A supercapacitor is not a battery but it does have some similarities. (For the ‘seaweed curious’, there’s this somewhat related May 17, 2017 posting titled “Seaweed supercapacitors.” It doesn’t seem to be quite as popular as butterfly wings or a crustacean’s shell but seaweed does seem to have a following in the materials community. From an October 5, 2022 news item on Nanowerk,
Bristol-led team uses nanomaterials made from seaweed to create a strong battery separator, paving the way for greener and more efficient energy storage.
Sodium-metal batteries (SMBs) are one of the most promising high-energy and low-cost energy storage systems for the next-generation of large-scale applications. However, one of the major impediments to the development of SMBs is uncontrolled dendrite growth, which penetrate the battery’s separator and result in short-circuiting.
Building on previous work at the University of Bristol and in collaboration with Imperial College and University College London, the team has succeeded in making a separator from cellulose nanomaterials derived from brown seaweed.
The research, published in Advanced Materials, describes how fibres containing these seaweed-derived nanomaterials not only stop crystals from the sodium electrodes penetrating the separator, they also improve the performance of the batteries.
“The aim of a separator is to separate the functioning parts of a battery (the plus and the minus ends) and allow free transport of the charge. We have shown that seaweed-based materials can make the separator very strong and prevent it being punctured by metal structures made from sodium. It also allows for greater storage capacity and efficiency, increasing the lifetime of the batteries – something which is key to powering devices such as mobile phones for much longer,” said Jing Wang, first author and PhD student in the Bristol Composites Institute (BCI).
Dr Amaka Onyianta, also from the BCI, who created the cellulose nanomaterials and co-authored the research, said: “I was delighted to see that these nanomaterials are able to strengthen the separator materials and enhance our capability to move towards sodium-based batteries. This means we wouldn’t have to rely on scarce materials such as lithium, which is often mined unethically and uses a great deal of natural resources, such as water, to extract it.”
“This work really demonstrates that greener forms of energy storage are possible, without being destructive to the environment in their production,” said Professor Steve Eichhorn who led the research at the Bristol Composites Institute.
The next challenge is to upscale production of these materials and to supplant current lithium-based technology.
It is a staple of science fiction to mock sutures as outdated. The technique has, after all, been in use for at least 5,000 years. Surely medicine should have advanced since ancient Egypt. Professor Hossam Haick from the Wolfson Department of Chemical Engineering at the Technion has finally turned science fiction into reality. His lab succeeded in creating a smart sutureless dressing that binds the wound together, wards off infection, and reports on the wound’s condition directly to the doctors’ computers. Their study was published in Advanced Materials.
Current surgical procedures entail the surgeon cutting the human body, doing what needs to be done, and sewing the wound shut – an invasive procedure that damages surrounding healthy tissue. Some sutures degrade by themselves – or should degrade – as the wound heals. Others need to be manually removed. Dressing is then applied over the wound and medical personnel monitor the wound by removing the dressing to allow observation for signs of infection like swelling, redness, and heat. This procedure is painful to the patient, and disruptive to healing, but it is unavoidable. Working with these methods also mean that infection is often discovered late, since it takes time for visible signs to appear, and more time for the inspection to come round and see them. In developed countries, with good sanitation available, about 20% of patients develop infections post-surgery, necessitating additional treatment and extending the time to recovery. The figure and consequences are much worse in developing countries.
How will it work with Prof. Haick’s new dressing?
Prior to beginning a procedure, the dressing – which is very much like a smart band-aid – developed by Prof. Haick’s lab will be applied to the site of the planned incision. The incision will then be made through it. Following the surgery, the two ends of the wound will be brought together, and within three seconds the dressing will bind itself together, holding the wound closed, similarly to sutures. From then, the dressing will be continuously monitoring the wound, tracking the healing process, checking for signs of infection like changes in temperature, pH, and glucose levels, and report to the medical personnel’s smartphones or other devices. The dressing will also itself release antibiotics onto the wound area, preventing infection.
“I was watching a movie on futuristic robotics with my kids late one night,” said Prof. Haick, “and I thought, what if we could really make self-repairing sensors?”
