Crystallization behavior studied by synchrotron small-angle X-ray scattering of poly (lactic acid)/cellulose nanofibers composites

2017 ◽  
Vol 143 ◽  
pp. 106-115 ◽  
Author(s):  
Thanh Chi Nguyen ◽  
Chaiwat Ruksakulpiwat ◽  
Supagorn Rugmai ◽  
Siriwat Soontaranon ◽  
Yupaporn Ruksakulpiwat
Keyword(s):  
Lactic Acid ◽  
Small Angle ◽  
Crystallization Behavior ◽  
Cellulose Nanofibers ◽  
Poly Lactic Acid ◽  
X Ray ◽  
X Ray Scattering ◽  
Ray Scattering

Crystallization Behavior of Poly(ethylene oxide) and Its Blends Using Time-Resolved Wide- and Small-Angle X-ray Scattering

2000 ◽  
Vol 33 (13) ◽  
pp. 4842-4849 ◽  
Author(s):  
Melissa S. Lisowski ◽  
Qiang Liu ◽  
Jaedong Cho ◽  
James Runt ◽  
Fengji Yeh ◽  
...  
Keyword(s):  
Ethylene Oxide ◽  
Small Angle ◽  
Crystallization Behavior ◽  
Time Resolved ◽  
X Ray ◽  
X Ray Scattering ◽  
Poly Ethylene Oxide ◽  
Poly Ethylene ◽  
Ray Scattering

Precursors in stereo-complex crystals of poly(L-lactic acid)/poly(D-lactic acid) blends under shear flow

2014 ◽  
Vol 47 (1) ◽  
pp. 14-21 ◽  
Author(s):  
Kota Hemmi ◽  
Go Matsuba ◽  
Hideto Tsuji ◽  
Takahiko Kawai ◽  
Toshiji Kanaya ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Shear Flow ◽  
Density Fluctuations ◽  
Poly Lactic Acid ◽  
Order Structure ◽  
X Ray ◽  
X Ray Scattering ◽  
Complex Crystals ◽  
Ray Scattering

To improve the mechanical and the thermal performance of poly(lactic acid) materials, this work focuses on the formation of stereo-complex crystals by blending poly(L-lactic acid) (PLLA) with poly(D-lactic acid) (PDLA). The resulting structure was analyzed using time-resolvedin situX-ray scattering, optical microscopy, differential scanning calorimetry and viscoelastic measurements. The objective of this study is to investigate the effect of shear flow imposed prior to crystallization on higher-order structure formation and acceleration of stereo-complex crystal growth of PLLA and PDLA blends using a wide spatial scale analysis and viscoelastic measurements. Density fluctuations of 100 nm scale were observed prior to nucleation byin situsimultaneous wide- and small-angle X-ray scattering measurements. These density fluctuations grew with time and the intensity increased with increasing shear rate. Furthermore, the results revealed that the PLLA and PDLA chains were only partially interpenetrated; consequently, stereo-complex crystals could grow only in the mixed PLLA/PDLA phase. The correlation length of density fluctuation prior to nucleation was strongly dependent on the mixed phases.

Characterization of TEMPO-oxidized cellulose nanofibers in aqueous suspension by small-angle X-ray scattering

2014 ◽  
Vol 47 (2) ◽  
pp. 788-798 ◽  
Author(s):  
Ying Su ◽  
Christian Burger ◽  
Benjamin S. Hsiao ◽  
Benjamin Chu
Keyword(s):  
Cross Section ◽  
Small Angle ◽  
Structural Information ◽  
Rectangular Cross Section ◽  
Aqueous Suspension ◽  
Cellulose Nanofibers ◽  
Weighted Average ◽  
X Ray ◽  
X Ray Scattering ◽  
Ray Scattering

Cellulose nanofibers, extracted from wood pulps using the (2,2,6,6-tetramethylpiperidine-1-yl)oxyl (TEMPO)-mediated oxidation method, are low-cost, sustainable and high-performance materials with potential usage in many applications. The structural information of these cellulose nanofibers in aqueous suspension was characterized by synchrotron small-angle X-ray scattering (SAXS). A simplified ribbon model having a near rectangular cross section was found to give the best fit to the SAXS results. The analytical expression of the ribbon model also led to a higher calculation efficiency compared with the more conventional parallelepiped model. The extracted structural information included the cross-section size and size distribution of the cellulose nanofibers. For example, for nanofibers prepared from the dried pulp of the maritime pine, the size-weighted averages of thickness and width were 3.2 and 12.7 nm, respectively, and the corresponding standard deviations were 2.2 and 5.5 nm, respectively. The scattering results of the size-weighted average of the nanofiber width are also consistent with those determined directly from transmission electron microscopy.

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.

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