Category Archives: environment

Rapid formation of micro- and nanoplastics in the environment

Image: Nora Meides.

A June 18, 2021 news item on phys.org announces the results of research into how materials made of plastic break down into micro- and nanoplastic particles in the environment,

Most microplastic particles in the environment originate from larger pieces of plastic. In a long-term study, an interdisciplinary research team at the University of Bayreuth has simulated how quickly plastic breaks down into fragments under natural influences. High-tech laboratory tests on polystyrene show two phases of abiotic degradation. To begin with, the stability of the plastic is weakened by photo-oxidation. Then cracks form and more and more and smaller fragments are released into the environment. The study, published in the journal Environmental Science & Technology, allows conclusions to be drawn about other plastics that are common in the environment.

A June 17, 2021 University of Bayreuth press release, which originated the news item, provides more detail,

Polystyrene is an inexpensive plastic that is often used for packaging and thermal insulation, and is therefore particularly common in plastic waste. As part of their long-term study, the Bayreuth researchers for the first time combined analytical investigations, which were also carried out on polystyrene particles at the atomic level, with measurements determining the behaviour of these particles under mechanical stress. On the basis of this, they developed a model for abiotic degradation, i.e. degradation without the influence of living organisms.

“Our study shows that a single microplastic particle with a diameter of 160 micrometres releases about 500 particles in the order of 20 micrometres – i.e. 0.02 millimetres – over the course of one and a half years of being exposed to natural weathering processes in the environment. Over time, these particles in turn break down into smaller and smaller fragments. An ecocorona can form around these tiny particles, possibly facilitating penetration into the cells of living organisms. This was discovered a few months ago by another Bayreuth research group,” says first author Nora Meides, a doctoral student in macromolecular chemistry at the University of Bayreuth.

n the water, the microplastic particles were exposed to two stress factors: intense sunlight and continuous mechanical stress produced by agitation. In the real-world environment, sunlight and mechanical stress are in fact the two main abiotic factors that contribute to the gradual fragmentation of the particles. Irradiation by sunlight triggers oxidation processes on the surface of the particles. This photo-oxidation, in combination with mechanical stress, has significant consequences. The polystyrene chains become ever shorter. Furthermore, they become increasingly polar, i.e. centres of charge are formed in the molecules. In the second phase, the microplastic particles begin to fragment. Here, the particles break down into smaller and smaller micro- and nanoplastic fragments.

“Our research results are a valuable basis for investigating the abiotic degradation of macro- and microplastics in the environment – both on land and at the surface of water – in more detail, using other types of plastic as examples. We were surprised by the speed of fragmentation ourselves, which again shows the potential risks that could emanate from the growing burden of plastics on the environment. Especially larger plastic waste objects, are – when exposed to sunlight and abrasion – a reservoir of constant microplastic input. It is precisely these tiny particles, barely visible to the naked eye, that spread to the remotest ecosystems via various transport routes,” says Teresa Menzel, PhD student in the area of Polymer Engineering.

“The polystyrene investigated in our long-term study has a carbon-chain backbone, just like polyethylene and polypropylene. It is very likely that the two-phase model we have developed on polystyrene can be transferred to these plastics,” adds lead author Prof. Dr. Jürgen Senker, Professor of Inorganic Chemistry, who coordinated the research work. 

The study that has now been published is the result of the close interdisciplinary cooperation of a working group belonging to the DFG Collaborative Research Centre “Microplastics” at the University of Bayreuth. In this team, scientists from macromolecular chemistry, inorganic chemistry, engineering science, and animal ecology are jointly researching the formation and degradation of microplastics. Numerous types of research technology are available on the Bayreuth campus for this purpose, which were used in the long-term study: among others, ¹³C-MAS-NMR spectroscopy, energy dispersive X-ray spectroscopy (EDX), scanning electron microscopy (SEM), and gel permeation chromatography (GPC).

Here’s a link to and a citation for the paper,

Reconstructing the Environmental Degradation of Polystyrene by Accelerated Weathering by Nora Meides, Teresa Menzel, Björn Poetzschner, Martin G. J. Löder, Ulrich Mansfeld, Peter Strohriegl, Volker Altstaedt, and Jürgen Senker. Environ. Sci. Technol. 2021, 55, 12, 7930–7938 DOI: https://doi.org/10.1021/acs.est.0c07718 Publication Date: May 21, 2021 Copyright © 2021 The Authors. Published by American Chemical Society

This paper is behind a paywall.

Walrus from Space project (citizen science)

Image:: Norwegian Atlantic Walrus. Photo: Tor Lund / WWF [Downloaded from: https://eminetra.co.uk/climate-change-the-walrus-from-space-project-is-calling-on-the-general-public-to-help-search-for-animals-on-satellite-imagery-climate-news/755984/]

Yesterday (October 14, 2021), the World Wildlife Federation (WWF) announced their Walrus from Space project in a press release,

WWF and British Antarctic Survey (BAS) are seeking the public’s help to search for walrus in thousands of satellite images taken from space, with the aim of learning more about how walrus will be impacted by the climate crisis. It’s hoped half a million people worldwide will join the new ‘Walrus from Space’ research project, a census of Atlantic walrus and walrus from the Laptev Sea, using satellite images provided by space and intelligence company Maxar Technologies’ DigitalGlobe.

Walrus are facing the reality of the climate crisis: their Arctic home is warming almost three times faster than the rest of the world and roughly 13% of summer sea ice is disappearing per decade.

From the comfort of their own homes, aspiring conservationists around the world can study the satellite pictures online, spot areas where walrus haul out onto land, and then count them. The data collected in this census of Atlantic and Laptev walrus will give scientists a clearer picture of how each population is doing—without disturbing the animals. The data will also help inform management decisions aimed at conservation efforts for the species.

Walrus use sea ice for resting and to give birth to their young. As sea ice diminishes, more walrus are forced to seek refuge on land, congregating for the chance to rest. Overcrowded beaches can have fatal consequences; walrus are easily frightened, and when spooked they stampede towards the water, trampling one another in their panic. Resting on land (as opposed to sea ice) may also force walrus to swim further and expand more energy to reach their food—food which in turn is being negatively impacted by the warming and acidification of the ocean.

