5
Polymers Division

SUMMARY

The stated mission of the Polymers Division is based on NIST’s overall mission. Namely,

To enable U.S. innovation and industrial competitiveness in the development and use of materials by advancing measurement science, standards, and technology—in ways that enhance economic security and improve the quality of life.

Within the general framework of polymers, the work of the division encompasses a broad range of activities that include advanced imaging measurements of the interaction of biological systems with polymer materials, organic photovoltaics and electronics, small-angle neutron and x-ray scattering measurements of nanostructured materials, the separation and purification of single-wall carbon nanotubes, and the enabling of new tests of the reliability of soft body armor. It would perhaps be best to articulate the mission in the following terms: “The mission of the Polymers Division ties into NIST’s overall mission as restricted to measurement sciences involving polymeric materials and complex fluids.”

The Polymers Division consists of 31 permanent technical staff (includes 2 NIST fellows), 19 NRC postdoctoral researchers, 2 term employees/students, and 67.6 NIST associates (see footnote 1), plus 5 administrative support staff. The total budget in FY 2009 was $15.1 million, with $2.3 million coming from other agencies. Of the technical staff members, 5 are involved with significant amounts of administrative and supervisory duties, and roughly 15 members are associated with the externally funded American Dental Association Foundation portfolio. Hence, the number of the active permanent staff members in the core portfolio unsaddled with supervisory and administrative duties is 26. In response to suggestions offered by the panel that reviewed the laboratory in 2008, the division has consolidated six groups into four groups and has consolidated the number of programs from 22 to 13. Each group has anywhere from 20 to 30 scientists, with roughly a 1:2 ratio of NIST permanent staff and postdoctoral researchers and NIST associates, a more leveraged organization than other areas of the MSEL or other Department of Energy national laboratories.

The Polymers Division continues to do outstanding research, to collaborate worldwide with academia and industry, and to have a great impact on the industry through CRADAs, Materials Transfer Agreements (MTAs), and various other technology transfer mechanisms. The Polymers Division displayed a high degree of coordination among staff members within the four core groups. This was particularly evident in the selection of equipment that was chosen for ARRA stimulus funding. This equipment expands the core capabilities of the Polymers Division in energy and materials characterization in ways that cut across the division and work also with staff in the NIST



The National Academies | 500 Fifth St. N.W. | Washington, D.C. 20001
Copyright © National Academy of Sciences. All rights reserved.
Terms of Use and Privacy Statement



Below are the first 10 and last 10 pages of uncorrected machine-read text (when available) of this chapter, followed by the top 30 algorithmically extracted key phrases from the chapter as a whole.
Intended to provide our own search engines and external engines with highly rich, chapter-representative searchable text on the opening pages of each chapter. Because it is UNCORRECTED material, please consider the following text as a useful but insufficient proxy for the authoritative book pages.

Do not use for reproduction, copying, pasting, or reading; exclusively for search engines.

