Advancing Technology Through Measurement Science in the NIST Polymers Division

Abstract

Established in 1962, the Polymers Division in the Material Measurement Laboratory of the National Institute of Standards and Technology (NIST) will soon celebrate its 50 th year as a world leader in polymers research. The mis-sion of the NIST Polymers Division is to serve as the Nation's reference laboratory responsible for producing the measurement methods, standards, and data needed to advance the manufacture and use of “soft” materials (poly-mers and complex fl uids), with the goal of improving industrial competitive-ness and addressing national needs. The NIST mission is unique because the work of the organization focuses on a facilitation role for technology development in the United States through a combination of strict objectivity and the highest levels of technical expertise. In order to maintain the broadest impact in facilitating technical competiveness, the Polymers Division advances the measurement science of polymers and complex fluids rather than engage in the development of new advanced materials for commercial use. NIST focuses on the underlying measurements needed for all companies competing in a particular sector, i.e., the important pre-competitive technical work that is needed to advance the fi eld rather than one company in particular. We develop measurement methods for physical/chemical properties and structure; processing, flow, and transport; and functional properties and performance (electrical, optical, biolog-ical, mechanical) of polymers and complex fluids. Measurement development has often accompanied fundamental break-throughs in polymer science within the Division. Novel measurements have lead to theoretical advances; precision measurements of semicrystalline polymers, polymer blends, and piezoelectric polymers resulted in leading theories of polymer morphology and crystallization kinetics, phase separation kinetics, and the current model for piezoelectric polymers, respectively. Alternatively, theoretical developments have often resulted in breakthroughs in polymer measurements and standards, such as the BKZ theory of non-linear viscoelasticity resulting in improved measurements of mechanical properties and theories for polymer chains in solution resulting in methods and standards for molecular mass distribution. Currently, the Polymers Division consists of nearly one hundred scientists with a broad portfolio of research that includes advanced imaging measurements of the interaction of biological systems with polymer materials, smallangle neutron and X-ray scattering measurements of nanostructured materials, the separation and purifi cation of single-wall carbon nanotubes, and the development of new tests for the reliability of soft body armor. The Division works closely with industry, government, and university partners to ensure that the critical measurement needs of the Nation are being met. For example, the Division has worked with International SEMATECH and Intel on identifying the potential limits of next-generation photoresist materials; the National Institutes of Health on standards development for dental materials; and with university groups around the world including Seoul National University, Stanford University, the University of Delaware, and the University of Colorado. Recent progress in some of these major areas is highlighted in this special issue. The unrelenting drive to shorter lengthscales in microelectronics presents new challenges in control of chemical and physical processes at molecular dimensions. Three papers highlight recent advances understanding and controlling these processes. One paper focuses on characterization of the complex interplay of chemistry and transport for photoresist development. Another paper focuses on high-performance mold materials for nanoimprint lithography. The fi nal paper highlights progress in identifying the potential limits and power of self-assembled nanoscale patterns with block copolymer thin films. Much of the work the Polymers Division does revolves around development of new and powerful characterization techniques. Several papers highlight advances following this theme. Surface wrinkling has been developed in the Polymers Division as a tool for making very sensitive rheological measurements of thin and ultrathin polymer membranes; we include a review of this topic. Also represented is pioneering work in the Division on interfacial rheological characterization of small volume liquid samples, characterization and separation of carbon nanotube dispersions, use of combinatorial methods to characterize interactions of mammalian cells with polymeric materials, and new conceptual approaches to understanding initial cell morphological response to polymeric surfaces. We hope you enjoy the issue. More information about the Division and its programs can be found at http://www.nist.gov/mml/polymers/.