Preparation of Carboxyl-Functionalized Polystyrene/Silica Composite Nanoparticles

✍ Scribed by Zhong Zeng; Jian Yu; Zhao-Xia Guo

• Publisher: John Wiley and Sons
• Year: 2004
• Tongue: English
• Weight: 207 KB
• Volume: 205
• Category: Article
• ISSN: 1022-1352
• DOI: 10.1002/macp.200400201

✦ Synopsis

Abstract

Summary: This paper describes the synthesis of carboxyl‐functionalized polystyrene/silica (PS/SiO~2~) composite nanoparticles with various contents of poly(methacrylic acid) (PMAA) on the surface by post‐addition of methacrylic acid (MAA) via emulsion polymerization. High yields and binding efficiencies (around 90%) are achieved by an optimal procedure mainly involving the appropriate addition of MAA and amounts of surfactant and silica. The kinetics investigated indicates that the polymerization follows a mechanism different than that found in some earlier studies. The amount of grafted PMAA was determined by titration and FT‐IR, and altered in a wide range (1–40 wt.‐% to PS). Transmission electron microscopy (TEM) photographs show that the composite nanoparticles are about 60 nm in spherical shape and have a multi‐layered core‐shell structure with a cluster of primary silica beads as the core and PMAA as the outmost shell. There are approximately 4 to 21 primary silica beads in one composite nanoparticle, depending on the amount of silica added.

Preparation of carboxyl‐functionalized polystyrene(PS)/silica composite nanoparticles.

magnified imagePreparation of carboxyl‐functionalized polystyrene(PS)/silica composite nanoparticles.