OCR for page 41
5 Polymers Division SUMMARY The stated mission of the Polymers Division is based on NIST’s overall mission. Namely, To enable U.S. innovation and industrial competitiveness in the development and use of materials by advancing measurement science, standards, and technology— in ways that enhance economic security and improve the quality of life. Within the general framework of polymers, the work of the division encompasses a broad range of activities that include advanced imaging measurements of the interaction of biological systems with polymer materials, organic photovoltaics and electronics, small-angle neutron and x-ray scattering measurements of nanostructured materials, the separation and purification of single-wall carbon nanotubes, and the enabling of new tests of the reliability of soft body armor. It would perhaps be best to articulate the mission in the following terms: “The mission of the Polymers Division ties into NIST’s overall mission as restricted to measurement sciences involving polymeric materials and complex fluids.” The Polymers Division consists of 31 permanent technical staff (includes 2 NIST fellows), 19 NRC postdoctoral researchers, 2 term employees/students, and 67.6 NIST associates (see footnote 1), plus 5 administrative support staff. The total budget in FY 2009 was $15.1 million, with $2.3 million coming from other agencies. Of the technical staff members, 5 are involved with significant amounts of administrative and supervisory duties, and roughly 15 members are associated with the externally funded American Dental Association Foundation portfolio. Hence, the number of the active permanent staff members in the core portfolio unsaddled with supervisory and administrative duties is 26. In response to suggestions offered by the panel that reviewed the laboratory in 2008, the division has consolidated six groups into four groups and has consolidated the number of programs from 22 to 13. Each group has anywhere from 20 to 30 scientists, with roughly a 1:2 ratio of NIST permanent staff and postdoctoral researchers and NIST associates, a more leveraged organization than other areas of the MSEL or other Department of Energy national laboratories. The Polymers Division continues to do outstanding research, to collaborate worldwide with academia and industry, and to have a great impact on the industry through CRADAs, Materials Transfer Agreements (MTAs), and various other technology transfer mechanisms. The Polymers Division displayed a high degree of coordination among staff members within the four core groups. This was particularly evident in the selection of equipment that was chosen for ARRA stimulus funding. This equipment expands the core capabilities of the Polymers Division in energy and materials characterization in ways that cut across the division and work also with staff in the NIST 41

OCR for page 41
Chemical Science and Technology Laboratory (CSTL) and the NIST Electronics and Electrical Engineering Laboratory. TECHNICAL MERIT RELATIVE TO STATE OF THE ART The projects described in all four of the Polymers Division’s groups demonstrate outstanding technical performance in most areas, with accomplishments that are competitive with those of external academic, industrial, and government laboratories. There is a balance between research that is on the frontier of fundamental polymer science and metric science and technology, with outstanding accomplishments in each category. The Polymers Division continues to transfer technological developments into the industrial sector to have an economic impact and contribute to U.S. competitiveness on the international level. In the period since March 2008, the division has published 137 refereed journal articles and 3 book chapters. The division is disseminating its results and findings through the literature at a rate commensurate with its size. It is hitting its internal targets for 4+ papers per year by senior principal investigators, with publications spread out over specialty journals and high-impact journals—for example, Science and Nature. The awards in the past 2 years—including the 2009 Presidential Early Career Award for Scientists and Engineers, the 2008 and 2010 Sigma Xi Young Investigator Award (NIST), the 2008 Spicer Award (Stanford Synchrotron Radiation Lightsource), the 2010 Outstanding Young Scientist (Adhesion Society), and the 2008 Distinguished Committee Service Awards—speak to the quality of the young scientists who have been recruited into the division. Two of the division scientists hold the rare honor of being NIST fellows, with one of them having been so named in 2009. Recent recognition of the senior staff members includes the 2009 Patrick Laing Award (ASTM) and induction as a fellow in the American Physical Society. The division’s programs are very highly leveraged with CRADAs, MTAs, interagency agreements, international research collaborations, an extremely active NRC postdoctoral program, and a highly successful national and international visiting scientist program. In project after project, examples of measurement methods that are on the leading edge and that are also being applied and/or transitioned to the business sector are evident. NIST-developed measurement methods are continuing to have far-reaching consequences in transforming U.S. industries and promoting U.S. competitiveness. ADEQUACY OF FACILITIES, EQUIPMENT, AND HUMAN RESOURCES Although the overall size of the Polymers Division staff has remained stable over the past 5 years, there has been a significant amount of turnover in the division. It lost several key administrators and scientists. With the realignment and in response to recommendations offered by the NCR panel that reviewed the laboratory in 2008, the Polymers Division has consolidated six groups into four groups and made changes in group leadership. One of the groups, however, is led temporarily by the division chief. These extraordinary changes in leadership over the past 2 years seem to be a concern to 42

