The addition of simple salt to a solution of conjugated polyelectrolyte can lead to substantial changes in its optical properties caused by the conformational change of the polymer chain. The effect of the addition of alkali metal and tetraalkylammonium chlorides to solutions of lithium salt of poly(thiophen-3-ylacetic acid) is investigated by NMR. The fractions of free alkali metal counterions...

DNA is a strong polyelectrolyte macromolecule making metal ions (counterions) condense to cloud around the double helix. The counterions may be localized outside and inside minor major grooves of In present work, distribution condensed between inner outer regions has been studied using approaches counterion condensation theory. results have shown that number trapped should greater than 0.16 per...

We predict a condensation phenomenon in an overall neutral system, consisting of a single charged plate and its oppositely charged counterions. Based on the " two-fluid " model, in which the counterions are divided into a " free " and a " condensed " fraction, we argue that for high surface charge, fluctuations can lead to a phase transition in which a large fraction of counterions is condensed...

We predict a condensation phenomenon in an overall neutral system, consisting of a single charged plate and its oppositely charged counterions. Based on the "two-fluid" model, in which the counterions are divided into a "free" and a "condensed" fraction, we argue that for high surface charge, fluctuations can lead to a phase transition in which a large fraction of counterions is condensed. Furt...

We investigate the properties of rigid polyelectrolyte solutions in the presence of monovalent salt. The free energy within the Debye-Hückel-Bjerrum (DHBj) theory (Fisher, M. E.; Levin, Y. Phys. Rev. Lett. 1993, 71, 3826) is constructed. It is found that at thermodynamic equilibrium the polyelectrolyte solution consists of clusters composed of one polyion and various counterions. The distributi...

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Two types of lanthanide selenidostannates(iv) [Ln2(tepa)2(μ-OH)2Sn2Se6] {Ln = Y(), Pr (), Dy (), Er (), Tm (); tepa = tetraethylenepentamine} and [Ln2(tepa)2(μ2-OH)2Cl2]2[Sn4Se10]·4H2O {Ln = Y (), Dy (), Er (), Tm ()} have been synthesized under identical solvothermal conditions and characterized structurally. Type I (, , , and ) displays 1-D neutral chains [Ln2(tepa)2(μ-OH)2Sn2Se6]n, while typ...

The conformational vibrations of Z-DNA with counterions are studied in framework of phenomenological model developed. The structure of left-handed double helix with counterions neutralizing the negatively charged phosphate groups of DNA is considered as the ion-phosphate lattice. The frequencies and Raman intensities for the modes of Z-DNA with Na + and Mg 2+ ions are calculated, and the low-fr...

Hydrophilic and hydrophobic weak polybasic brushes immersed in aqueous solutions of mixed salt counterions are considered using a mean-field numerical self-consistent field approach. On top of the solvent quality of the polymer, the counterion-solvent interactions are accounted for by implementing Flory-Huggins interaction parameters. We show that ion specificity within the brush can bring abou...

– The persistence length of a single, strongly charged, stiff polyelectrolyte chain is investigated theoretically. Path integral formulation is used to obtain the effective electrostatic interaction between the monomers. We find significant deviations from the classical Odijk, Skolnick and Fixman (OSF) result. An induced attraction between monomers is due to thermal fluctuations and correlation...