Polystyrene latex aggregates

Figure 14.4 Comparison of predicted (solid line) and experimental (symbols) size distributions of polystyrene latex aggregates obtained after 10 min of aggregation using 20 ppm cationic quaterna ammonium based derivative of polyac7lamide [25]. (Experimental data from [52].)...

Polystyrene latex particles were coagulated by the addition of Ba(N03)2. The number of dispersed particles deposited onto a planar polystyrene surface was determined 15 min after the addition of salt by optical microscopy. The light microscope does not permit the aggregation of the deposited particles to be determined subsequent examination by the electron microscope gives this information. Clint et al. obtained the following results ... 

The polystyrene latex (PSL) spheres were obtained from Seragen Diagnostics. The nominal sizes of these standards were from electron microscopy measurements. The samples were prepared by diluting the 10% solids in filtered, doubly distilled water, adding a small amount of SDS to help disperse the samples and sonicating with Branson 60 watt bath sonicator for 30 seconds to disperse any aggregates. The relative volumes (weights) of the two sizes of PSL in the mixed sample were estimated to be accurate to about 5-10%. 

The mixture was sonicated to eliminate aggregates. A polystyrene latex with a broad distribution was obtained from Kodak. This distribution had been characterized previously by electron microscopy, ultra centrifuge and Coulter counter. A monodlsperse, surfactant free, sulfated, polystyrene standard and a mixture of 10 such monodlsperse standards were purchased from Interfaclal Dynamics Corporation. A polyvinyl chloride latex with a broad distribution was donated by B. F. Goodrich. This sample had been characterized by Joyce Loebl disc centrifuge. These samples were diluted to 0.01% solids and sonicated to eliminate aggregates. 

Oles V. Shear-induced aggregation and breakup of polystyrene latex particles. J Colloid Interface Sci 1992 154 351-358. 

FIG. 4 Mass frequency curves during aggregation representation of the reduced concentration c(n, t) S2(r)//Vi as a function of the reduced variable n/S(t) for the system (polystyrene latex particles bearing carboxylic acid surface groups) suspended in 0.15 mol/L NaCl at pH 3.0. 

Figure 3 shows the adsorption isotherm for the HMHEG D-47 onto a cleaned polystyrene latex with a particle diameter of 140 nm. The curve shows a relatively slow approach to a plateau. At concentrations in excess of 0.08 g dL" a step occurs in the isotherm. The area occupied per molecule on the plateau before the step was 26.1 nm mol whereas after the step, the area was reduced to 17.1 nm mol" although a true plateau was not reached even at equilibrium concentrations as high as 0.18 g dLThe data in Figures 2 and 3 confirm the polymer aggregation process at c > 0.075 g... 

Lipps et al. (10,11) assumed a system mix of three types of aggregates (linear, planar, and close-packed three dimensional) in deriving form factors for singlet multiplicities up to 13. In coagulation experiments on polystyrene latex, Lips et al. (10) concluded that aggregates consisting of more than 13 singlets accounted for less than 0.5% of the... 

Kusters et al. [22] analysed polystyrene latex particles of about 1 p,m diameter aggregated in salt solution in a stirred tank, with samples withdrawn from the tank by pipette for light-scattering measurements. They found mass fractal dimensions of around 2.5 using the volume obscuration method. 

E. Barouch, Heterocoagulation. VI. Interactions of monodispersed hydrous aluminum oxide sol with polystyrene latex, /. Colloid Interf. Sci. 1980, 76,319-329 (c) K. Csoban, E. PefFerkorn, Perikinetic aggregation induced by chromium hydrolytic polymer and sol,/. Colloid Interf. Sci. 1998, 205,516-527. 

The size of obtained microcapsules is defined by the one of colloid microparticles (cores) and can be in an interval from several tens nanometers up to tens micrometers. A wide variety of colloid microparticles of organic and inorganic nature can be used as soluble cores for reception of microcapsules. There are microparticles based on melamine formaldehyde polymers and polystyrene latex, crystals of organic dyes, particles based on inorganic compounds such as metal carbonates Si02, protein aggregates, cellular constructions. ... 

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