Polyelectrolyte chain length

The kinetics of vinyl acetate emulsion polymeriza tion in the presence of alkyl phenyl ethoxylate surfactants of various chain lengths indicate that part of the emulsion polymerization occurs in the aqueous phase and part in the particles (115). A study of the emulsion polymerization of vinyl acetate in the presence of sodium lauryl sulfate reveals that a water-soluble poly(vinyl acetate)—sodium dodecyl sulfate polyelectrolyte complex forms, and that latex stabihty, polymer hydrolysis, and molecular weight are controlled by this phenomenon (116). 

M. Houska, E. Brynda, and K. Bohata, "The Effect of Polyelectrolyte Chain Length on Layer-by-layer Protein/Polyelectrolyte Assembly - an Experimental Study," Journal Of Colloid And Interface Science 213, 140-147 (2004). 

K. Thalberg, B. Lindman, and G. Karlstrom Phase Behavior of Cationic Surfactant and Anionic Polyelectrolyte Influence of Surfactant Chain Length and Polyelectrolyte Molecular Weight. J. Phys. Chem. 95, 3370 (1991). 

K. Hayakawa and J.C.T. Kwak Surfacatant-Polyelectrolyte Interactions. 4. Surfactant Chain Length Dependence on the Binding of Alkylpyridinium Cations to Dextran Sulfate. J. Phys. Chem. 88, 1930 (1984). 

Izumrudov, V.A., Bronich, T.K., Saburova, O.S., Zezin, A.B. and Kabanov, V.A. (1988) The influence of chain length of a competitive polyanion and nature of monovalent counterions on the direction of the substitution reaction of polyelectrolyte complexes. Makromol. Chem., Rapid Commun., 9, 7-12. 

The location of the phase boundaries as function of added salt was monitored as a function of temperature, charge density, chain length and hy-drophobicity of the polyelectrolyte. The polyion concentration was kept constant at 0.1%. However, the results did not change significantly if cp was increased to 2%. Higher polyion concentrations were not investigated systematically. 

The contour length of the polyelectrolyte shows only a minor influence on the miscibility gap. With decreasing size of the chain length the two phase region increases and is moved to slightly lower salt concentrations for intermediate degrees of quaternization. Moreover the temperature dependence of the phase boundary decreases. 

Flory-type free energy calculations show that the root mean square end-to-end distance of a polyelectrolyte increases linearly with the chain length at infinite dilution and without added salt [40]. Using the above perturbation theory, scaling relations at finite densities are obtained. The influence of the interaction with other polymer chains, counterions, and added salt is captured in the Debye screening length xT1. 

Fig. 4 Root mean square end-to-end distance of flexible polyelectrolyte chains as a function of chain length for lB/b=0.5. The Debye screening length decreases from top to bottom (tc=0.05, 0.1, 0.2, 0.4, 0.8). The slopes of the straight lines are 1 and 3/5, respectively...

Fig. 5 Electrostatic persistence length of a flexible polyelectrolyte chain as function of k/v b for the Bjerrum lengths lB/b=0.1, 0.5, 1.0 (bottom to top). The chain length is N=1000. The slopes of the straight lines are -1 and -2, respectively...

The first volume concentrates on separation techniques. H. Pasch summarizes the recent successes of multi-dimensional chromatography in the characterization of copolymers. Both, chain length distribution and the compositional heterogeneity of copolymers are accessible. Capillary electrophoresis is widely and successfully utilized for the characterization of biopolymers, particular of DNA. It is only recently that the technique has been applied to the characterization of water soluble synthetic macromolecules. This contribution of Grosche and Engelhardt focuses on the analysis of polyelectrolytes by capillary electophore-sis. The last contribution of the first volume by Coelfen and Antonietti summarizes the achievements and pitfalls of field flow fractionation techniques. The major drawbacks in the instrumentation have been overcome in recentyears and the triple F techniques are currently advancing to a powerful competitor to size exclusion chromatography. 

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