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High PVC film‐forming composite latex particles via miniemulsification, part 2: Efficiency of encapsulation
Author(s) -
AlGhamdi Ghurmallah H.,
Sudol E. David,
Dimonie Victoria L.,
ElAasser Mohamed S.
Publication year - 2006
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/app.24243
Subject(s) - materials science , copolymer , particle size , dynamic light scattering , composite number , styrene , chemical engineering , particle size distribution , acrylate , polymer chemistry , light scattering , composite material , polymer , nanoparticle , scattering , nanotechnology , optics , physics , engineering
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