Light-scattering intensity calculation

Figure 7 Concentration dependence of the reduced light scattering intensity extrapolated to zero angle for PS-S03Li-40 in cyclohexane at 27.5°C. The solid line represents the model calculation with 3 10 (1/mol) and N 12. The dashed line indicates M] = 49,000.

B. M. Ladanyi and T. Keyes. New method for the calculation of light-scattering intensities Application to depolarized scattering from simple fluids. Molec. Phys., 57 1685-1701 (1976). B. M. Ladanyi. Local Fields in Liquids. In G. Birnbaum (ed.). Phenomena Induced by Intermolecular Interactions, Plenum Press, New York, 1985, pp. 497-523. 

J. H. R. Clarke and L. V. Woodcock. Boundary problems in the calculations of light scattering intensities from liquids using computer simulation. Chem. Phys. Lett., 73 121-124 (1981). 

Fig. 40. A comparison of the theoretically calculated and experimentally measured variation of light scattered intensity with scattering angle 0 for Hr scattering at 45 to the polariser and analyser direction. (From Hashimoto, T.. Prud homme, R. E. and Stein. R. S. (1973). J. Polymer Sci., A-2, U693. 709.)...

Fig. 44 Upper graph Reduced light scattering intensity R q = 0)/c)compiex measured at one small but finite concentration and extrapolated to zero scattering vector of the complexes between cylindrical brushes with PSS-C12 side chains and with PEI-PEO side chains. Values are normalized by the respective calculated scattering intensity of the mixture, R q = 0)/c)mkture, as function of the weight fraction of the cylindrical bmsh with PEI-PEO side chains. Lower graph Apparent radu of gyration measured at one small but finite concentration. From [152]...

Attempt of correlating the molecular structures and experimental data, for example, cmc, and the thermodynamic parameters of micellization (enthalpy, entropy, and free energy), rests on the assumption that they have been calculated by a consistent procedure this point needs further consideration. At the outset, it should be noticed that there are systematic differences between the results, for example, the cmc, obtained by using distinct experimental techniques. The reason is that the function plotted (absorbance of micelle-solubilized dye, conductivity, surface tension, light scattering intensity, etc.) versus [surfactant] measures different averages of the various species in solution. Examples are surface tension that primarily depends on monomer concentration and solubilization of (water-insoluble) dye that depends mainly on the total amount of micelles present. The consequence is that cmc measured from surface tension will always be lower than cmc measured by dye solubilization [28]. In fact, values of the cmc of the same surfactant, determined by different groups, by the same technique show differences. For example, fifty-four erne s determined by the same technique for Cj NMe Br (measurements at 25°C) differ by 22% [29]. 

Laser light scattering (LLS) s Intrinsic scattering intensities of carbohydrate-protein complex used to calculate stoichiometry... 

---