Light scattering apparatus for

Figure 6. Light scattering apparatus for nucleation kinetics...

Oka, K., Otani, W., Kameyama, K., Kidai, M., Takagi, T., Development of a High-performance Electrophoretic Light Scattering Apparatus for Mobility Determination of Particles with Their Stokes Radii of Several Nanometers, Appl. Theoretical Electrophoresis, 1990, 1, 273-2IS. 

The light-scattering apparatus and procedure have been formerly described (15). The only modification and precaution with polybutadienes were to use the appropriate refractive index differential for each polymer as this was observed to decrease with vinyl content values used were 0.118, 0.112, and 0.106 dl/gram for 2, 10, and 20% vinyl polybutadienes in cyclohexane at 25 °C and 546 m//,. 

The static laser light scattering apparatus used as an on-line GPC detector has been popular for a while. Here, we illustrate another but less known method of combining the results from (gel permeation chromatography) and DLS. The basic principle is as follows There is a similarity between these two tools in that the translational diffusion coefficient D obtained by DLS and the elution volume V in GPC are related to the hydrodynamic size of a given macromolecule. In a first approximation, if the hydrodynamic size is proportional to the molar mass, we have... 

Fig. 18. Diagram of reactive scattering apparatus for the study of non-metal reactions A, scattering chamber B, source chambers C, liquid nitrogen cooled cold shield D, detector E, source bulkheads G, liquid nitrogen trap H, oil diffusion pumps N, free radical source P, nozzle source Q, skimmer E, ion source H, liquid He trap I, ion lenses P, photomultiplier Q, quadrupole rods R, light baffle S, slide valve T, radial electric field pumps (from C. F. Carter et al. 02 by permission of the Chemical...

Fig. 7.1. Schematic view of the light-scattering apparatus 1, stainless steel vessel 2, inlet for thennostatting fluid 3, windows to illuminate the film 4, film 5, ground glass frame 6, glass vessel with soap solution 7, mechanism to move vessel up and down 8, tumable part of the cover 9, tube 10, photomultiplier 11, prism 12, concentric grooves filled with high-viscosity paraffinic oil 13, concentric rims. (From Ref. 138, courtesy of American Institute of Physics.)...

For the thermostatting of the light-scattering apparatus, see Section VI.A.l. The resulting long-term temperature stability inside the apparatus is 0.002°C. 

Figure 4. Temperature dependence of the PNIPAM colloid diameter and turbidity. The diameter was determined using a commercial quasielastic light scattering apparatus (Malvern Zetasizer 4). The turbidity was measured for a disordered dilute dispersion of these PNIPAM colloids by measuring light transmission through a 1.0 cm pathlength quartz cell with a UV-visible-near IR spectrophotometer. Solids content of the sample in the turbidity experiment was 0.071%, which corresponds to a particle concentration of 2.49 x 10 spheres/cc. Also shown is the temperature dependence of the turbidity of this random colloidal dispersion. The light scattering increases as the particle becomes more compact due to its increased refractive index mismatch from the aqueous medium (76) (Adapted from ref 16).

To prepare micelle solutions, diblock copolymers were first dissolved in a small amount of THF, a common solvent for both blocks. Hexane, a precipitant for PFDMS, was added dropwise afterward with gentle stirring, and the solutions were monitored in a light-scattering apparatus. When a strong increase in lightscattering intensity indicated the onset of the aggregate formation, the addition of hexane was stopped. The solution was left to stir for 3 days at 23 °C to equilibrate the micellar structures. All micelle solutions have a final polymer concentration of 1 mg/mL. 

Polarizability a is usually measured in terms of refiractive index n or dielectric constant s and the light-scattering apparatus can be designed in relation to the measurement of refractive index. (Note according to Maxwell s theory.) For that reason, we utilize the relation... 

The An/Ac values are obtained from the measurement of the solutions (same solutions as for light-scattering apparatus) with a differential refractometer (a separate instrument). 

Arachin, 93.7% iS2o 13.3 and 6.3% <820" 21.1, was examined in phosphate buffer, n = 0.5, pH 7.4, protein concentration 0.38 g./lOO ml., by means of light scattering apparatus. In a filtered solution arachin had an apparent molecular weight of 17,000,000 with ho/1120 of 1.8. On further clarification by ultrafiltration, the molecular weight was 333,000 with ho/1 no of 1.074. This value is in agreement with the accepted value for the molecular weight of arachin of 330,000 calculated from sedimentation and diffusion constants (89). 

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