Category Archives: environment

Terahertz imagers at your fingertips

It seems to me that I stumbled across quite a few carbon nanotube (CNT) stories in 2018. This one comes courtesy of Japan (from a June 28, 2018 news item on Nanowerk),

Researchers at Tokyo Tech have developed flexible terahertz imagers based on chemically “tunable” carbon nanotube materials. The findings expand the scope of terahertz applications to include wrap-around, wearable technologies as well as large-area photonic devices.

Here’s a peek at an imager,

Figure 1. The CNT-based flexible THz imager (a) Resting on a fingertip, the CNT THz imager can easily wrap around curved surfaces. (b) Just by inserting and rotating a flexible THz imager attached to the fingertip, damage to a pipe was clearly detected. Courtesy Tokyo Tech

A June 28, 2018 Tokyo Tech Institute press release (also on Eurekalert), which originated the news item, provides more detail,

Carbon nanotubes (CNTs) are beginning to take the electronics world by storm, and now their use in terahertz (THz) technologies has taken a big step forward.

Due to their excellent conductivity and unique physical properties, CNTs are an attractive option for next-generation electronic devices. One of the most promising developments is their application in THz devices. Increasingly, THz imagers are emerging as a safe and viable alternative to conventional imaging systems across a wide range of applications, from airport security, food inspection and art authentication to medical and environmental sensing technologies.

The demand for THz detectors that can deliver real-time imaging for a broad range of industrial applications has spurred research into low-cost, flexible THz imaging systems. Yukio Kawano of the Laboratory for Future Interdisciplinary Research of Science and Technology, Tokyo Tech, is a world-renowned expert in this field. In 2016, for example, he announced the development of wearable terahertz technologies based on multiarrayed carbon nanotubes.

Kawano and his team have since been investigating THz detection performance for various types of CNT materials, in recognition of the fact that there is plenty of room for improvement to meet the needs of industrial-scale applications.

Now, they report the development of flexible THz imagers for CNT films that can be fine-tuned to maximize THz detector performance.

Publishing their findings in ACS Applied Nano Materials, the new THz imagers are based on chemically adjustable semiconducting CNT films.

By making use of a technology known as ionic liquid gating1, the researchers demonstrated that they could obtain a high degree of control over key factors related to THz detector performance for a CNT film with a thickness of 30 micrometers. This level of thickness was important to ensure that the imagers would maintain their free-standing shape and flexibility, as shown in Figure 1 [see above].

“Additionally,” the team says, “we developed gate-free Fermi-level2 tuning based on variable-concentration dopant solutions and fabricated a Fermi-level-tuned p-n junction3 CNT THz imager.” In experiments using this new type of imager, the researchers achieved successful visualization of a metal paper clip inside a standard envelope (see Figure 2.)

Non-contact, non-destructive visualization

Figure 2. Non-contact, non-destructive visualization

The CNT THz imager enabled clear, non-destructive visualization of a metal paper clip inside an envelope.

The bendability of the new THz imager and the possibility of even further fine-tuning will expand the range of CNT-based devices that could be developed in the near future.

Moreover, low-cost fabrication methods such as inkjet coating could make large-area THz imaging devices more readily available.

1 Ionic liquid gating

A technique used to modulate a material’s charge carrier properties.

2 Fermi level

A measure of the electrochemical potential for electrons, which is important for determining the electrical and thermal properties of solids. The term is named after the Italian–American physicist Enrico Fermi.

3 p-n junction

Refers to the interface between positive (p-type) and negative (n-type) semiconducting materials. These junctions form the basis of semiconductor electronic devices.

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

Fermi-Level-Controlled Semiconducting-Separated Carbon Nanotube Films for Flexible Terahertz Imagers by Daichi Suzuki, Yuki Ochiai, Yota Nakagawa, Yuki Kuwahara, Takeshi Saito, and Yukio Kawano. ACS Appl. Nano Mater., 2018, 1 (6), pp 2469–2475 DOI: 10.1021/acsanm.8b00421 Publication Date (Web): June 6, 2018

Copyright © 2018 American Chemical Society

This paper is behind a paywall.

Metcalf Institute Science Immersion Fellowship 2019 for journalists: applications open

I received this January 4, 2018 announcement from the Metcalf Institute at the University of Rhode Island (URI; US) in my email this morning. In other words, this is fresh off the email,

Get Science Tools to Break Stories
About Global Change & Water Resources

Apply for Metcalf Institute’s Career-Changing Science Immersion Fellowship
tuition, room and board, and travel support included

Global Change Impacts and Water
According to the United Nations, water is the “primary medium through which we will feel the effects of climate change” and water scarcity alone affects nearly half the global population.

Do you have the science tools to make the connection between shrinking water supplies, water quality, food production and climate change? Are you looking for story ideas to convey these global change impacts to your news audience? Would you like to build your confidence in discerning the credibility of scientific sources?

Call for Applications
The University of Rhode Island’s Metcalf Institute is accepting applications for its 21th Annual Science Immersion Workshop for Journalists, June 2-7, 2019. Ten journalists will be awarded Workshop fellowships, which include tuition, room and board, and travel support, thanks to the generosity of private donors and Metcalf Institute’s endowment. Two of the ten slots will be awarded to journalists based outside of the U.S.

