Nanoparticles on Polyelectrolytes at Low Concentration: Controlling Concentration and Size

Previously reported results on nanoparticle distribution control on polyelectrolyte multilayers at high concentrations are presented here for the case of low concentration (Skirtach, A. G.; Dejugnat, C.; Braun, D.; Susha, A. S.; Rogach, A. L.; Sukhorukov, G. B. J. Phys. Chem. C 2007, 111, 555). In sharp contrast to the earlier presented method, nonaggregated distributions of nanoparticles are obtained here by admixing them directly with polyelectrolyte multilayers; preaggregation of nanoparticles is used for aggregated distributions. Furthermore, control over the distribution of nanoparticles at low concentration is extended here for the case of the synthesis of silver nanoparticles or their reduction in a solution by the so-called silver mirror or Tollens reaction directly on polyelectrolyte multilayer capsules. In this case, temperature and time are found to control the size and the concentration of nanoparticles. Controlling size and distribution of nanoparticles on polyelectrolyte multilayer capsules is relevant for intracellular delivery and release.