Advanced Photon Source

A U.S. Department of Energy, Office of Science,
Office of Basic Energy Sciences national synchrotron x-ray research facility

Publications from year 2009

Ultra-small-angle X-ray scattering at the Advanced Photon Source. The design and operation of a versatile ultra-small-angle X-ray scattering (USAXS) instrument at the Advanced Photon Source (APS) at Argonne National Laboratory are presented. The instrument is optimized for the high brilliance and low emittance of an APS undulator source. It has angular and energy resolutions of the order of 10-4, accurate and repeatable X-ray energy tunability over its operational energy range from 8 to 18 keV, and a dynamic intensity range of 108 to 109, depending on the configuration. It further offers quantitative primary calibration of X-ray scattering cross sections, a scattering vector range from 0.0001 to 1 A-1, and stability and reliability over extended running periods. Its operational configurations include one-dimensional collimated (slit-smeared) USAXS, two-dimensional collimated USAXS and USAXS imaging. A robust data reduction and data analysis package, which was developed in parallel with the instrument, is available and supported at the APS. J. Ilavsky, P.R. Jemian, A.J. Allen, F. Zhang, L.E. Levine and G.G. Long. Cited: Journal of Applied Crystallography, 2009, 42 (3), p 469-479.

Irena: tool suite for modeling and analysis of small-angle scattering. Irena, a tool suite for analysis of both X-ray and neutron small-angle scattering (SAS) data within the commercial Igor Pro application, brings together a comprehensive suite of tools useful for investigations in materials science, physics, chemistry, polymer science and other fields. In addition to Guinier and Porod fits, the suite combines a variety of advanced SAS data evaluation tools for the modeling of size distribution in the dilute limit using maximum entropy and other methods, dilute limit small-angle scattering from multiple non-interacting populations of scatterers, the pair-distance distribution function, a unified fit, the Debye-Bueche model, the reflectivity (X-ray and neutron) using Parratt's formalism, and small-angle diffraction. There are also a number of support tools, such as a data import/export tool supporting a broad sampling of common data formats, a data modification tool, a presentation-quality graphics tool optimized for small-angle scattering data, and a neutron and X-ray scattering contrast calculator. These tools are brought together into one suite with consistent interfaces and functionality. The suite allows robust automated note recording and saving of parameters during export. J. Ilavsky and P.R. Jemian. Cited: Journal of Applied Crystallography, 2009, 42 Apr, p 347-353

Anisotropic self-assembly of spherical polymer-grafted nanoparticles. P. Akcora, H. Liu, S.K. Kumar, J. Moll, Y. Li, B.C. Benicewicz, L.S. Schadler, D. Acehan, A.Z. Panagiotopoulos, V. Pryamitsyn, V. Ganesan, J. Ilavsky, P. Thiyagarajan, R.H. Colby and J.F. Douglas. Nature Materials, 2009, 8 (4), p 354-359.

Morphology of PEG-Stabilized Carbon Nanofibers in Water. J. Zhao and D.W. Schaefer. Cited: Journal of Physical Chemistry B, 2009, 112 (39), p 15306-15310.

Glassy Carbon as an Absolute Intensity Calibration Standard for Small-Angle Scattering.
Absolute calibration of small-angle scattering (SAS) intensity data (measured in terms of the differential scattering cross section per unit sample volume per unit solid angle) is essential for many important aspects of quantitative SAS analysis, such as obtaining the number density, volume fraction, and specific surface area of the scatterers. It also enables scattering data from different instruments (light, X-ray, or neutron scattering) to be combined, and it can even be useful to detect the existence of artifacts in the experimental data. Different primary or secondary calibration methods are available. In the latter case, absolute intensity calibration requires a stable artifact with the necessary scattering profile. Glassy carbon has sometimes been selected as this intensity calibration standard. Here we review the spatial homogeneity and temporal stability of one type of commercially available glassy carbon that is being used as an intensity calibration standard at a number of SAS facilities. We demonstrate that glassy carbon is sufficiently homogeneous and stable during routine use to be relied upon as a suitable standard for absolute intensity calibration of SAS data. F. Zhang, J. Ilavsky, G. Long, J. Quintana, A. Allen and P. Jemian. Cited: Metallurgical and Materials Transactions A, 2009,

Poly (3-hydroxybutyrate-co-3-hydroxyhexanoate) Nanocomposites with Optimal Mechanical Properties. Y. Xie, D. Kohls, I. Noda, D.W. Schaefer and Y.A. Akpalu. Macromolecules (Accepted), 2009

Towards Next Generation TATB-based Explosives by Understanding Voids and Microstructure from 10 nm to 1 cm. T.M. Willey and G.E. Overturf. Proceedings of the 40th International Annual Conference of the Fraunhofer Institute for Chemical Technology; Energetic Materials: Characterization, Modelling, and Validation (Conf. Proc.) (Karlsruhe, Germany, June 23-29), Vol. (19.11-19.12), Ed., 2009, p. 19.11-19.12.

