Simha solution viscosity

Simha,R., Zakin,J.L. Solution viscosities of linear flexible high polymers. J. Colloid Sci. 17,270-287 (1962). 

Although one might imagine that at USC Simha s interests were focused solely on solution viscosity and statistical thermodynamics, he found time to be involved in such diverse topics as computation of DNA sequences (with Jovan Moacanin from the Jet Propulsion Laboratory), in glass transition phenomena and thermal expansion of polymers (with Moacanin and Ray Boyer of the Dow Chemical Co.), observation of multiple subglass transitions in polymers (with a research associate, Robert Haldon), and thermal degradation (another collaboration with Leo Wall from NBS). 

Weissberg, S. G., and Simha, R., Viscosities of solutions of cellulose acetate in solvent-precipitant mixtures, J. ColloidSci., 2(2), 305-306 (1947). 

Utracki, L. A., and Simha, R., Viscosity of polymer solutions scaling relationships, J. RheoL, 25,329-350 (1981). 

Simha, R., Viscosity of concentrated polymer solutions. Journal ofMacromolecular Science -Physics, B5(2), pp. 425 28 (1971). 

Simha, R., Viscosity of solutions of macromolecules. Record Chem. Progr., 10, p. 157(1949). 

Guth, E., and A. R. Simha. 1936. Viscosity of suspensions and solutions. KoIIoid-Z, 74, 266. Quoted in Wasp, E. J., J. P. Kenny, and R. L. Gandhi. 1977. Solid-Liquid Flow—Slurry Pipeline Transportation. AedermaniBdorf, Switzerland Trans. Tech. Publications. 

Simha equation), where a/b is the length/diameter ratio of these cigarshaped particles. Doty et al.t measure the intrinsic viscosity of poly(7-benzyl glutamate) in a chloroform-formamide solution and obtained (approximately) the following results ... 

Simha, R. The Influence of Brownian Movement on the Viscosity of Solutions. J. Phys. Chem. 44, (1940) 25-34. 

The viscosity increment was determined as v = B v = 172.7 ( 2 5 for spheres) where B is the viscosity coefficient characteristic of a given solue-solvent pair, and amounts to (9.91 0.24)xl0" ff/ A g" for PGA in aqueous solution. is the partial specific volume of the macromolecular component equal to [Pg.612]

The length L and diameter d of a rigid rod are related to the major axis a and minor axis b of the equivalent ellipsoid of revolution by a=L and b=(3/2)ll2d. It should be noted that, for actual molecules in solution, the quantity d can be defined only vaguely. With these relations, Simha s equation (64) for the intrinsic viscosity of an elongated ellipsoid of revolution can be rewritten for a thin rod (L/d> 1)... 

Frisch,H.L., Simha.R. The viscosity of colloidal suspensions and macromolecular solutions, Vol. 1, Chapter 14. In Eirich,F.R. (Ed.) Rheology. New York Academic Press 1956. 

Utracki,L., Simha,R. Corresponding states relations for the viscosity of moderately concentrated polymer solutions. J. Polymer Sci. Pt. A1,1089-1098 (1963). 

Simha,R., Utracki,L.A. The viscosity of concentrated polymer solutions corresponding states principles. Rheol. Acta 12,455-462 (1973). 

Simha,R., Chan,F.S. Corresponding states relations for the newtonian viscosity of concentrated polynier solutions. Temperature dependence. J. Phys. Chem. 75,256-267... 

Frisch, H. L and R- Simha Viscosity of colloidal suspensions and macro-molecular solutions. In Rheology, Vol. I, pp. 525—-613. edited by F. Eirich, New York Academic Press 1956. 

Simha (1940) employing Eq. (10) solved the equation for the viscosities of solutions of ellipsoids of revolution for the limiting case a —> 0. Under this condition the distribution of the particles can be regarded as almost completely random. Simha also found that for large axial ratios the viscosity increment at a0 for very dilute solutions or suspensions (i.e., 4> —> 0) can be approximately represented by... 

SiMHA, R, The Influence of Brownian Movement on the Viscosity of Solutions. 

Before discussing the Kerr measurements on the solutions, we briefly outline how the size of the polymers was obtained from viscosity and relaxation data. Two well-known expressions which are useful in interpreting these data are the Simha and Burgers equations. The Simha equation (20) relates the intrinsic viscosity of a solution of elongated ellipsoids... 

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