Researchers at Binghamton and Rutgers Universities, USA, have developed a self-healing fungi concrete mix that could help solve the issue of crumbling infrastructure – caused by cracks in the structure’s concrete. The team received support from the Research Foundation for the State University of New York’s Sustainable Community Transdisciplinary Area of Excellence Program.
Assistant Professor Congrui Jin, Binghamton University, commented, ‘Without proper treatment, cracks tend to progress further and eventually require costly repair […] If micro-cracks expand and reach the steel reinforcement, not only the concrete will be attacked, but also the reinforcement will be corroded, as it is exposed to water, oxygen, possibly CO2 and chlorides, leading to structural failure.’
The team found that mixing Trichoderma reesei – a fungus – with the concrete could solve this issue. The fungus lies dormant in the mix until water and oxygen reach it through cracks in the concrete.
‘With enough water and oxygen, the dormant fungal spores will germinate, grow and precipitate calcium carbonate to heal the cracks,’ commented Jin. ‘When the cracks are completely filled and ultimately no more water or oxygen can enter inside, the fungi will again form spores. As the environmental conditions become favorable in later stages, the spores could be wakened again.’
Further research is needed to ensure the fungus can survive in the concrete mix.
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When you purchase anything from makeup to paint to sunscreen, chances are it contains engineered nanoparticles. These nanoscale materials have properties that are revolutionizing products—from medicine to agriculture to electronics. But eventually, those nanoparticles will reach natural environments. To use them safely and to their fullest potential, we need to know how they behave in real environments—and if that behavior leads to any unintended consequences.
Greg Lowry, professor of civil and environmental engineering at Carnegie Mellon University, studies how nanoparticles behave in and impact the environment. One way researchers have studied nanoparticle fate is by tracking gold nanoparticles—because they are stable and easy to find, or so researchers thought.
Recently, Lowry and Post-doctoral Researcher Astrid Avellan have made a breakthrough discovery: gold nanoparticles actually dissolve in freshwater environments, when they come into contact with mircroorganisms found on aquatic plants. During the dissolution process, gold ions are released, which will behave differently from the nanoparticles and could be toxic to some microorganisms. The study did not measure toxicity so this doesn’t mean gold nanoparticles are harmful—instead, by better understanding their behavior in biologically active environments, scientists can ultimately use this knowledge to design better nanomaterials. Their findings were published in Nature Nanotechnology.
Something New Grows on Trees: Biodegradable Chips for Electronics
It was just a couple of weeks ago when we featured nanocellulose, a natural supermaterial derived from plants that is getting ready for the spotlight. Researchers are looking at it for durable, transparent composites because of its strength. Others are investigating its use in applications from biocompatible implants and flexible displays and solar panels to better bioplastics, cosmetics and concrete.
Now we hear from the University of Wisconsin-Madison and the U.S. Department of Agriculture Forest Products Laboratory that scientists have demonstrated a new product for the nanoscopic fibers of cellulose, a carbohydrate that gives structure to plant cell walls. Turning the material into a film, they’ve been able to produce high-performance computer chips made almost entirely of wood.
By replacing the semiconducting foundation of modern chips with biodegradable nanocellulose, electronics could become significantly less of an environmental burden when they are discarded.
Sea sponges known as Venus’ flower baskets remain fixed to the sea floor with nothing more than an array of thin, hair-like anchors made essentially of glass. It’s an important job, and new research suggests that it’s the internal architecture of those anchors, known as basalia spicules, that helps them to do it.
The spicules, each about half the diameter of a human hair, are made of a central silica (glass) core clad within 25 thin silica cylinders. Viewed in cross-section, the arrangement looks like the rings in a tree trunk. The new study by researchers in Brown University’s School of Engineering shows that compared to spicules taken from a different sponge species that lacks the tree-ring architecture, the basalia spicules are able to bend up to 2.4 times further before breaking.
“We compared two natural materials with very similar chemical compositions, one of which has this intricate architecture while the other doesn’t,” said Michael Monn a Brown University graduate student and first author of the research. “While the mechanical properties of the spicules have been measured in the past, this is the first study that isolates the effect of the architecture on the spicules’ properties and quantifies how the architecture enhances the spicules’ ability to bend more before breaking.”
It’s October, which in the Northern Hemisphere means spiders are out and about – and there are plenty of spider webs about ️ Here’s the science behind their elasticity and surprising strength in C&EN: https://ift.tt/3lb7yhAhttps://ift.tt/3ip3Te9
Lithuanian researchers from Kaunas University of Technology and Vilnius University synthesised and tested a bio-based resin for optical 3D printing (O3DP). The bio-based resin made from renewable raw materials proved to be universal for both table-top 3D printers and state-of-the-art ultrafast laser, suitable for O3DP in the scales from nano- to macro- dimensions. This, according to the researchers, is a unique property for a single photo-resin.
Optical 3D printing (O3DP) is a rapid prototyping tool and an additive manufacturing technique being developed as a choice for efficient and low waste production, yet currently associated with petroleum-derived resins. During O3DP, the photo-curable resin is solidified by treating it with light; such technology makes 3D printing very flexible and precise – the elements can reach sub-micrometres, and also can reach macro- dimensions. The main shortcoming of O3DP is connected to the limitations of the printing materials: their origin, physical and chemical properties, which make the resins not suitable for all setups.
“A universal bio-based resin developed by KTU researchers can be used for a multi-scale 3D printing. Up to now, no single resin was developed which would allow manufacturing of ultra-fine nano-/micro-features and macro-objects out of the same composition,” says Dr Mangirdas Malinauskas, Laser NanoPhotonics Research Group Leader at Laser Research Centre of Vilnius University (VU).
