Dispersion of polystyrene inside polystyrene-b-poly(N-isopropylacrylamide) micelles in water

✍ Scribed by Xiaodong Ye; Jingyi Fei; Juan Guan; Xuechang Zhou; Guangzhao Zhang

• Publisher: John Wiley and Sons
• Year: 2010
• Tongue: English
• Weight: 344 KB
• Volume: 48
• Category: Article
• ISSN: 0887-6266
• DOI: 10.1002/polb.21948

✦ Synopsis

Abstract

The addition of mixture of polystyrene‐b‐poly(N‐isopropylacrylamide) (PS‐b‐PNIPAM) and polystyrene homopolymer (h‐PS) in tetrahydrofuran dropwise into water leads to nanoparticles with a PS core and a thermally sensitive PNIPAM shell. The effects of the ratio of the homopolymer to copolymer and temperature on the formation and stabilization of the dispersion were investigated by using a combination of static and dynamic laser light scattering. PNIPAM shell continuously collapses as temperature increases in the range 20–40 °C. Such formed particles are stable even at temperatures much higher than lower critical solution temperature (LCST ∼ 32 °C) of PNIPAM. Our results reveal that the area occupied per hydrophilic PNIPAM chain on the hydrophobic PS core remains nearly a constant regardless of the amount of h‐PS in the polymer mixture. This clearly indicates that the surface area occupied per hydrophilic group is a critical parameter for stabilizing particles dispersed in water. © 2010 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 48: 749–755, 2010