Trapping metal nanoclusters in ‘soap and water’ soft crystals


Dr. F. Bouchama, ITS-UvA


We report the elaboration of a lyotropic hexagonal phase doped with metal nanoclusters. This concept is general and may be applied to many metal clusters. The system is made from sodium dodecyl sulfate, water, pentanol and toluene. It displays a hexagonal phase of direct type, namely, nonpolar tubes in a polar medium swollen by the organic phase. We succeeded in trapping stable clusters of different metals, viz. palladium, ruthenium, silver, gold and copper inside the nonpolar tubes by using a suspension of metal clusters (2nm size) in toluene. The growth of the doped hexagonal phase was monitored using cross-polarized microscopy, and its structure studied by Small Angle X-ray Scattering. Evidence that clusters are inside the worm-like micelles is presented. By confining the nano-clusters in a well defined cylindrical micelle rods, we may direct their cold welding so they grow into wires.