Apply for the Workshop here.

About the Workshop
The Metcalf Institute Annual Science Immersion Workshop provides professional journalists with hands-on experience in field and laboratory science with expertise from leading scientists and policymakers who are working to project the impacts of global change, identify adaptation measures, and investigate the most effective ways to communicate these challenges. The workshop will address water resource and climate change topics of global significance while focusing on local and regional case studies in and around Narragansett Bay, among the world’s best studied estuaries. Held at the URI Graduate School of Oceanography, one of the nation’s premier oceanographic research institutions, the Metcalf Workshop provides an intense week of learning in the field, classroom and lecture hall.

Metcalf Fellows will:

  • Receive a comprehensive overview of climate science and global change
  • Gain a deeper understanding of how scientists conduct research and handle scientific uncertainty
  • Develop the skills and confidence to interpret and translate the language of scientific journals for news audiences
  • Build confidence in their abilities to discern the credibility of scientific sources
  • Board a research vessel to study the impacts of rising water temperatures and ocean acidification on coastal ecosystems
  • Explore the study of “emerging contaminants” such as PFAS that affect freshwater and marine ecosystems and public health
  • Visit wetlands, shorelines, and coastal communities to better understand adaptive management efforts and solutions in response to sea level rise and coastal storms
  • Discover new ways to write about global change to build audience understanding and engagement
  • Cultivate new sources by interacting with leading researchers and policy experts in an informal, off-deadline atmosphere
  • Network and develop lasting relationships with journalists from around the globe

Metcalf Alumni
Metcalf Institute has helped nearly 900 journalists cover the environment with greater accuracy and nuance since its first program in 1999. Metcalf alumni represent all media types and a wide variety of large and small news organizations ranging from local and regional newspapers and broadcast outlets to online and national/international outlets such as the Los Angeles Times, Reuters, National Geographic, China Global Television Network, Marketplace, Politico and PBS NewsHour. Metcalf Institute alumni hail from the U.S. and around the world, including Pakistan, Brazil, Nigeria, Israel, Egypt, Italy, South Africa, and China.

“This experience has changed my entire outlook on covering the environment and climate science. I may have only been in Rhode Island for a week, but the tools I gained during my Metcalf fellowship will stay with me for the entirety of my career.” Tony Briscoe, Chicago Tribune reporter and 2018 Annual Workshop alumnus.
                                                    
“Metcalf has greatly enhanced my ability to break down complex issues for my audience. Not only am I headed back home with a bunch of great story ideas, but the ability to set them against an international background and draw broader connections between issues in my region and the rest of the world.” Tegan Wendland, New Orleans Public Radio interim news director, lead coastal reporter, and 2017 Annual Workshop alumna.

Note for journalists applying from outside of the U.S.
While the Workshop addresses environmental topics of global significance, it focuses on U.S. case studies and a U.S. perspective on environmental policies. Metcalf Institute receives applications from journalists worldwide. However, due to funding limitations, only two of the ten fellowships will be awarded to journalists based outside of the U.S.

Eligibility
The Fellowship is designed for early- to mid-career, full-time journalists from all media who are looking to start or expand their coverage of the environment. Applicants must demonstrate a clear need for scientific training in topics relating to global change in coastal environments, specifically related to climate change and water resources. The fellowship includes room, board, tuition, and travel reimbursement paid after the program in the amount of up to US$500 for U.S.-based journalists and up to US$1,000 for journalists based outside of the U.S. Journalists applying from outside the U.S. must provide written assurance that they have full travel funds and can obtain the appropriate visa. Applications for the 2019 Annual Science Immersion Workshop for Journalists must be submitted by February 18, 2019.

Apply for the Workshop here.

About Metcalf Institute
Metcalf Institute is a global leader in environmental science training for journalists and communication training for scientists and other science communicators, as well as provider of science resources for journalists and free public programs and webinars on environmental topics. Metcalf Institute was established at the University of Rhode Island’s Graduate School of Oceanography in 1997 with funding from three media foundations: the Belo Corporation, the Providence Journal Charitable Foundation and the Philip L. Graham Fund, with additional support from the Telaka Foundation. In 2017, the Institute joined the URI College of the Environment and Life Sciences.

Metcalf Institute Funding
Metcalf programming is underwritten by federal and foundation grants, as well as donations from individuals and an endowment managed by the University of Rhode Island Foundation.

I headed off to the Metcalf Institute Fellowship application webpage and decided to include a few details here,

Email Stamp/Postmark Deadline: February 18, 2019

This application has two parts – an online form and a set of required inclusions. Read thoroughly before applying for the workshop below.

Application packages (online form and required enclosures together) will be used to evaluate applicants. Any hard copies of application materials will not be returned.

All application forms and required enclosures must be submitted in English. Application packages in languages other than English will not be reviewed.

Application packages that are not complete by midnight, U.S. Eastern Time, on February 18, 2019, will not be reviewed. …

Good luck!

