Studies of Molecular Orientation in Deformed Semicrystalline Polymers by X- Ray Scattering Employing Synchrotron Radiation

1986 ◽  
Vol 79 ◽  
Author(s):  
S. Röber ◽  
R. Gehrke ◽  
H. G. Zachmann

IntroductionThe possibility of using synchrotron radiation as a source of X-rays for scattering experiments has considerably improved the methods of the characterisation of the molecular orientation and molecular order in polymers. In another publication [1], it has been shown that the morphology of ultra highly drawn polyethylene is correlated to the kinetics of isothermal melting, as determined by X- ray scattering employing synchrotron radiation. In this paper we present some results on chain orientation and orientation of crystal lamellae surfaces in uniaxially and biaxially drawn films of polyethyleneterephthalate (PET). These results were obtained by inserting a pole figure goniometer into the synchrotron radiation beam and measuring the wide angle X-ray scattering (WAXS) and small angle X- ray scattering (SAXS) with different angles of incidence of the primary beam onto the sample.

2014 ◽  
Vol 369 (1647) ◽  
pp. 20130315 ◽  
Author(s):  
Derek Mendez ◽  
Thomas J. Lane ◽  
Jongmin Sung ◽  
Jonas Sellberg ◽  
Clément Levard ◽  
...  

Tools to study disordered systems with local structural order, such as proteins in solution, remain limited. Such understanding is essential for e.g. rational drug design. Correlated X-ray scattering (CXS) has recently attracted new interest as a way to leverage next-generation light sources to study such disordered matter. The CXS experiment measures angular correlations of the intensity caused by the scattering of X-rays from an ensemble of identical particles, with disordered orientation and position. Averaging over 15 496 snapshot images obtained by exposing a sample of silver nanoparticles in solution to a micro-focused synchrotron radiation beam, we report on experimental efforts to obtain CXS signal from an ensemble in three dimensions. A correlation function was measured at wide angles corresponding to atomic resolution that matches theoretical predictions. These preliminary results suggest that other CXS experiments on disordered ensembles—such as proteins in solution—may be feasible in the future.


1997 ◽  
Vol 30 (1) ◽  
pp. 49-54 ◽  
Author(s):  
J.-M. Dubuisson ◽  
T. Decamps ◽  
P. Vachette

An evacuated, temperature-controlled cell has been built for use on the small-angle X-ray scattering instrument D24 at the synchrotron radiation facility LURE. The sample is placed in a quartz capillary sealed in a stainless-steel holder using a vacuum-tight glue. Several O rings provide a vacuum path upstream and downstream from the cell, so that the X-ray beam only meets the capillary walls and the solution under study between the slits and the beam stop, while the sample is maintained under atmospheric pressure. The cell temperature is controlled via a water circulation through a copper sheath in tight contact with the steel holder. The use of this cell results in a marked reduction of the background, as observed in two series of parallel experiments using a conventional cell and this evacuated cell. The decrease ranges from a factor of 2 at s 1 values larger than 0.008 Å−1 to more than 15 at s = 0.00116 Å−1, where s is the modulus of the scattering vector (s = 2sin θ/λ, 2θ is the scattering angle and λ is the wavelength of the X-rays).


Polymers ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 1624
Author(s):  
Atsushi Takahara ◽  
Yuji Higaki ◽  
Tomoyasu Hirai ◽  
Ryohei Ishige

Light produced by synchrotron radiation (SR) is much brighter than that produced by conventional laboratory X-ray sources. The photon energy of SR X-ray ranges from soft and tender X-rays to hard X-rays. Moreover, X-rays become element sensitive with decreasing photon energy. By using a wide energy range and high-quality light of SR, different scattering and spectroscopic methods were applied to various soft matters. We present five of our recent studies performed using specific light properties of a synchrotron facility, which are as follows: (1) In situ USAXS study to understand the deformation behavior of colloidal crystals during uniaxial stretching; (2) structure characterization of semiconducting polymer thin films along the film thickness direction by grazing-incidence wide-angle X-ray scattering using tender X-rays; (3) X-ray absorption fine structure (XAFS) analysis of the formation mechanism of poly(3-hexylthiophene) (P3HT); (4) soft X-ray absorption and emission spectroscopic analysis of water structure in polyelectrolyte brushes; and (5) X-ray photon correlation spectroscopic analysis of the diffusion behavior of polystyrene-grafted nanoparticles dispersed in a polystyrene matrix.


2008 ◽  
Vol 599 ◽  
pp. 107-125 ◽  
Author(s):  
Martin Müller

X-ray scattering techniques have been a very useful tool for the non-destructive analysis of the wood structure. X-rays are sensitive to structural parameters such as the composite structure of wood cell walls, the crystal structure of cellulose microfibrils and their helical arrangement in the cell wall, which is usually described by the microfibril angle (MFA). With the availability of synchrotron radiation sources novel experiments on wood have become possible. The increased flux of X-rays makes the in situ and time-resolved investigation of structural changes upon mechanical stress possible. The low-divergence synchrotron radiation X-rays can be focused down to sub-micrometer size, enabling scanning studies of the wood nanostructure with (sub-)microscopic position resolution. This chapter highlights very recent advances in the understanding of wood micro- and nanostructure, which were only possible using synchrotron radiation. Examples include the MFA determination in the individual layers of the secondary cell wall, the imaging of the helical structure of the cellulose microfibrils in the cell wall, lattice strain as induced by applied mechanical stress and the structural changes of different wood types under external tensile stress.


2019 ◽  
Author(s):  
Hao Wu ◽  
Jeffrey Ting ◽  
Siqi Meng ◽  
Matthew Tirrell

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.


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