High PVC film-forming composite latex particles via miniemulsification, part 2: Efficiency of encapsulation

✍ Scribed by Ghurmallah H. Al-Ghamdi; E. David Sudol; Victoria L. Dimonie; Mohamed S. El-Aasser

• Book ID: 101592282
• Publisher: John Wiley and Sons
• Year: 2006
• Tongue: English
• Weight: 293 KB
• Volume: 101
• Category: Article
• ISSN: 0021-8995
• DOI: 10.1002/app.24243

✦ Synopsis

Abstract

The application of a density gradient column (DGC) method using sodium polytungstate (SPT) solutions as the medium was investigated for determining the encapsulation efficiency of 11–30% pigment volume concentration (PVC)) latex particles prepared by the miniemulsification process. The encapsulation efficiencies for 11, 20, and 30% PVCs were found to be 100% of the TiO~2~ encapsulated inside 86.3, 98, and 98.9% of the styrene/n‐butyl acrylate copolymer, respectively. The copolymer not participating in the encapsulation (free copolymer) was found in the 1.04 g/mL density layer of the DGC. Particle size analysis by DLS (dynamic light scattering) showed that the encapsulated particle size increased with increasing density. Thus, the number of TiO~2~ particles (primary particles) inside each encapsulated particle increased to accommodate both the increased size and density. The results obtained by DLS for each DGC layer of the 30% PVC system were confirmed qualitatively by TEM in terms of the increasing encapsulated particle size and broadening of the size distribution as the density increased in the DGC. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 4517–4525, 2006