Sound-absorbing nanofoam

In these increasingly noisy days (there’s construction going on around me), news of a cheaper, easier way to dull the noise is very attractive. From a June 25, 2018 Far Eastern Federal University (Russia) press release on EurekAlert,

The breakthrough material reduces a noise level by 100% more efficient comparing to standard analogs, cutting the level of noise transmission by 20-22 dB. The new foam reacts to sound waves not only of high but also of low frequencies, which can damage human health. A young scientist from the Far Eastern Federal University (FEFU) took part in the development.

PARTNERSHIP DEVELOPMENT

Alexey Zavjalov, postdoc, researcher at the Academic Department of Nuclear Technologies School of Natural Science, FEFU, worked as a part of the international team of Russian and South Korean scientists under professor S.P. Bardakhanov. Alexey’s research performance led to the creation of nanofoam – the new noise-absorbing composite material. The results of the work are published in ‘Applied Acoustics’.

‘The problem of noise is the problem of modern technogenic civilization. In South Korea, cities are equipped with round-the-clock working stationary and mobile networks for noise levels monitoring. The urbanization level of such territorially small countries as South Korea is much higher than in Russia. However, in our country this problem is still crucial for big cities,’ – explained Alexey Zavjalov. – ‘The development of new noise-absorbing materials is especially interesting for the automotive industry. Modern people spend a lot of time driving cars and the noise level inside the vehicles’ directly determines the quality of life. For East Asian countries, the issue of noise control is relevant for high-speed rail lines.’ Porous materials are excellent sound absorbers but their noise-absorbing properties can be significantly enhanced by nanoporous grit injected into the foam structure and formed internal channels in it. Alexey Zavjalov has developed approaches for saturation of macroporous foam material with nanoporous grit.

HARMFULNESS OF THE LOW FREQUENCIES NOISES.

Along with the rapid development of nanotechnology, there have been many attempts to mix nano- and microsized materials to create a modified material with enhanced strength, elastic, dynamical and vibrational properties. The acoustic parameters of such materials could not be fundamentally enhanced thus far.

Foam materials are most often used for soundproofing purposes. They provide the proper quality at a reasonable cost, but until today have been effective against high-frequency noise only. At the same time, low frequencies can be much more harmful to human health.

Infra- and low-frequency vibrations and noise (less than 0.4 kHz) are most harmful and dangerous for human health and life. Especially unfavorable is their long-lasting impact, since leads to serious diseases and pathologies. Complaints on such oppressions exceed 35% of the sum total of complaints on harmful environmental conditions.

The foam material, developed by Russian and Korean scientists, demonstrated promising results at medium frequencies and, therefore, more specialized low-frequency noise tests are needed.

CHEAPER AND EASIER FOR APPLICATION THAN AEROGEL.

The improved acoustic characteristics of the newest hybrid nanofoam were obtained by additional impregnation of the standard off-the-shelf sound-absorbing foam with porous granules of silica and magnetite nanoparticles. The porous foam was immersed in nanopowder suspensions in the liquid, subjected to ultrasonic treatment and dried.

The nanoparticles granules formed in the result can be compared structurally to a widely known class of materials – aerogel. It has not only excellent thermal insulation properties but also has a good noise-proof. However, aerogels are quite expensive and complex when used in structures. The new material, created according to the scheme developed by the FEFU researcher, is structurally similar to aerogel but is free of such shortcomings as a high price and engineering problems.

COMPOSITE TECHNOLOGY

The mechanism of sound absorption of a new foam is based on the fact that its sound-absorbing surface is significantly scaled due to the presence of a large number of nanopores in the particles injected, as well as the location of these particles in the foam matrix in the form of distinct channels. Nanoparticles dissipate the energy of a sound wave transforming it into heat. The soundproof properties of the material increase.

Scientists found out that the composite structure is most effective for noise reduction. Thin layers of foam impregnated with nanoparticles are connected to each other in a “sandwich”-construction. This design significantly improves the soundproof properties of the resulting material. The outcome of the study also suggests that the more foamy material is impregnated with nanoparticles, the better it’s sound absorption is.

‘In some approximation, any material can be represented as a network of weights connected by springs. Such a mechanical system always has its own frequency bands, in which the oscillations propagate in the system relatively freely. There are also forbidden frequency bands in which the oscillations rapidly fade out in the system. To effectively extinguish the transmission of oscillations, including sound waves, the materials should be alternated in such a way that the fluctuations that propagate freely in the first material would be in the forbidden band for the second layer,’- commented Alexey Zavjalov. – ‘Of course, for our foam material, this idealization is too crude. However, it allows us to clearly illustrate the fundamentally conditioned necessity of creating a “sandwich” structure.’

RESEARCH OUTCOME

The study showed the effectiveness of the method of foams impregnation with nanosilica or nanomagnetite, which form granules up to several hundred micrometers (in accordance with the pore sizes of the modified foam material) and having pores about 15 nm. This small addition provided a more complex and branched 3D network of nanochannels which led to an additional absorption of noise energy.

Due to the method used, the noise absorption efficiency was achieved in the range of 2.0-6.3 kHz and at lower frequencies 0.5-1.6 kHz. The degree of absorption was increased by 60-100% and the sound transmission was reduced by 20-22 dB, regardless of the type of nanofiller.