Most people discard their late-night cinema-inspired ideas. Not Prof. Haick, who, the very next day after his Eureka moment, was researching and making plans. The first publication about a self-healing sensor came in 2015 (read more about it on the Technion website here). At that time, the sensor needed almost 24 hours to repair itself. By 2020, sensors were healing in under a minute (read about the study by Muhammad Khatib, a student in Prof. Haick’s lab here), but while it had multiple applications, it was not yet biocompatible, that is, not usable in contact with skin and blood. Creating a polymer that would be both biocompatible and self-healing was the next step, and one that was achieved by postdoctoral fellow Dr. Ning Tang.
The new polymer is structured like a molecular zipper, made from sulfur and nitrogen: the surgeon’s scalpel opens it; then pressed together, it closes and holds fast. Integrated carbon nanotubes provide electric conductivity and the integration of the sensor array. In experiments, wounds closed with the smart dressing healed as fast as those closed with sutures and showed reduced rates of infection.
“It’s a new approach to wound treatment,” said Prof. Haick. “We introduce the advances of the fourth industrial revolution – smart interconnected devices, into the day-to-day treatment of patients.”
Prof. Haick is the head of the Laboratory for Nanomaterial-based Devices (LNBD) and the Dean of Undergraduate Studies at the Technion. Dr. Ning Tang was a postdoctoral fellow in Prof. Haick’s laboratory and conducted this study as part of his fellowship. He has now been appointed an associate professor in Shanghai Jiao Tong University.
I usually like to have three links to a news/press release and in my searches for a third source for this press release, I stumbled onto the technioncanada.org website. They seemed to have scooped everyone including Technion as they have a November 25, 2021posting of the press release.
On a practical level, it’s becoming clear that we need to become more thoughtful about our use of water. We here in Canada tend to take our water for granted, as if we have an inexhaustible supply. According to this August 21, 2008 CBC (Canadian Broadcasting Corporation) online news item, that’s not the case,
Canada’s stores of fresh water are not as plentiful as once thought, and threaten to pinch the economy and pit provinces against each other, a federal document says.
An internal report drafted last December [2007] by Environment Canada warns that climate change and a growing population will further drain resources.
“We can no longer take our extensive water supplies for granted,” says the report, titled A Federal Perspective on Water Quantity Issues.
The Canadian Press obtained the 21-page draft report under the Access to Information Act.
It suggests the federal government take a more hands-on role in managing the country’s water, which is now largely done by the provinces. Ottawa still manages most of the fresh water in the North through water boards.
The Conservatives promised a national water strategy in last fall’s throne speech but have been criticized since for announcing only piecemeal projects.
The Tories, like the previous Liberal government, are also behind in publishing annual reports required by law that show how water supplies are used and maintained.
The last assessment posted on Environment Canada’s website is from 2005-06.
The internal draft report says the government currently does not know enough about the country’s water to properly manage it.
‘This is not a crisis yet. Why would we expect any government, regardless of political leaning or level, to do anything about it?’
“Canada lacks sound information at a national scale on the major uses and user[s] of water,” it says.
“National forecasting of water availability has never been done because traditionally our use of the resource was thought to be unlimited.”
Canada has a fifth of the world’s supply of fresh water, but only seven per cent of it is renewable. The rest comes from ice-age glaciers and underground aquifers.
One per cent of Canada’s total water supply is renewed each year by precipitation, the report says.
Moreover, government data on the country’s groundwater reserves is deemed “sparse and often inadequate.”
That’s in contrast to the United States, which has spent more than a decade mapping its underground water reserves. Canada shares aquifers with the U.S., and the report says: “Our lack of data places Canada at strategic disadvantage for bilateral negotiations with the U.S.”
A comprehensive review [World Wildlife Federation: a national assessment of of Canada’s freshwater Watershed Reports; 2017] freshwater ecosystems reveals rising threats from pollution, overuse, invasive species and climate change among other problems. Yet, the biggest threat of all may be a lack of information that hinders effective regulation, Ivan Semeniuk reports. …
Some of that information may be out of date.
