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Title: Analysis of Gouy interference patterns from binary free-diffusion systems when the diffusion coefficient and refractive index have c/sup 1/2/ and C/sup 3/2/ terms, repsectively

Journal Article · · J. Phys. Chem.; (United States)
DOI:https://doi.org/10.1021/j100448a022· OSTI ID:5183514

Gouy fringe patterns are treated by numerical intergration and analytical techniques for binary electrolyte systems whose diffusion coefficients D and refractive indices n have concentration dependences including 1/2 and 3/2 powers. If one initial solution is pure water, skewing from the ideal case (constant D, linear n) is substantial; correction factors are large; and no averages of experimental quantities will yield D(anti-C). Refractive-index effects were much larger than expected. Analytical results include extension of the Gosting-Fujita theory to yield fringe positions and proof that f(zeta)/sup 2/3/ is a proper extrapolation function to get D/sub A/. Numerical integration results show (1) that the Gosting-Onsager theory for ideal systems is better than previously believed at high fringe numbers or low total number of fringes, (2) that masks are more important than previously assumed, and (3) that calculated corrections to experimental quantities can be least squared successfully in terms of variables suggested by the analytical theory. As anti C/(..delta..C/2) increases (C/sub 0/ moves away from infinite dilution), analytical results approach the numerical values. Proper analyses of dilute electrolyte data require several experiments to obtain the concentration-dependent correction factors. Examples for KCl and CaCl/sub 2/ are given. 4 figures, 4 tables.

Research Organization:
Univ. of California, Livermore
DOE Contract Number:
W-7405-ENG-48
OSTI ID:
5183514
Journal Information:
J. Phys. Chem.; (United States), Vol. 84:11
Country of Publication:
United States
Language:
English