A Simple Method To Estimate Chain Conformations of Polyelectrolytes in the Semidilute Regime

Abstract

In semidilute polyelectrolyte solutions, reduced viscosity (ηr) versus concentration (cp) plots follow the relation ηr ∼ cp n , where n is dependent on the chain conformations. Using de Gennes' scaling arguments, we show that the average end-to-end distance of a polyelectrolyte chain, R ) N ν a (N is the number of mers in a chain and a is the length per mer), can be estimated by ν ) (n + 2)/3(n + 1). The new scaling relation was employed to estimate the chain conformations of poly(xylylene tetrahydrothiophenium chloride) (PXT) in salt-free and salt-containing aqueous and methanol solutions.

Consequences of the nanoporosity of cellulosic fibers on their streaming potential and their interactions with cationic polyelectrolytes

“…The fact that similar decay phenomena were observed for both chemical and mechanical pulp fiber slurries tends to weaken explanations that are based only on the nanoporosity of the cell walls, neglecting any effects due to fibrillation. Mechanical pulp fibers are known to have much smaller (Lin and Cheng 2000).…”

Dependence of chain conformation on degree of sulfonation and counterion dissociation of sodium poly(styrene sulfonate) in semidilute aqueous solution

“…According to our derived scaling relation, [6] the average end-to-end distance R ¼ N n a of NaPSS in the semidilute regime can be estimated by Eq. (4), i.e., n ¼ ðn þ 2Þ=3ðn þ 1Þ; where n in h red , c n p was obtained from the slope of Fig.…”

“…Eq. (6) indicates that f theo only depends on the charge densities and is not a function of the concentration, whereas L obtained from Eq. (5) slightly depends on the segmental concentration because of l p : We have used Eqs.…”

“…In 1976, de Gennes et al [2] derived a similar expression h red , c 21=2 p ; by assuming that the polyelectrolyte chains were in a rod form. However, most of the experimental data [3 -5] did not support the relation h red , c 21=2 p : Recently, we have suggested the polyelectrolytes as a flexible chain with a succession of segments (or blobs) each carrying a g-number of monomers [6]. By referring to Rouse dynamics and neglecting the entanglement effects, the viscosity of the polyelectrolyte solutions, h was expressed as follows [7] …”

“…A similar result was also obtained by Muthukumar [8], who give n ¼ 0:25 for the polyelectrolyte solutions with high salt content. The above new scaling relation was able to be employed to estimate the chain conformations of polyelectrolytes in the semidilute regime with and without containing external salts, simply by calculating n from the double-logarithmic plots of reduced viscosity versus concentration [6]. It is noteworthy that the conformation of polyelectrolyte chains is mainly influenced by their charge density and counterion dissociation.…”