Unification of lower and upper critical solution temperature phase behavior of globular protein solutions in the presence of multivalent cations

Soft Matter ◽  
2020 ◽  
Vol 16 (8) ◽  
pp. 2128-2134 ◽  
Author(s):  
Nafisa Begam ◽  
Olga Matsarskaia ◽  
Michael Sztucki ◽  
Fajun Zhang ◽  
Frank Schreiber
Keyword(s):  
Phase Behavior ◽  
Globular Protein ◽  
Solution Temperature ◽  
Protein Solutions ◽  
Temperature Phase ◽  
Critical Solution Temperature ◽  
Upper Critical Solution Temperature

Here we report that a unified LCST and UCST phase behavior in protein solutions can be achieved by tuning the concentration of multivalent salts.

scholarly journals Lower Critical Solution Temperature Phase Behavior of Natural Rubber/Polybutadiene Blend

2002 ◽  
Vol 34 (1) ◽  
pp. 1-8 ◽  
Author(s):  
Seiichi Kawahara ◽  
Yasuhiro Asada ◽  
Yoshinobu Isono ◽  
Kiyoshige Muraoka ◽  
Yasuhisa Minagawa
Keyword(s):  
Natural Rubber ◽  
Phase Behavior ◽  
Lower Critical Solution Temperature ◽  
Solution Temperature ◽  
Temperature Phase ◽  
Critical Solution Temperature

Polymer Fractionation at a Lower Critical Solution Temperature Phase Boundary

1967 ◽  
Vol 40 (5) ◽  
pp. 1544-1552
Author(s):  
C. H. Baker ◽  
C. S. Clemson ◽  
G. Allen
Keyword(s):  
Molecular Weight ◽  
Phase Boundary ◽  
Lower Critical Solution Temperature ◽  
Solution Temperature ◽  
Temperature Phase ◽  
Critical Solution Temperature ◽  
Upper Critical Solution Temperature ◽  
Two Samples ◽  
Polymer Fractionation ◽  
Molecular Weight Fractions

Abstract The influence of pressure on a lower critical solution temperature is much more pronounced than on an upper critical solution temperature. Accordingly it is possible to control phase separation at a LCST phase boundary under isothermal conditions by merely adjusting the pressure on the system. An apparatus has been constructed to investigate the isothermal fractionation of polyisobutene in which precipitation is controlled by pressure. Two samples of polyisobutene of Mv=1.76×106 and 9.0×104 have been fractionated in isopentane solution so as to yield up to six and nine fractions respectively. The integral molecular weight distribution curves thus obtained are compared with those obtained from conventional fractionations at an UCST. The sensitivity of the method is poor with regard to the separation of low molecular weight fractions and degradation occurs at the higher temperatures to an appreciable extent.

scholarly journals Unusual Lower Critical Solution Temperature Phase Behavior of Poly(benzyl methacrylate) in a Pyrrolidinium-Based Ionic Liquid

Molecules ◽  
2021 ◽  
Vol 26 (16) ◽  
pp. 4850
Author(s):  
Brian R. Carrick ◽  
Claire L. Seitzinger ◽  
Timothy P. Lodge
Keyword(s):  
Ionic Liquid ◽  
Phase Behavior ◽  
Lower Critical Solution Temperature ◽  
Second Virial Coefficient ◽  
Coexistence Curve ◽  
Solution Temperature ◽  
Temperature Phase ◽  
Strong Concentration ◽  
Critical Solution Temperature ◽  
Heating And Cooling

Polymer/ionic liquid systems are being increasingly explored, yet those exhibiting lower critical solution temperature (LCST) phase behavior remain poorly understood. Poly(benzyl methacrylate) in certain ionic liquids constitute unusual LCST systems, in that the second virial coefficient (A2) in dilute solutions has recently been shown to be positive, indicative of good solvent behavior, even above phase separation temperatures, where A2 < 0 is expected. In this work, we describe the LCST phase behavior of poly(benzyl methacrylate) in 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide for three different molecular weights (32, 63, and 76 kg/mol) in concentrated solutions (5–40% by weight). Turbidimetry measurements reveal a strong concentration dependence to the phase boundaries, yet the molecular weight is shown to have no influence. The critical compositions of these systems are not accessed, and must therefore lie above 40 wt% polymer, far from the values (ca. 10%) anticipated by Flory-Huggins theory. The proximity of the experimental cloud point to the coexistence curve (binodal) and the thermo-reversibility of the phase transitions, are also confirmed at various heating and cooling rates.

scholarly journals Role of Entropy in Determining the Phase Behavior of Protein Solutions Induced by Multivalent Ions

Soft Matter ◽  
2021 ◽  
Author(s):  
Anil Kumar Sahoo ◽  
Frank Schreiber ◽  
Roland Netz ◽  
Prabal Kumar Maiti
Keyword(s):  
Aqueous Solutions ◽  
Phase Behavior ◽  
Lower Critical Solution Temperature ◽  
Solution Phase ◽  
Solution Temperature ◽  
Protein Solutions ◽  
Critical Solution Temperature ◽  
Multivalent Ions

Recent experiments have reported lower critical solution temperature (LCST) phase behavior of aqueous solutions of proteins induced by multivalent ions, where the solution phase separates upon heating. This phenomenon is...

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