COLL 402 |
| G. Decher, Institut Charles Sadron, 6 rue Boussingault, Strasbourg, 67083, France and Gregory Schneider, CNRS Institut Charles Sadron, Université Louis Pasteur, 6, rue Boussingault, Strasbourg, F-67083, France. |
| The Layer-by-Layer assembly of multicomponent films has originally been developed for the functionalization of planar surfaces and has in the meantime evolved into a process that has led to two commercial applications. Later on, the technique was extended to the coating of micron sized objects by the team of G. Sukhorukov and F. Caruso. We have recently been interested to develop stable core/shell nanoparticle dispersions based on polyelectrolyte multilayer coatings. It is obvious that the deposition of layers of alternating charge on the surface of charged nanoparticles is not trivial. Ideally, one has to work as close to flocculation conditions as possible but at the same time to avoid flocculation or even aggregation completely. We describe here how core/shell nanoparticle dispersions consisting of metallic colloids of 13 nm size with a coating of up to 20 polyelectrolyte layers are prepared by consecutive polymer addition/centrifugation/ redispersion cycles. Such multilayer coatings can only be developed with particles that allow to monitor their dispersion state by a combination of classic with in-situ methods. Interestingly, core/shell nanocolloidal dispersions can be remarkably robust: using the right conditions allows to centrifuge such particles and to redisperse them by slight agitation only. |
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“Smart” Polymers on Surfaces and Colloids
8:30 AM-11:40 AM, Wednesday, March 31, 2004 Marriott -- Grand Ballroom J, Oral
Division of Colloid and Surface Chemistry |