scholarly journals Phase Analysis of the Cellulose Triacetate-Nitromethane System

2012 ◽  
Vol 2012 ◽  
pp. 1-12
Author(s):  
Anna B. Shipovskaya ◽  
Natalia O. Gegel ◽  
Sergei L. Shmakov ◽  
Sergei Yu. Shchyogolev
Keyword(s):  
Liquid Crystal ◽  
Phase Separation ◽  
Light And Electron Microscopy ◽  
State Diagram ◽  
Cellulose Triacetate ◽  
Cellulose Ester ◽  
Turbidity Spectrum ◽  
Solvent Systems ◽  
Liquid Liquid Phase Separation ◽  
Comprehensive Study

A comprehensive study was made on the cellulose triacetate-nitromethane system to explore its phase separation within ranges 2–25 wt.% and−5÷+80°Cby means of polarization light and electron microscopy, the turbidity spectrum method, differential thermal and X-ray analyses, and rheological techniques. The physical state of the polymer was identified within the phase coexistence boundaries on the phase diagram which included three types of phase separation (amorphous (with a UCST atTcr=57∘Candccr=7.3 wt.%), crystal, and liquid crystal). The boundaries of the regions determining the coexistence of the liquid crystal (LC) and the partly crystal phase were found to be inside the region of amorphous liquid-liquid phase separation. For cellulose ester-solvent systems, this state diagram is the first experimental evidence for the possibility of coexistence of several phases with amorphous, LC, and crystal polymer ordering.

Liquid - liquid phase separation in linear low density polyethylene - solvent systems

1996 ◽  
Vol 117 (1-2) ◽  
pp. 40-47 ◽  
Author(s):  
Th.W. de Loos ◽  
L.J. de Graaf ◽  
J. de Swaan Arons
Keyword(s):  
Phase Separation ◽  
Liquid Phase ◽  
Liquid Phase Separation ◽  
Low Density Polyethylene ◽  
Low Density ◽  
Linear Low Density Polyethylene ◽  
Solvent Systems ◽  
Liquid Liquid Phase Separation

Phase separation and liquid-crystal state of cellulose triacetate in nitromethane

2008 ◽  
Vol 81 (6) ◽  
pp. 1222-1231 ◽  
Author(s):  
A. B. Shipovskaya ◽  
G. N. Timofeeva ◽  
N. O. Gegel’ ◽  
S. Yu. Shchegolev
Keyword(s):  
Liquid Crystal ◽  
Phase Separation ◽  
Cellulose Triacetate ◽  
Crystal State

scholarly journals A Thermodynamic Approach for the Prediction of Oiling Out Boundaries from Solubility Data

Processes ◽  
2019 ◽  
Vol 7 (9) ◽  
pp. 577 ◽  
Author(s):  
Bhamidi ◽  
Abolins
Keyword(s):  
Phase Separation ◽  
Liquid Phase ◽  
Crystallization Process ◽  
Process Development ◽  
Liquid Phase Separation ◽  
Solubility Data ◽  
Modeling Framework ◽  
Theoretical Concepts ◽  
Solvent Systems ◽  
Liquid Liquid Phase Separation

Many pharmaceutical molecules, fine chemicals, and proteins exhibit liquid–liquid phase separation (LLPS, also known as oiling out) during solution crystallization. LLPS is of significant concern in crystallization process development, as oiling out can compromise the effectiveness of a crystallization and can lead to operational problems. A comprehensive methodology that allows a process scientist/engineer to characterize the various phase boundaries relevant to oiling out is currently lacking. In this work, we present a modeling framework useful in predicting the binodal, spinodal, and gelation boundaries starting from the solubility data of a solute that is prone to oiling out. We collate the necessary theoretical concepts from the literature and describe a unified approach to model the phase equilibria of solute–solvent systems from first principles. The modeling effort is validated using experimental data reported in the literature for various solute–solvent systems. The predictive methods presented in this work can be easily implemented and help a process engineer establish the design space for a crystallization process that is affected by liquid–liquid phase separation.

scholarly journals Birnaviridae virus factories show features of liquid-liquid phase separation, and are distinct from paracrystalline arrays of virions observed by electron microscopy

2021 ◽  
Author(s):  
Vishwanatha R.A.P. Reddy ◽  
Elle A. Campbell ◽  
Joanna Wells ◽  
Jennifer Simpson ◽  
Salik Nazki ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Phase Separation ◽  
Liquid Phase ◽  
Rna Synthesis ◽  
De Novo ◽  
Light And Electron Microscopy ◽  
Region Of Interest ◽  
Liquid Phase Separation ◽  
Infected Cells ◽  
Liquid Liquid Phase Separation

