Synthesis of Clean Hydrogen Gas from Waste Plastic at Zero Net Cost

Science Daily  September 14, 2023 Hydrogen gas is the primary storable fuel for pollution-free energy production, with over 90 million tonnes used globally per year. More than 95% of H2 is synthesized through metal-catalyzed steam methane reforming that produces 11 tonnes of CO2 per tonne H2. “Green H2” from water electrolysis using renewable energy evolves no CO2, but costs 2–3x more, making it presently economically unviable. Researchers at Rice University have demonstrated catalyst-free conversion of waste plastic into clean H2 along with high purity graphene. The scalable procedure evolved no CO2 when deconstructing polyolefins and produces H2 in purities up […]

New catalyst transforms carbon dioxide into sustainable byproduct

Science Daily  May 3, 2023 About 90% of the acetic acid market is for feedstock in the manufacture of paints, coatings, adhesives, and other products. Production at this scale is primarily derived from methanol, which comes from fossil fuels. An international team of researchers (China, Canada, New Zealand, USA – Northwestern University) has created acetic acid out of carbon monoxide derived from captured carbon. Their process consisted of capturing CO2 and passing it through an electrolyzer where it reacted with water and electrons to form carbon monoxide. Gaseous CO was then passed through a second electrolyzer, where another catalyst transformed […]

A counterintuitive way to make stronger alloys

Phys.org  February 9, 2023 Low-temperature decomposition of supersaturated solid solution into unfavorable intergranular precipitates is a long-standing bottleneck limiting the practical applications of nanograined aluminum alloys that are prepared by severe plastic deformation. Minimizing the vacancy concentration is generally regarded as an effective approach in suppressing the decomposition process. An international team of researchers (China, Norway, Italy) has developed a strategy to stabilize supersaturated solid solution in nanograined Al-Cu alloys via high-density vacancies in combination with Sc microalloying. By generating a two orders of magnitude higher concentration of vacancies bonded in strong (Cu, Sc, vacancy)-rich atomic complexes, a high thermal […]

Software lets researchers create tiny rounded objects out of DNA. Here’s why that’s cool

Phys.org  December 23, 2022 A team of researchers in the US (Duke University, UCSF, Arizona State University, Rutgers University, NCAR) has developed and automated the application of a set of previously unknown design principles that now includes a multilayer design for closed and curved DNA nanostructures to resolve past obstacles in shape selection, yield, mechanical rigidity, and accessibility. The objects were made from threadlike molecules of DNA, bent, and folded into complex three-dimensional objects with nanometer precision. They designed, analyzed, and experimentally demonstrated a set of diverse 3D curved nanoarchitectures, showing planar asymmetry and examining partial multilayer designs. The automated […]

Chemists create quantum dots at room temperature using lab-designed protein

Phys.org  December 12, 2022 Researchers at Princeton University used a lab-designed protein (ConK) which facilitated the formation of cadmium sulfide quantum dots by catalyzing the production of a reactive sulfur species from the amino acid cysteine. ConK catalyzed the desulfurization of cysteine to H2S, which was used to synthesize CdS nanocrystals in solution. The quantum dots had optical properties like those seen in chemically synthesized quantum dots. CdS nanocrystals synthesized using ConK have slower growth rates and a different growth mechanism than those synthesized using natural biomineralization pathways and have two desirable properties not observed during biomineralization using natural proteins […]

Using lasers to bond semiconductor electronics components

Phys.org  December 5, 2022 Important physical limitations have prevented applying laser micro-welding to silicon (Si) and other technology-essential semiconductors. High intensities are required for internal glass modification. However, they result in strong propagation nonlinearities which defocus and delocalize intense infrared radiation. To overcome this, researchers in France created defects inside silicon that later serve as weak points to produce clean-edge cuts. The defects acted as strong bonding points. After setting up the right conditions to circumvent the effects, they successfully made the first experimental demonstration of silicon-silicon laser welding. After an optimization process, they extended the technique to gallium arsenide […]

Scientists develop a new printable, wearable insect repellent

Phys.org  October 11, 2022 With the help of a 3D printer, researchers in Germany encapsulated the active ingredient IR3535, designed to repel mosquitoes, and formed it into the desired shape, such as a ring, or a bracelet. The item can be worn, and it releases the agent for a long time. The basic idea is that the insect repellent continuously evaporates and forms a barrier for insects. Mosquito sprays containing IR3535 are very gentle on the skin and have been used all over the world for many years. The rate at which the insect repellent evaporates depends on many different […]

3D printing drones work like bees to build and repair structures while flying

Science Daily  September 21, 2022 An international team of researchers (UK, Germany, USA – University of Pennsylvania, Switzerland) introduced aerial additive manufacturing (Aerial-AM) that utilizes a team of aerial robots inspired by natural builders such as wasps. They developed a scalable multi-robot 3D printing and path-planning framework that enabled robot tasks and population size to be adapted to variations in print geometry throughout a building mission. To validate Aerial-AM they developed BuilDrones for depositing materials during flight and ScanDrones for measuring the print quality and integrated a generic real-time model-predictive-control scheme with the Aerial-AM robots. The manufacturing accuracy was five […]

Light-powered microbes are super-producing chemical factories

Phys.org  April 11, 2022 Microorganisms that produce useful substances are usually developed by modifying metabolism to convert energy that would normally be used for growth into a resource for synthesizing these target substances. Researchers in Japan used light, an external energy source, to improve production of useful substances without disrupting the microorganisms’ natural metabolism. As a test they introduced a heterologous membrane protein called rhodopsin into Escherichia coli. Rhodopsin is a pump that is activated by light, and the action of the pump leads to the generation of ATP without using the cell’s natural machinery to produce it. This approach […]

Pollen paper that you can print on and ‘unprint’

Nanowerk  April 5, 2022 Conventional paper is made of cellulose fibres found in wood, and the process involves energy-intensive steps that include logging, debarking, and chipping. Making pollen-based paper is similar to traditional soapmaking, which is much simpler and less energy-intensive. Researchers in Singapore used potassium hydroxide to remove the cellular components encapsulated in tough sunflower pollen grains and turned them into soft microgel particles. This step also removes allergens from the pollen. They used deionized water to remove unwanted particles from the microgel, before casting it into a 22 cm x 22 cm mould for air-drying, forming a piece […]