‘There is room to further improve the sound absorbing properties of the new material for medium and low frequencies using the” active control” strategy’. – Alexey Zavjalov comments on the plans for further development of such an important scientific topic. – ‘First of all, this refers to the materials obtained by using a magnetite nanopowder. Active noise protection systems have long been used in the world. The main idea is to detect the noise acoustic fields “online” and to generate sound waves in antiphase by means of loudspeakers. That allows achieving a significant reduction of noise in a given area. Concerning the nanofoam, it’s proposed to adapt this approach and to actively exert on a material saturated with granules of magnetite nanoparticles by magnetic fields. This will achieve even better noise reduction.’

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

Hybrid sound-absorbing foam materials with nanostructured grit-impregnated pores by S.P.Bardakhanov, C.M.Lee, V.N.Goverdovskiy, A.P.Zavjalov, K.V.Zobov, M.Chen, Z.H.Xu, I.K.Chakin, D.Yu.Trufanov. Applied Acoustics Volume 139, October 2018, Pages 69-74
https://doi.org/10.1016/j.apacoust.2018.04.024 Available online 23 April 2018.

This paper is behind a paywall.

If you have difficulty seeing the press release on EurekAlert, there is a June 26, 2018 news item on a Russian news site, RSF News and there is an edited version in a June 26, 2018 news item on Azonano.

Chinese scientists strike gold in plant tissues

I have heard of phytomining in soil remediation efforts (reclaiming nanoscale metals in plants near mining operations; you can find a more detailed definition here at Wiktionary) but, in this case, scientists have discovered plant tissues with nanoscale gold in an area which has no known deposits of gold. From a June 14, 2018 news item on Nanowwerk (Note: A link has been removed),

Plants containing the element gold are already widely known. The flowering perennial plant alfafa, for example, has been cultivated by scientists to contain pure gold in its plant tissue. Now researchers from the Sun Yat-sen University in China have identified and investigated the characteristics of gold nanoparticles in two plant species growing in their natural environments.

The study, led by Xiaoen Luo, is published in Environmental Chemistry Letters (“Discovery of nano-sized gold particles in natural plant tissues”) and has implications for the way gold nanoparticles are produced and absorbed from the environment.

A June 14, 2018 Springer Publications press release, which originated the news item, delves further and proposes a solution to the mystery,

Xiaoen Luo and her colleagues investigated the perennial shrub B. nivea and the annual or biennial weed Erigeron Canadensis. The researchers collected and prepared samples of both plants so that they could be examined using the specialist analytical tool called field-emission transmission electron microscope (TEM).

Gold-bearing nanoparticles – tiny gold particles fused with another element such as oxygen or copper – were found in both types of plant. In E. Canadensis these particles were around 20-50 nm in diameter and had an irregular form. The gold-bearing particles in B. nivea were circular, elliptical or bone-rod shaped with smooth edges and were 5-15 nm.

“The abundance of gold in the crust is very low and there was no metal deposit in the sampling area so we speculate that the source of these gold nanoparticles is a nearby electroplating plant that uses gold in its operations, “ explains Jianjin Cao who is a co-author of the study.

Most of the characteristics of the nanoparticles matched those of artificial particles rather than naturally occurring nanoparticles, which would support this theory. The researchers believe that the gold-bearing particles were absorbed through the pores of the plants directly, indicating that gold could be accumulated from the soil, water or air.

“Discovering gold-bearing nanoparticles in natural plant tissues is of great significance and allows new possibilities to clean up areas contaminated with nanoparticles, and also to enrich gold nanoparticles using plants,” says Xiaoen Luo.

The researchers plan to further study the migration mechanism, storage locations and growth patterns of gold nanoparticles in plants and also verify the absorbing capacity of different plants for gold nanoparticles in polluted areas.

For anyone who’d like to find out more about electroplating, there’s this January 25, 2018 article by Anne Marie Helmenstine for ThoughtCo.

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

Discovery of nano-sized gold particles in natural plant tissues by Xiaoen Luo (Luo, X.) and Jianjin Cao (Cao, J.). Environ Chem Lett (2018) pp 1–8 https://doi.org/10.1007/s10311-018-0749-0 First published online 14 June 2018

This paper appears to be open access.

New semiconductor material from pigment produced by fungi?

Chlorociboria Aeruginascens fungus on a tree log. (Image: Oregon State University)

Apparently the pigment derived from the fungi you see in the above picture is used by visual artists and, perhaps soon, will be used by electronics manufacturers. From a June 5, 2018 news item on Nanowerk,

Researchers at Oregon State University are looking at a highly durable organic pigment, used by humans in artwork for hundreds of years, as a promising possibility as a semiconductor material.

Findings suggest it could become a sustainable, low-cost, easily fabricated alternative to silicon in electronic or optoelectronic applications where the high-performance capabilities of silicon aren’t required.

Optoelectronics is technology working with the combined use of light and electronics, such as solar cells, and the pigment being studied is xylindein.