To gain more information about the nature of Birnaviridae virus factories (VFs), we used a recombinant infectious bursal disease virus (IBDV) expressing split-GFP11 tagged to the polymerase (VP1) that we have previously shown is a marker for VFs in infected cells expressing GFP1-10. We found that VFs co-localized with 5-ethynyl uridine in the presence of actinomycin D, confirming they were the site of de novo RNA synthesis, and VFs were visible in infected cells that were fixed and permeabilized with digitonin, demonstrating that they were not membrane bound. Fluorescence recovery after photobleaching (FRAP) a region of interest within the VFs occurred rapidly, recovering from approximately 25% to 87% the original intensity over 146 seconds, and VFs were dissolved by 1,6-hexanediol treatment, demonstrating they showed properties consistent with liquid-liquid phase separation. There was a lower co-localization of the VF GFP signal with the capsid protein VP2 (Manders coefficient (MC) 0.6), compared to VP3 (MC, 0.9), which prompted us to investigate the VF ultrastructure by transmission electron microscopy (TEM). In infected cells, paracrystalline arrays (PAs) of virions were observed in the cytoplasm, as well as discrete electron dense regions. Using correlative light and electron microscopy (CLEM), we observed that the electron dense regions correlated with the GFP signal of the VFs, which were distinct from the PAs. In summary, Birnaviridae VFs are sites of de novo RNA synthesis, are not bound by a membrane, show properties consistent with liquid-liquid phase separation, and are distinct from the PAs observed by TEM.

Phase Separation and Liquid Crystal Self-Assembly in Surfactant−Inorganic−Solvent Systems

Langmuir ◽  
2003 ◽  
Vol 19 (6) ◽  
pp. 2049-2057 ◽  
Author(s):  
Flor R. Siperstein ◽  
Keith E. Gubbins
Keyword(s):  
Liquid Crystal ◽  
Phase Separation ◽  
Self Assembly ◽  
Solvent Systems

Electron Microscopic Characterization and Quantitation of Air Borne Particulate Matter with Special Emphasis on Asbestos

1972 ◽  
Vol 30 ◽  
pp. 356-357
Author(s):  
Peter K. Mueller ◽  
Glenn R. Smith ◽  
Leslie M Carpenter ◽  
Ronald L. Stanley
Keyword(s):  
Electron Microscopy ◽  
Light And Electron Microscopy ◽  
Ambient Air ◽  
Quality Standard ◽  
Primary Objective ◽  
Cellulose Ester ◽  
Main Concept ◽  
Electron Microscopic ◽  
Air Samples ◽  
Diffraction Patterns

At the present time the primary objective of the electron microscopy group of the Air and Industrial Hygiene Laboratory is the development of a method suitable for use in establishing an air quality standard for asbestos in ambient air and for use in its surveillance. The main concept and thrust of our approach for the development of this method is to obtain a true picture of fiber occurrence as a function of particle size and asbestos type utilizing light and electron microscopy.We have now available an electron micrographic atlas of all asbestos types including selected area diffraction patterns and examples of fibers isolated from air samples. Several alternative approaches for measuring asbestos in ambient air have been developed and/or evaluated. Our experiences in this regard will be described. The most promising method involves: 1) taking air samples on cellulose ester membrane filters with a nominal pore size of 0.8 micron; 2) ashing in a low temperature oxygen plasma for several hours;

scholarly journals Liquid-Liquid Phase Separation of Tau Driven by Hydrophobic Interaction Facilitates Fibrillization of Tau

2021 ◽  
Vol 433 (2) ◽  
pp. 166731
Author(s):  
Yanxian Lin ◽  
Yann Fichou ◽  
Andrew P. Longhini ◽  
Luana C. Llanes ◽  
Pengyi Yin ◽  
...  
Keyword(s):  
Phase Separation ◽  
Liquid Phase ◽  
Hydrophobic Interaction ◽  
Liquid Phase Separation ◽  
Liquid Liquid Phase Separation

scholarly journals Amyloid Aggregation under the Lens of Liquid–Liquid Phase Separation

2020 ◽  
pp. 368-378
Author(s):  
Yanting Xing ◽  
Aparna Nandakumar ◽  
Aleksandr Kakinen ◽  
Yunxiang Sun ◽  
Thomas P. Davis ◽  
...  
Keyword(s):  
Phase Separation ◽  
Liquid Phase ◽  
Liquid Phase Separation ◽  
Amyloid Aggregation ◽  
Liquid Liquid Phase Separation
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