Plastics are made of polymers, which are a challenge for scientists to study. Their chain-like strands of thousands of atoms are tangled up in a spaghetti-like jumble, their motion can be measured at many time scales and they are essentially invisible to some common x-ray study techniques. A better understanding of polymers at the molecular scale could lead to improved manufacturing techniques and the creation of new materials.
Polymers come with a range of properties dictated...
Injuries, birth defects (such as cleft palates) or...
Wrapping wound dressings around fingers and toes can be tricky, but for burn victims, guarding them against infection is critical. At the National Meeting & Exposition of the American Chemical Society scientists have reported the development of new ultra-thin coatings called nanosheets that can cling to the body's contours and keep bacteria at bay. The super-thin sheets have been tested on mice and could help transform burn treatment.
An outline of Marilyn Monroe's iconic face appeared on the clear, plastic film when a researcher fogs it with her breath. Terry Shyu, a doctoral student in chemical engineering at the Univ. of Michigan, was demonstrating a new high-tech label for fighting drug counterfeiting. While the researchers don't envision movie stars on medicine bottles, they used Monroe's image to prove their concept.
Long before humans figured out how to create colors, nature had already perfected the process. Now scientists are tapping into those secrets to develop a more environmentally friendly way to make colored plastics. Their paper on using structure—or the shapes and architectures of materials—rather than dyes, to produce color appears in Nano Letters.
Rice Univ. researchers are using magnetic beads and DNA “springs” to create chains of varying flexibility that can be used as microscale models for polymer macromolecules. The experiment is visual proof that “bead-spring” polymers, introduced as theory in the 1950s, can be made as stiff or as flexible as required and should be of interest to materials scientists who study the basic physics of polymers.
Highly purified crystals that split light with precision are valued in specialized optics. But photonic crystals are difficult to make with current techniques, namely electron beam etching. Researchers at Princeton and Columbia universities have proposed a new method derived from colloidal suspensions that could allow scientists to customize and grow optimal crystals with relative ease.
Marilyn Minus, a materials expert and assistant professor at Northeastern Univ., is exploring directed self-assembly methods using carbon nanotubes and polymer solutions. So far, she’s used the approach to develop a polymer composite material that is stronger than Kevlar yet much lighter and less expensive. Minus is now expanding this work to incorporate more polymer classes: flame retardant materials and biological molecules.
Plastic junk is floating widely on the world's oceans, but there's less of it than expected, a study says. A newly published study drew on results from an around-the-world cruise by a research ship that towed a mesh net at 141 sites, as well as other studies. Researchers estimated the total amount of floating plastic debris in open ocean at 7,000 to 35,000 tons.
In wind farms across North America and Europe, sleek turbines equipped with state-of-the-art technology convert wind energy into electric power. But tucked inside the blades of these feats of modern engineering is a decidedly low-tech core material: balsa wood.
Superlyophobic surfaces are simultaneously repellant for almost any liquid and exhibit high contact angles and low flow resist. But the demanding and usually expensive fabrication remains a bottleneck for further development. Researchers in Shenzhen, China, however, have now formulated a facile and inexpensive microfabrication method that uses polymers to help transfer the superlyophobic structures to curable materials.
Since the early 1970s, lithium has been the most popular element for batteries because of it’s low weight and good electrochemical potential. But it is also highly flammable. Researchers have recently married two traditional theories in materials science that can explain how the charge dictates the structure of the material. And using this they may be able to move to other materials, such as block copolymers, for use in batteries.
A new nanoparticle platform developed in California increases the efficiency of drug delivery and allows excess particles to be washed away. A simple etching technique using biocompatible chemicals rapidly disassembles and removes the silver nanoparticles outside living cells. This method leaves only the intact nanoparticles for imaging or quantification, revealing which cells have been targeted and how much each cell internalized.
When stem cells are used to regenerate bone tissue, many wind up migrating away from the repair site, which disrupts the healing process. But a technique employed by a Univ. of Rochester research team keeps the stem cells in place, resulting in faster and better tissue regeneration. The keyis encasing the stem cells in polymers that attract water and disappear when their work is done.