A June 5, 2018 Oregon State University news release by Steve Lundeberg, which originated the news item, expands on the theme,

“Xylindein is pretty, but can it also be useful? How much can we squeeze out of it?” said Oregon State University [OSU] physicist Oksana Ostroverkhova. “It functions as an electronic material but not a great one, but there’s optimism we can make it better.”

Xylindien is secreted by two wood-eating fungi in the Chlorociboria genus. Any wood that’s infected by the fungi is stained a blue-green color, and artisans have prized xylindein-affected wood for centuries.

The pigment is so stable that decorative products made half a millennium ago still exhibit its distinctive hue. It holds up against prolonged exposure to heat, ultraviolet light and electrical stress.

“If we can learn the secret for why those fungi-produced pigments are so stable, we could solve a problem that exists with organic electronics,” Ostroverkhova said. “Also, many organic electronic materials are too expensive to produce, so we’re looking to do something inexpensively in an ecologically friendly way that’s good for the economy.”

With current fabrication techniques, xylindein tends to form non-uniform films with a porous, irregular, “rocky” structure.

“There’s a lot of performance variation,” she said. “You can tinker with it in the lab, but you can’t really make a technologically relevant device out of it on a large scale. But we found a way to make it more easily processed and to get a decent film quality.”

Ostroverkhova and collaborators in OSU’s colleges of Science and Forestry blended xylindein with a transparent, non-conductive polymer, poly(methyl methacrylate), abbreviated to PMMA and sometimes known as acrylic glass. They drop-cast solutions both of pristine xylindein and a xlyindein-PMMA blend onto electrodes on a glass substrate for testing.

They found the non-conducting polymer greatly improved the film structure without a detrimental effect on xylindein’s electrical properties. And the blended films actually showed better photosensitivity.

“Exactly why that happened, and its potential value in solar cells, is something we’ll be investigating in future research,” Ostroverkhova said. “We’ll also look into replacing the polymer with a natural product – something sustainable made from cellulose. We could grow the pigment from the cellulose and be able to make a device that’s all ready to go.

“Xylindein will never beat silicon, but for many applications, it doesn’t need to beat silicon,” she said. “It could work well for depositing onto large, flexible substrates, like for making wearable electronics.”

This research, whose findings were recently published in MRS Advances, represents the first use of a fungus-produced material in a thin-film electrical device.

“And there are a lot more of the materials,” Ostroverkhova said. “This is just first one we’ve explored. It could be the beginning of a whole new class of organic electronic materials.”

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

Fungi-Derived Pigments for Sustainable Organic (Opto)Electronics by Gregory Giesbers, Jonathan Van Schenck, Sarath Vega Gutierrez, Sara Robinson. MRS Advances https://doi.org/10.1557/adv.2018.446 Published online: 21 May 2018

This paper is behind a paywall.

Nanoplastics accumulating in marine organisms

I’m starting to have a collection of postings related to plastic nanoparticles and aquatic life (I have a listing below). The latest originates in Singapore (from a May 31, 2018 news item on ScienceDaily),

Plastic nanoparticles — these are tiny pieces of plastic less than 1 micrometre in size — could potentially contaminate food chains, and ultimately affect human health, according to a recent study by scientists from the National University of Singapore (NUS). They discovered that nanoplastics are easily ingested by marine organisms, and they accumulate in the organisms over time, with a risk of being transferred up the food chain, threatening food safety and posing health risks.

A May 31, 2018 NUS press release (also on EurekAlert), which originated the news item, expands on the theme,

Ocean plastic pollution is a huge and growing global problem. It is estimated that the oceans may already contain over 150 million tonnes of plastic, and each year, about eight million tonnes of plastic will end up in the ocean. Plastics do not degrade easily. In the marine environment, plastics are usually broken down into smaller pieces by the sun, waves, wind and microbial action. These micro- and nanoplastic particles in the water may be ingested by filter-feeding marine organisms such as barnacles, tube worms and sea-squirts.

Using the acorn barnacle Amphibalanus amphitrite as a model organism, the NUS research team demonstrated for the first time that nanoplastics consumed during the larval stage are retained and accumulated inside the barnacle larvae until they reach adulthood.

“We opted to study acorn barnacles as their short life cycle and transparent bodies made it easy to track and visualise the movement of nanoplastics in their bodies within a short span of time,” said Mr Samarth Bhargava, a PhD student from the Department of Chemistry at the NUS Faculty of Science, who is the first author of the research paper.

“Barnacles can be found in all of the world’s oceans. This accumulation of nanoplastics within the barnacles is of concern. Further work is needed to better understand how they may contribute to longer term effects on marine ecosystems,” said Dr Serena Teo, Senior Research Fellow from the Tropical Marine Science Institute at NUS, who co-supervised the research.

Studying the fate of nanoplastics in marine organisms

The NUS research team incubated the barnacle larvae in solutions of their regular feed coupled with plastics that are about 200 nanometres in size with green fluorescent tags. The larvae were exposed to two different treatments: ‘acute’ and ‘chronic’.

Under the ‘acute’ treatment, the barnacle larvae were kept for three hours in a solution that contained 25 times more nanoplastics than current estimates of what is present in the oceans. On the other hand, under the ‘chronic’ treatment, the barnacle larvae were exposed to a solution containing low concentrations of nanoplastics for up to four days.

