Australian researchers figure out a new way to apply extreme pressure and squeeze out diamonds.
- Diamonds aren't just beautiful, they're also excellent at cutting through most anything.
- Researchers have worked out how to create the gems without the high temperatures that accompany their natural formation.
- The researchers were able to create two different types of diamonds that also occur naturally.
They totally crushed it<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yNDgyNzYxOC9vcmlnaW4ucG5nIiwiZXhwaXJlc19hdCI6MTYxMjc2MjA5OH0.Td-IiqixMYd-0OEn3vunxg5gFbPEyzKiSVOcxr6rdDs/img.png?width=980" id="75686" class="rm-shortcode" data-rm-shortcode-id="fe32f066e6fc40c8b19a793828a97b4b" data-rm-shortcode-name="rebelmouse-image" />
The telltale clue<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yNDgyNzYyNi9vcmlnaW4ucG5nIiwiZXhwaXJlc19hdCI6MTY2NDAxODQ2Nn0.yVllyyJOAk7No8cnTPyQQMky00Q8awt0KfPDHF95ud4/img.png?width=980" id="45646" class="rm-shortcode" data-rm-shortcode-id="b3d62e6d2b2a26dc2cc73b4de24519e6" data-rm-shortcode-name="rebelmouse-image" />
Credit: kento/Adobe Stock<p>The rest of the team's formula has to do with how the pressure is applied.</p><p>Co-leader of the research, <a href="https://www.rmit.edu.au/contact/staff-contacts/academic-staff/m/mcculloch-professor-dougal" target="_blank">Dougal McCullough</a>, and his team working at RMIT used cutting-edge advanced electron microscopy to image slices of experimental diamond samples that provided a peak into their formation.</p><p>One revelation was the relationship between the two diamond types. "Our pictures showed that the regular diamonds only form in the middle of these Lonsdaleite veins," says McCulloch. "Seeing these little rivers of Lonsdaleite and regular diamond for the first time was just amazing and really helps us understand how they might form."</p><p>"The twist in the story ," says Bradby, "is how we apply the pressure. As well as very high pressures, we allow the carbon to also experience something called 'shear' — which is like a twisting or sliding force. We think this allows the carbon atoms to move into place and form Lonsdaleite and regular diamonds."</p><p>The diamonds produced by the team confirm this idea. Bradby recalls, "Seeing these little rivers of Lonsdaleite and regular diamond for the first time was just amazing and really helps us understand how they might form [in nature]."</p>
New diamonds made to order<p>"Creating more of this rare but super-useful diamond is the long-term aim of this work," says Bradby.</p><p>While many may think of diamonds only for their ornamental value, their hardness makes them excellent for cutting through most anything, and they're used in some of the world's most advanced precision cutting systems.</p><p>Bradby notes that, "Lonsdaleite [in particular] has the potential to be used for cutting through ultra-solid materials on mining sites."</p><p>Next up: flight and x-ray vision. (Joking.)</p>
Can passenger airships make a triumphantly 'green' comeback?
Large airships were too sensitive to wind gusts and too sluggish to win against aeroplanes. But today, they have a chance to make a spectacular return.
Researchers design microdevices that can gradually deliver medicine by latching on to intestines.
- A research team from Johns Hopkins University designs microdevices that can deliver medicine.
- The tiny robots are based on parasite hookworms.
- The machines can latch on to the intestines and gradually release pain-relieving drugs.
March of the microscopic robots<span style="display:block;position:relative;padding-top:56.25%;" class="rm-shortcode" data-rm-shortcode-id="beb2343e06c26aa2bdd6658a72166dde"><iframe type="lazy-iframe" data-runner-src="https://www.youtube.com/embed/2TjdGuBK9mI?rel=0" width="100%" height="auto" frameborder="0" scrolling="no" style="position:absolute;top:0;left:0;width:100%;height:100%;"></iframe></span>
While it's always been a boon to Popeye's "muskles," it looks like spinach may also have a role to play in clean future batteries.
- Scientists are seeking sustainable, clean chemicals for use in future fuel cell and metal-air batteries.
- Platinum is the current go-to substance for battery cathode catalysts, but it poses a number of problems, including high cost and instability.
- Chemists at American University have developed a new high-performance catalyst from simple spinach, although its preparation as a catalyst is anything but simple.
