Hydrothermal aging mechanisms of aramid fibers via synchrotron small-angle X-ray scattering and dynamic thermal mechanical analysis

2012 ◽  
Vol 128 (2) ◽  
pp. 1291-1296 ◽  
Author(s):  
Chang-Sheng Li ◽  
Mao-Sheng Zhan ◽  
Xian-Cong Huang ◽  
Hong Zhou ◽  
Yan Li
Keyword(s):  
Small Angle ◽  
Mechanical Analysis ◽  
Aramid Fibers ◽  
Hydrothermal Aging ◽  
X Ray ◽  
X Ray Scattering ◽  
Dynamic Thermal Mechanical Analysis ◽  
Aging Mechanisms ◽  
Thermal Mechanical Analysis ◽  
Ray Scattering

Relationship between performance and microvoids of aramid fibers revealed by two-dimensional small-angle X-ray scattering

2013 ◽  
Vol 46 (4) ◽  
pp. 1178-1186 ◽  
Author(s):  
Caizhen Zhu ◽  
Xiaofang Liu ◽  
Jing Guo ◽  
Ning Zhao ◽  
Changsheng Li ◽  
...  
Keyword(s):  
Small Angle ◽  
Aramid Fiber ◽  
Angle Distribution ◽  
Two Dimensional ◽  
Fiber Morphology ◽  
Aramid Fibers ◽  
X Ray ◽  
X Ray Scattering ◽  
Fitting Method ◽  
Ray Scattering

Although the crystal structure in aramid fibers and the relationship between the size and orientation of crystallites and the performance of a material have been explored in detail, the effect of microvoids in an aramid fiber on its performance is still not clear. However, it is known that the mechanical properties depend strongly on the fiber morphology. In the present research, two-dimensional small-angle X-ray scattering is applied to characterize the microvoids in aramid fibers. Pauw's two-dimensional full pattern fitting method and scattering model have been enhanced by introducing orientation parameters, such as zenith angle distribution and azimuthal angle distribution, and instrumental parameters like point spread function and beam profile function. A series of aramid fibers with different strengths were studied using the new two-dimensional full pattern fitting method to extract the microvoid parameters from the scattering patterns. The results show that the microvoids in the aramid fiber affect the fiber strength directly. The greater the number of spherical microvoids and the larger the ellipsoidal microvoids, the weaker the aramid fiber.

A Revised O2 Reduction Model in Li-O2 Batteries as Revealed by in Situ Small Angle X-Ray Scattering

2019 ◽  
Author(s):  
Christian Prehal ◽  
Aleksej Samojlov ◽  
Manfred Nachtnebel ◽  
Manfred Kriechbaum ◽  
Heinz Amenitsch ◽  
...  
Keyword(s):  
Small Angle ◽  
Wide Angle ◽  
Reduction Mechanism ◽  
Reduction Model ◽  
X Ray ◽  
X Ray Scattering ◽  
O2 Reduction ◽  
Ray Scattering

<b>Here we use in situ small and wide angle X-ray scattering to elucidate unexpected mechanistic insights of the O2 reduction mechanism in Li-O2 batteries.<br></b>

In situ Time-Resolved Small-Angle X-ray Scattering Reveals the Formation Kinetics of Polyelectrolyte Complex Micelles

2019 ◽  
Author(s):  
Hao Wu ◽  
Jeffrey Ting ◽  
Siqi Meng ◽  
Matthew Tirrell
Keyword(s):  
Small Angle ◽  
Self Assembly ◽  
Electrostatic Interactions ◽  
Polyelectrolyte Complex ◽  
Time Resolved ◽  
X Ray ◽  
X Ray Scattering ◽  
Kinetics Of ◽  
Ray Scattering

We have directly observed the <i>in situ</i> self-assembly kinetics of polyelectrolyte complex (PEC) micelles by synchrotron time-resolved small-angle X-ray scattering, equipped with a stopped-flow device that provides millisecond temporal resolution. This work has elucidated one general kinetic pathway for the process of PEC micelle formation, which provides useful physical insights for increasing our fundamental understanding of complexation and self-assembly dynamics driven by electrostatic interactions that occur on ultrafast timescales.

Small angle X-ray scattering study of porosity variation in a styrene-divinylbenzene copolymer

1981 ◽  
Vol 46 (7) ◽  
pp. 1675-1681 ◽  
Author(s):  
Josef Baldrian ◽  
Božena N. Kolarz ◽  
Henrik Galina
Keyword(s):  
Small Angle ◽  
Structural Parameters ◽  
Two Phase ◽  
X Ray ◽  
Porosity Variation ◽  
Swelling Agent ◽  
X Ray Scattering ◽  
Styrene Divinylbenzene ◽  
Ray Scattering

Porosity variations induced by swelling agent exchange were studied in a styrene-divinylbenzene copolymer. Standard methods were used in the characterization of copolymer porosity in the dry state and the results were compared with related structural parameters derived from small angle X-ray scattering (SAXS) measurements as developed for the characterization of two-phase systems. The SAXS method was also used for porosity determination in swollen samples. The differences in the porosity of dry samples were found to be an effect of the drying process, while in the swollen state the sample swells and deswells isotropically.

Mirror to measure small angle x-ray scattering signal in high energy density experiments

2020 ◽  
Vol 91 (12) ◽  
pp. 123501
Author(s):  
M. Šmíd ◽  
C. Baehtz ◽  
A. Pelka ◽  
A. Laso García ◽  
S. Göde ◽  
...  
Keyword(s):  
Energy Density ◽  
Small Angle ◽  
High Energy ◽  
High Energy Density ◽  
X Ray ◽  
X Ray Scattering ◽  
Scattering Signal ◽  
Ray Scattering
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