The larvae were subsequently filtered from the solution, and examined under the microscope. The distribution and movement of the nanoplastics were monitored by examining the fluorescence from the particles present within the larvae over time.

“Our results showed that after exposing the barnacle larvae to nanoplastics in both treatments, the larvae had not only ingested the plastic particles, but the tiny particles were found to be distributed throughout the bodies of the larvae,” said Ms Serina Lee from the Tropical Marine Science Institute at NUS, who is the second author of the paper.

Even though the barnacles’ natural waste removal pathways of moulting and excretion resulted in some removal of the nanoplastics, the team detected the continued presence of nanoplastics inside the barnacles throughout their growth until they reached adulthood.

“Barnacles may be at the lower levels of the food chain, but what they consume will be transferred to the organisms that eat them. In addition, plastics are capable of absorbing pollutants and chemicals from the water. These toxins may be transferred to the organisms if the particles of plastics are consumed, and can cause further damage to marine ecosystems and human health,” said marine biologist Dr Neo Mei Lin from the Tropical Marine Science Institute at NUS, who is one of the authors of the paper.

The team’s research findings were first published online in the journal ACS Sustainable Chemistry & Engineering in March 2018. The study was funded under the Marine Science Research and Development Programme of the National Research Foundation Singapore.

Next steps

The NUS research team seeks to further their understanding of the translocation of nanoparticles within the marine organisms and potential pathways of transfer in the marine ecosystem.

“The life span and fate of plastic waste materials in marine environment is a big concern at the moment owing to the large amounts of plastic waste and its potential impact on marine ecosystem and food security around the world. The team would like to explore such topics in the near future and possibly to come up with pathways to address such problems,” explained Associate Professor Suresh Valiyaveettil from the Department of Chemistry at the NUS Faculty of Science, who co-supervised the research.

The team is currently examining how nanoplastics affect other invertebrate model organisms to understand the impact of plastics on marine ecosystems.

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

Fate of Nanoplastics in Marine Larvae: A Case Study Using Barnacles, Amphibalanus amphitrite by Samarth Bhargava, Serina Siew Chen Lee, Lynette Shu Min Ying, Mei Lin Neo, Serena Lay-Ming Teo, and Suresh Valiyaveettil. ACS Sustainable Chem. Eng., 2018, 6 (5), pp 6932–6940 DOI: 10.1021/acssuschemeng.8b00766 Publication Date (Web): March 21, 2018

Copyright © 2018 American Chemical Society

This paper is behind a paywall.

Other plastic nanoparticle postings:

While this doesn’t relate directly to aquatic life, the research focuses on how plastic degrades into plastic nanoparticles,

That’s it for now.

All-natural agrochemicals

Michael Berger in his May 4, 2018 Nanowerk Spotlight article highlights research into creating all natural agrochemicals,

Widespread use of synthetic agrochemicals in crop protection has led to serious concerns of environmental contamination and increased resistance in plant-based pathogenic microbes.

In an effort to develop bio-based and non-synthetic alternatives, nanobiotechnology researchers are looking to plants that possess natural antimicrobial properties.

Thymol, an essential oil component of thyme, is such a plant and known for its antimicrobial activity. However, it has low water solubility, which reduces its biological activity and limits its application through aqueous medium. In addition, thymol is physically and chemically unstable in the presence of oxygen, light and temperature, which drastically reduces its effectiveness.

Scientists in India have overcome these obstacles by preparing thymol nanoemulsions where thymol is converted into nanoscale droplets using a plant-based surfactant known as saponin (a glycoside of the Quillaja tree). Due to this encapsulation, thymol becomes physically and chemically stable in the aqueous medium (the emulsion remained stable for three months).

In their work, the researchers show that nanoscale thymol’s antibacterial and antifungal properties not only prevent plant disease but that it also enhances plant growth.

“It is exciting how nanoscale thymol is more active,” says Saharan [Dr. Vinod Saharan from the Nano Research Facility Lab, Department of Molecular Biology and Biotechnology, at Maharana Pratap University of Agriculture and Technology], who led this work in collaboration with Washington University in St. Louis and Haryana Agricultural University, Hisar. “We found that nanoscale droplets of thymol can easily pass through the surfaces of bacteria, fungi and plants and exhibit much faster and strong activity. In addition nanodroplets of thymol have a larger surface area, i.e. more molecules on the surface, so thymol becomes more active at the target sites.”

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

Thymol nanoemulsion exhibits potential antibacterial activity against bacterial pustule disease and growth promotory effect on soybean by Sarita Kumari, R. V. Kumaraswamy, Ram Chandra Choudhary, S. S. Sharma, Ajay Pal, Ramesh Raliya, Pratim Biswas, & Vinod Saharan. Scientific Reportsvolume 8, Article number: 6650 (2018) doi:10.1038/s41598-018-24871-5 Published: 27 April 2018

This paper is open access.

