Matrix-Bound Nanochemical Possibilities

Abstract

In this paper we highlight through two examples the potential of zeolitic host materials for the production of totally engineered macroscopic-scale electronic structures that are made up of vast arrays of reduced dimensionality subunits. Through a novel contactless microwave cavity technique we have investigated the electrical conductivity and dielectric properties of a mesoscopic assembly of ultrafine (atomic-scale) wires of potassium prepared within a highly structured aluminosilicate matrix, zeolite L. We have observed an increase in room-temperature conductivity of around 5 orders of magnitude relative to unmodified zeolite, which may be ascribed to thermally activated electronic conduction. In our second example, a combined X-ray/EXAFS study has provided valuable insights into the reduction process involved in the preparation of nanoscale ferromagnetic cobalt particles in zeolite X. In addition, detailed calculations of cation solvation energies represent the first attempt to explain the driving force behind the two important and related chemical processesnamely the dissolution of elemental metals and ionic salts in dehydrated zeolitesused to incorporate metal species into the zeolite matrix in these two cases.