In addition walrus can also be disturbed by shipping traffic and industrial development as the loss of sea ice makes the Arctic more accessible. Walrus are almost certainly going to be impacted by the climate crisis, which could result in significant population declines.

Rod Downie, chief polar adviser at WWF, said:

“Walrus are an iconic species of great cultural significance to the people of the Arctic, but climate change is melting their icy home. It’s easy to feel powerless in the face of the climate and nature emergency, but this project enables individuals to take action to understand a species threatened by the climate crisis, and to help to safeguard their future. “What happens in the Arctic doesn’t stay there; the climate crisis is a global problem, bigger than any person, species or region. Ahead of hosting this year’s global climate summit, the UK must raise its ambition and keep all of its climate promises—for the sake of the walrus, and the world.”

Previous population estimates are based upon the best data and knowledge available, but there are challenges associated with working with marine mammals in such a vast, remote and largely inaccessible place. This project will build upon the knowledge of Indigenous communities, using satellite technology to provide an up-to-date count of Atlantic and Laptev walrus populations.

Hannah Cubaynes, wildlife from space research associate at British Antarctic Survey, said:

“Assessing walrus populations by traditional methods is very difficult as they live in extremely remote areas, spend much of their time on the sea ice and move around a lot, Satellite images can solve this problem as they can survey huge tracts of coastline to assess where walrus are and help us count the ones that we find. “However, doing that for all the Atlantic and Laptev walrus will take huge amounts of imagery, too much for a single scientist or small team, so we need help from thousands of citizen scientists to help us learn more about this iconic animal.”

Earlier this year Cub Scouts from across the UK became walrus spotters to test the platform ahead of its public release. The Scouts have been a partner of WWF since the early 1970s, and over 57 million scouts globally are engaged in environmental projects.

Cub Scout Imogen Scullard, age 9, said:

“I love learning about the planet and how it works. We need to protect it from climate change. We are helping the planet by doing the walrus count with space satellites, which is really cool. It was a hard thing to do but we stuck at it”

The ‘Walrus From Space’ project, which is supported by players of the People’s Postcode Lottery, as well as RBC Tech For Nature and WWF supporters, aims to recruit more than 500,000 citizen scientists over the next five years. Over the course of the project counting methods will be continually refined and improved as data is gathered.

Laura Chow, head of charities at People’s Postcode Lottery, said:

“We’re delighted that players’ support is bringing this fantastic project to life. We encourage everyone to get involved in finding walrus so they can play a part in helping us better understand the effects of climate change on this species and their ecosystem. “Players of People’s Postcode Lottery are supporting this project as part of our Postcode Climate Challenge initiative, which is providing 12 charities with an additional £24 million for projects tackling climate change this year.”

Aspiring conservationists can help protect the species by going to wwf.org.uk/walrusfromspace where they can register to participate, and then be guided through a training module before joining the walrus census.

Download our FAQ

The WWF has released a charming video invitation”Become A Walrus Detective,” (Note: It may be a little over the top for some),

The WWF has a Learn about Walrus from Space webpage, which features the video above and includes a registration button.

Is the United Kingdom an Arctic nation?

No. They are not. (You can check here on the Arctic Countries webpage of The Arctic Institute website.)

Nonetheless and leaving aside that the Arctic and the Antarctic are literally polar opposites, I gather that the British Government in the form of the British Antarctic Survey (BAS), is quite interested in the Arctic, viz.: the Walrus from Space project.

If you keep digging you’ll find a chain of UK government agencies, from the BAS About page (at the bottom), Note: Links have been removed,,

British Antarctic Survey (BAS) is a component of the Natural Environment Research Council (NERC).

NERC is part of UK Research and Innovation

Keep digging (from the UK Research and Innovation entry on Wikipedia), Note: Links have been removed,

UK Research and Innovation (UKRI) is a non-departmental public body of the Government of the United Kingdom that directs research and innovation funding, funded through the science budget of the Department for Business, Energy and Industrial Strategy [emphases mine].

Interesting, non?

There doesn’t have to be a sinister connection between a government agency devoted to supporting business and industry and a climate change project. If we are to grapple with climate change in a significant way, we will need cooperation from many groups and coutnries (some of which may have been adversaries in the past).

Of course, the problem with the business community is that efforts aimed at the public good are often publicity stunts.

For anyone curious about the businesses mentioned in the press release, Maxar Technologies can be found here, Maxar’s DigitalGlobe here, and RBC (Royal of Bank of Canada) Tech for Nature here.

BTW, I love that walrus picture at the beginning of this posting.

A library of properties for nanomaterials

Researchers at the University of Birmingham (UK) announced the development of a library of nanomaterial properties according to a June 8, 2021 news item on Nanowerk (Note: Links have been removed),

Researchers have developed a ‘library of properties’ to help identify the environmental impact of nanomaterials faster and more cost effectively.

Whilst nanomaterials have benefited a wide range of industries and revolutionized everyday life, there are concerns over potential adverse effects—including toxic effects following accumulation in different organs and indirect effects from transport of co-pollutants.

The European Union H2020-funded NanoSolveIT project is developing a ground-breaking computer-based Integrated Approach to Testing and Assessment (IATA) for the environmental health and safety of nanomaterials.

A June 8, 2021 University of Birmingham press release (also on EurekAlert) spells out the details,

Over the last two years, researchers from the University of Birmingham have worked with experts at NovaMechanics, in Nicosia, Cyprus to develop a decision support system in the form of both stand-alone open software and a Cloud platform.

The team has developed a freely available cloud library containing full physicochemical characterisation of 69 nanomaterials, plus calculated molecular descriptors to increase the value of the available information, details of which are published in NanoImpact. [link and citation follow]

Professor Iseult Lynch, from the University of Birmingham commented: “One of the limitations to widespread application of computer-based approaches is the lack of large well-organised high-quality datasets, or of data with adequate metadata that will allow dataset interoperability and their combination to create larger datasets.”

“Making the library of calculated and experimental descriptors available to the community, along with the detailed description of how they were calculated is a key first step towards filling this datagap.”

Development of the cloud-based nanomaterials library is the fifth freely available web-based application that the project has delivered.

