Flow Induced Liquid-Liquid Phase Separation in High Molecular Weight Polymer Solutions

1990 ◽  
pp. 20-24
Author(s):  
P. J. Barham
Keyword(s):  
Molecular Weight ◽  
Phase Separation ◽  
Liquid Phase ◽  
High Molecular Weight ◽  
Polymer Solutions ◽  
Liquid Phase Separation ◽  
High Molecular Weight Polymer ◽  
Molecular Weight Polymer ◽  
Liquid Liquid Phase Separation

Stereo-chemical contributions to the glass transition and liquid–liquid phase separation in high molecular weight poly(N-vinyl carbazole)

RSC Advances ◽  
2016 ◽  
Vol 6 (35) ◽  
pp. 29326-29333 ◽  
Author(s):  
Abdul G. Al Lafi ◽  
James N. Hay
Keyword(s):  
Molecular Weight ◽  
Glass Transition ◽  
Phase Separation ◽  
Liquid Phase ◽  
High Molecular Weight ◽  
Structural Properties ◽  
Thermal History ◽  
Liquid Phase Separation ◽  
High Molecular Weight Poly ◽  
Liquid Liquid Phase Separation

Thermal history and purification effects on the structural properties of PVK were investigated. Liquid–liquid phase separation is suggested to occur by separation of isotactic rich segments from a matrix which is predominantly atactic.

Rheological properties of high molecular weight polymer solutions

1973 ◽  
Vol 25 (6) ◽  
pp. 1554-1558
Author(s):  
Z. R. Gorbis ◽  
T. A. Rogovskii ◽  
S. P. Shul'gin
Keyword(s):  
Molecular Weight ◽  
Rheological Properties ◽  
High Molecular Weight ◽  
Polymer Solutions ◽  
High Molecular Weight Polymer ◽  
Molecular Weight Polymer

scholarly journals Effects of molecular weight and temperature on liquid–liquid phase separation in particles containing organic species and inorganic salts

2015 ◽  
Vol 15 (3) ◽  
pp. 1351-1365 ◽  
Author(s):  
Y. You ◽  
A. K. Bertram
Keyword(s):  
Molecular Weight ◽  
Phase Separation ◽  
Liquid Phase ◽  
Ammonium Sulfate ◽  
Atmospheric Particles ◽  
Liquid Phase Separation ◽  
Organic Species ◽  
Diffusion Rates ◽  
Measured Liquid ◽  
Liquid Liquid Phase Separation

Abstract. Atmospheric particles containing organic species and inorganic salts may undergo liquid–liquid phase separation when the relative humidity varies between high and low values. To better understand the parameters that affect liquid–liquid phase separation in atmospheric particles, we studied the effects of molecular weight and temperature on liquid–liquid phase separation in particles containing one organic species mixed with either ammonium sulfate or ammonium bisulfate. In the molecular-weight-dependent studies, we measured liquid–liquid phase separation relative humidity (SRH) in particles containing ammonium sulfate and organic species with large molecular weights (up to 1153 Da). These results were combined with recent studies of liquid–liquid phase separation in the literature to assess if molecular weight is a useful parameter for predicting SRH. The combined results, which include results from 33 different particle types, illustrate that SRH does not depend strongly on molecular weight (i.e., a clear relationship between molecular weight and SRH was not observed). In the temperature-dependent studies, we measured liquid–liquid phase separation in particles containing ammonium sulfate mixed with 20 different organic species at 244 ± 1 K, 263 ± 1 K, and 278 ± 1 K; a few particles were also studied at 290 ± 1 K. These new results were combined with previous measurements of the same particle types at 290 ± 1 K. The combined SRH data illustrate that for the organic–ammonium sulfate particles studied, the SRH does not depend strongly on temperature. At most the SRH varied by 9.7% as the temperature varied from 290 to 244 K. The high SRH values (> 65%) in these experiments may explain the lack of temperature dependence. Since water is a plasticizer, high relative humidities can lead to high water contents, low viscosities, and high diffusion rates in the particles. For these cases, unless the temperature is very low, liquid–liquid phase separation is not expected to be kinetically inhibited. The occurrence of liquid–liquid phase separation and SRH did depend strongly on temperature over the range of 290–244 K for particles containing α,4-dihydroxy-3-methoxybenzeneacetic acid mixed with ammonium bisulfate. For this particle type, a combination of low temperatures and low water content likely favored kinetic inhabitation of the liquid–liquid phase separation by slow diffusion rates in highly viscous particles. The combined results suggest that liquid–liquid phase separation is likely a common occurrence in atmospheric particles at temperatures from 244–290 K, although particles that do not undergo liquid–liquid phase separation are also likely common.

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