Cathodes and anodes, oh my<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yNDQ2OTU5MC9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTYyNDQ0NjA0OH0.Fe2eDSkzfzSBG3bGwDsEdrxOy14JYGuhJGjm9shhtkg/img.jpg?width=980" id="5e913" class="rm-shortcode" data-rm-shortcode-id="22095dc5998edbe5c1e27ec10b5a4cc9" data-rm-shortcode-name="rebelmouse-image" />
Flow of energy when battery is in use, discharging
Credit: VectorMine/Shutterstock/Big Think<p>Electrons travel within a battery from one electrode, called the anode, through the battery's electrolyte — either a powder or liquid barrier — to another electrode, called the cathode. The anode releases these electrons through a chemical process called oxidation, while the cathode accepts them through another, an oxygen reduction reaction. Together, this exchange is called a "<a href="https://en.wikipedia.org/wiki/Redox" target="_blank">redox</a>."</p><p>The electrons' return trip back to the anode, however, requires a "load" provided by an external device, which is fine, since that device — a flashlight, a phone, or a car, for example — operates on the energy produced by the battery's electrons passing through.</p><p>The electrons travel out from the cathode's positive terminal to the device then return to the battery's negative anode terminal. In this way the energy travels <a href="https://www.explainthatstuff.com/batteries.html#parts" target="_blank">round and round</a> the battery-device circuit. (When charging a battery, electrons go in the opposite direction connected to a charger.)</p><p>The new study is concerned with the <a href="https://en.wikipedia.org/wiki/Catalysis" target="_blank" rel="noopener noreferrer">catalyst</a> that produces the cathode's oxygen reduction reaction.</p>
Replacing a problematic, pricey catalyst<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yNDQ2OTU5Ni9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTYxMjYyNDI1Nn0.pI9itmS82CPFV4nUOAURwP9amjNi6HpPpU2biikLxYs/img.jpg?width=980" id="9685a" class="rm-shortcode" data-rm-shortcode-id="3a29c292ad8026d129250d041f1fac9e" data-rm-shortcode-name="rebelmouse-image" alt="platinum bricks" />
Credit: AlexLMX/Shutterstock<p><a href="https://en.wikipedia.org/wiki/Fuel_cell" target="_blank" rel="noopener noreferrer">Fuel cell batteries</a> and <a href="https://en.wikipedia.org/wiki/Metal%E2%80%93air_electrochemical_cell" target="_blank">metal-air batteries</a> use the surrounding air outside the battery as their cathode. It's clean, free, plentiful, and it works, as long as there's a catalyst that can adequately prompt the requisite oxygen reduction reaction.</p><p>The most commonly used catalysts for such batteries have been based on platinum. There are problems with these, though. Of course, platinum is expensive. Also, as the study notes, "the lack of long-term stability and the vulnerability to surface poisoning by various chemicals such as methanol and carbon monoxide, call for the development of non-Pt group metal (NPGM) catalysts."</p><p>Researchers have therefore been exploring non-toxic, carbon-based catalyst alternatives since they may be more stable and exhibit resistance to surface poisoning. And because carbon is everywhere, they'd be inexpensive to produce. However, some of the materials being investigated don't do the job as well as platinum-based catalysts. The chemical reaction they produce is slow, posing a speed bottleneck to the flow of electrons.</p>
Enter spinach<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yNDQ2OTYwMy9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTYzNjIxNzI1MX0.Ru_hwAVllm7R2mCfu0X94MdVXpCYbZz3VjcfvsRMaTo/img.jpg?width=980" id="6321d" class="rm-shortcode" data-rm-shortcode-id="f8285054c63c2fc02bef8fba3b29a7cf" data-rm-shortcode-name="rebelmouse-image" />
Credit: Liu, et al./ACS Omega 2020, 5, 38, 24367-24378<p><span style="background-color: initial;"><a href="https://www.american.edu/cas/faculty/szou.cfm" target="_blank">Shouzhong Zou</a></span>, of American University's <a href="https://www.american.edu/cas/chemistry/" target="_blank">Department of Chemistry</a>, is the paper's senior author. The lead author is Xiaojun Liu, with Wenyue Li as co-author. Professor Zou reports:</p><p style="margin-left: 20px;">"The method we tested can produce highly active, carbon-based catalysts from spinach, which is a renewable biomass. In fact, we believe it outperforms commercial platinum catalysts in both activity and stability. The catalysts are potentially applicable in hydrogen fuel cells and metal-air batteries."</p><p>While other catalyst research has involved plants such as rice and cattails, Zou believes spinach has a few things that make it a superior candidate as a catalyst material. For one thing, it's rich in iron and nitrogen, both essential catalyst ingredients. In addition, it's easy and inexpensive to grow, and it's abundant.</p><p>Zou and his students developed spinach-based carbon nanosheets a thousand times thinner than a human hair. The process is complex, a combination of basic and advanced techniques.</p><p>To begin, the researchers washed, juiced, and freeze-dried the vegetable before grinding it by hand into a fine powder using a mortar and pestle. Next, the spinach powder was dissolved and mixed with <a href="https://en.wikipedia.org/wiki/Melamine" target="_blank">melamine</a>, sodium chloride, and potassium chloride in water and cooked together at 120°C. This mixture was then rapid-cooled in liquid nitrogen and freeze-dried. Then it was <a href="https://en.wikipedia.org/wiki/Pyrolysis" target="_blank">pyrolized</a> twice.</p><p>It may well have been worth the effort. Measurements of the resulting nanosheet indicated that it can out-perform platinum as a catalyst in both speed and stability. Of course, that's on top of being made from such an unassuming, inexpensive, and widely available plant.</p><p>"This work," says Zou, "suggests that sustainable catalysts can be made for an oxygen reduction reaction from natural resources." The next step for Zou and his students is to try out their spinach catalyst in prototype fuel cells to assess its performance in action. They're also looking into the use of other plant materials for catalysts.</p><p>Finally, Zou understandably hopes to develop a simple, less energy-intensive way to make their catalyst nanosheets.</p>
New experiments find weird quantum activity in supercold gas.