Road salt, used in copious helpings each winter to protect them from ice and preserve safe driving conditions, is slowly degrading the concrete they’re made of.
Engineers have known for some time that calcium chloride salt, commonly used as deicer, reacts with the calcium hydroxide in concrete to form a chemical byproduct that causes roadways to crumble. A civil engineer from Drexel University is working on a new recipe for concrete, using cast-off products from furnaces, that can hold its own against the forces of chemical erosion.
More than 900,000 tons of deicing salt is used each winter in Pennsylvania alone. While winters in the Northeast put pressure on departments of transportation to keep roads clear and deicer is an effective part of that process, it also contributes to the thousands of miles of roads that need to be patched and repaired... more
EPFL scientists have developed a mathematical “face-recognition” method for identifying and discovering nanoporous materials based on their pore size.
Materials classified as “nanoporous” have structures (or “frameworks”) with pores up to 100 nm in diameter. These include diverse materials used in different fields from gas separation, catalysis, and even medicine (e.g. activated charcoal). The performance of nanoporous materials depends on both their chemical composition and the shape of their pores, but the latter is very difficult to quantify. So far, chemists rely on visual inspection to see whether two materials have similar pores. EPFL scientists, in the framework of NCCR-MARVEL, have now developed an innovative mathematical method that allows a computer to quantify similarity of pore structures. The method makes it possible... more
Scientists at Rice University and Ben-Gurion University of the Negev (BGU) have discovered that laser-induced graphene (LIG) is a highly effective anti-fouling material and, when electrified, bacteria zapper.
LIG is a spongy version of graphene, the single-atom layer of carbon atoms. The Rice lab of chemist James Tour developed it three years ago by burning partway through an inexpensive polyimide sheet with a laser, which turned the surface into a lattice of interconnected graphene sheets. The researchers have since suggested uses for the material in wearable electronics and fuel cells and for superhydrophobic or superhydrophilic surfaces.
According to their report in the American Chemical Society’s ACS Applied Materials and Interfaces, LIG also protects surfaces from biofouling, the buildup of microorganisms, plants or other biological material on wet surfaces.
“This form of graphene... more
Ventilating flaps lined with live cells open and close in response to an athlete’s sweat.
A team of MIT researchers has designed a breathable workout suit with ventilating flaps that open and close in response to an athlete’s body heat and sweat. These flaps, which range from thumbnail- to finger-sized, are lined with live microbial cells that shrink and expand in response to changes in humidity. The cells act as tiny sensors and actuators, driving the flaps to open when an athlete works up a sweat, and pulling them closed when the body has cooled off.
The researchers have also fashioned a running shoe with an inner layer of similar cell-lined flaps to air out and wick away moisture. Details of both designs are published today in Science Advances.
Why use live cells in responsive... more
Rice University scientists have created a rechargeable lithium metal battery with three times the capacity of commercial lithium-ion batteries by resolving something that has long stumped researchers: the dendrite problem.
The Rice battery stores lithium in a unique anode, a seamless hybrid of graphene and carbon nanotubes. The material first created at Rice in 2012 is essentially a three-dimensional carbon surface that provides abundant area for lithium to inhabit.
The anode itself approaches the theoretical maximum for storage of lithium metal while resisting the formation of damaging dendrites or “mossy” deposits.
Dendrites have bedeviled attempts to replace lithium-ion with advanced lithium metal batteries that last longer and charge faster. Dendrites are lithium deposits that grow into the battery’s electrolyte. If they bridge the anode and cathode and create a short circuit, the battery may fail... more
A small, thin square of an organic plastic that can detect disease markers in breath or toxins in a building’s air could soon be the basis of portable, disposable sensor devices.
By riddling the thin plastic films with pores, University of Illinois researchers made the devices sensitive enough to detect at levels that are far too low to smell, yet are important to human health.
In a new study in the journal Advanced Functional Materials, professor Ying Diao’s research group demonstrated a device that monitors ammonia in breath, a sign of kidney failure.
“In the clinical setting, physicians use bulky instruments, basically the size of a big table, to detect and analyze these compounds. We want to hand out a cheap sensor chip to patients so they can use it and throw it away,” said Diao, a professor of chemical and biomolecular engineering at Illinois.
Roll-up computer screens and other flexible electronics are getting closer to reality as scientists improve upon a growing number of components that can bend and stretch. One team now reports in the journal ACS Applied Materials & Interfaces another development that can contribute to this evolution: a low-cost conductive paper that would be easy to manufacture on a large scale.
Current flexible electronic prototypes are commonly built using polymer thin films. But the cost of these films becomes a factor when they are scaled up. To address this issue, scientists have turned to paper, which is renewable, biodegradable and a fraction of the cost of polymer thin films. The downside of paper... more
Chemists, materials scientists and nanoengineers at UC San Diego have created what may be the ultimate natural sunscreen.
In a paper published in the American Chemical Society journal ACS Central Science, they report the development of nanoparticles that mimic the behavior of natural melanosomes, melanin-producing cell structures that protect our skin, eyes and other tissues from the harmful effects of ultraviolet radiation.
“Basically, we succeeded in making a synthetic version of the nanoparticles that our skin uses to produce and store melanin and demonstrated in experiments in skin cells that they mimic the behavior of natural melanosomes,” said Nathan Gianneschi, a professor of chemistry and biochemistry, materials science and engineering and nanoengineering at UC San Diego, who headed the team of... more
UC San Diego Jacobs School of Engineering / David Baillot
Engineers at the University of California San Diego have developed the first soft robot that is capable of walking on rough surfaces, such as sand and pebbles. The 3D-printed, four-legged robot can climb over obstacles and walk on different terrains.
Researchers led by Michael Tolley, a mechanical engineering professor at the University of California San Diego, will present the robot at the IEEE International Conference on Robotics and Automation from May 29 to June 3 in Singapore. The robot could be used to capture sensor readings in dangerous environments or for search and rescue.
The breakthrough was possible thanks to a high-end printer that allowed researchers to print soft and rigid materials together within the same components. This made it possible for researchers to design more complex shapes for the robot’s legs.
Bringing together soft and rigid materials will help create a new generation of fast, agile robots that are... more
When building with molecules, it is important to understand how they stick together when, amongst others, designing capsules for transportation of medication in the body. After all, how can you construct a car if you don’t know how the components work?
Researchers of the TU Eindhoven enable us to measure how long it takes for small molecules (monomers) to break free from a larger molecular complex (polymer), without influencing the movement of the polymers. Today, biomedical engineer René Lafleur, dr. Xianwen Lou, professor Bert Meijer and colleagues published a paper about this research in Nature Communications.
The movements of molecules is often measured by connecting a coloring to the molecule. However, the coloring is large in size in relation to the molecule, therefore influencing the movement. PhD candidate Lafleur now proved, together with colleague Xianwen Lou, that the technique used for studying the folding of proteins (also... more