The National Institute of Standards and Technology (NIST) is launching a new consortium that will take the measure of a growing and increasingly important class of materials—so-called soft materials. Soft materials is a huge field that ranges from products as commonplace as detergents, paints and chocolate bars to some as sophisticated as flexible electronic displays and solar cells, therapeutic drugs and plastics with tailor-made properties.
Two key objectives of the effort are optimizing properties of selected soft materials and maximizing production yields. Beams of neutrons, which are uncharged particles in the nucleus of atoms, provide an unparalleled portal into the workings of materials. The NCNR's specialized neutron-based equipment and measurement methods not only afford glimpses into the interior of soft materials, but they also can probe the movements of their molecular components.
"Over the last few decades, university, government, and a relative handful of industrial researchers have demonstrated the power of neutron probes in solving high-impact materials problems," explains Ronald Jones, the NIST polymer scientist who is the director of nSoft. "We want to make measurement solutions based on neutrons more accessible to materials manufacturers and to help them develop internal expertise for exploiting these tools to address their own particular needs."
Related to liquids and to rigid solids, but distinct from both, soft materials encompass polymers, glasses, complex fluids, gels, foams, proteins, DNA, membranes, and many other natural and synthetic materials. Unifying characteristics are their complexity, a tendency to self-assemble, and the somewhat feeble bonds between their components. Because of these halfhearted internal linkages, soft materials are sensitive to changes in pressure and temperature.
Advances in nanotechnology create opportunities for new types of soft materials optimized for particular uses. Many of these customized materials are based on processing methods that result in internal molecular arrangements far from the material's preferred state of equilibrium. According to a 2009 National Research Council report, manufacturing plants that make some types of these out-of-equilibrium materials may only operate at 50 to 60 percent of their design capacity.
"Small variations in processing parameters can drastically change material properties," Jones says. "The need to precisely and accurately measure the response of soft materials to processing parameters increases as materials become more complex by design."
On the basis of a planning workshop held last year and other outreach efforts, NIST expects industry interest in nSoft to be high. Academic and government research organizations also are welcome to join.