Microgel Reactors

See allHide authors and affiliations

Science  18 Jun 2004:
Vol. 304, Issue 5678, pp. 1719
DOI: 10.1126/science.304.5678.1719d

The procedures for synthesizing nanoparticles of metals, semiconductors, or magnetic materials are often very material-specific. Current methods aimed at loading nanoparticles into the interior of microspheres either lead to low loading concentrations or alter the properties of the nanoparticles. By using the spherical container as the synthesis template, Zhang et al. show that they can successfully load microspheres and also synthesize a wide range of inorganic nanoparticles, while achieving narrow size distributions. Polymer microgels of highly cross-linked polymer chains with diameters between 200 and 600 nm were produced. Then ion exchange reactions were used to dope the microgels with metal particles, which could then be oxidized, reduced, or exposed to a counterion to form nanoparticles of the desired type. Tuning the level of metal ion, and controlling the size and void structure of the microgel particles through variations in temperature and acidity, controlled particle size and distribution. Heat treatment of the microgels doped with semiconducting nanoparticles reduced the polydispersity of the particle sizes and allowed for tuning of the photoluminescence spectra. — MSL

J. Am. Chem. Soc. 10.1021/ja031523k (2004).

Navigate This Article