OCR for page 41
the division staff. The current and proposed names for the groups in the Polymers Division are these:  Current: Characterization and Measurement Group; proposed: Sustainable Polymers Group;  Current: Electronic Materials Group; proposed: Energy and Electronic Materials Group;  Current: Processing Characterization Group; proposed: Complex Fluids Group; and  Current: Biomaterials Group; proposed: remain unchanged. Division activities that engage substantial numbers of staff members were presented as “Supporting Activities.” At present, the division has identified four supporting activities: Safety, Standards, Theory and Modeling, and Industry Consortium: Soft Matter with Neutrons. Some of these have been grouped under the auspices of a named director, and others are loose confederacies (called working groups) with no clear reporting structure. As these and other supporting activities are critical in establishing the core competencies of the division, it would be advisable to make this structure more formal, with clear leads for each such crosscutting capability. Adding a reporting structure based on capabilities to the existing structure based on programmatic themes would lead to a matrix structure which would ensure that both problems and competencies persist as individual staff members enter or leave the division. The Polymers Division has a large number of facilities and capabilities that are consistent with the breadth of its mission. The use of the facilities is generally managed on an ad hoc basis, with primary care performed by the users of the given equipment. The division has core competencies in areas as diverse as controlled biopolymer interfaces, combinatorial methods and fabrication, scaffold fabrication, optimal imaging and characterization, nonlinear optical spectroscopy, mechanical and adhesion property testing, polymer synthesis, microfluidics, mass spectroscopy, chromatography, x-ray and neutron characterization and reflectivity, electron microscopy, quantitative calorimetry, solid-state nuclear magnetic resonance (NMR), Brownian dynamics, fluid mechanics simulations, and phase-field simulations. Two notable mismatches between the capability suite and the existing facilities are the lack of significant computing resources (balancing the computational capabilities) and a wide-bore NMR (balancing the emerging solid-state NMR capabilities). Two ARRA-funded acquisitions are also coming online in 2010– 2011: an organic photovoltaic test facility ($1.2 million) and sum frequency generation and thin-film nonlinear optical spectroscopy ($750,000). The latter is notable because it involved collaboration (and an MOU) with the CSTL where it will be housed, although the asset is owned by the MSEL. The quality and number of facilities are impressive, but more acquisitions or MOUs with other NIST units will be needed in the future to maintain the needs of the programs. ACHIEVEMENT OF OBJECTIVES AND IMPACT The panel reviewed selected examples of the technological research covered by the Polymers Division. Because of time constraints, it was not possible to review the 43

OCR for page 41
Polymers Division programs and projects exhaustively. The examples reviewed by the panel were selected by the Polymers Division. Biomaterials Group (Bioimaging and Biomaterials Measurements and Standards) The four main projects in the Biomaterials Group within the Polymers Division of the MSEL are Quantitative Bioimaging, 3D Tissue Scaffolds, Protein Preservation, and Dental Materials. The group is composed of 7 permanent technical staff, 6 postdoctoral researchers, 38.2 research associates (see footnote 1), and 1 administrative support staff member. Three major advances were described: broadband three-dimensional chemical imaging of biological tissue, deoxyribonucleic acid (DNA)-derivatized water-soluble quantum dots for functional bioimaging, and standards for dental materials and tissue engineering scaffolds. The technical merit of the programs described was outstanding, leveraging the unique measurement capabilities of NIST with innovation in both standardization and in preparing unique and interesting materials. As described below, the research programs in the areas of Bioimaging and Protein Preservation are outstanding. This is illustrated in terms of the relatively large amount of extramural funding, recognition, and dissemination. The work also contains significant collaboration outside NIST. Although this is generally positive, the downside is that the number of NIST staff members involved in the two projects is somewhat small. Due to the injection of ARRA funds, the budgets were adequate to acquire two major instrumental facilities important to the continued development of new standards and for advancing the research objectives, while also hiring an additional 10 postdoctoral fellows, doubling the number. Every program showed significant advances in measurement science. Novel Spectroscopies The Novel Spectroscopies work was the first to demonstrate broadband Coherent Anti-Stokes Raman Scattering (CARS) microscopy, and it continues to develop this powerful microscopy. The method uses two broad input light pulses and one narrow one to read out the vibrational susceptibility of a sample. This possesses the inherent chemical sensitivity required to spatially map cell phenotype noninvasively. This achievement is a major scientific breakthrough that was pursued by a number of groups. NIST succeeded by developing signal background reduction and analysis methods and improved signal generation methods to obtain sufficient sensitivity and specificity that CARS microscopy can be applied successfully to biological systems. Quantitative Bioimaging Project The Quantitative Bioimaging project is developing noninvasive optical methods and high-affinity probes for the quantitative imaging-based characterization of the structures inside the cell. This allows the researchers to gain information about cell- biomaterial interactions, including molecular signatures of cellular proliferation and 44

