Polystyrene Latex Coagulation: A Study Using Centrifugation in Density Gradients

✍ Scribed by Miriam Michiyo Takayasu; Fernando Galembeck

• Publisher: Elsevier Science
• Year: 1993
• Tongue: English
• Weight: 432 KB
• Volume: 155
• Category: Article
• ISSN: 0021-9797
• DOI: 10.1006/jcis.1993.1003

✦ Synopsis

Coagulation of polystyrene latices was followed by using a combination of centrifugation in density gradients and lightscattering densitometry. Second-order rate constants (\left(k_{11}\right)) were obtained under various conditions. At (25^{\circ}) and (45^{\circ} \mathrm{C}) under 0.5 (\mathrm{mol} \mathrm{dm}^{-3} \mathrm{NaCl}), they agreed with the predictions of von Smoluchowski's theory, corrected for viscous interactions. However, some discrepancies with theory were found under other conditions. Monomer and oligomer concentrations decayed more slowly than predicted, with time. Detectable, steady concentrations of these species were found at (t \rightarrow \infty). The formation and decay of large ( (n>15) ) aggregates was also followed. & 1993 Academic Press, Inc.