Antreas Afantitis, from NovaMechanics, commented: “Over the last two years, this project has already presented some very impressive results with more than 30 publications, making NanoSolveIT one of the most active projects in the nanomaterials safety and informatics space.”

Concerns about nanomaterials are also arising as risk assessment is lagging behind product development, mainly because current approaches to assessing exposure, hazard and risk are expensive and time-consuming, and frequently involve testing in animal models. The NanoSolveIT project aspires to address these challenges.

The latest development aims to enrich our knowledge of nanomaterials properties and the link from property to (cytotoxic) effect. The enriched dataset contains over 70 descriptors per nanomaterial.

The dataset was used to develop a computer-based workflow to predict nanomaterials’ effective surface charge (zeta-potential) based on a set of descriptors that can be used to help design and produce safer and more functional nanomaterials.

The resulting predictive read-across model has been made publicly and freely available as a web service through the Horizon 2020 (H2020) NanoCommons project (http://enaloscloud.novamechanics.com/nanocommons/mszeta/ ) and via the H2020 NanoSolveIT Cloud Platform (https://mszeta.cloud.nanosolveit.eu/ ) to ensure accessibility to the community and interested stakeholders.

In addition, the full data set, ready for further computational modeling, is available through the NanoPharos database, as the project consortium supports the FAIR data principles – committing to making its data Findable, Accessible, Interoperable and Re-usable.

I quite like this image of how the scales are illustrated (BTW, you can find NanoSolveIT here the NanoCommons project [closing date May 15, 2021] here, and NovaMechanics here)

Scales of descriptors – from whole nanoparticle to unit cell to individual atoms Courtesy University of Birmingham and NanoSolveIT

Here’s a link to and a citation for the paper,

Computational enrichment of physicochemical data for the development of a ζ-potential read-across predictive model with Isalos Analytics Platform by Anastasios G. Papadiamantis, Antreas Afantitis, Andreas Tsoumanis, Eugenia Valsami-Jones, Iseult Lynch, Georgia Melagraki. NanoImpact Volume 22, April 2021, 100308 DOI: https://doi.org/10.1016/j.impact.2021.100308 Available online 18 March 2021

This paper is open access.

The coolest paint

It’s the ‘est’ of it all. The coolest, the whitest, the blackest … Scientists and artists are both pursuing the ‘est’. (More about the pursuit later in this posting.)

In this case, scientists have developed the coolest, whitest paint yet. From an April 16, 2021 news item on Nanowerk,

In an effort to curb global warming, Purdue University engineers have created the whitest paint yet. Coating buildings with this paint may one day cool them off enough to reduce the need for air conditioning, the researchers say.

In October [2020], the team created an ultra-white paint that pushed limits on how white paint can be. Now they’ve outdone that. The newer paint not only is whiter but also can keep surfaces cooler than the formulation that the researchers had previously demonstrated.

“If you were to use this paint to cover a roof area of about 1,000 square feet, we estimate that you could get a cooling power of 10 kilowatts. That’s more powerful than the central air conditioners used by most houses,” said Xiulin Ruan, a Purdue professor of mechanical engineering.

Caption: Xiulin Ruan, a Purdue University professor of mechanical engineering, holds up his lab’s sample of the whitest paint on record. Credit: Purdue University/Jared Pike

This is nicely done. Researcher Xiulin Ruan is standing close to a structure that could be said to resemble the sun while in shirtsleeves and sunglasses and holding up a sample of his whitest paint in April (not usually a warm month in Indiana).

An April 15, 2021 Purdue University news release (also on EurkeAlert), which originated the news item, provides more detail about the work and hints about its commercial applications both civilian and military,

The researchers believe that this white may be the closest equivalent of the blackest black, “Vantablack,” [emphasis mine; see comments later in this post] which absorbs up to 99.9% of visible light. The new whitest paint formulation reflects up to 98.1% of sunlight – compared with the 95.5% of sunlight reflected by the researchers’ previous ultra-white paint – and sends infrared heat away from a surface at the same time.

Typical commercial white paint gets warmer rather than cooler. Paints on the market that are designed to reject heat reflect only 80%-90% of sunlight and can’t make surfaces cooler than their surroundings.

The team’s research paper showing how the paint works publishes Thursday (April 15 [2021]) as the cover of the journal ACS Applied Materials & Interfaces.

What makes the whitest paint so white

Two features give the paint its extreme whiteness. One is the paint’s very high concentration of a chemical compound called barium sulfate [emphasis mine] which is also used to make photo paper and cosmetics white.

“We looked at various commercial products, basically anything that’s white,” said Xiangyu Li, a postdoctoral researcher at the Massachusetts Institute of Technology who worked on this project as a Purdue Ph.D. student in Ruan’s lab. “We found that using barium sulfate, you can theoretically make things really, really reflective, which means that they’re really, really white.”

The second feature is that the barium sulfate particles are all different sizes in the paint. How much each particle scatters light depends on its size, so a wider range of particle sizes allows the paint to scatter more of the light spectrum from the sun.

“A high concentration of particles that are also different sizes gives the paint the broadest spectral scattering, which contributes to the highest reflectance,” said Joseph Peoples, a Purdue Ph.D. student in mechanical engineering.

There is a little bit of room to make the paint whiter, but not much without compromising the paint.”Although a higher particle concentration is better for making something white, you can’t increase the concentration too much. The higher the concentration, the easier it is for the paint to break or peel off,” Li said.

How the whitest paint is also the coolest

The paint’s whiteness also means that the paint is the coolest on record. Using high-accuracy temperature reading equipment called thermocouples, the researchers demonstrated outdoors that the paint can keep surfaces 19 degrees Fahrenheit cooler than their ambient surroundings at night. It can also cool surfaces 8 degrees Fahrenheit below their surroundings under strong sunlight during noon hours.

The paint’s solar reflectance is so effective, it even worked in the middle of winter. During an outdoor test with an ambient temperature of 43 degrees Fahrenheit, the paint still managed to lower the sample temperature by 18 degrees Fahrenheit.

This white paint is the result of six years of research building on attempts going back to the 1970s to develop radiative cooling paint as a feasible alternative to traditional air conditioners.

