NSF Award
9707585
9707585 Alexander In this CAA project complex susceptibility and resistivity measurements will be used to investigate electric and magnetic properties of composites of quasi one- and two- dimensional molecular metal crystals in conventional polymers. The effect of molecular dimensionality of the conducting particles on the percolation threshold and conductivity of the composites will be instigated. Data will also be related to bulk crystal shape and dimensions, molecular metal composition and metal concentration in the composites. We will investigate the properties of the composites when the conducting phase becomes magnetic and look for evidence of proximity effect and tuneling when the conductor becomes superconducting. Dielectric relaxation measurements will be used to investigate interfacial chemical and electromagnetic interactions between the conducting and insulating phases of the composites. These materials have potential as coatings or extruded plastics for electromagnetic shielding or electrostatic dissipation applications. %%% Composite materials made by combining conventional polymers with carbon or metal powders or fibers are currently used for industrial applications, because of their good electrical conductivity and mechanical properties. In this CAA project, we plan to form, for the first time, composites of conventional polymers with "molecular metals". These are metallorganic or purely organic substances that conduct electricity. Some are practically one-dimensional chains of molecules weakly linked together. Others are almost two- dimensional "sheets" of molecules that are weakly linked together. This work will yield results of both fundamental and practical importance. We will gain understanding of the effect of molecular dimensions on the electrical conductivity of a composites and study the effect of dispersing one- or two- dimensional superconducting or magnetic crystals in an insulating, non-magnetic matrix. These composi te magterials may exhibit good conductivity and/or useful magnetic properties, making them important as materials for electrostatic dissipation or electromagnetic shielding. In addition to journal publications, a patent application is anticipated. Detailed study of these composites will take several years and will provide the base for a long-term vigorous research program. ***
