#ionic liquids

Hollow-sphere catalyst enables greener production of 99% pure propene at room temperature

The world's appetite for propene (propylene) is growing faster than the chemical industry can keep up. This petrochemical product powers the production of acrylonitrile, propylene oxide, high-velocity fuels, and, most importantly, polypropylene plastic—used in everyday food packaging and textiles, as well as in essential medical equipment. In a study published in Science, researchers demonstrated a new way of generating propene from propane at room temperature using an electrochemical process that is way less energy hungry than the traditional high-temperature method. The process of converting propane (C3H8) to propene (C3H6) involves dehydrogenation. To facilitate the process, the team created a new catalyst made of hollow spheres of tin dioxide (SnO2) coated with a thin layer of ionic liquid (IL).

Explaining the Conductivity of Ionic Liquids

Researchers have used molecular dynamics simulations to study changes in the charge-transport properties of a room-temperature ionic liquid under a strong electric field. [...] In most rechargeable batteries, ions move between electrodes by traveling through electrolytic solutions, which can be volatile and flammable. Room-temperature ionic liquids (RTILs)—salts with melting points below 100 °C—could offer a less hazardous alternative, but their behavior under strong electric fields remains unclear. Now Yufeng Cheng and colleagues at Beihang University in China and the University of Seville in Spain have simulated ion transport in one of the mainstays of RTIL research, an ionic liquid known as [BMIM][TFSI] [1]. The team explained a distinct high-field regime that had been observed before and discovered unexpected dynamics at still higher fields.

A safer, nonflammable battery electrolyte exists, but self-assembly flaw is holding it back

Many important technologies, from handheld phones to medical devices and transportation vehicles, rely on rechargeable batteries. Modern top-of-the-line rechargeable batteries transport lithium ions between electrodes to store and deliver energy. However, as many viral videos have demonstrated, the electrolytes in batteries can pose a significant safety risk, causing overheated laptops, electric bikes, cars, and more to catch fire. Polymeric ionic liquids (PILs), a nonflammable type of electrolytic (ion-conductive) polymer, offer great promise for lithium ion and lithium metal batteries—as well as other technologies, including thin-film transistors and actuators. Unfortunately, the PILs that conduct ions best at room temperature also tend to be very soft, reducing the materials' functionality and making them a challenge to use in devices.

Lethal weapon: New antimicrobial coating could revolutionize cleaning methods

We've gained a new weapon in the fight against harmful and often antibiotic-resistant pathogens with the development of a unique material engineered to limit disease spread and replace current cumbersome cleaning protocols on high-touch surfaces like door knobs and hand rails. Using the Canadian Light Source (CLS) at the University of Saskatchewan (USask), researchers from the University of Windsor (UWindsor) have developed and tested a compound of ionic (salt-based) fluids and copper nanoparticles that can coat surfaces and provide germ-free protection that lasts far longer than conventional bleach-based cleaning. For Dr. Abhinandan (Ronnie) Banerjee, the composite material is far superior to "somebody with bleach and a rag trying to keep surfaces sanitized." Early in the COVID-19 pandemic, Banerjee and colleagues on the UWindsor's Trant Team—a research group focused on synthetic bioorganic materials—set their sights on improving sanitizing protocols, which at the time often involved frequent application of compounds like bleach.

UC Riverside chemical engineers have designed a fuel that ignites only with the application of electric current. Since it doesn't react to flames and cannot start accidental fires during storage or transport, it is a "safe" liquid fuel. "The fuel we're normally using is not very safe. It evaporates and could ignite, and it's difficult to stop that," said Yujie Wang, UCR chemical engineering doctoral student and co-author of a new paper about the fuel. "It is much easier to control the flammability of our fuel and stop it from burning when we remove voltage." The Journal of the American Chemical Society paper describes how the team created the fuel, and additional technical details are also included in the patent they filed. When fuel combusts, it is not the liquid itself that burns. Instead, it is the volatile fuel molecules hovering above the liquid that ignite on contact with oxygen and flame. Removing an oxygen source will extinguish the flame, but this is difficult to do outside of an engine.

Researchers have taken the first steps toward finding liquid solvents that may someday help extract critical building materials from lunar and Martian-rock dust, an important piece in making long-term space travel possible. Using machine learning and computational modeling, Washington State University researchers have found about half a dozen good candidates for solvents that can extract materials on the moon and Mars usable in 3D printing. The work, reported in the Journal of Physical Chemistry B, is led by Soumik Banerjee, associate professor in WSU's School of Mechanical and Materials Engineering. The powerful solvents, called ionic liquids, are salts that are in a liquid state. "The machine learning work brought us down from the 20,000-foot to the 1,000-foot level," Banerjee said. "We were able to down select a lot of ionic liquids very quickly, and then we could also scientifically understand the most important factors that determine whether a solvent is able to dissolve the material or not."

The discovery that football players were unknowingly acquiring permanent brain damage as they racked up head hits throughout their professional careers created a rush to design better head protection. One of these inventions is nanofoam, the material on the inside of football helmets. Thanks to mechanical and aerospace engineering associate professor Baoxing Xu at the University of Virginia and his research team, nanofoam just received a big upgrade and protective sports equipment could, too. This newly invented design integrates nanofoam with "non-wetting ionized liquid," a form of water that Xu and his research team now know blends perfectly with nanofoam to create a liquid cushion. This versatile and responsive material will give better protection to athletes and is promising for use in protecting car occupants and aiding hospital patients using wearable medical devices. The team's research was recently published in Advanced Materials.