Electrophoresis of polyelectrolyte in salt solutions

ABSTRACT:A method of determining the charge density distribution of polyelectrolytes is discussed. Since the electrophoretic mobility of polyelectrolytes is independent of molecular weight, the distribution of charge density of polyelectrolytes can be calculated from the spreading of electrophoretic patterns, provided corrections for the spreading of the boundary due to diffusion and for the polymer concentration dependence of electrophoretic velocity are made. Also the relationship between the electrophoretic mobility and the charge density of the polyelectrolyte needs to be known. Examples of determination of the distribution of the degree of etherification of carboxymethyl cellulose by this method are shown.KEY WORDS Charge Density Distribution / Electrophoresis / Sodium Carboxymethyl Cellulose / Degree of Etherification / Mobility Distribution / Some polyelectrolytes used for practical purpose, such as, carboxymethyl cellulose, partially hydrolized polyacrylamide, etc., are generally mixtures of the molecules having different charge densities. The physical properties of those polyelectrolytes are affected not only by their average charge densities but also by their charge density distributions. Nevertheless, the effect of charge density distribution on physical properties of polyelectrolytes has not as yet been studied well, partly because the method of determining the distribution of charge density of polyelectrolytes has not been established. This paper is to show that the electrophoretic velocity method is useful for determination of the charge density distribution, i.e., distribution of the degree of etherification (DS) of carboxymethyl cellulose (CMC), which is now widely used in such industrial applicat,ions as paste, gums, food additives and in civil engineering works. A few theoretical and pioneering experimental works on this method can be found in the literature, though the theories were given for proteins. 1 -4

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“…It was also pointed out that ambiguities arising from skewness of the pattern could be eliminated by this extrapolation. 8 …”

Section: Determination Of Average Electrophoretic Mobility Of Samplesmentioning

confidence: 99%

Determination of the Charge Density Distribution of Polyelectrolytes by Electrophoresis

Terajima

Takahashi

Nagasawa

1976

Polym J

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“…The actual range of Q fix in practice can go over several orders of magnitude as a result, depending on the specific particle radius a of interest. Nagasawa et al [26] reported a Na-PVS polyelectrolyte system with Q fix smaller than 100. In reality, As far as the counterion condensation is concerned, Q fix = 50 is high enough to represent the electrostatic behavior of a porous particle in general.…”

Section: Resultsmentioning

confidence: 99%

Counterion Condensation of a Polyelectrolyte within a Micro/Nanochannel

Huang¹,

Lee²,

Lee³

2016

IJCEA

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“…2 The conformational parameters I, ML, (Rex), and the intensity at zero angle have been obtained from this calculation. These parameters are listed in Table 3; instead of the zero angle intensity, we show the scattering length increment, A b, which we have obtained by inserting the known molecular weight in Equation (5). We have also calculated the z-average of the mean square radius, (R2>z, and the number of statistical chain elements, n. …”

Section: D20mentioning

confidence: 99%

“…[1]). This consequence of the strong coulombic interactions between the charges on the chain has been studied with several experimental techniques such as viscosimetry [2,3], light scattering [4], and electrophoresis [5]. Excluded volume has been regarded as being responsible for the expansion of a polyion by varying ionic strength (see for example Ref.…”

Section: Introductionmentioning

confidence: 99%

Conformation of a chain polyelectrolyte in solution with low molecular weight salt: small angle neutron scattering measurements

Ragnetti

Oberthür²

1986

Colloid & Polymer Sci

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Small angle neutron scattering measurements have been carried out on the tetramethylammonium salt of the polystyrenesulfonic acid with DPw = 310 and 1060 in water solution with tetramethylammonium chloride with ionic strength between 0.02 M and 1.0 M. The scattering curves in the scattering vector range 0.05 nm -1 < Q < 1.8 nm -1 have been fitted using the form factor of a worm-like chain of finite thickness. The conformational parameters mean square radius of gyration, statistic chain element, mass per unit length and mean square radius of the cross-section have been determined experimentally and used for describing the conformation of the coils. By these molecular weights and ionic strengths, excluded volume is not necessary to explain the conformation changes depending on the salt content of the solutions; relatively short coil molecules can be described in their unperturbed dimensions even in a thermodynamically good solvent: a change in the stiffness of the chain according to Odijk's theory succeeds in describing the conformation of the polyions. Together with a slow decrease of the coil dimension by increasing salt content, a transition at ionic strength 0.1-0.5 M between two different conformations has been observed. The conformation at lower ionic strength is characterized by higher stiffness of the chain and lower mass per unit length than the form at hlgtier salt concentration.

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Electrophoresis of polyelectrolyte in salt solutions

Cited by 41 publications

References 8 publications

Determination of the Charge Density Distribution of Polyelectrolytes by Electrophoresis

Determination of the Charge Density Distribution of Polyelectrolytes by Electrophoresis

Counterion Condensation of a Polyelectrolyte within a Micro/Nanochannel

Conformation of a chain polyelectrolyte in solution with low molecular weight salt: small angle neutron scattering measurements

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