Ruan’s lab had considered over 100 different materials, narrowed them down to 10 and tested about 50 different formulations for each material. Their previous whitest paint was a formulation made of calcium carbonate, an earth-abundant compound commonly found in rocks and seashells.

The researchers showed in their study that like commercial paint, their barium sulfate-based paint can potentially handle outdoor conditions. The technique that the researchers used to create the paint also is compatible with the commercial paint fabrication process.

Patent applications for this paint formulation have been filed through the Purdue Research Foundation Office of Technology Commercialization. This research was supported by the Cooling Technologies Research Center at Purdue University and the Air Force Office of Scientific Research [emphasis mine] through the Defense University Research Instrumentation Program (Grant No.427 FA9550-17-1-0368). The research was performed at Purdue’s FLEX Lab and Ray W. Herrick Laboratories and the Birck Nanotechnology Center of Purdue’s Discovery Park.

Here’s a link to and a citation for the paper,

Ultrawhite BaSO4 Paints and Films for Remarkable Daytime Subambient Radiative Cooling by Xiangyu Li, Joseph Peoples, Peiyan Yao, and Xiulin Ruan. ACS Appl. Mater. Interfaces 2021, XXXX, XXX, XXX-XXX DOI: https://doi.org/10.1021/acsami.1c02368 Publication Date:April 15, 2021 © 2021 American Chemical Society

This paper is behind a paywall.

Vantablack and the ongoing ‘est’ of blackest

Vantablack’s 99.9% light absorption no longer qualifies it for the ‘blackest black’. A newer standard for the ‘blackest black’ was set by the US National Institute of Standards and Technology at 99.99% light absorption with its N.I.S.T. ultra-black in 2019, although that too seems to have been bested.

I have three postings covering the Vantablack and blackest black story,

The third posting (December 2019) provides a brief summary of the story along with what was the latest from the US National Institute of Standards and Technology. There’s also a little bit about the ‘The Redemption of Vanity’ an art piece demonstrating the blackest black material from the Massachusetts Institute of Technology, which they state has 99.995% (at least) absorption of light.

From a science perspective, the blackest black would be useful for space exploration.

I am surprised there doesn’t seem to have been an artistic rush to work with the whitest white. That impression may be due to the fact that the feuds get more attention than quiet work.

Dark side to the whitest white?

Andrew Parnell, research fellow in physics and astronomy at the University of Sheffield (UK), mentions a downside to obtaining the material needed to produce this cooling white paint in a June 10, 2021 essay on The Conversation (h/t Fast Company), Note: Links have been removed,

… this whiter-than-white paint has a darker side. The energy required to dig up raw barite ore to produce and process the barium sulphite that makes up nearly 60% of the paint means it has a huge carbon footprint. And using the paint widely would mean a dramatic increase in the mining of barium.

Parnell ends his essay with this (Note: Links have been removed),

Barium sulphite-based paint is just one way to improve the reflectivity of buildings. I’ve spent the last few years researching the colour white in the natural world, from white surfaces to white animals. Animal hairs, feathers and butterfly wings provide different examples of how nature regulates temperature within a structure. Mimicking these natural techniques could help to keep our cities cooler with less cost to the environment.

The wings of one intensely white beetle species called Lepidiota stigma appear a strikingly bright white thanks to nanostructures in their scales, which are very good at scattering incoming light. This natural light-scattering property can be used to design even better paints: for example, by using recycled plastic to create white paint containing similar nanostructures with a far lower carbon footprint. When it comes to taking inspiration from nature, the sky’s the limit.

The power of art and science policy

For Berta (They Fear Us Because We Are Fearless) Materials: [detail] Shell casings, shale, smalti, stained glass Size: 16″h x 16″w Year: 2019 [Artist: Julie Sperling]

At first glance I thought those were coins—they’re bullet casings. Science policy isn’t always a boring meeting or report.

Here’s a little more about the artist Julie Sperling, from the About page on her website,

I am a Canadian mosaic artist based in Kitchener, Ontario. My studio practice finds me camped out at the intersection of art, environment, science, and policy. I firmly believe in the important role that artists play as advocates, activists, and change-makers.

When I’m not wearing my work overalls I am a policy analyst with Environment and Climate Change Canada. [emphasis mine] But really, I’m happiest when I have a rock in one hand and my hammer in the other.

Getting back to ‘Berta‘, which is part of a series “By Our Own Hands.” Spence tells the story of how the mosaic was inspired (Note: Links have been removed),

Every week, about 4 people are killed for standing up to those (predominantly industry of various stripes) who are encroaching on their traditional lands and resources, threatening the environment and their very survival. That adds up to hundreds of lives each year. More often than not, their killers go unpunished as land grabs and environmental exploitation advance, leaving death and destruction in their wake.

I’ve been waiting three years to make this mosaic. The issue planted itself firmly in my brain in 2016 with the assassination of Berta Cáceres, one of Honduras’ most prominent environmental activists and winner of the Goldman Environmental Prize. Cáceres co-founded the National Council of Popular and Indigenous Organizations of Honduras (COPINH) and before her murder had been working with the Lenca people to stop the Agua Zarca dam, which would have affected the Gualcarque River, a sacred river for the Lenca people. The dam would have diverted 3 kilometres of river, displacing communities and jeopardizing their water resources and livelihoods. COPINH employed many tactics to stop the construction of the dam, most notably a blockade that lasted over a year. In the end, Cáceres, who had been receiving death threats for years, was shot and killed in her home. In November 2018, seven men were convicted of her murder. Among those convicted were two employees of the construction company, DESA (one of whom was, ironically enough, the company’s “community and environmental affairs manager”), a retired military officer turned DESA employee, and an active military officer. DESA’s then-CEO is being tried separately this year [2019].

Science policy and real life consequences.

Because it’s Friday (September 24, 2021) I wanted to end on a more hopeful note,

Bioswale (Slow It Down, Soak It Up) [detail] Materials: Asphalt, limestone, sandstone, marble, litovi, smalti Size: 18″h x 20″w (approximately) Year: 2017 [Artist: Julie Sperling]

From the Bioswale webpage,

This mosaic is all about using nature (specifically, rain gardens) to slow down and soak up the rain as extreme precipitation increases with climate change. …

Technology for mopping up oil spills

It’s a little disheartening to write about technology for mopping up oils spills as there doesn’t to be much improvement in the situation as Adele Peters notes in her June 4, 2021 article (A decade after Deepwater Horizon, we’re still cleaning up oil spills the same way) for Fast Company (Note: Links have been removed),

Off the coastline of Sri Lanka, where a burning cargo ship has been spilling toxic chemicals and plastic pellets over the past two weeks, the government is preparing for the next possible stage of the disaster: As the ship sinks, it may also spill some of the hundreds of tons of oil in its fuel tanks.

