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Archive for the ‘chemistry’ category: Page 12

Mar 2, 2024

Cold Chemistry is Different

Posted by in categories: chemistry, particle physics, quantum physics, space travel

Experiments demonstrate some of the unusual features of molecular reactions that occur in the deep cold of interstellar space.

Many common small molecules are formed in interstellar space, and their low temperatures are expected to have profound effects on their chemical reactions because of quantum-mechanical effects that are masked at higher temperatures. Researchers have now demonstrated some of these cold chemistry phenomena—such as the effects of molecular rotation and collision energy on reaction rates—in a reaction between a hydrogen ion and an ammonia molecule in the lab. The results, while intuitively surprising at first glance, can be explained by a careful theoretical analysis of the quantum chemistry.

Measuring reaction rates at low temperatures is useful for testing quantum-chemical theory because in those conditions molecules may occupy only a few well-defined quantum states. Such experiments could also offer insights into chemical processes in the cold clouds of gas in star-forming regions of interstellar space, where many of the simple molecules that make up solar systems are formed. But low-temperature experiments are difficult, especially for charged atoms and molecules (ions), because they are very sensitive to stray electric fields in the environment, which accelerate and heat up the ions.

Mar 2, 2024

Chemical etching method opens pores for fuel cells and more

Posted by in categories: chemistry, climatology, economics, sustainability

A chemical etching method for widening the pores of metal-organic frameworks (MOFs) could improve various applications of MOFs, including in fuel cells and as catalysts. Researchers at Nagoya University in Japan and East China Normal University in China developed the new method with collaborators elsewhere in Japan, Australia, and China, and their work was published in the Journal of the American Chemical Society.

MOFs are composed of metal clusters or ions interconnected by carbon-based (organic) linker groups. Varying the metallic and organic components generates a variety of MOFs suitable for a wide range of applications, including catalysis, , and gas storage.

Some MOFs have clear potential for catalyzing the inside fuel cells, which are being explored as the basis of renewable energy systems. Because they don’t use , fuel cells could play a key role in the transition to a low-or zero-emissions economy to combat climate change.

Mar 1, 2024

Quantum to Classical Cavity Chemistry Electrodynamics

Posted by in categories: chemistry, quantum physics

Polaritonic chemistry has ushered in new avenues for controlling molecular dynamics. However, two key questions remain: (i) Can classical light sources elicit the same effects as certain quantum light sources on molecular systems? (ii) Can semiclassical treatments of light–matter interactions capture nontrivial quantum effects observed in molecular dynamics? This work presents a quantum-classical approach addressing issues of realizing cavity chemistry effects without actual cavities. It also highlights the limitations of the standard semiclassical light–matter interaction. It is demonstrated that classical light sources can mimic quantum effects up to the second order of light–matter interaction provided that the mean-field contribution, the symmetrized two-time correlation function, and the linear response function are the same in both situations. Numerical simulations show that the quantum-classical method aligns more closely with exact quantum molecular-only dynamics for quantum light states such as Fock states, superpositions of Fock states, and vacuum squeezed states than does the conventional semiclassical approach.

Mar 1, 2024

Producing quantum materials with precision, with the help of AI

Posted by in categories: chemistry, quantum physics, robotics/AI

A team of NUS researchers led by Associate Professor Lu Jiong from the Department of Chemistry and Institute for Functional Intelligent Materials, together with their international collaborators, have developed a novel concept of a chemist-intuited atomic robotic probe (CARP).

This innovation, which uses artificial intelligence (AI) to mimic the decision-making process of chemists, enables the manufacturing of quantum materials with unrivaled intelligence and precision for future quantum technology applications such as data storage and quantum computing.

Open-shell magnetic nanographene is a type of carbon-based quantum material that possesses key electronic and that are important for developing extremely fast electronic devices at the , or creating quantum bits, the building blocks of quantum computers. The processes used to develop such materials have progressed over the years due the discovery of a new type of solid-phase chemical reaction known as on-surface synthesis.

Mar 1, 2024

‘Oceans are hugely complex’: modelling marine microbes is key to climate forecasts

Posted by in categories: biological, chemistry, climatology, computing

An interesting exploration of the importance of oceanic microorganisms to biogeochemical processes, how existing computational climate models do not adequately capture the complexity introduced by these microbes, and suggestions for future directions in climate modeling that better incorporate the…


Microorganisms are the engines that drive most marine processes. Ocean modelling must evolve to take their biological complexity into account.