Synthesis of Polystyrene - Polylactide Bottlebrush Block Copolymers and Their Melt Self-Assembly into Large Domain Nanostructures. High molecular weight polystyrene-polylactide (PS-PLA) bottlebrush block copolymers have been shown to self-assemble into highly ordered lamellae structures with domain spacings as large as 163 nm, as identified by ultrasmall-angle X-ray scattering. Bottlebrush block copolymers were synthesized by a combination of living radical and ring-opening polymerizations. The backbone was prepared by RAFT block copolymerization of solketal methacrylate (SM) and 2-(bromoisobutyryl)ethyl methacrylate (BIEM). Polystyrene branches were grafted by ATRP from poly(BIEM) block, and PLA branches were grafted from the poly(SM) block after the removal of ketal groups. The investigation into the self-assembly of PS-PLA bottlebrush block copolymers with varying lengths of branches and backbones revealed a number of unusual trends, which were attributed to their dynamic, three-dimensional structure. The results suggest that in phase-separated melts the bottlebrush block copolymer backbone, while extended, still possesses a certain degree of flexibility to accommodate for different interfacial areas necessary to pack into lamellae microstructures. J. Rzayev. Cited: Macromolecules, 2009, 42 (6), Mar 24, p 2135-2141.

Assessing the potential for CO2 adsorption in a subbituminous coal, Huntly Coalfield, New Zealand, using Small Angle Scattering techniques. T.E. Mares, A.P. Radlinski, T.A. Moore, D. Cookson, P. Thiyagarajan, J. Ilavsky and J.R. Klepp. International Journal of Coal Geology, 2009, 77 p 54-68.

Process-Controlled Plasma-Sprayed Yttria-Stabilized Zirconia Coatings: New Insights from Ultrasmall-Angle X-ray Scattering. A multicomponent microstructure model is applied in ultrasmall-angle X-ray scattering studies of two groups of plasma-sprayed yttria-stabilized zirconia thermal barrier coatings (TBCs). One group was sprayed from a single powder feedstock using controlled processing conditions. The other group included three different feedstock morphologies (obtained from different manufacturing methods), each with a similar particle size distribution and sprayed under the same average controlled processing conditions. The microstructure is quantitatively related to the feedstock morphology and processing conditions. Relationships are explored among these microstructures and the coating properties (e.g., thermal conductivity, elastic modulus). The degree of microstructural anisotropy is demonstrated to be pore-size dependent, being more pronounced for larger pores, and more sensitive to feedstock morphology (powder processing) than to spray processing. The microstructure analysis indicates two broad distributions of interlamellar pores, which combined, account for 70%-80% of the pore volume. The total porosity is found to increase with decreasing particle temperature or velocity. For all coatings, a negative linear relationship exists between thermal conductivity and total porosity. Comparison of the new analysis is made with earlier small-angle neutron scattering results, and implications are considered for a more general application of this metrology in TBC microstructure design. Y.P. Li, W.G. Chi, S. Sampath, A. Goland, H. Herman, A.J. Allen and J. Ilavsky. Cited: Journal of the American Ceramic Society, 2009, 92 (2), Feb, p 491-500.

Quantification of the coarsening kinetics of γ′ precipitates in Waspaloy microstructures with different prior homogenizing treatments. We report on quantification of the γ′ precipitate population, and its coarsening behavior, in controlled Waspaloy microstructures synthesized to possess γ matrix grain sizes ranging from 13 to 89 μm. The grain microstructures were produced by initial solution-treatments at 1045, 1090 and 1145 °C. The γ′ precipitates were obtained by aging at 779 and 796 °C for times ranging from 0.1 to 263.5 h. Specimen characterization was conducted via optical microscopy and scanning electron microscopy, DC four-point probe resistivity and ex situ ultra-small-angle X-ray scattering (USAXS) experiments at each aging time. The γ′ size distribution, obtained from the USAXS analysis, transformed from an initial unimodal to an eventual bimodal distribution with continued aging. The overall coarsening kinetics, although non-steady state, followed t1/3 behavior, when the primary γ′ radius was used as the quantifying precipitate dimension. The coarsening rate constants were primarily determined by the aging temperature used, while the influence of prior homogenizing treatments was minimal to non-existent. A generic correlation was found to exist between a newly proposed figure-of-merit of scattering, η based on the USAXS-derived γ′ precipitate distribution(s) and the measured electrical resistivity. V.S.K. Kelekanjeri, L.K. Moss, R.A. Gerhardt and J. Ilavsky. Cited: Acta Materialia, 2009, 57 p 4658-4670.

Characterization of Complex Thermal Barrier Deposits Pore Microstructures by a Combination of Imaging, Scattering and Intrusion Techniques. J. Ilavsky. Expanding Thermal Spray Performance to New Markets and Applications, Thermal Spray 2009: Proceedings of the International Thermal Spray Conference (Conf. Proc.) May 4-7, 2009 (Las Vegas, NV), Vol. (920-930), Ed., ASM International, 2009, p. 920-930.

Porous Architecture of SPS Thick YSZ Coatings Structured at the Nanometer Scale (~50nm). A. Bacciochini, G. Montavon, J. Ilavsky, A. Denoirjean and P. Fauchais. Expanding Thermal Spray Performance to New Markets and Applications, Thermal Spray 2009: Proceedings of the International Thermal Spray Conference (Conf. Proc.) May 4-7, 2009 (Las Vegas, NV), Vol. (931-938), Ed., ASM International, 2009, p. 931-938.

Tensile and tribological properties of high-crystallinity radiation crosslinked UHMWPE. A. Bistolfi, M.B. Turell, Y.L. Lee and A. Bellare. Journal of Biomedical Materials Research B. Applied Biomaterials, 2009, 90 (1), July 2009, p 137-144.

Multi-scale Microstructure Characterization of Solid Oxide Fuel Cell Assemblies with Ultra Small-Angle X-Ray Scattering. A.J. Allen, J. Ilavsky and A. Braun. Advanced Engineering Materials, 2009, 11 (6), p 495-501.