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from the good-prospects-for-grave-robbers dept.
Membrane inspired by bone and cartilage efficiently produces electricity from saltwater:
Inspired by membranes in the body tissues of living organisms, scientists have combined aramid nanofibers used in Kevlar with boron nitride to construct a membrane for harvesting ocean energy that is both strong like bone and suited for ion transport like cartilage. The research, published December 18 in the journal Joule, overcomes major design challenges for technologies that harness osmotic energy (pressure and salinity gradient differences between freshwater and ocean water) to generate an eco-friendly and widely available form of renewable energy.
Osmotic energy generators vary less from one day to the next than solar and wind energy farms, making them more reliable than these green energy staples. However, the clay, graphene oxide, MXene, and molybdenum disulfide nanomaterials commonly used in membranes tend to collapse and disintegrate in water.
While nanosheets made from boron nitride have recently shown promise, remaining stable as temperatures rise and not easily reacting with other substances, membranes made from boron nitride alone are not hardy enough to withstand water for a long time either, rapidly beginning to leak ions as they develop microscopic cracks.
"New advanced boron nitride composite membranes with novel and robust properties will solve this problem, which is in high demand now," says Weiwei Lei, the lead scientist of this project in Australia, a Senior Research Fellow at Deakin University's Institute for Frontier Materials (IFM).
"Osmotic energy represents an enormous resource for humankind, but its implementation is severely limited by the availability of the high-performance ion-selective membranes," says Nicholas Kotov (@kotov_group), the lead scientist in the US, a professor of engineering at the University of Michigan.
Lei, Kotov, and their colleagues set out to solve this problem by turning to the tissues of living creatures as a blueprint, observing that many different varieties of high-performance ion-selective membranes are needed to facilitate the biological reactions in their bodies. They noted that while soft tissues, such as cartilage, kidney membranes, and basement membranes, allow ions to pass through with ease, they are weak and flimsy. In contrast, bones are exceptionally strong and stiff, but without the benefit of efficient ion transport.
"We found a way to 'marry' these two types of materials to obtain both properties at the same time, using aramid nanofibers that make flexible fibrous materials similar to cartilage and boron nitride that makes platelets similar to bone," Kotov says.
Journal Reference:
Cheng Chen, Dan Liu, Li He, Si Qin, Jiemin Wang, Joselito M. Razal, Nicholas A. Kotov, Weiwei Lei. Bio-inspired Nanocomposite Membranes for Osmotic Energy Harvesting. Joule, 2019; DOI: 10.1016/j.joule.2019.11.010
(Score: 3, Informative) by barbara hudson on Thursday January 02 2020, @10:57PM (3 children)
SoylentNews is social media. Says so right in the slogan. Soylentnews is people, not tech.
(Score: 3, Interesting) by Unixnut on Thursday January 02 2020, @11:41PM (2 children)
There are quite a few places where freshwater rivers feed into saltwater seas. at the moment that energy is wasted anyway. If this technology pans out we should be able to extract energy out of the difference, just like we do with tidal water farms.
(Score: 3, Interesting) by MrGuy on Friday January 03 2020, @01:20AM (1 child)
I'm skeptical, the same way that I'm skeptical of the potential of pumping water at 4 degrees C out of the ocean and using it to drive thermal engines. Sure, there's a potential gradient there, and sure it could potentially be exploited. And exploiting it doesn't create the kinds of emissions other power generation does. But what it does do is mess with an ecosystem that's existed for centuries in a given state, and just assumes that no carbon must mean no downside.
Brackish estuaries are incredibly biodiverse, highly productive habitats that harbor life that exists nowhere else in the world. And many species (both fresh water and salt water) depend on the critters that make their homes there. It might not be impossible to set up a salinity gradient power production facility without massive disruption to the ecosystem, but it doesn't sound like it's exactly easy.
(Score: 2) by Unixnut on Friday January 03 2020, @02:45AM
Oh I am skeptical as well, just pointing out that if they can do it, there are places to apply it.
As for altering ecosystems, the only way to stop humans doing that is to kill off the entire species. For as long as we live, our existence will alter the world and the systems within it, it is unavoidable. And as carbon based life forms most of our alterations will involve the carbon cycle in some way.
We cannot exist separate of nature, we are a part of it. Trying to isolate humanity so it doesn't alter the world is a fools errand. If we want to live, function as an advanced society, and have a population of billions, we won't be able to avoid altering environments and ecosystems.