OCR for page 41
differentiation. These methods are promising for increased accuracy in evaluating biomaterials. These methods use aptamer-derivatized quantum dots as imaging probes for disease signatures. Here they apply surface plasmon resonance imaging to measure the adsorption potential of engineered quantum dots on surfaces and interfaces and to measure the binding constants of their biomarker probes to specific targets. This may facilitate the accelerated development of materials and expanded progenitor cells for use in regenerative medicine. The researchers on this project are working closely with the National Institutes of Health and other agencies. The 3D Tissue Scaffold Project The 3D Tissue Scaffold project is aimed at providing a reproducible combinatorial platform for screening cell response to three-dimensional tissue scaffold properties. The other stated goal of the project is to develop reference materials for tissue engineering. The platform combines noninvasive imaging with controlled scaffolds of multiple types (salt-leached scaffolds, hydrogels, electrospun nanofiber scaffolds). The arrays can provide gradients or discrete steps. This systematization of standardized arrays combines innovative science with unique imaging. This capability has been extended to provide Reference Materials Scaffolds, a unique service to academic and industrial research laboratories, very much in line with the NIST mission. Protein Preservation Project Stability of proteins is critical in biopharmaceutical and drug delivery applications. The Protein Preservation project is developing analytical tools for rapid formulation assessment to avoid the 6-month testing cycle times for current technology. Also the researchers are aiming these studies to obtain an understanding of the preservation mechanisms. They are developing measurements to characterize sugar-based glasses with respect to their ability to serve as preservation media for therapeutic proteins and cytokines, and are working to develop theoretical bases for those measurements. These methods are aimed at addressing critical needs of biopharmaceutical formulators, to allow sequestration of cytokines into and delivery from tissue scaffolds with minimal aggregation or chemical degradation. The project results indicate that the beta relaxation times correlated with the stability. The Dental Materials Project The Dental Materials project has developed unique tools for the characterization of dental composite materials. It uses x-ray microcomputed tomography (μCT) to quantify and map (1) polymerization shrinkage and (2) the resultant gaps that appear between the material and tooth structure and often produce leakage. These defects are likely to be responsible for the secondary tooth decay now becoming an increasing health problem. 45