Getting back on topic, here’s one possible solution to better managing our use of water.
Every day, more than 141 billion liters of water are used solely to flush toilets. With millions of global citizens experiencing water scarcity, what if that amount could be reduced by 50%?
The possibility may exist through research conducted at Penn State, released today (Nov. 18) in Nature Sustainability.
“Our team has developed a robust bio-inspired, liquid, sludge- and bacteria-repellent coating that can essentially make a toilet self-cleaning,” said Tak-Sing Wong, Wormley Early Career Professor of Engineering and associate professor of mechanical engineering and biomedical engineering.
…
Penn State researchers have developed a method that dramatically reduces the amount of water needed to flush a conventional toilet, which usually requires 6 liters. Image: Wong Laboratory for Nature Inspired Engineering
In the Wong Laboratory for Nature Inspired Engineering, housed within the Department of Mechanical Engineering and the Materials Research Institute, researchers have developed a method that dramatically reduces the amount of water needed to flush a conventional toilet, which usually requires 6 liters.
Co-developed by Jing Wang, a doctoral graduate from Wong’s lab, the liquid-entrenched smooth surface (LESS) coating is a two-step spray that, among other applications, can be applied to a ceramic toilet bowl. The first spray, created from molecularly grafted polymers, is the initial step in building an extremely smooth and liquid-repellent foundation.
“When it dries, the first spray grows molecules that look like little hairs, with a diameter of about 1,000,000 times thinner than a human’s,” Wang said.
While this first application creates an extremely smooth surface as is, the second spray infuses a thin layer of lubricant around those nanoscopic “hairs” to create a super-slippery surface.
“When we put that coating on a toilet in the lab and dump synthetic fecal matter on it, it (the synthetic fecal matter) just completely slides down and nothing sticks to it (the toilet),” Wang said.
With this novel slippery surface, the toilets can effectively clean residue from inside the bowl and dispose of the waste with only a fraction of the water previously needed. The researchers also predict the coating could last for about 500 flushes in a conventional toilet before a reapplication of the lubricant layer is needed.
While other liquid-infused slippery surfaces can take hours to cure, the LESS two-step coating takes less than five minutes. The researcher’s experiments also found the surface effectively repelled bacteria, particularly ones that spread infectious diseases and unpleasant odors.
If it were widely adopted in the United States, it could direct critical resources toward other important activities, to drought-stricken areas or to regions experiencing chronic water scarcity, said the researchers.
Driven by these humanitarian solutions, the researchers also hope their work can make an impact in the developing world. The technology could be used within waterless toilets, which are used extensively around the world.
“Poop sticking to the toilet is not only unpleasant to users, but it also presents serious health concerns,” Wong said.
However, if a waterless toilet or urinal used the LESS coating, the team predicts these types of fixtures would be more appealing and safer for widespread use.
To address these issues in both the United States and around the world, Wong and his collaborators, Wang, Birgitt Boschitsch, and Nan Sun, all mechanical engineering alumni, began a start-up venture.
With support from the Ben Franklin Technology Partners’ TechCelerator, the National Science Foundation, the Department of Energy, the Office of Naval Research, the Rice Business Plan Competition and Y-Combinator, their company, spotLESS Materials, is already bringing the LESS coating to market.
“Our goal is to bring impactful technology to the market so everyone can benefit,” Wong said. “To maximize the impact of our coating technology, we need to get it out of the lab.”
Looking forward, the team hopes spotLESS Materials will play a role in sustaining the world’s water resources and continue expanding the reach of their technology.
“As a researcher in an academic setting, my goal is to invent things that everyone can benefit from,” Wong said. “As a Penn Stater, I see this culture being amplified through entrepreneurship, and I’m excited to contribute.”
This paper is behind a paywall. However, the researchers have made a brief video available,
There you have it. One random thought, that toilet image reminded me of the controversy over Marcel Duchamp, the Fountain, and who actually submitted a urinal for consideration as a piece of art (Jan. 23, 2019 posting). Hint: Some believe it was Baroness Elsa von Freytag-Loringhoven.