Polymer scientists in Ohio have demonstrated how a transparent layer of electrodes on a polymer surface could be extraordinarily tough and flexible, withstanding repeated scotch tape peeling and bending tests. According to its developers, the new material could replace conventional indium tin oxide coatings currently used for touchscreens.
Terahertz, or T-ray, range of the electromagnetic has rich promise for scientific applications, but instrumentation that can take advantage of these rays for imaging are still in progress. Univ. of Michigan researchers have recently made a breakthrough by converting terahertz light into sound using a compact, sensitive detector that operates at room temperature and is fabricated in an unusual manner.
Scientists at IBM Research have used a new “computational chemistry” hybrid approach to accelerate the materials discovery process that couples laboratory experimentation with the use of high-performance computing. The new polymers are the first to demonstrate resistance to cracking, strength higher than bone, the ability to reform to their original shape (self-heal), and the ability to be completely recycled back to the starting material.
As news reports of lithium-ion battery (LIB) fires in Boeing Dreamliner planes and Tesla electric cars remind us, these batteries, which are in everyday portable devices, like tablets and smartphones, have their downsides. Now, scientists have designed a safer kind of lithium battery component that is far less likely to catch fire and still promises effective performance.
The mechanical properties of natural joints are considered unrivalled. Cartilage is coated with a special polymer layer allowing joints to move virtually friction-free, even under high pressure. Using simulations, scientists in Europe have developed a new process that technologically imitates biological lubrication and even improves it using two different types of polymers.
Looking at a smooth sheet of plastic in one Univ. of Illinois laboratory, no one would guess that an impact had recently blasted a hole through it. Illinois researchers have developed materials that not only heal, but regenerate. Until now, self-repairing materials could only bond tiny microscopic cracks. The new regenerating materials fill in large cracks and holes by regrowing material.
Research in Australia may help in the fight against terrorism with the creation of a sensor that can detect tiny quantities of explosives with the use of light and special glass fibers. The researchers have created a new optical fiber sensor which can detect explosives in concentrations as low as 6.3 ppm (parts per million). It requires an analysis time of only a few minutes.
Current approaches to flexible electronics, in which very thin semiconductor materials are applied to a thin, flexible substrate in wavy patterns and then applied to a deformable surface such as skin or fabric, are still built around hard composite materials that limit their elasticity. Researchers in California have made several discoveries, however, that could lead to electronics that are "molecularly stretchable."
Super-resolution microscopy has allowed optical imaging of objects with dimensions smaller than the diffraction limit. Researchers studying a type of material called supramolecular polymers have used this type of imaging to develop a new technique that allows them study molecular self-assembly at an unprecedented level of detail.
The ability to stick objects to a wide range of surfaces such as drywall, wood, metal and glass with a single adhesive has been the elusive goal of many research teams across the world, but now a team of Univ. of Massachusetts Amherst inventors describe a new, more versatile version of their invention, Geckskin, that can adhere strongly to a wider range of surfaces, yet releases easily, like a gecko's feet.
Scientists at Rice Univ. have created a nanoscale detector that checks for and reports on the presence of hydrogen sulfide in crude oil and natural gas while they’re still in the ground. The nanoreporter is based on nanometer-sized carbon material developed by a consortium of Rice labs led by chemist James Tour, R&D’s 2013 Scientist of the Year.
An international team of chemists from Italy, Germany and Poland have developed a polymer with unique optical and electrical properties. Components of this polymer change their spatial configuration depending on the electric potential applied. In turn, the polarization of transmitted light is affected. The new material could be used in a windows, polarization filters or chemical sensors.
Although it is relatively cheap and easy to encode information in light for fiber optic transmission, storing information is most efficiently done using magnetism, which ensures information will survive for years without any additional power. But a new proposal by researchers would replace silicon used in these devices with plastic. Their solution converts magnetic information to light in a flexible plastic device.
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