OCR for page 41
The researchers find that slight variations in polymer fabrication protocol can alter the surface hydrophobicity and surface chemistry, which in turn can dramatically affect the initial bacterial colonization on films prepared from the same dental polymer. To enable the use of these new NIST tools in an industrial laboratory environment, the project team has explained its method to instrument suppliers, industrial customers, other government agencies, and academia. Moreover, they are involved in the American Dental Association-Standards Committee for Dental Products to ensure the adoption of standardized tools. Findings and Recommendations The panel’s finding and recommendation for the Biomaterials Group are as follows: Finding: The Bioimaging and Protein Preservation core areas are understaffed for the scope and importance of the work. Recommendation: The outstanding technical progress in the Bioimaging and Protein Preservation areas should be leveraged to grow these programs with additional staff and resources. Characterization and Measurement Group The Characterization and Measurement Group (composed of 7 permanent technical staff, 4 postdoctoral researchers, and 6.8 NIST associates [see footnote 1]) has completed a significant reorganization, with the merger of the Combinatorial Methods Group with the Characterization and Measurement Group, with a focus on sustainable materials. This transition is quite significant, and it was apparent in that there was not really a clear vision of this group, or at least a vision that reflected the ongoing research in the group. This mismatch in research and vision is not unusual at such an early stage in a reorganization. Topics in the presentations included some beginning efforts on renewable materials, a complex interfaces (or a buckling and wrinkling) effort on thin polymer films, and a ballistic resistance effort. The quality of the research being presented was adequate, but the overall effort seemed a catchall, with a group of nonrelated topics being put together under one heading. It was not made clear how these different research efforts meshed toward a common goal, nor was it really clearly stated what the potential impact of the research would be in the short term and in the long term. This is important in the framework of a public presentation of the research and for establishing a coherent effort that will have significant impact from the combined expertise of the investigators on sustainable materials. The advances made in the ballistic-resistant materials were significant, and the identification of extractable phosphorus-containing materials as one route by which a chemical degradation of the soft body armor could occur was important. The expected route of wear by a continued mechanical working of the material was also uncovered. Test protocols were established in both cases, which is in line with the overall mission of NIST and, as a research topic, was quite appropriate for research at NIST. 46

OCR for page 41
However, there is no apparent reason why this should have been placed under the heading of sustainable materials. There are clearly some initial efforts being made on the enzymatic synthesis of some polycaprolactone materials and, along with notable external researchers, advances have been made in the adsorption/desorption of enzymes from polylactic acid (PLA) polymers (biodegradable polymers), by use of microfluidic devices pushing the synthesis to higher molecular weights was demonstrable but, in the long term, it is not clear how this will have a great impact. Another area of research under this theme was on instabilities in thin polymer films. This effort was really focused on the advances made in the area of wrinkling in a composite film architecture where moduli, relaxation behavior, and dynamics in thin polymer films can be assessed. Some very tenuous coupling to sustainable materials was made, and some indications on the measurement of the mechanical properties of sustainable materials were made. However, it was very clear that this is an ongoing, successful research effort that has had a track record of accomplishments and that is not being integrated into an effort that really does fit with the other topics. There is no question that the surface is quite important in the degradation of materials and that the surface is the first part of a material that will fail and that the measurements can clearly provide information on the surface behavior of a material. What was not done in the presentation was to draw the results of the studies into a clear framework under the heading of sustainable materials. Findings and Recommendations The panel’s findings and recommendations for the Characterization and Measurement Group are as follows: Finding: Sustainable materials are an important topic in which NIST should have a presence and be developing measurement standards or generating novel materials that will set their own standards; however, the Characterization and Measurement Group is not in a position at present to do this. Recommendation: To have a significant impact in this area, some effort on the synthesis of new materials is critical. . Finding: While this research is topical and the group could have significant impact, the effort is certainly not complete yet. Recommendation: A rescoping of the effort is needed; a redefinition of the vision is in order; a set of objectives, goals, and milestones needs to be established; and the researchers in this effort must work in a quasi-unified manner toward this common goal. Electronic Materials Group The Electronic Materials Group is composed of 7 permanent technical staff, 5 postdoctoral researchers, 11 NIST associates (see footnote 1), and 1 administrative 47