Rice University (Texas, US) researchers have published a study which follows quantum dot nanoparticles as they enter the water supply and are taken up by plant roots and leaves and eaten by caterpillars. From a Dec. 16, 2014 news item on ScienceDaily,
In one of the most comprehensive laboratory studies of its kind, Rice University scientists traced the uptake and accumulation of quantum dot nanoparticles from water to plant roots, plant leaves and leaf-eating caterpillars.
The study, one of the first to examine how nanoparticles move through human-relevant food chains, found that nanoparticle accumulation in both plants and animals varied significantly depending upon the type of surface coating applied to the particles. The research is available online in the American Chemical Society’s journal Environmental Science & Technology.
“With industrial use of nanoparticles on the rise, there are increasing questions about how they move through the environment and whether they may accumulate in high levels in plants and animals that people eat,” said study co-author Janet Braam, professor and chair of the Department of BioSciences at Rice.
Braam and colleagues studied the uptake of fluorescent quantum dots by Arabidopsis thaliana, an oft-studied plant species that is a relative of mustard, broccoli and kale. In particular, the team looked at how various surface coatings affected how quantum dots moved from roots to leaves as well as how the particles accumulated in leaves. The team also studied how quantum dots behaved when caterpillars called cabbage loopers (Trichoplusia ni) fed upon plant leaves containing quantum dots.
“The impact of nanoparticle uptake on plants themselves and on the herbivores that feed upon them is an open question,” said study first author Yeonjong Koo, a postdoctoral research associate in Braam’s lab. “Very little work has been done in this area, especially in terrestrial plants, which are the cornerstone of human food webs.”
Some toxins, like mercury and DDT, tend to accumulate in higher concentrations as they move up the food chain from plants to animals. It is unknown whether nanoparticles may also be subject to this process, known as biomagnification.
While there are hundreds of types of nanoparticles in use, Koo chose to study quantum dots, submicroscopic bits of semiconductors that glow brightly under ultraviolet light. The fluorescent particles — which contained cadmium, selenium, zinc and sulfur — could easily be measured and imaged in the tests. In addition, the team treated the surface of the quantum dots with three different polymer coatings — one positively charged, one negatively charged and one neutral.
“In industrial applications, nanoparticles are often coated with a polymer to increase solubility, improve stability, enhance properties and for other reasons,” said study co-author Pedro Alvarez, professor and chair of Rice’s Department of Civil and Environmental Engineering. “We expect surface coatings to play a significant role in whether and how nanomaterials may accumulate in food webs.”
Previous lab studies had suggested that the neutral coatings might cause the nanoparticles to aggregate and form clumps that were so large that they would not readily move from a plant’s roots to its leaves. The experiments bore this out. Of the three particle types, only those with charged coatings moved readily through the plants, and only the negatively charged particles avoided clumping altogether. The study also found that the type of coating impacted the plants’ ability to biodegrade, or break down, the quantum dots.
Koo and colleagues found caterpillars that fed on plants containing quantum dots gained less weight and grew more slowly than caterpillars that fed on untainted leaves. By examining the caterpillar’s excrement, the scientists were also able to estimate whether cadmium, selenium and intact quantum dots might be accumulating in the animals. Again, the coating played an important role.
“Our tests were not specifically designed to measure bioaccumulation in caterpillars, but the data we collected suggest that particles with positively charged coatings may accumulate in cells and pose a risk of bioaccumulation,” Koo said. “Based on our findings, more tests should be conducted to determine the extent of this risk under a broader set of ecological conditions.”
The researchers have a couple of images illustrating their work,
The buildup of fluorescent quantum dots in the leaves of Arabidopsis plants is apparent in this photograph of the plants under ultraviolet light. Credit: Y. Koo/Rice University
This paper is open access but you must be registered on the website.
One final thought about the research, it did take place in a laboratory environment and there doesn’t seem to have been any soil involved so the uptake can not be directly compared (as I understand matters) to the uptake characteristics where plant cultivation requires soil. This seems to have been a study involving hydroponic framing practices.
