scholarly journals Correlated X-ray Ptychography and Fluorescence Nano-Tomography on the Fragmentation Behavior of an Individual Catalyst Particle during the Early Stages of Olefin Polymerization

2020 ◽  
Vol 142 (8) ◽  
pp. 3691-3695 ◽  
Author(s):  
Koen W. Bossers ◽  
Roozbeh Valadian ◽  
Silvia Zanoni ◽  
Remy Smeets ◽  
Nic Friederichs ◽  
...  
Keyword(s):  
Olefin Polymerization ◽  
Catalyst Particle ◽  
X Ray ◽  
Fragmentation Behavior ◽  
Early Stages

Influence of Porosity on the Fragmentation of Ziegler-Natta Catalyst in the Early Stages of Propylene Polymerization

e-Polymers ◽  
2006 ◽  
Vol 6 (1) ◽  
Author(s):  
Xuejing Zheng ◽  
Makarand S. Pimplapure ◽  
Günter Weickert ◽  
Joachim Loos
Keyword(s):  
Catalyst Particle ◽  
Particle Growth ◽  
Polymer Particle ◽  
Propylene Polymerization ◽  
Cross Sectional ◽  
Porous Catalyst ◽  
Fragmentation Behavior ◽  
Early Stages ◽  
Natta Catalyst ◽  
Highly Porous

AbstractCatalyst fragmentation and polymer growth in the early stages of propylene polymerization has been investigated using different Ziegler-Natta catalysts. Polymerization was carried out in slurry under mild conditions and stopped at low yield. Scanning electron microscopy (SEM) has been used to characterize the surface and cross sectional morphology of polymer particles at different stages of particle growth. Different fragmentation behavior is observed, and it is found that the way that catalyst fragments in the early stages of polymerization is greatly influenced by the porosity of the catalyst. When a less porous catalyst was used, the resulting mass diffusion limitation causes layer-bylayer fragmentation, starting at the outer surface of the catalyst particle to the center. In contrast, for highly porous catalyst, monomer can easily penetrate into the pores of the catalyst / polymer particle. The polymer growing throughout the particle results in a coarse and instantaneous fragmentation.

Fragmentation Behavior of Silica-Supported Metallocene/MAO Catalyst in the Early Stages of Olefin Polymerization

2005 ◽  
Vol 38 (11) ◽  
pp. 4673-4678 ◽  
Author(s):  
Xuejing Zheng ◽  
Madri Smit ◽  
John C. Chadwick ◽  
Joachim Loos
Keyword(s):  
Olefin Polymerization ◽  
Fragmentation Behavior ◽  
Early Stages

scholarly journals Observations of anomalous x-ray emission at early stages of hot-spot formation in deuterium-tritium cryogenic implosions

2021 ◽  
Vol 103 (2) ◽  
Author(s):  
R. C. Shah ◽  
S. X. Hu ◽  
I. V. Igumenshchev ◽  
J. Baltazar ◽  
D. Cao ◽  
...  
Keyword(s):  
Hot Spot ◽  
X Ray ◽  
Early Stages ◽  
Hot Spot Formation ◽  
Spot Formation

Synchrotron X-ray Topography Studies of Dislocation Behavior During Early Stages of PVT Growth of 4H-SiC Crystals

2021 ◽  
Author(s):  
Tuerxun Ailihumaer ◽  
Hongyu Peng ◽  
Yafei Liu ◽  
Balaji Raghothamachar ◽  
Michael Dudley ◽  
...  
Keyword(s):  
X Ray ◽  
Early Stages ◽  
Dislocation Behavior

scholarly journals Correlating Metal Poisoning with Zeolite Deactivation in an Individual Catalyst Particle by Chemical and Phase-Sensitive X-ray Microscopy

2013 ◽  
Vol 52 (23) ◽  
pp. 5983-5987 ◽  
Author(s):  
Javier Ruiz-Martínez ◽  
Andrew M. Beale ◽  
Upakul Deka ◽  
Mathew G. O'Brien ◽  
Paul D. Quinn ◽  
...  
Keyword(s):  
Catalyst Particle ◽  
X Ray ◽  
Metal Poisoning ◽  
Phase Sensitive

Ultrahigh Vacuum Deposition ofl-Cysteine on Au(110) Studied by High-Resolution X-ray Photoemission:  From Early Stages of Adsorption to Molecular Organization

2005 ◽  
Vol 109 (38) ◽  
pp. 18003-18009 ◽  
Author(s):  
Grazia Gonella ◽  
Silvana Terreni ◽  
Dean Cvetko ◽  
Albano Cossaro ◽  
Lorenzo Mattera ◽  
...  
Keyword(s):  
High Resolution ◽  
Ultrahigh Vacuum ◽  
Molecular Organization ◽  
Vacuum Deposition ◽  
X Ray ◽  
Early Stages

X-ray optics of in-situ synchrotron topography studies of the early stages of relaxation in epitaxial InGaAs on GaAs

1998 ◽  
Author(s):  
Brian K. Tanner ◽  
Andrew M. Keir ◽  
Peter Moeck ◽  
Colin R. Whitehouse ◽  
Gareth Lacey ◽  
...  
Keyword(s):  
Ray Optics ◽  
X Ray ◽  
Early Stages
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