New well-defined hybrid materials with thermoresponsive PNIPAM-shells and inorganic nanoparticle-cores

COLL 179

Matthias Karg, Matthias.Karg@tu-berlin.de1, Isabel Pastoriza-Santos, pastoriza@uvigo.es2, Luis M. Liz-Marzán, lmarzan@uvigo.es2, and Thomas Hellweg, thomas.hellweg@tu-berlin.de3. (1) Stranski Laboratory of Physical and Theoretical Chemistry, Technical University Berlin, Strasse des 17. Juni 124, 10623 Berlin, Germany, (2) Departamento de Quimica Fisica, Universidade de Vigo, Campus Universitario, 36310, Vigo, Spain, (3) Physical Chemistry I, University Bayreuth, Universitaetsstrasse 30, Bayreuth, 95440, Germany
Poly-(N-ispropylacrylamide) microgels are thermoresponsive and can therefore be classified as smart materials. As these particles react much faster on external stimuli such as temperature, pH and ionic strength than their macroscopic counterparts they are interesting for different applications including sensors, drug delivery and separation media. Nevertheless the optical properties of organic polymers are poor because of their rather low refractive index (~1,5). Composite materials made of microgels and inorganic nanoparticles combine the temperature-dependend swelling-behavior of the microgel and the high refractive index of the nanoparticles. Here, we present different types of PNIPAM hybrids with cores of silica and silica-coated gold. Characterization has been done using electron microscopy, atomic force microscopy, dynamic light scattering, small angle neutron scattering as well as UV-VIS-spectroscopy. The results show that well-defined core-shell systems with just a single nanoparticle as core can be synthesized. These particles are promising candidates for the preparation of photonic crystals.
 

Fundamental Research in Colloid and Surface Chemistry
6:00 PM-8:00 PM, Monday, August 20, 2007 BCEC -- East Registration, Poster

Division of Colloid & Surface Chemistry

The 234th ACS National Meeting, Boston, MA, August 19-23, 2007