The government is readying oil dispersants, booms, and oil skimmers, all tools that were used in the massive Deepwater Horizon oil spill in the Gulf of Mexico in 2010. They didn’t work perfectly then—more than 1,000 miles of shoreline were polluted—and more than a decade later, they’re still commonly used. But solutions that might work better are under development, including reusable sponges that can suck up oil both on the surface and underwater.

Dispersants, one common tool now, are chemicals designed to break up the oil into tiny droplets so that, in theory, microorganisms in the water can break down the oil more easily. But at least one study found that dispersant could harm those organisms. Deep-sea coral also appears to suffer more from the mix of dispersant and oil than oil alone. Booms are designed to contain oil on the surface so it can be scraped off with a skimmer, but that only works if the water’s relatively calm, and it doesn’t deal with oil below the surface. The oil on the surface can also be burned, but it creates a plume of thick black smoke. “That does get rid of the oil from the water, but then it turns a water pollution problem into an air pollution problem,” says Seth Darling, a senior scientist at Argonne National Laboratory who developed an alternative called the Oleo Sponge [emphasis mine].

… a team from two German universities that developed a system of wood chips that can be dropped in the water to collect oil even in rough weather, when current tools don’t work well. The system is ready for deployment if a spill happens in the Baltic Sea. Another earlier-stage solution proposes using a robot to detect and capture oil.

I’m glad to see at least one new oil spill cleanup technology being readied for deployment in Peters’ June 4, 2021 article, we should be preparing for more spills as the Arctic melts and plans are made to develop new shipping routes.

Amongst other oil spill cleanup technologies, Peters mentions the ‘Oleo Sponge’, which was featured here in a March 30, 2017 posting when researchers were looking for investors to commercialize the product. According to Peters the oleo sponge hasn’t yet made it to market; it’s a fate many of these technologies are destined to meet. Meanwhile, scientists continue to develop new methods and techniques for mopping up oil spills as safely as possible. For example, there’s an oil spill sucking robot mentioned in my October 30, 2020 posting, which features yet another article by Peters.

In the summer of 2020 there were two major oil spills, one in the Russian Arctic and one in an ecologically sensitive area near Mauritius. For more about those events, there’s an August 14, 2020 posting, which starts with news of an oil spill technology featuring dog fur and then focuses primarily on the oil spill in the Russian Arctic with a brief mention of the spill near Mauritius in June 2020 (scroll down to the ‘Exceptionally warm weather’ subhead and see the paragraph above it for the mention and a link to a story).

Canadian and Guadeloupean oysters: exposure to nanoplastics and arsenic

A May 27, 2021 news item on phys.org describes research into oysters and nanoplastics,

Oysters’ exposure to plastics is concerning, particularly because these materials can accumulate and release metals which are then absorbed by the mollusks. According to a recent study published in the journal Chemosphere, the combined presence of nanoplastics and arsenic affects the biological functions of oysters. This study was conducted by the Institut national de la recherche scientifique (INRS) in Québec City and the French National Centre for Scientific Research (CNRS) at the University of Bordeaux in France

A May 27, 2021 INRS news release (French language version here and an English language version on EurekAlert), which originated the news item, provides fascinating details,

The international research team chose to study arsenic, since it is one of the most common metals absorbed by the plastic debris collected from the beaches of Guadeloupe. “Oysters easily accumulate metals from the environment into their tissues. We therefore wanted to test whether the combined exposure to nanoplastics and arsenic would increase the bioaccumulation of this contaminant,” reported Marc Lebordais, the Master’s student in charge of the research.

The scientists proved that the bioaccumulation of arsenic does not increase when nanoplastics are also present. However, it remained higher in the gills of the Canadian Crassostrea virginica oyster [emphasis mine] than in the Isognomon alatus oyster, found in Guadeloupe. These results are the first to highlight the diverging sensitivity of different species. [emphasis mine]

Gene deregulation

In addition to bioaccumulation, the team also observed an overexpression of genes responsible for cell death and the number of mitochondria–a cell’s energy centres–in C. virginica. In I. alatus, the expression of these same genes was less significant.

“Evaluating the expression of genes involved in important functions, such as cell death and detoxification, gives us information on the toxicity of nanoplastics and arsenic on a cellular level,” explained the young researcher, who is co-directed by Professors Valérie Langlois of INRS and Magalie Baudrimont of the University of Bordeaux.

The food chain

The next step, after characterizing the presence of nanoplastics and arsenic in oysters, would be to study how these contaminants are transferred through the food chain.

“Analytical tools are currently being developed to quantify the presence of nanoplastics in biological tissues,” said Marc Lebordais. “Understanding the amount of nanoplastics in farmed oysters currently boils down to a technical issue.” ?

Here’s a link to and a citation for the paper,

Molecular impacts of dietary exposure to nanoplastics combined with arsenic in Canadian oysters (Crassostrea virginica) and bioaccumulation comparison with Caribbean oysters (Isognomon alatus) by Marc Lebordais, Juan Manuel Gutierrez-Villagomez, Julien Gigault, Magalie Baudrimont, and Valérie Langlois. Chemosphere Volume 277, August 2021, 130331 DOI: https://doi.org/10.1016/j.chemosphere.2021.130331 First published online 19 March 2021.

This paper is open access.

Mini T-shirt demonstrates photosynthetic living materials

Caption: A mini T-shirt demonstrates the photosynthetic living materials created in the lab of University Rochester biologist Anne S. Meyer and Delft University of Technology bionanoscientist Marie-Eve Aubin-Tam using 3D printers and a new bioink technique. Credit: University of Rochester photo

I’m not sure how I feel about a t-shirt, regardless of size, made of living biological material but these researchers seem uniformly enthusiastic. From a May 3, 2021 news item on phys.org (Note: A link has been removed),

Living materials, which are made by housing biological cells within a non-living matrix, have gained popularity in recent years as scientists recognize that often the most robust materials are those that mimic nature.

