Colloid and Polymer Science

, Volume 283, Issue 11, pp 1259–1266

Monodisperse thermosensitive particles prepared by emulsifier-free emulsion polymerization with microwave irradiation

Short communication

DOI: 10.1007/s00396-005-1318-1

Cite this article as:
Yi, C., Deng, Z. & Xu, Z. Colloid Polym Sci (2005) 283: 1259. doi:10.1007/s00396-005-1318-1


The emulsifier-free emulsion polymerization of styrene (St) and N-isopropylacrylamide (NIPAAm) was successfully carried out with microwave irradiation, and the monodisperse thermoresponsive poly(styrene-co-N-isopropylacrylamide) (poly(St-co-NIPAAm)) particles with diameters in the range 100–130 nm were prepared. The morphology, size and size distribution of the poly(St-co-NIPAAm) particles were characterized by transmission electron microscopy, scanning electron microscopy (SEM) and photon correlation spectroscopy (PCS), respectively. The results showed that poly(St-co-NIPAAm) particles had spherical morphology, and the poly(St-co-NIPAAm) particles prepared by emulsifier-free emulsion polymerization with microwave irradiation were smaller, more uniform than those obtained with conventional heating. The hydrodynamic diameters of poly(St-co-NIPAAm) particles were decreased as the temperature increased from 25 °C to 40 °C, and poly(St-co-NIPAAm) particles collapsed remarkably at 32 °C, which is the lower critical solution temperature of the poly(N-isopropylacrylamide). The morphology of the assembled poly(St-co–NIPAAm) particles was observed by SEM, it was found that monodisperse poly(St-co-NIPAAm) particles could assemble to form the two-dimensional order structures.


Microwave irradiationParticleEmulsifier-free emulsion polymerizationN-isopropylacrylamide

Copyright information

© Springer-Verlag 2005

Authors and Affiliations

  1. 1.College of Chemistry and Materials ScienceHubei UniversityWuhanChina