OCR for page 41
support staff member. The group’s vision is to transform itself to have an impact on both electronics and energy industries. The group’s efforts have been expanded to include significant work in organic electronics and photovoltaics, and some effort in energy storage and delivery materials toward accomplishing that vision. Some of the CRADAs in semiconductor electronics have been successfully completed, and several new CRADAs and MTAs have been initiated in organic photovoltaics. Key facilities and instrumentation to which the group has access and developed include x-ray measurement capabilities, materials measurements, and a newly developed organic electronics processing laboratory. The group has been successful in obtaining close to $2 million for setting up an organic photovoltaic test facility and femtosecond laser-based nonlinear optical spectroscopy for thin-films analysis. A strategic planning process has streamlined and integrated the group’s multiple programs into three broad umbrellas of dimensional metrology for nanofabrication, a new focus on materials for energy storage and delivery, and a focus on organic electronics and photovoltaics. The dimensional metrology for nanofabrication activity is continuing to focus on addressing dimensional metrology needs as well as other critical issues of importance to lithography, such as line edge roughness, linewidth roughness, and the International Technology Roadmap for Semiconductors through a variety of techniques that include x-ray scattering, critical-dimension small-angle x-ray scattering (CD-SAXS), grazing incidence small-angle x-ray scattering (GISAXS), and quantitative rotational SANS. The group has validated and propagated the methods to industry through CRADAs, workshops at conferences, participation in industrial consortia meetings (e.g., SEMATECH), and participation in round-robin critical-dimension scanning electron microscopy (CD-SEM) and optical scatterometry measurement comparisons. The Energy Storage and Delivery Materials project is focused on understanding the charge transport and device performance of fuel cells and batteries through an elucidation of the structure and dynamics in transport media of membranes. The researchers have demonstrated that ineleastic neutron scattering is sensitive to both nanosecond and picosecond dynamics, which dictate ion transport in Nafion in the case of fuel cells and polyethylene oxide (PEO) in the case of batteries. The effort unraveled an interface defined structure in Nafion that is subject to strong deviations in water diffusivity, solubility, and permeability in thin films. Polarization-modulation infrared reflectance spectroscopy measurements have demonstrated how interfacial regions of Nafion can impede water diffusion because of lamellar-like ion transport channels in Nafion. The study also established a strong correlation between the nanosecond and picosecond dynamics data obtained for hyperbranched PEO with neutron scattering to lithium-ion mobility in batteries. The effort is conducted through collaborations with both industry and global academia. The Organic Electronics and Photovoltaics project has established several collaborations with academic institutions, the National Renewable Energy Laboratory, and many industrial institutions through CRADAs and MTAs, with a vision to develop a fundamental understanding of polymer semiconductors and polymer bulk heterojunction (BHJ) devices. Materials’ electrical parameters and device performance have been correlated to both molecular properties of constituent layers and the microstructure and interfacial properties of thin films. The microstructure and interfaces in turn are defined 48

OCR for page 41
by the process parameters. This insight is extremely important for taking the important fields of organic electronics and organic photovoltaics from an empirical state to a science-based understanding that will help develop reproducible devices from robust manufacturing processes. Some of the key accomplishments of the effort include the following:  An integrated suite of measurement techniques that determined the importance of conjugated plane tilt and side chain interdigitation in pBTTT polymers and its importance to their semiconducting properties.  Dark field TEM to quantify the size and orientation of the grains and correlate the domain size changes to semiconducting properties on the one hand and the process parameters on the other.  Interfacial segregation in BHJ films by a combination of NEXAFS, variable- angle spectroscopic ellipsometry, and neutron reflectivity both to obtain composition information as a function of depth and to ascertain the role of substrate or superstrate.  Solid-state NMR to obtain phase and interface information and model bilayers to measure the exciton diffusion lengths and decouple the role of BHJ interfaces from morphology. Despite this success, it suggests an emerging need for a wide-bore solid-state NMR instrument capable of assessing heterogeneous materials and devices whose size exceeds that of the solid-state NMR equipment available at present in the laboratory.  The effort is well recognized, with 55 peer-reviewed publications; more than 75 invited talks at conferences, industry, and academia; 15 industrial collaborations; 18 academic collaborations; 4 CRADAs; 2 MTAs; and conversion of MSEL funding to scientific and technical research services (STRS) base ($263,000) and 6 academic interns. The Processing Characterization Group The Processing Characterization Group comprises 7 permanent technical staff, 4 NRC postdoctoral researchers, 10.2 NIST associates (see footnote 1), and 1 administrative support member. The mission of this group is to develop measurement methods that quantify the mesoscopic structures, the interactions, and the ultimate product performance of complex fluids. The proposed name change to “Complex Fluids Group” is logical. The technical leaders are very visible in the complex fluids community. Their publications and presentations are at a high technical level. Project areas of each group member were listed, but indications of quality such as publications and impact factor were not provided. The group lost one very visible staff member in the past year to academia and one to retirement, while one senior hire and one internal transfer were made. There appear to be many connections to industry, but these were not clearly documented or summarized. The panel reviewed selected examples of the technological research covered by the Processing Characterization Group; however, the examples chosen did not tell a cohesive story that related how the changes implemented since the previous assessment improved the effectiveness of the group. 49