For the first time, an international team of researchers from the University of Rochester [located in New York state, US] and Delft University of Technology in the Netherlands used 3D printers and a novel bioprinting technique to print algae into living, photosynthetic materials that are tough and resilient. The material has a variety of applications in the energy, medical, and fashion sectors. The research is published in the journal Advanced Functional Materials.

An April 30, 2021 University of Rochester new release (also on EurekAlert but published May 3, 2021) by Lindsey Valich, which originated the news item, delves further into the topic of living materials,

“Three-dimensional printing is a powerful technology for fabrication of living functional materials that have a huge potential in a wide range of environmental and human-based applications.” says Srikkanth Balasubramanian, a postdoctoral research associate at Delft and the first author of the paper. “We provide the first example of an engineered photosynthetic material that is physically robust enough to be deployed in real-life applications.”

HOW TO BUILD NEW MATERIALS: LIVING AND NONLIVING COMPONENTS

To create the photosynthetic materials, the researchers began with a non-living bacterial cellulose–an organic compound that is produced and excreted by bacteria. Bacterial cellulose has many unique mechanical properties, including its flexibility, toughness, strength, and ability to retain its shape, even when twisted, crushed, or otherwise physically distorted.

The bacterial cellulose is like the paper in a printer, while living microalgae acts as the ink. The researchers used a 3D printer to deposit living algae onto the bacterial cellulose.

The combination of living (microalgae) and nonliving (bacterial cellulose) components resulted in a unique material that has the photosynthetic quality of the algae and the robustness of the bacterial cellulose; the material is tough and resilient while also eco-friendly, biodegradable, and simple and scalable to produce. The plant-like nature of the material means it can use photosynthesis to “feed” itself over periods of many weeks, and it is also able to be regenerated–a small sample of the material can be grown on-site to make more materials.

ARTIFICIAL LEAVES, PHOTOSYNTHETIC SKINS, AND BIO-GARMENTS

The unique characteristics of the material make it an ideal candidate for a variety of applications, including new products such as artificial leaves, photosynthetic skins, or photosynthetic bio-garments.

Artificial leaves are materials that mimic actual leaves in that they use sunlight to convert water and carbon dioxide–a major driver of climate change–into oxygen and energy, much like leaves during photosynthesis. The leaves store energy in chemical form as sugars, which can then be converted into fuels. Artificial leaves therefore offer a way to produce sustainable energy in places where plants don’t grow well, including outer space colonies. The artificial leaves produced by the researchers at Delft and Rochester are additionally made from eco-friendly materials, in contrast to most artificial leaf technologies currently in production, which are produced using toxic chemical methods.

“For artificial leaves, our materials are like taking the ‘best parts’ of plants–the leaves–which can create sustainable energy, without needing to use resources to produce parts of plants–the stems and the roots–that need resources but don’t produce energy,” says Anne S. Meyer, an associate professor of biology at Rochester. “We are making a material that is only focused on the sustainable production of energy.”

Another application of the material would be photosynthetic skins, which could be used for skin grafts, Meyer says. “The oxygen generated would help to kick-start healing of the damaged area, or it might be able to carry out light-activated wound healing.”

Besides offering sustainable energy and medical treatments, the materials could also change the fashion sector. Bio-garments made from algae would address some of the negative environmental effects of the current textile industry in that they would be high-quality fabrics that would be sustainability produced and completely biodegradable. They would also work to purify the air by removing carbon dioxide through photosynthesis and would not need to be washed as often as conventional garments, reducing water usage.

“Our living materials are promising because they can survive for several days with no water or nutrients access, and the material itself can be used as a seed to grow new living materials,” says Marie-Eve Aubin-Tam, an associate professor of bionanoscience at Delft. “This opens the door to applications in remote areas, even in space, where the material can be seeded on site.”

Here’s a link to and a citation for the paper,

Bioprinting of Regenerative Photosynthetic Living Materials by Srikkanth Balasubramanian, Kui Yu, Anne S. Meyer, Elvin Karana, Marie-Eve Aubin-Tam DOI: https://doi.org/10.1002/adfm.202011162 First published: 29 April 2021

This paper is open access.

The researchers have provided this artistic impression of 3D printing of living (microalgae) and nonliving materials (bacterial cellulose),

An artist’s illustration demonstrates how 3D printed materials could be applied as durable, living clothing. (Lizah van der Aart illustration)

Concrete collapse and research into durability

I have two items about concrete buildings, one concerns the June 24, 2021 collapse of a 12-storey condominium building in Surfside, close to Miami Beach in Florida. There are at least 20 people dead and, I believe, over 120 are still unaccounted for (July 2, 2021 Associated Press news item on Canadian Broadcasting Corporation news online website).

Miami collapse

Nate Berg’s June 25, 2021 article for Fast Company provides an instructive overview of the building collapse (Note: A link has been removed),

Why the building collapsed is not yet known [emphasis mine]. David Darwin is a professor of civil engineering at the University of Kansas and an expert in reinforced concrete structures, and he says the eventual investigation of the Surfside collapse will explore all the potential causes, ranging from movement in the foundation before the collapse, corrosion in the debris, and excessive cracking in the part of the building that remains standing. “There are all sorts of potential causes of failure,” Darwin says. “At this point, speculation is not helpful for anybody.”

Sometimes I can access the entire article, and at other times, only a few paragraphs; I hope you get access to all of it as it provides a lot of information.

The Surfside news puts this research from Northwestern University (Chicago, Illinois) into much sharper relief than might otherwise be the case. (Further on I have some information about the difference between cement and concrete and how cement leads to concrete.)

Smart cement for more durable roads and cities

Coincidentally, just days before the Miami Beach building collapse, a June 21, 2021 Northwestern University news release (also on EurekAlert), announced research into improving water and fracture resistance in cement,

Forces of nature have been outsmarting the materials we use to build our infrastructure since we started producing them. Ice and snow turn major roads into rubble every year; foundations of houses crack and crumble, in spite of sturdy construction. In addition to the tons of waste produced by broken bits of concrete, each lane-mile of road costs the U.S. approximately $24,000 per year to keep it in good repair.

