electronics&mdash;is struggling to meet soaring demand, according to a report by business data and analytics firm, GlobalData.BCS, a global IT industry body, argues that a primary driver of the strain on semiconductor supply has been the constant demand for upgraded products every few years. According to Alex Bardell from BCS, the underlying challenge that must be addressed is the very short life span of the devices themselves. If developers prioritized longevity and repairability in their designs, fewer chips would be needed.<h2>Sustainability advantages</h2>The constant demand for new gadgets has implications beyond chip logistics. Today, smartphone manufacturing alone has an annual carbon footprint equal to that of a small country. Moreover, smartphones comprise 10 percent of global e-waste &ndash; which contains toxic substances that can be dangerous to human health and the environment if not disposed of properly.The call from bodies like BCS for more durable products, supported for longer and more suitable to repair, engenders an approach not only for more sustainability in chip supply, but also for the health of the planet.A report commissioned by Microsoft found that repairing a product instead of replacing it can reduce potential waste and greenhouse emissions by 92 percent. While the study partly focused on devices being taken to an approved service center or shipped to a factory, this projection was also based on designing devices in ways that make them easier to fix.<h2>Durable chip architecture</h2>Chip companies are taking a positive approach to sustainability. Nordic Semiconductor, for instance, is committed to contributing to the UN&rsquo;s Sustainable Development Goals (SDGs). It actively supports customers looking for alternatives to one-time or minimal usage solutions and enthusiastically supports IoT applications to optimize resources in energy, travel, transport, agriculture, manufacturing, waste handling, and smart cities. Nordic strongly favors trying to extend the lifetime of products using its chips for as long as practical.The company&rsquo;s technology is designed to help end-product makers meet this goal. In the first instance, Nordic creates technology with the future in mind. Its chip architecture is designed with powerful processors and lots of memory to cope with not only what innovative designers come up with today but also to cope with what they might come up with tomorrow. That means today&#39;s Nordic-powered devices could still be doing their jobs in ten years.Better yet, firmware can be easily upgraded over the air, extending the life of hardware and allowing in-situ IoT devices to be upgraded to new applications. Nordic also makes its products backward compatible so that tomorrow&#39;s products will seamlessly connect with today&#39;s.The outlook will be even more promising if we continue towards a battery-free IoT world through energy harvesting from the environment, which promises to eliminate battery replacements in IoT sensors.Recommended reading:&nbsp;<a href="https://www.wevolver.com/article/how-the-iot-can-help-create-a-more-sustainable-future" rel="noopener noreferrer" target="_blank">How the IoT can help create a more sustainable future</a>By designing electronic products so they can be fixed rather than discarded and equipping them to last for a long time, manufacturers will be making a big difference towards a sustainable future.<hr>This article was first published on Nordic&#39;s&nbsp;<a href="https://blog.nordicsemi.com/getconnected" target="_blank" rel="nofollow" id="isPasted"></a><a href="https://blog.nordicsemi.com/getconnected?utm_campaign=2021%20wevolver" rel="nofollow" target="_blank">Get Connected Blog</a>. &nbsp;

If devices lasted longer and were easier to fix, they could provide many years of good service before recycling. That saves precious materials and the energy needed to manufacture new products.

Designing IoT products for many years of service

EPFL scientists have developed a new, PET-like plastic that is easily made from the non-edible parts of plants. The plastic is tough, heat-resistant, and a good barrier to gases like oxygen, making it a promising candidate for food packaging. Due to its structure, the new plastic can also be chemically recycled and degrade back to harmless sugars in the environment.&nbsp;It is becoming increasingly obvious that moving away from fossil fuels and avoiding the accumulation of plastics in the environment are key to addressing the challenge of climate change. In that vein, there are considerable efforts to develop degradable or recyclable polymers made from non-edible plant material referred to as &ldquo;lignocellulosic biomass&rdquo;.Of course, producing competitive biomass-based plastics is not straightforward. There is a reason that conventional plastics are so widespread, as they combine low cost, heat stability, mechanical strength, processability, and compatibility &ndash; features that any alternative plastic replacements must match or surpass. And so far, the task has been challenging.Until now, that is. Scientists led by Professor Jeremy Luterbacher at EPFL&rsquo;s School of Basic Sciences have successfully developed a biomass-derived plastic, similar to PET, that meets the criteria for replacing several current plastics while also being more environmentally friendly.<img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1657285739569-6e37cc10.jpg" style="width: 766px;" class="fr-fic fr-dib">Highly transparent and flexible strand of the bioplastic. Credit: Lorenz Manker&nbsp;&ldquo;We essentially just &lsquo;cook&rsquo; wood or other non-edible plant material, such as agricultural wastes, in inexpensive chemicals to produce the plastic precursor in one step,&rdquo; says Luterbacher. &ldquo;By keeping the sugar structure intact within the molecular structure of the plastic, the chemistry is much simpler than current alternatives.&rdquo;The technique is based on a discovery that Luterbacher and his colleagues published <a href="https://actu.epfl.ch/news/turning-biofuel-waste-into-wealth-in-a-single-step/" target="_blank">in 2016</a>, where adding an aldehyde could stabilize certain fractions of plant material and avoid their destruction during extraction. By repurposing this chemistry, the researchers were able to rebuild a new useful bio-based chemical as a plastic precursor.<img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1657285759962-6049d711.jpg" style="width: 766px;" class="fr-fic fr-dib">Processing of the bioplastic by extrusion to make fibers for 3D-printing. Credit Maxime Hedou.&nbsp;&ldquo;By using a different aldehyde &ndash; glyoxylic acid instead of formaldehyde &ndash; we could simply clip &lsquo;sticky&rsquo; groups onto both sides of the sugar molecules, which then allows them to act as plastic building blocks,&rdquo; says Lorenz Manker, the study&rsquo;s first author. &ldquo;By using this simple technique, we are able to convert up to 25% of the weight of agricultural waste, or 95% of purified sugar, into plastic.&rdquo;The well-rounded properties of these plastics could allow them to be used in applications ranging from packaging and textiles to medicine and electronics. The researchers have already made packaging films, fibers that could be spun into clothing or other textiles, and filaments for 3D-printing.<img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1657285778244-2a3e2c42.jpg" style="width: 766px;" class="fr-fic fr-dib">Lorenz Manker, the study&#39;s lead author, holding a 3D-printed EPFL logo made with the bioplastic. Credit: Stefania Bertella.&nbsp;&ldquo;The plastic has very exciting properties, notably for applications like food packaging,&rdquo; says Luterbacher. &ldquo;And what makes the plastic unique is the presence of the intact sugar structure. This makes it incredibly easy to make because you don&rsquo;t have to modify what nature gives you, and simple to degrade because it can go back to a molecule that is already abundant in nature.&rdquo;Other contributors<ul><li>EPFL Laboratory for Processing of Advanced Composites</li><li>University of Natural Resources and Life Sciences (Austria)</li><li>Competence Center for Wood Composites &amp; Wood Chemistry (Austria)</li><li>EPFL Industrial Energy Systems Laboratory</li></ul>

A 3D-printed “leaf” made with the new bioplastic. Credit: Alain Herzog (EPFL)

EPFL scientists have developed a new, PET-like plastic that is easily made from the non-edible parts of plants. The plastic is tough, heat-resistant, and a good barrier to gases like oxygen, making it a promising candidate for food packaging.