The average number of kinks of a short polyelectrolyte chain: A Monte Carlo study

Abstract

An interesting connection between the mean straight length 〈ls〉 and the defined average number of kinks 〈nkink〉 in a polyelectrolyte chain configuration is found and described. 〈nkink〉 is found to be the dominant parameter throughout the entire range of the Bjerrum length λ and very sensitive to salt concentration. Identification of λm where (nkink values for various chain lengths coincide, as a percolation threshold is suggested. Considering the kink as a bond, it is found to be much more significant than the contacts described in a previous article as a new type of bonds. It is shown that the family of the physical statistical bonds includes not only contacts but also kinks. The kink fraction in a chain and the effective screening of 〈nkink〉 are defined and described for various values of λ. Through the use of these new parameters, pronounced size effects appear clearly. A connection between polymer systems and molecular cluster systems is proposed.

Effect of Polymer Size on the Polyelectrolyte−Surfactant Interaction

“…Unlike the longer chain polymer, turbidity occurred even at a lower part of binding (β < 0.5) for the Asp12 sample, while in other systems a precipitate usually appears when the binding becomes saturated just below β = 1. This phenomenon may be due to the conformational change of polymer chain from the extended random coil to globules, which may happen more easily in oligoelectrolyte like Asp12, since the short chain is less stretched than the infinite one . The conformational change would make the aggregates of the hydrophobic polymer−surfactant complex with more ease and subsequent precipitation in the early stage of binding.…”

Screening in Short Polyelectrolyte Chains. A Monte Carlo Study

“…Note the almost identical values of h for small n over the entire investigated range of λ (i.e., h D (2) (5) ). These values are lower than the values of h D(16) , h D(29) , and h D(30) .…”

“…Figure 3 describes values of D(2), D(3), D(4), and D(5) for various λ and N ) 16 at various salt concentrations. For C ) 0, it is apparent that the slope of the curve for D (5) is steeper than that for D (4) and that of D(4) is steeper than that of D(3) etc. It is interesting to note that in Figure 3, 5, and 6 of ref 6, we found that, when we divided D(n) by n 2 (n 2 is the squared end-to-end distance at the rodlike maximum stretch), chains of small n are relatively more stretched (less flexible) than chains of large n, i.e., the values of the "normalized" D(n) are higher for n ) 2 than for n ) 3 and those of n ) 3 are higher than for n ) 4 etc.…”

“…In recent articles − we studied the polyelectrolyte thermal effect, i.e., the unfolding of a charged polymer chain caused by temperature decrease. A screening effect was found in that increased salt concentration was shown to diminish the unfolding process by screening .…”

Continuous Monitoring of the Effect of Changing Solvent Conditions on Polyelectrolyte Conformations and Interactions

“…Treatments of electrostatic persistence lengths and excluded volume and their relation to polyelectrolyte conformations and interactions were first made by Odijk [1,2] , Skolnick and Fixman [3,4] . Because precise analytical solutions to the excluded volume problem do not exist, there have also been computer simulation approaches [5][6][7][8][9] . A general review of polyelectrolytes was given recently by Fo¨rster and Schmidt [10] .…”