Small Angle X-Ray Scattering of Crystalline Polymer Blends

1993 ◽  
Vol 321 ◽  
Author(s):  
Peter P. Huo ◽  
Peggy Cebe ◽  
Malcolm Capel

ABSTRACTBinary blends of a semicrystalline polymer, poly (butylene terephthalate), PBT, with an amorphous polymer, polyarylate, PAr, were studied for a wide range of compositions. SMall angle x-ray scattering, thermal and mechanical analyses were conducted to determine the location of the uncrystallizable PAr relative to the crystal lamellae of PBT, for blends crystallized by heating from the quenched state. Comparison of experimental and calculated long periods indicates that interlamellar PAr placement becomes less probable as the PAr composition increases. When PBT crystallizes in these blends, Most PAr is rejected from the regions near the crystal surfaces when PAr fraction exceeds about 0.40.

Catalysts ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 730
Author(s):  
Erik Sarnello ◽  
Tao Li

Enzyme immobilization techniques are widely researched due to their wide range of applications. Polymer–protein core–shell nanoparticles (CSNPs) have emerged as a promising technique for enzyme/protein immobilization via a self-assembly process. Based on the desired application, different sizes and distribution of the polymer–protein CSNPs may be required. This work systematically studies the assembly process of poly(4-vinyl pyridine) and bovine serum albumin CSNPs. Average particle size was controlled by varying the concentrations of each reagent. Particle size and size distributions were monitored by dynamic light scattering, ultra-small-angle X-ray scattering, small-angle X-ray scattering and transmission electron microscopy. Results showed a wide range of CSNPs could be assembled ranging from an average radius as small as 52.3 nm, to particles above 1 µm by adjusting reagent concentrations. In situ X-ray scattering techniques monitored particle assembly as a function of time showing the initial particle growth followed by a decrease in particle size as they reach equilibrium. The results outline a general strategy that can be applied to other CSNP systems to better control particle size and distribution for various applications.


2013 ◽  
Vol 46 (5) ◽  
pp. 1508-1512 ◽  
Author(s):  
Byron Freelon ◽  
Kamlesh Suthar ◽  
Jan Ilavsky

Coupling small-angle X-ray scattering (SAXS) and ultra-small-angle X-ray scattering (USAXS) provides a powerful system of techniques for determining the structural organization of nanostructured materials that exhibit a wide range of characteristic length scales. A new facility that combines high-energy (HE) SAXS and USAXS has been developed at the Advanced Photon Source (APS). The application of X-rays across a range of energies, from 10 to 50 keV, offers opportunities to probe structural behavior at the nano- and microscale. An X-ray setup that can characterize both soft matter or hard matter and high-Zsamples in the solid or solution forms is described. Recent upgrades to the Sector 15ID beamline allow an extension of the X-ray energy range and improved beam intensity. The function and performance of the dedicated USAXS/HE-SAXS ChemMatCARS-APS facility is described.


2018 ◽  
Vol 51 (3) ◽  
pp. 867-882 ◽  
Author(s):  
Jan Ilavsky ◽  
Fan Zhang ◽  
Ross N. Andrews ◽  
Ivan Kuzmenko ◽  
Pete R. Jemian ◽  
...  

Following many years of evolutionary development, first at the National Synchrotron Light Source, Brookhaven National Laboratory, and then at the Advanced Photon Source (APS), Argonne National Laboratory, the APS ultra-small-angle X-ray scattering (USAXS) facility has been transformed by several new developments. These comprise a conversion to higher-order crystal optics and higher X-ray energies as the standard operating mode, rapid fly scan measurements also as a standard operational mode, automated contiguous pinhole small-angle X-ray scattering (SAXS) measurements at intermediate scattering vectors, and associated rapid wide-angle X-ray scattering (WAXS) measurements for X-ray diffraction without disturbing the sample geometry. With each mode using the USAXS incident beam optics upstream of the sample, USAXS/SAXS/WAXS measurements can now be made within 5 min, allowingin situandoperandomeasurement capabilities with great flexibility under a wide range of sample conditions. These developments are described, together with examples of their application to investigate materials phenomena of technological importance. Developments of two novel USAXS applications, USAXS-based X-ray photon correlation spectroscopy and USAXS imaging, are also briefly reviewed.


1994 ◽  
Vol 38 ◽  
pp. 489-493
Author(s):  
Mark V. Brilihart ◽  
Peggy Cebe ◽  
Malcolm Capel

X-ray scattering is a powerful analytical tool for evaluation of phase structure in crystallizable polymers blends. Our group has been studying crystallization kinetics and micro structure development in binary polymer blends using real-time small angle X-ray scattering (SAXS). Here we describe our research on blends of a crystallizable polymer, poly(burylene terephthalate), PBT, with an amorphous polymer, polycarbonate), PC. In prior studies, we used the same crystalline polymer blended with amorphous polyarylate, PAr. The PBT/PAr system was shown to be inisciblu at all compositions in the melt state. In the present case, PBT/PC blends are not believed to be miscible in the melt. This study was undertaken to determine whether the PBT crystallization kinetics were affected by the presence of low molecular weight PC. This is part of a larger study to investigate the effects of different molecular weights on partial miscibility and on structure development in binary polymer blends.


2000 ◽  
Vol 33 (18) ◽  
pp. 6856-6860 ◽  
Author(s):  
Anton A. Apostolov ◽  
Stoyko Fakirov ◽  
Manfred Stamm ◽  
Rahul D. Patil ◽  
James E. Mark

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