Engineers tackling this issue with smart materials typically enhance the function of materials by increasing the amount of carbon, but doing so makes materials lose some mechanical performance. By introducing nanoparticles into ordinary cement, Northwestern University researchers have formed a smarter, more durable and highly functional cement.

The research was published today (June 21 [2021]) in the journal Philosophical Transactions of the Royal Society A.

With cement being the most widely consumed material globally and the cement industry accounting for 8% of human-caused greenhouse gas emissions, civil and environmental engineering professor Ange-Therese Akono turned to nanoreinforced cement to look for a solution. Akono, the lead author on the study and an assistant professor in the McCormick School of Engineering, said nanomaterials reduce the carbon footprint of cement composites, but until now, little was known about its impact on fracture behavior.

“The role of nanoparticles in this application has not been understood before now, so this is a major breakthrough,” Akono said. “As a fracture mechanics expert by training, I wanted to understand how to change cement production to enhance the fracture response.”

Traditional fracture testing, in which a series of light beams is cast onto a large block of material, involves lots of time and materials and seldom leads to the discovery of new materials.

By using an innovative method called scratch testing, Akono’s lab efficiently formed predictions on the material’s properties in a fraction of the time. The method tests fracture response by applying a conical probe with increasing vertical force against the surface of microscopic bits of cement. Akono, who developed the novel method during her Ph.D. work, said it requires less material and accelerates the discovery of new ones.

“I was able to look at many different materials at the same time,” Akono said. “My method is applied directly at the micrometer and nanometer scales, which saves a considerable amount of time. And then based on this, we can understand how materials behave, how they crack and ultimately predict their resistance to fracture.”

Predictions formed through scratch tests also allow engineers to make changes to materials that enhance their performance at the larger scale. In the paper, graphene nanoplatelets, a material rapidly gaining popularity in forming smart materials, were used to improve the resistance to fracture of ordinary cement. Incorporating a small amount of the nanomaterial also was shown to improve water transport properties including pore structure and water penetration resistance, with reported relative decreases of 76% and 78%, respectively.

Implications of the study span many fields, including building construction, road maintenance, sensor and generator optimization and structural health monitoring.

By 2050, the United Nations predicts two-thirds of the world population will be concentrated in cities. Given the trend toward urbanization, cement production is expected to skyrocket.

Introducing green concrete that employs lighter, higher-performing cement will reduce its overall carbon footprint by extending maintenance schedules and reducing waste.

Alternately, smart materials allow cities to meet the needs of growing populations in terms of connectivity, energy and multifunctionality. Carbon-based nanomaterials including graphene nanoplatelets are already being considered in the design of smart cement-based sensors for structural health monitoring.

Akono said she’s excited for both follow-ups to the paper in her own lab and the ways her research will influence others. She’s already working on proposals that look into using construction waste to form new concrete and is considering “taking the paper further” by increasing the fraction of nanomaterial that cement contains.

“I want to look at other properties like understanding the long-term performance,” Akono said. “For instance, if you have a building made of carbon-based nanomaterials, how can you predict the resistance in 10, 20 even 40 years?”

The study, “Fracture toughness of one- and two-dimensional nanoreinforced cement via scratch testing,” was supported by the National Science Foundation Division of Civil, Mechanical and Manufacturing Innovation (award number 18929101).

Akono will give a talk on the paper at The Royal Society’s October [2021] meeting, “A Cracking Approach to Inventing Tough New Materials: Fracture Stranger Than Friction,” which will highlight major advances in fracture mechanics from the past century.

I don’t often include these kinds of photos (one or more of the researchers posing (sometimes holding something) for the camera but I love the professor’s first name, Ange-Therese (which means angel in French, I don’t know if she ever uses the French spelling for Thérèse),

Caption: Professor Ange-Therese Akono holds a sample of her smart cement. Credit: Northwestern University

Here’s a link to and a citation for the paper,

Fracture toughness of one- and two-dimensional nanoreinforced cement via scratch testing by Ange-Therese Akono. Philosophical Transactions of the Royal Society A: Mathematical, Physical & Engineering Sciences 2021 379 (2203): 20200288 DOI: 10.1098/rsta.2020.0288 Published June 21, 2021

This paper appears to be open access.

Cement vs. concrete

Andrew Logan’s April 3, 2020 article for MIT (Massachusetts Institute of Technology) News is a very readable explanation of how cement and concrete differ and how they are related,

There’s a lot the average person doesn’t know about concrete. For example, it’s porous; it’s the world’s most-used material after water; and, perhaps most fundamentally, it’s not cement.

Though many use “cement” and “concrete” interchangeably, they actually refer to two different — but related — materials: Concrete is a composite made from several materials, one of which is cement. [emphasis mine]

Cement production begins with limestone, a sedimentary rock. Once quarried, it is mixed with a silica source, such as industrial byproducts slag or fly ash, and gets fired in a kiln at 2,700 degrees Fahrenheit. What comes out of the kiln is called clinker. Cement plants grind clinker down to an extremely fine powder and mix in a few additives. The final result is cement.

“Cement is then brought to sites where it is mixed with water, where it becomes cement paste,” explains Professor Franz-Josef Ulm, faculty director of the MIT Concrete Sustainability Hub (CSHub). “If you add sand to that paste it becomes mortar. And if you add to the mortar large aggregates — stones of a diameter of up to an inch — it becomes concrete.”

Final thoughts

I offer my sympathies to the folks affected by the building collapse and my hopes that research will lead the way to more durable cement and, ultimately, concrete buildings.

Fish DJ makes discoveries about fish hearing

A March 2, 2021 University of Queensland press release (also on EurekAlert) announces research into how fish brains develop and how baby fish hear,

A DJ-turned-researcher at The University of Queensland has used her knowledge of cool beats to understand brain networks and hearing in baby fish

The ‘Fish DJ’ used her acoustic experience to design a speaker system for zebrafish larvae and discovered that their hearing is considerably better than originally thought.