Mar 1, 2024

‘This is my calling’: building point-of-care diagnostic tools to fight tuberculosis

Posted by in categories: biotech/medical, chemistry

Inside her small office, with a window overlooking the iconic Kerckhoff Hall student centre at University of California, Los Angeles (UCLA), chemical biologist Mireille Kamariza is pursuing her big dream. Since 2015, she has steadily worked to stop transmission of deadly tuberculosis (TB) superbugs, which in 2022 infected more than 10 million people and killed more than one million.

As a PhD student working with Nobel laureate Carolyn Bertozzi, now a chemist at Stanford University in California, she developed a fluorescent diagnostic test that could be used for quick detection of TB, especially in resource-poor settings. In 2019, alongside Bertozzi, Kamariza founded the biotech start-up company OliLux Biosciences, based in Los Angeles, to develop reliable tools for detecting TB that are tailored to the complex needs of poorer countries. Nature sat down with Kamariza to talk about her progress in testing these diagnostic tools for use in the real world, and the uphill battle in fighting the spread of TB.

Mar 1, 2024

Designing organic mixed conductors for electrochemical transistor applications

Posted by in categories: biological, chemistry, computing

The organic electrochemical transistor (OECT), with its organic mixed ionic–electronic conductor (OMIEC) channel, serves as an amplifying transducer of biological signals. This Review highlights OMIEC design milestones and illustrates how incorporating specific properties into OMIECs can extend OECT applications beyond biosensing.

Mar 1, 2024

A new theoretical development clarifies water’s electronic structure

Posted by in categories: biological, chemistry, physics, solar power, sustainability

There is no doubt that water is significant. Without it, life would never have begun, let alone continue today—not to mention its role in the environment itself, with oceans covering over 70% of Earth.

But despite its ubiquity, liquid water features some electronic intricacies that have long puzzled scientists in chemistry, physics, and technology. For example, the , i.e., the energy stabilization undergone by a free electron when captured by water, has remained poorly characterized from an experimental point of view.

Even today’s most accurate electronic structure has been unable to clarify the picture, which means that important physical quantities like the energy at which electrons from external sources can be injected in liquid water remain elusive. These properties are crucial for understanding the behavior of electrons in water and could play a role in , environmental cycles, and technological applications like solar energy conversion.

Mar 1, 2024

Scientists use food industry byproduct to recover gold from electronic waste

Posted by in categories: chemistry, computing, food, mobile phones, sustainability

Transforming base materials into gold was one of the elusive goals of the alchemists of yore. Now Professor Raffaele Mezzenga from the Department of Health Sciences and Technology at ETH Zurich has accomplished something in that vein. He has not of course transformed another chemical element into gold, as the alchemists sought to do. But he has managed to recover gold from electronic waste using a byproduct of the cheesemaking process.

Electronic waste contains a variety of valuable metals, including copper, cobalt, and even significant amounts of gold. Recovering this gold from disused smartphones and computers is an attractive proposition in view of the rising demand for the precious metal.

However, the recovery methods devised to date are energy-intensive and often require the use of highly toxic chemicals. Now, a group led by ETH Professor Mezzenga has come up with a very efficient, cost-effective, and above all far more sustainable method: with a sponge made from a , the researchers have successfully extracted gold from electronic waste.

Feb 29, 2024

Scientists reveal how first cells could have formed on Earth

Posted by in categories: chemistry, evolution

Roughly 4 billion years ago, Earth was developing conditions suitable for life. Origin-of-life scientists often wonder if the type of chemistry found on the early Earth was similar to what life requires today. They know that spherical collections of fats, called protocells, were the precursor to cells during this emergence of life. But how did simple protocells first arise and diversify to eventually lead to life on Earth?

Now, Scripps Research scientists have discovered one plausible pathway for how protocells may have first formed and chemically progressed to allow for a diversity of functions.

The findings, published online on February 29, 2024, in the journal Chem, suggest that a chemical process called phosphorylation (where are added to the molecule) may have occurred earlier than previously expected. This would lead to more structurally complex, double chained protocells capable of harboring chemical reactions and dividing with a diverse range of functionalities. By revealing how protocells formed, scientists can better understand how could have taken place.

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