OCR for page 41
Carbon Nanotube Metrology The objective of this group is to develop and augment measurement technologies for identifying and predicting the properties of carbon nanotubes (CNTs). The Nanotube Metrology Program has made noteworthy progress since the assessment 2 years ago. It has developed a CNT SRM, which will be introduced this year. An indication of the need for this CNT SRM and who the customers will be were not presented. The addition of expertise in DNA that has been made allows CNT separation by chirality in addition to the group’s scalable centrifugation technique and has accelerated the Nanotube Metrology Program. Although the size of the group appears sufficient to achieve the stated objectives and meet the challenges articulated, the long-term vision, impact, and future plans were not clear. The fact that no mention was made that this work was an improvement upon the state of the art seems an indication that there was no real excitement about the magnitude of the group’s accomplishments. Nanoparticle Assembly in Complex Fluids The objective of this group is to develop in situ measurements that quantify the dynamic structure, transport properties, and stability of nanoparticle assemblies in multicomponent fluids. The motivation statement is vague, and it does not capture that complex fluids can comprise a rich variety of systems including colloidal suspensions, surfactant mixtures, polymeric liquids, and biomolecular assemblies. This rich variety should make an interesting pathway for industry and academic collaboration. For example, the research efforts of the University of Illinois in soft materials, interfaces, and complex fluids can tie their theoretical/simulation efforts with the measurement paradigm at NIST. The pH jump experiments are impressive but need to show a tie to NIST missions, perhaps to environmental health and safety. The objectives of this program are unclear, as there was no clear statement of need from an external customer or partner. Micro-rheometry The objective of the Micro-rheometry Program is to develop micro- and nanofluidic tools that measure rheological properties of complex fluids. Over the past several years, the group has developed a clever, very small volume capillary rheometer for polymer melts. The microfluidic-based technology that it has developed to measure drop deformation and velocity tracking inside droplets is cutting-edge work. Although the ability to obtain interfacial tension, adsorption kinetics, as well as interfacial viscosity and especially dilation simultaneously was impressive, technical aspects were hard to understand, and the impact and importance to the field were not clearly articulated. Further, the step change advancement in rheological measurement was not framed within the overall space of the current state of the art. This provides another opportunity for broad dissemination of this work within the context of measurement science. This work seems to fit into the NIST mission of new measurement methods. 50

OCR for page 41
Although commercialization is being pursued under an SBIR by a respectable small company, Cambridge Polymer Group, the group should also contact RheoSense to see if there is interest in its MEMS-based dynamic rheome. FINDINGS AND RECOMMENDATIONS Finding: The vision for the Polymers Division needs to be more clearly defined and presented in a more compelling manner. Recommendation: A crisper vision should be developed for the Polymers Division, portraying where the orgainization will be in a 5-year time period. The aspiration should be specified away from the simple aim of being a “great research laboratory.” Instead a clear vision should be articulated of which areas will be grown, the resources required (staff and equipment), and how this plan will lead to maintaining and enhancing the Polymers Division’s national and global prominence. Finding: The successful semiconductor electronics project appears to be terminating while substantial industrial interest in it remains. Recommendation: The Polymers Division should look for ways to maintain the size and scope of the semiconductor electronics effort to continue to have an impact on this important industry. Finding: The current division structure does not clearly align staff with core capabilities. Recommendation: A divisional structure should be considered that is more clearly matrixed to classify staff both along the lines of groups and of core capabilities. A capability leader should be identified for each core capability in order to ensure that the capabilities are appropriately managed and maintained through staff turnovers. Finding: There is a certain amount of anxiety and uncertainty owing to the loss of key personnel and an unfilled group leader position. Recommendation: The position of group leader for the Biomaterials Group should be filled as soon as possible. Finding: In some groups, particularly the Biomaterials Group, the substantial strength of the research area is strongly reliant on the competencies of non-NIST collaborators. Recommendation: These programs should be grown to increase the NIST competency, and this could be done through the leveraging of existing strengths. Finding: Theoretical and computational groups are not adequately integrated and would also benefit from increased ties to other groups outside NIST. At present they 51