This video clip features zebrafish larvae listening to music, MC Hammer’s ‘U Can’t Touch This’ (1990),

Here’s the rest of the March 2, 2021 University of Queensland press release,

PhD candidate Rebecca Poulsen from the Queensland Brain Institute said that combining this new speaker system with whole-brain imaging showed how larvae can hear a range of different sounds they would encounter in the wild.

“For many years my music career has been in music production and DJ-ing — I’ve found underwater acoustics to be a lot more complicated than air frequencies,” Ms Poulsen said.

“It is very rewarding to be using the acoustic skills I learnt in my undergraduate degree, and in my music career, to overcome the challenge of delivering sounds to our zebrafish in the lab.

“I designed the speaker to adhere to the chamber the larvae are in, so all the sound I play is accurately received by the larvae, with no loss through the air.”

Ms Poulsen said people did not often think about underwater hearing, but it was crucial for fish survival – to escape predators, find food and communicate with each other.

Ms Poulsen worked with Associate Professor Ethan Scott, who specialises in the neural circuits and behaviour of sensory processing, to study the zebrafish and find out how their neurons work together to process sounds.

The tiny size of the zebrafish larvae allows researchers to study their entire brain under a microscope and see the activity of each brain cell individually.

“Using this new speaker system combined with whole brain imaging, we can see which brain cells and regions are active when the fish hear different types of sounds,” Dr Scott said.

The researchers are testing different sounds to see if the fish can discriminate between single frequencies, white noise, short sharp sounds and sound with a gradual crescendo of volume.

These sounds include components of what a fish would hear in the wild, like running water, other fish swimming past, objects hitting the surface of the water and predators approaching.

“Conventional thinking is that fish larvae have rudimentary hearing, and only hear low-frequency sounds, but we have shown they can hear relatively high-frequency sounds and that they respond to several specific properties of diverse sounds,” Dr Scott said.

“This raises a host of questions about how their brains interpret these sounds and how hearing contributes to their behaviour.”

Ms Poulsen has played many types of sounds to the larvae to see which parts of their brains light up, but also some music – including MC Hammer’s “U Can’t Touch This”– that even MC Hammer himself enjoyed.

The March 3, 3021 story by Graham Readfearn originally published by The Guardian (also found on MSN News), has more details about the work and the researcher,

As Australia’s first female dance music producer and DJ, Rebecca Poulsen – aka BeXta – is a pioneer, with scores of tracks, mixes and hundreds of gigs around the globe under her belt.

But between DJ gigs, the 46-year-old is now back at university studying neuroscience at Queensland Brain Institute at the University of Queensland in Brisbane.

And part of this involves gently securing baby zebrafish inside a chamber and then playing them sounds while scanning their brains with a laser and looking at what happens through a microscope.

The analysis for the study doesn’t look at how the fish larvae react during Hammer [MC Hammer] time, but how their brain cells react to simple single-frequency sounds.

“It told us their hearing range was broader than we thought it was before,” she says.

Poulsen also tried more complex sounds, like white noise and “frequency sweeps”, which she describes as “like the sound when Wile E Coyote falls off a cliff” in the Road Runner cartoons.

“When you look at the neurons that light up at each sound, they’re unique. The fish can tell the difference between complex and different sounds.”

This is, happily, where MC Hammer comes in.

Out of professional and scientific curiosity – and also presumably just because she could – Poulsen played music to the fish.

She composed her own piece of dance music and that did seem to light things up.

But what about U Can’t Touch This?

“You can see when the vocal goes ‘ohhh-oh’, specific neurons light up and you can see it pulses to the beat. To me it looks like neurons responding to different parts of the music.

“I do like the track. I was pretty little when it came out and I loved it. I didn’t have the harem pants, though, but I did used to do the dance.”

How do you stop the fish from swimming away while you play them sounds? And how do you get a speaker small enough to deliver different volumes and frequencies without startling the fish?

For the first problem, the baby zebrafish – just 3mm long – are contained in a jelly-like substance that lets them breathe “but stops them from swimming away and keeps them nice and still so we can image them”.

For the second problem, Poulsen and colleagues used a speaker just 1cm wide and stuck it to the glass of the 2cm-cubed chamber the fish was contained in.

Using fish larvae has its advantages. “They’re so tiny we can see their whole brain … we can see the whole brain live in real time.”

If you have the time, I recommend reading Readfearn’s March 3, 3021 story in its entirety.

Poulsen as Bexta has a Wikipedia entry and I gather from Readfearn’s story that she is still active professionally.

Here’s a link to and a citation for the published paper,

Broad frequency sensitivity and complex neural coding in the larval zebrafish auditory system by Rebecca E. Poulsen, Leandro A. Scholz, Lena Constantin, Itia Favre-Bulle, Gilles C. Vanwalleghem, Ethan K. Scott. Current Biology DOI:https://doi.org/10.1016/j.cub.2021.01.103 Published: March 02, 2021

This paper appears to be open access.

There is an earlier version of the paper on bioRxiv made available for open peer review. Oddly, I don’t see any comments but perhaps I need to login.

Related research but not the same

I was surprised when a friend of mine in early January 2021 needed to be persuaded that noise in aquatic environments is a problem. If you should have any questions or doubts, perhaps this March 4, 2021 article by Amy Noise (that is her name) on the Research2Reality website can answer them,

Ever had builders working next door? Or a neighbour leaf blowing while you’re trying to make a phone call? Unwanted background noise isn’t just stressful, it also has tangible health impacts – for both humans and our marine cousins.

Sound travels faster and farther in water than in air. For marine creatures who rely heavily on sound, crowded ocean soundscapes could be more harmful than previously thought.

Marine animals use sound to navigate, communicate, find food and mates, spot predators, and socialize. But since the Industrial Revolution, humans have made the planet, and the oceans in particular, exponentially noisier.

From shipping and fishing, to mining and sonar, underwater anthropogenic noise is becoming louder and more prevalent. While parts of the ocean’s chorus are being drowned out, others are being permanently muted through hunting and habitat loss.

[An] international team, including University of Victoria biologist Francis Juanes, reviewed over 10,000 papers from the past 40 years. They found overwhelming evidence that anthropogenic noise is negatively impacting marine animals.

Getting back to Poulsen and Queensland, her focus is on brain development not noise although I imagine some of her work may be of use to researchers investigating anthropogenic noise and its impact on aquatic life.