Birefringence streaming

Munk,P, Peterlin,A. Streaming birefringence. IX. Invariant expressions for chain molecules. Rheol. Acta 9,288-293 (1970). 

M. Copic, Streaming birefringence of polymer solutions anisotropy of internal field, J. Chem. Phys. 26,1382 (1957). 

W.H. Talbott and J.D. Goddard, Streaming birefringence in extensional flow of polymer solutions, Rheol. Acta, 18, 507 (1979). 

K 15 Kuhn,H., W. Kuhn and A. Silberberg Improved relations for diffusion and sedimentation constants and for viscosity and streaming birefringence of solutions of polymers. J. Polymer Sci. 14, 193 (1954). 

Cohen s studies of electrophoretic mobility of samples of desoxy-ribosenucleic acid isolated in different ways, indicate that the acid may possess either four or five acidic groups per tetranucleotide unit, depending upon the previous treatment. Indeed, according to Bredereck, depolymerization to the pentabasic tetranucleotide state can be induced by treatment of the polymer with dilute sodium hydroxide at 60 , followed by neutralization with acetic acid and two precipitations with alcoholic hydrochloric acid at 10 . This supposed tetranucleotide did not form a gel or exhibit streaming birefringence it had a molecular weight of 1,196 to 1,274. 

Edsall, J. T. Streaming Birefringence and Its Relation to Particle Size... 

Table I shows that at least one of the phases is birefringent between 0.8 and 2.0 gm/dl NaCl. Three phases exist for certain compositions with a lamellar phase at the top, a streaming birefringent phase in the middle and an isotropic phase at the bottom. Such is the case when the salinity is 1.4 or 1.8 gm/dl and the polymer concentration is 750 ppm Xanthan (Figure 2(b)). With or without polymer, two phases are present at 2.2 gm/dl NaCl. The added polymer appears to remain mostly in the lower phase and consequently increases the viscosity. When no salt is present, the aqueous solutions containing polymer are isotropic phases up to a polymer concentration of 1000 ppm. The aqueous solutions at 1500 ppm and higher concentrations of polymer show streaming birefringence.

Legend B, non-laraellar birefringent BR, brine C, "C" phase described in text I, isotropic L, lamellar P, polymer-rich brine S, spherulite S+L, spherulite plus lamellar SB, streaming birefringent. 

Besides being enormously expanded and spheroidal, the mucins also appear very flexible evidence for this derives from the ease with which these molecules are deformed with shear, as shown in streaming-birefringence experiments, from the concentration dependence of viscosity, and the temperature-dependence of sedimentation coeflScients. Mikkelsen and co-workers confirmed these observations by using the dependence on field strength of electric birefringence relaxation-phenomena. Evidence for local flexibility in the carbohydrate side-chains has come from, for example, n.m.r.-spectral studies. ... 

Edsall, J. T. (1942). Streaming Birefringence and Its Relation to Particle Size and Shape, in Advances in Colloid Science , Volume 1, Interscience Publ., New York, p. 269. 

Other methods used for stereoregularity determinations involve the use of dipole moments, streaming birefringence, rate of saponification, and cloud-point titration. However, all these methods are only applicable to special polymers and/or are only indirect methods, and so they have not found general application. 

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