Final note

There is a Canadian company which specialises in nanoscale products for the agricultural sector, Vive Crop Protection. I don’t believe they claim their products are ‘green’ but due to the smaller quantities needed of Vive Crop Protection’s products, the environmental impact is less than that of traditional agrochemicals.

‘Green’ concrete with graphene

It’s thrilling and I hope they are able to commercialize this technology which makes concrete ‘greener’. From an April 23, 2018 news item on ScienceDaily,

A new greener, stronger and more durable concrete that is made using the wonder-material graphene could revolutionise the construction industry.

Experts from the University of Exeter [UK] have developed a pioneering new technique that uses nanoengineering technology to incorporate graphene into traditional concrete production.

The new composite material, which is more than twice as strong and four times more water resistant than existing concretes, can be used directly by the construction industry on building sites. All of the concrete samples tested are according to British and European standards for construction.

Crucially, the new graphene-reinforced concentre material also drastically reduced the carbon footprint of conventional concrete production methods, making it more sustainable and environmentally friendly.

The research team insist the new technique could pave the way for other nanomaterials to be incorporated into concrete, and so further modernise the construction industry worldwide.

I love the image they’ve included with the press materials (if they hadn’t told me I wouldn’t know that this is the ‘new’ concrete; to me, it looks just like the other stuff),

Caption: The new concrete developed using graphene by experts from the University of Exeter (credit: Dimitar Dimov / University of Exeter) Credit: Dimitar Dimov / University of Exeter

An April 23, 2018 University of Exeter press release (also on EurekAlert), which originated the news item,  provides more details about the work, future applications, and its potential impact,

Professor Monica Craciun, co-author of the paper and from Exeter’s engineering department, said: “Our cities face a growing pressure from global challenges on pollution, sustainable urbanization and resilience to catastrophic natural events, amongst others.

“This new composite material is an absolute game-changer in terms of reinforcing traditional concrete to meets these needs. Not only is it stronger and more durable, but it is also more resistant to water, making it uniquely suitable for construction in areas which require maintenance work and are difficult to be accessed .

“Yet perhaps more importantly, by including graphene we can reduce the amount of materials required to make concrete by around 50 per cent — leading to a significant reduction of 446kg/tonne of the carbon emissions.

“This unprecedented range of functionalities and properties uncovered are an important step in encouraging a more sustainable, environmentally-friendly construction industry worldwide.”

Previous work on using nanotechnology has concentrated on modifying existing components of cement, one of the main elements of concrete production.

In the innovative new study, the research team has created a new technique that centres on suspending atomically thin graphene in water with high yield and no defects, low cost and compatible with modern, large scale manufacturing requirements.

Dimitar Dimov, the lead author and also from the University of Exeter added: “This ground-breaking research is important as it can be applied to large-scale manufacturing and construction. The industry has to be modernised by incorporating not only off-site manufacturing, but innovative new materials as well.

“Finding greener ways to build is a crucial step forward in reducing carbon emissions around the world and so help protect our environment as much as possible. It is the first step, but a crucial step in the right direction to make a more sustainable construction industry for the future.”

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

Ultrahigh Performance Nanoengineered Graphene–Concrete Composites for Multifunctional Applications by Dimitar Dimov, Iddo Amit, Olivier Gorrie, Matthew D. Barnes, Nicola J. Townsend, Ana I. S. Neves, Freddie Withers, Saverio Russo, and Monica Felicia Craciun. Advanced Functional Materials https://doi.org/10.1002/adfm.201705183 First published: 23 April 2018

This paper is open access.

View Dynamic Glass—intelligent windows sold commercially

At last, commercially available ‘smart’, that is, electrochromic windows.

An April 17, 2018 article by Conor Shine for Dallas News describes a change at the Dallas Fort Worth (DFW) International Airport that has cooled things down,

At DFW International Airport, the coolest seats in the house can be found near Gate A28.

That’s where the airport, working with California-based technology company View, has replaced a bank of tarmac-facing windows with panes coated in microscopic layers of electrochromic ceramic that significantly reduce the amount of heat and glare coming into the terminal.

The technology, referred to as dynamic glass, uses an electrical current to change how much light is let in and has been shown to reduce surface temperatures on gate area seats and carpets by as much as 15 degrees compared to standard windows. All that heat savings add up, with View estimating its product can cut energy costs by as much as 20 percent when the technology is deployed widely in a building.

At DFW Airport, the energy bill runs about $18 million per year, putting the potential savings from dynamic glass into the hundreds of thousands, or even millions of dollars, annually.

Besides the money, it’s an appealing set of characteristics for DFW Airport, which is North America’s only carbon-neutral airport and regularly ranks among the top large airports for customer experience in the world.

After installing the dynamic glass near Gate A28 and a nearby Twisted Root restaurant in September at a cost of $49,000, the airport is now looking at ordering more for use throughout its terminals, although how many and at what cost hasn’t been finalized yet.

On a recent weekday morning, the impact of the dynamic glass was on full display. As sunlight beamed into Gate A25, passengers largely avoided the seats near the standard windows, favoring shadier spots a bit further into the terminal.

A few feet away, the bright natural light takes on a subtle blue hue and the temperature near the windows is noticeably cooler. There, passengers seemed to pay no mind to sitting in the sun, with window-adjacent seats filling up quickly.

