Understanding what happens to a material as it undergoes phase transformations is of fundamental scientific interest. For metal nanocrystals, assumptions about the size-dependence of phase transformations were made that now need re-evaluating. A team of researchers at Lawrence Berkeley National Laboratory has demonstrated that as metal nanocrystals go through phase transformations, size can make a bigger difference than previously believed.
Over the last few years, the use of nanomaterials for water treatment, food packaging, pesticides, cosmetics and other industries has increased. A growing concern is that these particles could pose a potential health risk has prompted a large number of studies, including recent work at the Univ. of Missouri that showed the retention of silver nanoparticles in pear skin, even after repeated washing.
Cells are very good at protecting their precious contents. As a result, it’s very difficult to penetrate their membrane walls without damaging or destroying the cell. One effective way of doing so, discovered in 2008, is to use nanoparticles of pure gold, coated with a thin layer of a special polymer. But nobody knew exactly why this combination worked so well, or how it made it through the cell wall, until now.
The evolution of fluid drops deposited on solid substrates has been a focus of large research effort for decades, and most recently it has focused on nanoscale properties. Two New Jersey Institute of Technology researchers are the first to demonstrate that simulations based on continuum fluid mechanics can explain the nanoscale dynamics of liquid metal particles on a substrate.
Researchers at the Univ. of Georgia are developing a new treatment technique that uses nanoparticles to reprogram immune cells so they are able to recognize and attack cancer. The human body operates under a constant state of martial law. Chief among the enforcers charged with maintaining order is the immune system. The immune system is good at its job, but it's not perfect.
Nanocrystals can grab specific molecules and particles out the air, hold on to them and then release them. But progress in utilizing adsorption and desorption has been hindered by limitations in existing methods for measuring the physical and chemical changes that take place in individual nanocrystals. A newly developed system may solve this by directly measuring the manner in which nanocrystals adsorb and release hydrogen and other gases.
Using imperfections in diamonds as nanoscale thermometers, and gold nanoparticles implanted in cells as laser-induced heating mechanisms, a team of researchers working on DARPA’s Quantum-Assisted Sensing and Readout program recently demonstrated sub-degree temperature measurement and control at the nanometer scale inside living cells.
Tiny silicon crystals caused no health problems in monkeys three months after large doses were injected, marking a step forward in the quest to bring such materials into clinics as biomedical imaging agents, according to a new study. The findings suggest that the silicon nanocrystals, known as quantum dots, may be a safe tool for diagnostic imaging in humans.
Using gold nanoparticles, Massachusetts Institute of Technology researchers have devised a new way to turn blood clotting on and off. The particles, which are controlled by infrared laser light, could help doctors control blood clotting in patients undergoing surgery, or promote wound healing.
The properties of nanomaterials could be easier to predict in the future thanks to work by researchers who have studied metal they have ground metal continuously finer powders. They have prepared a detailed catalogue of how the structure of the metal grains changes depending on grain size, and have discovered that the crystal lattices initially shrink, but expand again below a certain threshold grain size.
By feeding stem cells tiny particles made of magnetized iron oxide, scientists at Emory Univ. and Georgia Tech have used magnets to attract the cells to a particular location in the body after intravenous injection. The method could become a tool for directing stem cells’ healing powers to treat conditions such as heart disease or vascular disease.
When studying the reactions at the catalyst surface, scientists usually have to look into idealized systems under vacuum conditions rather than examining the reality of industrial catalytic processes in a gas environment. However, new electron microscopy technology developed at the York JEOL Nanocentre in the U.K. is allowing researchers to observe and analyze single atoms and nanoparticles in dynamic in situ experiments for the first time.
Andrew Greytak, a chemist at the University of South Carolina, is leading a research team that’s making the process of synthesizing quantum dots much more systematic. His group recently detailed an effective new method for purifying cadmium selenide nanocrystals with well-defined surface properties. The advance required the adoption of gel-permeation chromatography.
Researchers have developed a concept to potentially improve delivery of drugs for cancer treatment using nanoparticles that concentrate and expand in the presence of higher acidity found in tumor cells. The concept involves using nanoparticles made of "weak polybases," compounds that expand when transported into environments mimicking tumor cells, which have a higher acidity than surrounding tissues.
The ultimate dream come true for material scientists is to have the ability to make materials that can take on properties and behaviors to best suit our needs. But scientists first must truly understand the properties of cluster assembly through the individual cluster. Now, material scientists will have greater insight into the organizing principles that allow for the design of nanoscopic materials with specific band gap energy.
A new coating technology developed at Massachusetts Institute of Technology, combined with a novel nanoparticle-manufacturing technology developed at the Univ. of North Carolina at Chapel Hill, may offer scientists a way to quickly mass-produce tailored nanoparticles that are specially coated for specific applications, including medicines and electronics.
Biomaterials are susceptible to microbial colonization, which is why silver is often added to reduce the adhesion rate of bacteria. However, a recent study by researchers in Portugal suggests that—in one material—increasing levels of silver may indirectly promote bacterial adhesion instead of decrease it.
Comic book hero Popeye swears by it. And so do generations of parents who “spoil” their children with spinach. But too much iron content in the blood can indicate acute inflammatory responses, which makes it an important medical diagnostic agent. Using nanoscale diamonds which feature defects, researchers in Europe have developed a new, sensitive biosensor for determination of iron content.
Commonly found in many fruits, vegetables, coffees, teas, and wines, antioxidants are generally regarded as healthy chemicals. However, the problem with using antioxidants in other products is that many of these molecules are not actually very stable. Scientists have recently developed a nanomaterial that protects other molecules from oxidation, and unlike previous attempts the new antioxidant has a long shelf life.
Nanoscopic crystals of silicon assembled like skyscrapers on wafer-scale substrates are being intensely studied as a possible breakthrough in highly efficient battery technologies. A researcher at Northeastern University has been using computational to understand the atomic-scale interactions between the growth of nanowires and new development in this area of technology: alloyed metal droplets.
When petroleum companies abandon an oil well, more than half the reservoir’s oil is usually left behind as too difficult to recover. Now, however, much of the residual oil can be recovered with the help of nanoparticles and a simple law of physics. A partnership of Norwegian and Chinese scientists has succeeded in recovering up to 50% of residual in North Sea rock samples.
Cheaper clean-energy technologies could be made possible thanks to a new discovery. A Penn State Univ. research team has found that an important chemical reaction that generates hydrogen from water is effectively triggered—or catalyzed—by a nanoparticle composed of nickel and phosphorus, two inexpensive elements that are abundant on Earth.
Light-emitting diodes, or LEDs, are the most efficient and environmentally friendly light bulbs on the market. But they come at a higher up-front price than other bulbs, especially the ones with warmer and more appealing hues. Researchers at the Univ. of Washington have created a material they say would make LED bulbs cheaper and greener to manufacture, driving down the price.
Gold bars may signify great wealth, but gold packs a much more practical punch when shrunk down to nanoscale. Unfortunately, unlocking its potential often requires complex synthesis techniques that produce delicate structures with sensitivity to heat. Now, scientists have discovered a process of creating uniquely structured gold-indium nanoparticles that combine high stability, great catalytic potential and a simple synthesis process.
A new study involving researchers at Sanford-Burnham Medical Research Center and the University of California, Santa Barbara, found that the shape of nanoparticles can enhance drug targeting. The study found that rod-shaped nanoparticles—or nanorods—as opposed to spherical nanoparticles, appear to adhere more effectively to the surface of endothelial cells that line the inside of blood vessels.