Kinetics of crystallization of biodegradable PHA copolymers: a combined X-ray scattering and micro-indentation study

2011 ◽  
Vol 1301 ◽  
Author(s):  
Maraolina Domínguez-Díaz ◽  
Araceli Flores ◽  
Angel Romo-Uribe ◽  
Rodolfo Cruz-Silva
Keyword(s):  
Room Temperature ◽  
Degree Of Crystallinity ◽  
Indentation Hardness ◽  
X Ray ◽  
X Ray Scattering ◽  
Biodegradable Poly ◽  
Pha Copolymers ◽  
Ice Water ◽  
Kinetics Of ◽  
Ray Scattering

ABSTRACTWide Angle X-ray scattering (WAXS) and indentation hardness have been used to study the development of crystallinity at room temperature of biodegradable poly(hydroxybutyrate) (PHB) and its copolymer with hydroxyvalerate (PHB/HV) containing 12% of valerate. Measurements were carried out immediately after quenching the samples from the molten state (200 ºC) in ice water and over two weeks of storage at room temperature. WAXS showed that the crystallization of the PHB-based polymers initiated within the first minutes of storage at room temperature, the copolymer displaying a higher rate of crystallization than the homopolymer. For all samples, the degree of crystallinity,α, nearly reached a plateau value within the first hour of crystallization. Concurrently to the development of crystallinity, microhardness values,H, clearly rose as crystallization occurred. Monitoring the crystallization for over two weeks showed that after the rapid increase ofαandH, there was a slow monotonic growth of these properties. A correlation between nanostructure and microhardness is found at all stages of the crystallization process.

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.

scholarly journals Kinetics of Network Formation and Heterogeneous Dynamics of an Egg White Gel Revealed by Coherent X-Ray Scattering

2021 ◽  
Vol 126 (9) ◽  
Author(s):  
Nafisa Begam ◽  
Anastasia Ragulskaya ◽  
Anita Girelli ◽  
Hendrik Rahmann ◽  
Sivasurender Chandran ◽  
...  
Keyword(s):  
Network Formation ◽  
Egg White ◽  
X Ray ◽  
X Ray Scattering ◽  
Heterogeneous Dynamics ◽  
Kinetics Of ◽  
Ray Scattering

In Situ Wide- and Small-Angle X-ray Scattering Study of Melting Kinetics of Isotactic Poly(propylene)

2003 ◽  
Vol 36 (11) ◽  
pp. 4042-4050 ◽  
Author(s):  
Patrick S. Dai ◽  
Peggy Cebe ◽  
Malcolm Capel ◽  
Rufina G. Alamo ◽  
Leo Mandelkern
Keyword(s):  
Small Angle ◽  
X Ray ◽  
X Ray Scattering ◽  
Melting Kinetics ◽  
Scattering Study ◽  
Poly Propylene ◽  
Kinetics Of ◽  
Ray Scattering

scholarly journals In situ structural kinetics of picosecond laser-induced heating and fragmentation of colloidal gold spheres

2020 ◽  
Vol 22 (9) ◽  
pp. 4993-5001 ◽  
Author(s):  
Anna Rosa Ziefuss ◽  
Stefan Reich ◽  
Sven Reichenberger ◽  
Matteo Levantino ◽  
Anton Plech
Keyword(s):  
Colloidal Gold ◽  
Picosecond Laser ◽  
Time Resolved ◽  
Gold Colloids ◽  
X Ray ◽  
X Ray Scattering ◽  
Kinetics Of ◽  
Ray Scattering

The structural and energetic pathway of picosecond laser fragmentation of gold colloids has been clarified by time-resolved X-ray scattering.

Determination of Strain Distributions in Aluminum Thin Films as a Function of Temperature by the use of Synchrotron Grazing Incidence X-Ray Scattering

1991 ◽  
Vol 239 ◽  
Author(s):  
Ramnath Venkatraman ◽  
Paul R. Besser ◽  
Sean Brennan ◽  
John C. Bravman
Keyword(s):  
Thin Films ◽  
Room Temperature ◽  
Grazing Incidence ◽  
Surface Relaxation ◽  
Line Broadening ◽  
X Ray ◽  
Relaxation Effects ◽  
X Ray Scattering ◽  
Ray Scattering

ABSTRACTWe have measured elastic strain distributions with depth as a function of temperature in Al thin films of various thicknesses on oxidized silicon using synchrotron grazing incidence X-ray scattering (GIXS). Disregarding minor surface relaxation effects that depend on the film thickness, it is shown that there are no gross strain gradients in these films in the range of temperatures (between room temperature and 400°C) considered. We also observe X-ray line broadening effects, suggesting an accumulation of dislocations on cooling the films, and their annealing out as the films are reheated.

scholarly journals Kinetics of the 3C-6H polytypic transition in 3C-SiC single crystals: A diffuse X-ray scattering study

2011 ◽  
Vol 110 (5) ◽  
pp. 053508 ◽  
Author(s):  
D. Dompoint ◽  
A. Boulle ◽  
I. Galben-Sandulache ◽  
D. Chaussende ◽  
L. T. M. Hoa ◽  
...  
Keyword(s):  
Single Crystals ◽  
X Ray ◽  
X Ray Scattering ◽  
Scattering Study ◽  
Kinetics Of ◽  
Ray Scattering

Kinetics of Monolayer Bi Electrodeposition on Au(111):  Surface X-ray Scattering and Current Transients

2004 ◽  
Vol 108 (6) ◽  
pp. 1992-1998 ◽  
Author(s):  
K. Tamura ◽  
J. X. Wang ◽  
R. R. Adžic ◽  
B. M. Ocko
Keyword(s):  
X Ray ◽  
X Ray Scattering ◽  
Kinetics Of ◽  
Current Transients ◽  
Ray Scattering
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