Relaxational behavior of birefringence of aqueous carboxymethylcellulose under an alternating electric field at frequencies ranging from 0.1 Hz to 100 kHz

Abstract

The d. c. component of birefringence of aqueous carboxymethylcellulose (CMC) under an a. c. electric field was measured at frequencies ranging from 0.1 Hz to 100 kHz. Three samples of different molecular weights were studied with varying degree of neutralization, polymer concentration and added salt concentration. The dispersion curve of birefringence consists of three relaxation bands, A, B and C in order of decreasing frequency. Relaxation B with a negative relaxation strength is ascribed to end-over-end rotation of almost rodlike CMC molecules. Relaxation A with a positive strength is attributed to the relaxation of electrical polarizability along the minor axis of molecule. Relaxation C possesses also a positive strength and is induced by clusters of CMC molecules.

Electro-optics of colloid–polyelectrolyte complexes: Counterion condensation on free and adsorbed sodium carboxymethyl cellulose

“…The apparent rod length L a of the NaCMC polyion is evaluated from the rotational relaxation time τ r , related to the frequency of relaxation ν of the electro-optical effect in the lowfrequency (Hz) region as [31] (9)…”

“…Previously, we have shown that the electro-optical behavior of ellipsoidal β-FeOOH particles coated with highly charged polyelectrolyte (at overcompensation of the surface charge) is similar to that of the polyelectrolyte in a solution [27][28][29][30]. In particular, the relaxation frequency of the kilohertz electro-optical effect from polymercoated particles, measured by electric light scattering method, was compared with data reported in the literature for the electric birefringence of polyelectrolyte in a solution [31][32][33]. This similarity was associated with the fact that the polymer-coated particle assumes the electrical characteristics of the adsorbed polymer.…”

Electric Properties of Carboxymethyl Cellulose

“…[53]. In this work the sinusoidal field with low strength in combination with very sensitive detection (based on an amplitude modulation of the birefringence signal) is used.…”

Electric polarizability dispersion of alumina particles with adsorbed carboxymethyl cellulose

“…49 In the case of long chains having the conformation of a random coil (when L c [ l p ) the orientation of their segments is accompanied by deformation of the coil and the values of g, Dg and n ch are inuenced by the mechanical and hydrodynamical properties of the polyelectrolyte chain, which strongly complicates the interpretation of the experimental results. 50,51 A possible solution to the problem is immobilization of the chains by adsorption on a solid surface and then exploring the electrical properties of the polyelectrolyte layer. The electrooptical technique is applicable when the polymer adsorption is on non-spherical colloid particles.…”