Hard X-ray techniques suitable for polymer experiments (original) (raw)
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Iop Conference Series: Materials Science and Engineering, 2010
Most advanced applications of polymers rely on heterogeneous structures or specific interfacial properties to yield desired performance and functionalities. Rational design and application require that these structures be characterized. Recently, it has been demonstrated that soft x-ray scattering is a unique complementary technique to conventional hard x-ray and neutron scattering and an excellent tool for polymer structure determination with improved chemical sensitivity. Efforts to enhance the capabilities and efficiency of soft x-ray scattering through the use of a CCD detector will be delineated and first results presented. Development of a dedicated setup at beamline 11.0.1.2 of the Advanced Light Source will be described. This set-up has an elliptically polarized undulator as a source, which offers complete polarization control and hence unique capabilities.
2000
In the last 20 years, synchrotron based soft X-ray scanning transmission X-ray microscopy (STXM) [1,2] has emerged as a powerful micro-analytical technique with particular strengths in the analysis of soft matter — polymers, biological and environmental samples. Its analytical power stems from spatially resolved near-edge X-ray absorption spectroscopy (NEXAFS); thus it produces information analogous to that delivered by electron energy
The use of an imaging plate as a detecting system in X-ray diffraction of polymers
Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 1995
We present in this paper some applications of X-ray diffraction to polymer studies, using an imaging plate as the detector. The advantages of this system make it very attractive for a number of experimental measurements (WAXS and SAXS), especially on oriented polymer samples.
Journal of Polymer Science Part B: Polymer Physics, 2010
The mechanical behavior of polymer materials is strongly dependent on polymer structure and morphology of the material. The latter is determined mainly by processing and thermal history. Temperature-dependent on-line X-ray scattering during deformation enables the investigation of deformation processes, fatigue and failure of polymers. As an example, investigations on polypropylene are presented. By on-line X-ray scattering with synchrotron radiation, a time resolution in the order of seconds and a spatial resolution in the order of microns can be achieved. The characterization of the crystalline and amorphous phases as well as the study of cavitation processes were performed by simultaneous SAXS and WAXS. The results of scattering experiments are complemented by DSC measurements and SEM investigations.
Applied Physics Letters, 2004
Energy-dispersive small-angle X-ray scattering (ED-SAXS) with an innovative design of cone collimation based on an ellipsoidal single-bounce capillary (ESBC) and a polycapillary parallel X-ray lens (PPXRL) had been explored. Using this new cone collimation system, scattering angle 2θ has a theoretical minimum angle related to the mean half-opening angle of the hollow cone beam of 1.42 mrad, and with the usable X-ray energy ranging from 4 to 30 keV, the resulting observable scattering vector q is down to a minimum value of about 0.003 Å −1 (or a Bragg spacing of about 2100 Å). However, the absorption of lower energies by X-ray capillary optics, sample transmission, and detector response function limits the application range to lower energy. Cone collimation ED-SAXS experiments carried out on pure water, Lupolen, and in situ temperature-dependent measurement of diacetylenic acid/melamine micelle solid were presented at three different scattering angles 2θ of 0.18 • , 0.70 • and 1.18 • to illustrate the new opportunities offered by this technique as well as its limitations. Also, a comparison has been made by replacing the PPXRL with a pinhole, and the result shows that cone collimation ED-SAXS based on ESBC with PPXRL was helpful in improving the signal-to-noise ratio (i.e., reducing the parasitic background scattering) than ESBC with a pinhole. The cone collimation instrument based on X-ray capillary optics could be considered as a promising tool to perform SAXS experiments, especially cone collimation ED-SAXS has potential application for the in situ temperature-dependent studying on the kinetics of phase transitions.
European Physical Journal-special Topics, 2009
The utility of resonant soft x-ray scattering (RSoXS) and reflectivity (RSoXR) is extended and exemplified through the characterization of thin films of polymers relevant to organic solar cells and of dilute polymer solutions. RSoXS and RSoXR are methods that utilize anomalous scattering principles at soft x-ray energies. Soft X-rays cover the carbon, nitrogen and oxygen absorption edges, elements very relevant for polymers and colloids. The rapid changes of optical properties near these absorption edges provide selectivity to specific moieties and high contrast. RSoXR is shown to be a powerful tool for the characterization of bilayers of conducting polymers. The RSoXR results point to an interesting strategy that will allow the chemical interdiffusion and physical roughness at a buried polymer/polymer interface to be determined independently. The high scattering cross sections also allows the investigation of thin films of conjugated polymer blends in transmission at thicknesses for which hard X-rays or neutrons would yield relatively little scattering. By scattering at photon energies that provide strong scattering contrast, even very dilute polymeric solutions yield a useable signal.
Survey of contrasts of polymers under a high-contrast X-ray computerized tomography
Polymer, 2012
Contrasts of the polymer materials under a high contrast X-ray computerized tomography (XCT) are comprehensively investigated. We developed a high contrast XCT, and demonstrated its capabilities to polymer systems, such as polymer blends. Then we got a hypothesis that the pixel values of the crosssectional image obtained by XCT agree with the X-ray absorption coefficient at 15 keV. This hypothesis is intensively examined by using various polymers. Consequently, we propose an empirical criterion that 0.1 cm À1 difference in the X-ray absorption coefficients at 15 keV is necessary to distinguish the polymers under XCT. This criterion is also confirmed in the polymer blend systems.
European Polymer Journal, 2016
Modern synchrotron beamlines equipped with two-dimensional detectors and high-flux microfocus devices offer interesting possibilities for polymer characterization. This work presents three synchrotron X-ray studies performed in specific multicomponent polymer systems. In the first study, quantification of transcrystallinity in microfibrillar composites (MFC) by wide-angle X-ray scattering (WAXS) and a direct relation between the mechanical properties of the composites and the thickness of the transcrystalline layers is presented. The second study demonstrates monitoring of nanostructure development under controlled strain in MFC and their precursors by small-angle X-ray scattering (SAXS). A specially developed procedure for data treatment that uses the Chord Distribution Function formalism permitted to prove reversible strain-induced crystallization of matrix material in the MFC materials. In the third study, a 5 Â 5 lm high flux X-ray beam was used to scan in WAXS mode polymer microcapsules (average diameters of 20-50 lm) with polyamide shells in which various solid payloads were incorporated by in-situ polymerization. Exfoliation/intercalation phenomena and local inhomogeneity at micron scale are studied in clay and metal containing polyamide microcapsules that constitute a new platform for the development of polymer hybrids or smart micro devices. It was concluded that relating microscopy and/or mechanical data of various polymer samples to their synchrotron WAXS/SAXS patterns helps to understand the structure-properties relationship in complex polymer systems with controlled composition, morphology and nanostructure.