Dielectric scaling in polyelectrolyte solutions with different solvent quality in the dilute concentration regime

2006 ◽  
Vol 8 (31) ◽  
pp. 3653 ◽  
Author(s):  
F. Bordi ◽  
C. Cametti ◽  
S. Sennato ◽  
S. Zuzzi ◽  
S. Dou ◽  
...  
Keyword(s):  
Solvent Quality ◽  
Polyelectrolyte Solutions

Solvent quality influence on the dielectric properties of polyelectrolyte solutions: A scaling approach

2005 ◽  
Vol 72 (3) ◽  
Author(s):  
F. Bordi ◽  
C. Cametti ◽  
T. Gili ◽  
S. Sennato ◽  
S. Zuzzi ◽  
...  
Keyword(s):  
Dielectric Properties ◽  
Solvent Quality ◽  
Polyelectrolyte Solutions

Effect of Solvent Quality on the Behaviour of Highly Charged Polyelectrolytes

1995 ◽  
Vol 5 (9) ◽  
pp. 1269-1275 ◽  
Author(s):  
W. Essafi ◽  
F. Lafuma ◽  
C. E. Williams
Keyword(s):  
Effect Of Solvent ◽  
Solvent Quality

Donnan Equilibria in Polymeric Micellar Systems with Weak Polyelectrolyte Shells: The Lowering of the pH Value

1997 ◽  
Vol 62 (11) ◽  
pp. 1730-1736 ◽  
Author(s):  
Petr Munk ◽  
Zdeněk Tuzar ◽  
Karel Procházka
Keyword(s):  
Ionic Strength ◽  
Block Copolymer ◽  
Ph Value ◽  
Electrolyte Solutions ◽  
Hydrogen Ions ◽  
Micellar Systems ◽  
Weak Electrolytes ◽  
Block Copolymer Micelles ◽  
Copolymer Micelles ◽  
Polyelectrolyte Solutions

When two electrolyte solutions are separated and only some of the ions can cross the boundary, the concentrations of these ions are different on both sides of the boundary. This is the well-known Donnan effect. When weak electrolytes are involved, the imbalance includes also hydrogen ions: there is a difference of pH across the boundary and the dissociation of nondiffusible weak electrolytes is suppressed. The effect is very pronounced when the concentration of the weak electrolyte is high and ionic strength is low. The significance of this phenomenon is discussed for polyelectrolyte solutions, and particularly for block copolymer micelles with weak polyelectrolyte shells. The effect is quite dramatic in the latter case.

Crystallization of Isotactic Poly(propylene) in Solution as Followed by Slow Calorimetry

1995 ◽  
Vol 60 (11) ◽  
pp. 1905-1924 ◽  
Author(s):  
Hong Phuong-Nguyen ◽  
Geneviève Delmas
Keyword(s):  
Molecular Weight ◽  
Crystal Growth ◽  
High Temperature ◽  
Heat Of Fusion ◽  
Complete Dissolution ◽  
Polymer Molecular Weight ◽  
Solvent Quality ◽  
Temperature Ramp ◽  
Poly Propylene

Dissolution, crystallization and second dissolution traces of isotactic poly(propylene) have been obtained in a slow temperature ramp (3 K h-1) with the C80 Setaram calorimeter. Traces of phase-change, in presence of solvent, are comparable to traces without solvent. The change of enthalpy on heating or cooling, ∆Htotal, over the 40-170 °C temperature range, is the sum of two contributions, ∆HDSC and ∆Hnetwork. The change ∆HDSC is the usual heat obtained in a fast temperature ramp and ∆Hnetwork is associated with a physical network whose disordering is slow and subject to superheating due to strain. When dissolution is complete, ∆Htotal is equal to ∆H0, the heat of fusion of perfect crystals. The values of ∆Htota for nascent and recrystallized samples are compared. Dissolution is the tool to evaluate the quality of the crystals. The repartition of ∆Htotal, into the two endotherms, reflects the quality of crystals. The crystals grown more rapidly have a higher fraction of network crystals which are stable at high T in the solvents. A complete dissolution, i.e. a high temperature (170 °C or more) is necessary to obtain good crystals. The effect of concentration, polymer molecular weight and solvent quality on crystal growth is analyzed.

scholarly journals Bottlebrush polymers in the melt and polyelectrolytes in solution share common structural features

2020 ◽  
Vol 117 (10) ◽  
pp. 5168-5175 ◽  
Author(s):  
Joel M. Sarapas ◽  
Tyler B. Martin ◽  
Alexandros Chremos ◽  
Jack F. Douglas ◽  
Kathryn L. Beers
Keyword(s):  
Neutron Scattering ◽  
Correlation Length ◽  
Salt Concentration ◽  
Polymer Concentration ◽  
Structural Features ◽  
Peak Position ◽  
Correlation Peak ◽  
Grafting Density ◽  
Scattering Measurements ◽  
Polyelectrolyte Solutions

Uncharged bottlebrush polymer melts and highly charged polyelectrolytes in solution exhibit correlation peaks in scattering measurements and simulations. Given the striking superficial similarities of these scattering features, there may be a deeper structural interrelationship in these chemically different classes of materials. Correspondingly, we constructed a library of isotopically labeled bottlebrush molecules and measured the bottlebrush correlation peak position q*=2π/ξ by neutron scattering and in simulations. We find that the correlation length scales with the backbone concentration, ξ∼cBB−0.47, in striking accord with the scaling of ξ with polymer concentration cP in semidilute polyelectrolyte solutions (ξ∼cP−1/2). The bottlebrush correlation peak broadens with decreasing grafting density, similar to increasing salt concentration in polyelectrolyte solutions. ξ also scales with sidechain length to a power in the range of 0.35–0.44, suggesting that the sidechains are relatively collapsed in comparison to the bristlelike configurations often imagined for bottlebrush polymers.

scholarly journals Ion-Induced Volume Transition in Gels and Its Role in Biology

Gels ◽  
2021 ◽  
Vol 7 (1) ◽  
pp. 20
Author(s):  
Matan Mussel ◽  
Peter J. Basser ◽  
Ferenc Horkay
Keyword(s):  
Nonlinear Response ◽  
Structural Changes ◽  
Ionic Composition ◽  
Biological Systems ◽  
Experimental Results ◽  
Resting Potential ◽  
Cell Secretion ◽  
Solvent Quality ◽  
Volume Transition ◽  
Biological Milieu

Incremental changes in ionic composition, solvent quality, and temperature can lead to reversible and abrupt structural changes in many synthetic and biopolymer systems. In the biological milieu, this nonlinear response is believed to play an important functional role in various biological systems, including DNA condensation, cell secretion, water flow in xylem of plants, cell resting potential, and formation of membraneless organelles. While these systems are markedly different from one another, a physicochemical framework that treats them as polyelectrolytes, provides a means to interpret experimental results and make in silico predictions. This article summarizes experimental results made on ion-induced volume phase transition in a polyelectrolyte model gel (sodium polyacrylate) and observations on the above-mentioned biological systems indicating the existence of a steep response.

Shear Forces between Tethered Polymer Chains as a Function of Compression, Sliding Velocity, and Solvent Quality

2003 ◽  
Vol 36 (2) ◽  
pp. 389-398 ◽  
Author(s):  
Phillip A. Schorr ◽  
Thomas C. B. Kwan ◽  
S. Michael Kilbey ◽  
Eric S. G. Shaqfeh ◽  
Matthew Tirrell
Keyword(s):  
Polymer Chains ◽  
Sliding Velocity ◽  
Shear Forces ◽  
Solvent Quality ◽  
Tethered Polymer Chains
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