Toward molecular electronics. Self-screening of molecular wires.

One-dimensional polyelectrolytes are proposed as molecular devices based on soliton propagation. The use of such "molecular wires" as delay lines or shift registers raises the problem of their electrical screening, because, when a large number of these wires are densely packed, cross-talking between them might occur. In order to overcome such a drawback, a detailed study of the polyelectrolyte behavior in an ionic solution has been developed, under equilibrium conditions. The results bring into evidence a condensation process, around each molecular wire, of the mobile ions in the solution. The consequent self-screening effect could be relevant in reducing cross-talking.