Dimerization of the methylviologen cation radical in anionic micellar and polyelectrolyte solutions

Langmuir ◽  
1988 ◽  
Vol 4 (3) ◽  
pp. 663-667 ◽  
Author(s):  
Pablo A. Quintela ◽  
Abigail Diaz ◽  
Angel E. Kaifer
Keyword(s):  
Cation Radical ◽  
Polyelectrolyte Solutions

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.

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.

Conducting Cation-Radical Salts Bedt-TTF with Metal Complex Anions

1991 ◽  
Vol 62-64 ◽  
pp. 513-514
Author(s):  
N.D. Kushch ◽  
A.A. Ignatiev ◽  
V.N. Laukhin ◽  
M.K. Makova ◽  
V.A. Merzhanov ◽  
...  
Keyword(s):  
Metal Complex ◽  
Cation Radical ◽  
Complex Anions

Cation-radical salts of tetrachalcafulvalenes with a hydrofluoride anion

1986 ◽  
Vol 35 (12) ◽  
pp. 2530-2534
Author(s):  
L. M. Gol'denberg ◽  
R. N. Lyubovskaya ◽  
O. S. Roshchupkina ◽  
E. V. Smolina ◽  
M. L. Khidekel'
Keyword(s):  
Cation Radical
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