OCR for page 41
meet through an ad hoc consortium and do not appear to have any unifying mechanisms, such as a seminar series, that focuses on theoretical and computational tools, or a common computing facility. Their computing needs are currently addressed through the use of desktop computing or off-site high-performance computing (HPC) facilities. A mid-sized HPC facility somewhere between these two extremes, located within the division, is notably absent. Recommendation: The theoretical and computational groups, in particular, should be unified within a core capability, and a capability leader should be identified. Through this leadership, collaboration between theoretical groups and through programs to experimentalists should be built. While this area would likely benefit from additional staff—temporary or permanent—the core capability and collaboration could also benefit from increased ties to theoretical and computational laboratories throughout the nation. (That is not to say that ties do not exist at present as, for example, existing collaborators include Juan de Pablo at the University of Wisconsin-Madison and Glenn Fredrickson at the University of California, Santa Barbara.) The acquisition of a mid-sized HPC facility managed by division scientists would permit local users to explore larger systems than those accessible on their personal computers without the overhead of requesting time on off-site HPC facilities or the need to ensure that they satisfy the parallelization requirements for said off-site resources. If managed properly, it would also enable the development of codes that scale across a larger number of processors within an environment that is more conducive for fast coding than that which can be found in typical off-site HPC facilities. An additional benefit of a mid-sized HPC facility is the social networks that it would create between the current set of broadly distributed computational scientists across the division. Finding: The quality and number of Polymers Division facilities are impressive, but more acquisitions or MOUs with other NIST units will be needed in the future to maintain the needs of the programs. Recommendation: A prioritized list of acquisition needs and how they dovetail into the division’s strategic plan should be prepared. Examples of future need are (1) a high-field, wide-bore NMR to advance solid-state characterization; and (2) increased high-performance computing assets to simulate the large, multiscale and heterogeneous materials being designed and measured within the programs. The motivation for these two target acquisitions was detailed earlier in the chapter. Finding: Close ties to instrument companies have been beneficial to transferring technology from NIST to U.S. industry. Recommendation: Relationships with analytical equipment companies, both as customers and collaborators, should continue to be aggressively cultivated so as to define simple pathways to transfer Polymers Division technological developments to the marketplace. In addition, with the continued drive toward new areas of polymer and measurement science, the inroads that have been made to existing technologies, like the 52

OCR for page 41
microelectronics industry, must be maintained for the impact of prior accomplishments to be fully realized. Finding: Mentoring of postdoctoral associates is uneven across the Polymers Division. Recommendation: A mentoring program and a set of guidelines for mentoring postdoctoral associates as well as junior staff should be established, and an expectation should be set that mentoring is necessary to be promoted to positions of leadership. Finding: Division scientists are well qualified to receive more national awards. Recommendation: The Polymers Division should focus on conducting even- higher-impact research as well as on the marketing of the accomplishments and on obtaining due recognition for the work. Finding: The obvious strength of this very successful division needs to be enhanced by a bolder vision for expansion and growth. Recommendation: The Polymers Division should focus more on systematically pushing the boundaries of its budgets and its core competencies and less on addressing short-term administrative turnover and other exigencies. 53