As View’s Jeff Platón, the company’s vice president of marketing, notes in the video, there are considerable savings to be had when you cut down on air conditioning,

View’s April 17, 2018 news release (PDF) about a study of their technology in use at the airport provides more detail,

View®, the leader in dynamic glass, today announced the results of a study on the impact of in-terminal passenger experience and its correlation to higher revenues and reduced operational expenses.The study, conducted at Dallas Fort Worth International Airport (DFW), found that terminal windows fitted with View Dynamic Glass overwhelmingly improved passenger comfort over conventional glass, resulting in an 83 percent increase in passenger dwell time at a preferred gate seat and a 102 percent increase in concession spending. The research study was conducted by DFW Airport, View, Inc., and an independent aviation market research group.

It’s been a long time (I’ve been waiting about 10 years) but it seems that commercially available ‘smart’ glass is here—at the airport, anyway.

ht/ April 20, 2018 news item on phys.org

Clean up oil spills (on water and/or land) with oil-eating bacterium

Quebec’s Institut national de la recherche scientifique (INRS) announced an environmentally friendly way of cleaning up oil spills in an April 9, 2018 news item on ScienceDaily,

From pipelines to tankers, oil spills and their impact on the environment are a source of concern. These disasters occur on a regular basis, leading to messy decontamination challenges that require massive investments of time and resources. But however widespread and serious the damage may be, the solution could be microscopic — Alcanivorax borkumensis — a bacterium that feeds on hydrocarbons. Professor Satinder Kaur Brar and her team at INRS have conducted laboratory tests that show the effectiveness of enzymes produced by the bacterium in degrading petroleum products in soil and water. Their results offer hope for a simple, effective, and eco-friendly method of decontaminating water and soil at oil sites.

An April 8, 2018 INRS news release by Stephanie Thibaut, which originated the news item, expands on the theme,

In recent years, researchers have sequenced the genomes of thousands of bacteria from various sources. Research associate Dr.Tarek Rouissi poured over “technical data sheets” for many bacterial strains with the aim of finding the perfect candidate for a dirty job: cleaning up oil spills. He focused on the enzymes they produce and the conditions in which they evolve.

A. borkumensis, a non-pathogenic marine bacterium piqued his curiosity. The microorganism’s genome contains the codes of a number of interesting enzymes and it is classified as “hydrocarbonoclastic”—i.e., as a bacterium that uses hydrocarbons as a source of energy. A. borkumensis is present in all oceans and drifts with the current, multiplying rapidly in areas where the concentration of oil compounds is high, which partly explains the natural degradation observed after some spills. But its remedial potential had not been assessed.

“I had a hunch,” Rouissi said, “and the characterization of the enzymes produced by the bacterium seems to have proven me right!” A. borkumensis boasts an impressive set of tools: during its evolution, it has accumulated a range of very specific enzymes that degrade almost everything found in oil. Among these enzymes, the bacteria’shydroxylases stand out from the ones found in other species: they are far more effective, in addition to being more versatile and resistant to chemical conditions, as tested in coordination by a Ph.D. student, Ms. Tayssir Kadri.

To test the microscopic cleaner, the research team purified a few of the enzymes and used them to treat samples of contaminated soil. “The degradation of hydrocarbons using the crude enzyme extract is really encouraging and reached over 80% for various compounds,” said Brar. The process is effective in removing benzene, toluene, and xylene, and has been tested under a number of different conditions to show that it is a powerful way to clean up polluted land and marine environments.”

The next steps for Brar’s team are to find out more about how these bacteria metabolize hydrocarbons and explore their potential for decontaminating sites. One of the advantages of the approach developed at INRS is its application in difficult-to-access environments, which present a major challenge during oil spill cleanup efforts.

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

Ex-situ biodegradation of petroleum hydrocarbons using Alcanivorax borkumensis enzymes by Tayssir Kadri, Sara Magdouli, Tarek Rouissi, Satinder Kaur Brar. Biochemical Engineering Journal Volume 132, 15 April 2018, Pages 279-287 DOI: https://doi.org/10.1016/j.bej.2018.01.014

This paper is behind a paywall.

In light of this research, it seems remiss not to mention the recent setback for Canada’s Trans Mountain pipeline expansion. Canada’s Federal Court of Appeal quashed the approval as per this August 30, 2018 news item on canadanews.org. There were two reasons for the quashing (1) a failure to properly consult with indigenous people and (2) a failure to adequately assess environmental impacts on marine life. Interestingly, no one ever mentions environmental cleanups and remediation, which could be very important if my current suspicions regarding the outcome for the next federal election are correct.

Regardless of which party forms the Canadian government after the 2019 federal election, I believe that either Liberals or Conservatives would be equally dedicated to bringing this pipeline to the West Coast. The only possibility I can see of a change lies in a potential minority government is formed by a coalition including the NDP (New Democratic Party) and/or the Green Party; an outcome that seems improbable at this juncture.

Given what I believe to be the political will regarding the Trans Mountain pipeline, I would dearly love to see more support for better cleanup and remediation measures.