Using star-shaped block co-polymer structures as tiny reaction vessels, researchers have developed an improved technique for producing nanocrystals with consistent sizes, compositions and architectures—including metallic, ferroelectric, magnetic, semiconductor and luminescent nanocrystals. The technique relies on the length of polymer molecules and the ratio of two solvents to control the size and uniformity of colloidal nanocrystals.
Rice Univ. researchers have for the first time detailed the molecular mechanism that makes a particular combination of cement and polymer glue so tough. The theoretical research led to a fine picture of how hydrogen bonds control the properties of hybrid organic-inorganic materials. The finding has implications for understanding the interface bonding that is often a roadblock to improved composite properties.
Are teeth the latest victims of bisphenol A (BPA)? Yes, according to the conclusions of a team lead by researchers in France. They have shown that the teeth of rats treated with low daily doses of BPA could be damaged the chemical.
The potential energy available via solar power might seem limitless on a sunny summer day, but all that energy has to be stored for it to be truly useful. If you see a solar panel on a rooftop, a bulky battery or supercapacitor is hidden just out of sight, receiving energy from the panel through power lines. However, that's a storage method that doesn't scale well for solar-powered devices with no space for a battery pack.
A chemical that’s often the key ingredient in improvised explosive devices can be quickly and safely detected in trace amounts by a new polymer created by a team of Cornell Univ. chemists. The polymer, which potentially could be used in low-cost, handheld explosive detectors and could supplement or replace bomb-sniffing dogs, was invented in the lab of William Dichtel, assistant professor of chemistry and chemical biology.
A rabbit sculpture, the size of a typical bacterium, is one of several whimsical shapes created by a team of Japanese scientists using a new material that can be molded into complex, highly conductive 3D structures with features just a few micrometers across. The new resin holds promise for making customized electrodes for fuel cells or batteries, as well as biosensor interfaces for medical uses.
Human scabs have become the model for development of an advanced wound dressing material that shows promise for speeding the healing process, scientists are reporting. The team explains that scabs are a perfect natural dressing material for wounds. In addition to preventing further bleeding, scabs protect against infection and recruit the new cells needed for healing.
A new version of solar cells created by laboratories at Rice and Pennsylvania State universities could open the door to research on a new class of solar energy devices. The photovoltaic devices are based on block copolymers, self-assembling organic materials that arrange themselves into distinct layers. They easily outperform other cells with polymer compounds as active elements.
Nearly everyone is familiar with the polytetrafluoroethylene (PTFE), otherwise known as Teflon. Famous for being “non-sticky” and water repellent, PTFE is a dry lubricant used on machine components everywhere. Recently, engineering researchers at the University of Arkansas found a way to make the polymer even less adhesive.
In a quest to develop low-friction components for ever smaller mechanical systems, a team of physicists in Germany has recently discovered a previously unknown type of friction that they call “desorption stick.” The researchers examined how and why single polymer molecules in various solvents slide over or stick to certain surfaces. They found that an unexpected factor was responsible for the friction they observed.
Amid concerns over the potential health effects of existing flame retardants for home furniture, fabrics and other material, are reporting development of an “exceptionally” effective new retardant that appears safer and more environmentally friendly. The key is a nanocoating made with a relatively benign polymer that creates a “gas blanket,” preventing oxygen from fueling a fire.
Cells are the basic unit of life and are separated from the outside world by a thin organic membrane. A major function of this membrane is to allow certain molecules to enter or leave the cell whilst other molecules are blocked from the cell interior. This allows metabolic processes to take place. Controlling membrane permeability is therefore a key challenge when building artificial cells in the form of enclosed chemical systems.
A polymer thin film solar cell (PSC) produces electricity from sunlight by the photovoltaic effect. Though light and inexpensive, PSCs currently suffer from a lack of enough efficiency for large scale applications and they also have stability problems. Researches in Korea have designed and added multi-positional silica-coated silver nanoparticles that have greatly improved stability and performance of these cells.
A team led by Lawrence Berkeley National Laboratory Materials Sciences Division’s Jeffrey Urban and Rachel Segalman have discovered highly conductive polymer behavior occurring at a polymer/nanocrystal interface. The composite organic/inorganic material is a thermoelectric—a material capable of converting heat into electricity—and has a higher performance than either of its constituent materials.
Methanol to formaldehyde: This reaction is the starting point for the synthesis of many everyday plastics. Using catalysts made of gold particles, however, formaldehyde could be produced without the environmentally hazardous waste generated in conventional methods. But just how a gold catalyst could work has only recently been discovered by researchers.
Coating medical supplies with an antimicrobial material is one approach that bioengineers are using to combat the increasing spread of multidrug-resistant bacteria. A research team in Singapore has now developed a highly effective antimicrobial coating based on cationic polymers. The coating can be applied to medical equipment, such as catheters.
U.S. Naval Research Laboratory scientists have developed a second-generation, cost-effective polyetheretherketone (PEEK)-like phthalonitrile-resin demonstrating superior high-temperature and flammability properties for use in marine, aerospace, and domestic applications. The resin can be used to make composite components by established industrial methods and automated composite manufacturing techniques.
A new chemical process can transform waste sulfur into a lightweight plastic that may improve batteries for electric cars, reports a University of Arizona-led team. The new plastic has other potential uses, including optical uses. The team has successfully used the new plastic to make lithium-sulfur batteries.
The accidental discovery by Chemical Engineering Professor Tim Bender and postdoctoral fellow Benoit Lessard of an unexpected side product of polymer synthesis could have implications for the manufacture of commercial polymers used in sealants, adhesives, toys, and even medical implants, the researchers say.
Japan-based Teijin Limited has developed technology to significantly enhance the heat and impact resistance of PLANEXT, the company’s high-performance bioplastic. The technology modifies the molecular design of PLANEXT to achieve greatly improved heat resistance with a glass-transition temperature of 120 C, as well as superior resistance to impact.
Ditch the 3D glasses. Thanks to a simple plastic filter, mobile device users can now view unprecedented, distortion-free, brilliant 3D content with the naked eye. This latest innovation from researchers in Singapore is the first ever glasses-free 3D accessory that can display content in both portrait and landscape mode, and measures less than 0.1 mm in thickness.
Scientists may soon be able to turn to one of the most powerful forces in biology—evolution—to help in their quest to develop new synthetic polymers. As described in a recent paper, a team of Harvard University researchers has developed a new method to create synthetic polymers using the coding of genetic material. The method may eventually be used to evolve synthetic polymers with new or improved properties such as the ability to serve as catalysts in chemical reactions or enhanced therapeutic potential.
Chemical companies each year churn out billions of tons of acrylate, a valuable commodity chemical involved in the manufacture of everything from polyester cloth to disposable diapers. It is usually made by heating propylene, a compound derived from crude oil. Researchers at Brown and Yale universities have demonstrated a new “enabling technology” that could instead use excess carbon dioxide to produce acrylate.
Researchers from North Carolina State University have come up with a low-cost way to enhance a polymer called MEH-PPV's ability to confine light, advancing efforts to use the material to convert electricity into laser light for use in photonic devices.
MEH-PPV is a low-cost polymer that can be integrated with silicon chips, and researchers have sought to use it to convert electricity into laser light for use in photonic devices. However, attempts to do this have failed because the amount of electricity needed to generate laser light in MEH-PPV was so high that it caused the material to degrade. Researchers have recently come up with a low-cost way to enhance MEH-PPV’s ability to confine light, protecting the material.