Researchers have combined cutting-edge experimental techniques and computer simulations to find a new way of predicting how water dissolves crystalline structures like those found in natural stone and cement. The research could have wide-ranging impacts in diverse areas, including water quality and planning, environmental sustainability, corrosion resistance and cement construction.
Scientists from NIST and Sandia National Laboratories have added something new to a family of...
An interdisciplinary team of University of Pennsylvania researchers has already developed a...
Researchers at the Virginia Tech Carilion Research Institute have reported the first experimental evidence that supports the theory that a soccer ball-shaped nanoparticle, commonly called a buckyball, is the result of a breakdown of larger structures rather than being built atom-by-atom from the ground up.
Computer simulations conducted at Lawrence Berkeley National Laboratory could help scientists make sense of a recently observed and puzzling wrinkle in one of nature’s most important chemical processes. It turns out that calcium carbonate may momentarily exist in liquid form as it crystallizes from solution.
By determining the 3-D structure of proteins at the atomic level, researchers at the National Institutes of Health have discovered how some commonly used flame retardants, called brominated flame retardants (BFRs), can mimic estrogen hormones and possibly disrupt the body’s endocrine system. BFRs are chemicals added or applied to materials to slow or prevent the start or growth of fire.
A new study from an international team led by Oak Ridge National Laboratory is guiding drug designers toward improved pharmaceuticals to treat HIV. The scientists used neutrons and x-rays to study the interactions between HIV protease, a protein produced by the HIV virus, and an antiviral drug commonly used to block virus replication.
Researchers have been investigating the formation of defects occurring when a Coulomb crystal of ions is driven through a second-order phase transition. This process effectively models the universal Kibble-Zurek mechanism which describes the formation of such defects and is the basis of one theory of how matter was created 10-30 seconds after the Big Bang.
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.
In some ways, granular material can behave much like a crystal, with its close-packed grains mimicking the precise, orderly arrangement of crystalline atoms. Now researchers at Massachusetts Institute of Technology have pushed that similarity to a new limit, creating 2-D arrays of micrograins that can funnel acoustic waves, much as specially designed crystals can control the passage of light or other waves.
Chemists have unexpectedly made two differently colored crystals—one orange, the other blue—from one chemical in the same flask while studying a special kind of molecular connection called an agostic bond. The discovery is providing new insights into important industrial chemical reactions such as those that occur while making plastics and fuels.
If you squeeze a normal object in all directions, it shrinks in all directions. But a few strange materials will actually grow in one dimension when compressed. A team of chemists has now discovered a structure that takes this property to a new level, expanding more dramatically under pressure than any other known material.
Lawrence Livermore National Laboratory researchers, for the first time, have created movies of irreversible reactions that occur too rapidly to capture with conventional microscopy. The team used multiframe, nanosecond-scale imaging in the dynamic transmission electron microscope to create movies of the crystallization of phase-change materials used for optical and resistive memory.
Scientists at Ames Laboratory have discovered a new family of rare-earth quasicrystals using an algorithm they developed to help pinpoint them. Quasicrystalline materials may be found close to crystalline phases that contain similar atomic motifs, called crystalline approximants. And just like fishing experts know how to hook a big catch, the scientists used their knowledge to hone in on the right spot for their discovery.
An international collaboration of scientists has discovered a unique crystalizing behavior at the interface between two immiscible liquids that could aid in sustainable energy development. Liquid interface behavior cannot be investigated at atomic level by most modern methods. Only brilliant X-rays at world-leading light sources can investigate this type of important chemical processes.
With the hand of nature trained on a beaker of chemical fluid, the most delicate flower structures have been formed in a Harvard University laboratory—and not at the scale of inches, but microns. These minuscule sculptures, curved and delicate, don't resemble the cubic or jagged forms normally associated with crystals, though that's what they are. Rather, fields of flowers seem to bloom from the surface of a submerged glass slide.
A Purdue University-led team has revealed the proton transfer pathway responsible for a majority of energy storage in photosynthesis. The team used X-ray crystallography to describe the molecular structure of the cytochrome complex isolated from cyanobacteria, the most primitive photosynthetic organism. The findings contribute to the understanding of the function of photosynthesis and that of membrane proteins.
More powerful batteries could help electric cars achieve a considerably larger range and thus a breakthrough on the market. A new nanomaterial made from tiny tin crystals, deployed at the anode of lithium-ion batteries, has been developed in the labs of chemists in Europe and enables considerably more power to be stored in these batteries.
Quasiperiodic structures, or quasicrystals, because of their unique ordering of atoms and a lack of periodicity, possess remarkable crystallographic, physical and optical properties not present in regular crystals. Researchers at Syracuse University have recently authored a paper that presents the history of quasicrystals and how this area can open up numerous opportunities in fundamental optics research.
When a crystal is hit by an intense, ultrashort light pulse, its atomic structure is set in motion. Researchers in Germany have used intensive ultraviolet laser pulses of only a few femtoseconds duration to cause this change in titanium dioxide, a semiconductor. They report that they can observe how the configuration of electrons and atoms changes, confirming that even subtle changes in the electron distribution caused by the excitation can have a considerable impact on the whole crystal structure.
Northwestern University's Chad A. Mirkin, a leading nanotechnology researcher, has developed a completely new set of building blocks that is based on nanoparticles and DNA. Using these tools, which Mirkin presented at the American Association for the Advancement of Science annual meeting in Boston on Feb. 17, scientists will be able to build—from the bottom up, just as nature does—new and useful structures from artificial atoms.
A new way of making crystalline silicon, developed by University of Michigan researchers, could make this crucial ingredient of computers and solar cells much cheaper and greener. The researchers discovered a way to make silicon crystals, directly at just 180 F, the internal temperature of a cooked turkey, by taking advantage of a phenomenon seen in your kitchen.
Researchers from the NIST Center for Nanoscale Science and Technology and Johns Hopkins University have developed a technique to reliably manipulate hundreds of individual micrometer-sized colloid particles to create crystals with controlled dimensions. The accomplishment is an important milestone for understanding how to direct and control the assembly of microscale and nanoscale objects for nanomanufacturing applications.
A team of researchers in Austria has shown that so-called block copolymer stars—polymers that consist of two different blocks and are chemically anchored on a common point—have a robust and flexible architecture and they possess the ability to self-assemble at different levels. The team has called their invention, which can form complex crystal diamonds or cubes, the “soft Lego”.
Directed assembly is a growing field of research in nanotechnology in which scientists and engineers aim to manufacture structures on the smallest scales without having to individually manipulate each component. Rather, they set out precisely defined starting conditions and let the physics and chemistry that govern those components do the rest. An interdisciplinary team of researchers from the University of Pennsylvania has shown a new way to direct the assembly of liquid crystals.
Crystals growing near the bottom of a beaker are subject to convection, but it is much quieter near the top of the beaker. In that case, why not just let them grow hanging in the beaker? A researcher in The Netherlands who had already tried growing crystals in space has used magnets to grow suspended crystals that form more perfectly, allowing better X-ray diffraction.
A research team including scientists from NIST has confirmed long-standing suspicions among physicists that electrons in a crystalline structure called a kagome lattice can form a "spin liquid," a novel quantum state of matter in which the electrons' magnetic orientation remains in a constant state of change.
When a material is stressed, it changes shape. First, the changes are elastic, then become permanent: The material breaks, shatters, or is reshaped permanently. Researchers examining the latter phenomenon have achieved a better understanding of deformation processes by applying a radial diamond anvil cell X-ray diffraction method on nickel nanocrystals.
- Page 1