Polystyrene lattices

Goodwin, J. W. Ottewill, R. H. Pelton, R., Studies on the preparation and characterization of monodisperse polystyrene lattices V The preparation of cationic latices, Colloid Polymer Sci. 1979,257,61 69... 

Table 10.4 summarizes the compositions of some experiments as well as the colloid-analytical data of the final polystyrene lattices. A particle diameter of about lOOnm (including the shell of the adsorbed block copolymers in an extended conformation) is rather low for the product of a dispersion polymerization in unpolar solvents. In addition, a mean deviation (a) of about 20% of the particle size indicates a well-controlled and stable latex. 

Some typical transmission electron micrographs of these polystyrene lattices are shown (Sample 2 and Sample 3) in Figure 10.6. The effects ofthe amount of stabilizer S is the relative amount of stabilizer) on the particle size is strong the more stabilizer applied, the smaller the particles are. It must be emphasized that this effective stabilization of nanopowders by our fluorinated block copolymers is not restricted to polymerization processes, but can be generalized to the fabrication of all organic nanopowders in media with low cohesion energy density, e.g., to the dispersion of dyes, explosives, or drugs. 

OttewiU, R.H. and Satgurunathan, R. (1987) Nonionic lattices in aqueous media. 1. Preparation and characterisation of polystyrene lattices. Colloid Polym. Sci, 265, 845-53. 

FIGURE 12.12 Steady shear viscosity as a function of Peclet number for polystyrene lattices of radii of 54, 70, 90, 37, and 55 nm at 50% Iqr volume in different solvents (—, H2O O, benzyl alcohol and, meta-cresol), where tjq = 24.7tjn, >, = 13.97, . Data from Kreiger [42]. 

The conclusion drawn from equation (8.56) is at odds with published data on polystyrene lattices and silver bromide, in which a volume proportionality is found [37,38]. However these distributions w ere narrow, and with narrow distributions the difference between volume and surface distributions is small. The conclusion is also at variance with data published on BCR 66 quartz powder, ranging in size from 0.3 to 3 pm. In this case, the median for the attenuation curve was 1.52 pm which reduced to 1.14 pm with extinction factor correction [39] and a correction of this magnitude could hide the effect. 

Light Scattering/Absorption Techniques for the Analysis of Polystyrene Lattices... 

Having established that the multi-wavelength transmission techniques offer a number of advantages, the Uv-vis reflectance spectra from concentrated polystyrene lattices have been recorded using fiber optics reflection probes. Although some averaging of the individual particle properties can be expected, reliable calibration and estimation of the particle properties is possible, since discrimination to the desired particle properties is found as it will be shown below. 

To study the effect of the particle concentration on the reflectance spectra, two polystyrene lattices, which were synthesized in our lab using a seeded polymerization process, were extensively characterized. The mean particle sizes (MPS) were 82 nm and 155 nm for two lattices. The particle size data was obtained with the Coulter LS 230 Coulter particle analyzer. After the lattices were prepared and characterized 9 different dilutions were prepared to cover the concentration range reported in Table 5. 

Figure 15. Left. Effect of the particle concentration on the reflectance spectra measured from several polystyrene lattices (MPS 82nm) taken with probe configuration 2. Right. Fiber closest to the delivering fiber. See Table 5 for precise concentrations. ID 1.1-1.10.

It has been demonstrated that the Uv-vis reflectance spectra contain information on the particle size and concentration for polystyrene lattices. These data suggest that there is an optimal optical configuration in the tip of reflection probes for the estimation of particle size. 

Springer, M.M., Dielectric relaxation of dilute polystyrene lattices, Ph.D. thesis. University of Wageningen, The Netherlands, 1979. 

K. Furusawa, Y. Kimura, T. Tagawa, Synthesis of composite polystyrene lattices with silica particles in the core,/. Colloid Intef. Sci. 1986, 109, 69-76. 

G. Bolle, C. Cametti, P. Codastefano, P. Tartaglia, Kinetics of salt-induced aggregation in polystyrene lattices studied by quasielastic light scattering. Phys. Rev. A 35(2), 837-841 (1987). doiilO. 1103/PhysRevA.35.837... 

In order to visualize the flow patterns small particles with the required size, shape, density and wetting properties dispersed in the liquid phases were ehosen as tracer materials. Polystyrene lattices (diameter 10-15 pm) and polyethylene particles (diameter 15 — 25 pm) proved to be suitable for this purpose in the water and in the n-dodecane, respectively. 

Goodwin, J.W., Hearn, J., Ho, C.C., and Ottewill, R.H. (1974) Studies on preparation and characterization of monodisperse polystyrene lattices 3. Preparation without added surface-active agents. Colloid Polym. Sci., 252 (6), 464- 71. 

Elgersma, A.V., R.L.J. Zsom, W. Norde, and J. Lyklema. 1990. The adsorption of bovine serum-albumin on positively and negatively charged polystyrene lattices. Journal of Colloid and Interface Science 138 (1) 145-156. 

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