Jürgen Dr. Finter

Transparent electrically conductive composite materials: Methods of preparation and their application

One possibility to obtain transparent, electrically conductive materials is the crystallization of conducting charge-transfer-complexes (CT-complexes) in a polymer matrix in the form of needle-or dendrite-like structures. With tetraselenotetracene chloride ((TSeT)2Cl), a radical cation salt, as electroconductive filler, we have access to a thermally stable, highly conductive material, with values of the bulk conductivity of the composite material up to 1 S/cm at a loading of the conductive complex below 1 %(w/w). The preparation of such composite structures as free standing (cast) films and in the form of very thin coated layers is presented and their electrical, optical and mechanical properties are discussed. In addition we show their potential use for display electrodes, transparent heating elements, and for antistatic applications.

Transparent electrically conductive composites by in situ crystallization of (TSeT)2Cl in a polymer matrix

A new chemical pathway was found which offers access to the thermostable, highly conductive tetraselenotetracene chloride radical cation salt (TSeT)2Cl. This pathway allows the in-situ crystallization of (TSeT)2Cl in a vitrifying polymer matrix. So highly conductive films (σ= 1–5 Scm-1) with networks of (TSeT)2Cl crystallites of a 1: 1000 aspect ratio could be prepared at a fairly low percolation threshold of 0.4 – 1.6 % w/w. These films show metallic conductivity behavior in the 60 – 400 K range.

Photochemical imaging processes for the formation of metallic patterns on polymers

Abstract A homogeneous polymer for photometallization containing anthraquinonyl (AQ) and hydroxyalkyl groups was studied, where some of the hydroxyalkyl groups are complexed with copper carboxylate. On irradiation AQ is excited to an n → π * type of triplet state and subsequently reacts with a hydroxyalkyl group to form the semiquinone radical and the hydroxyalkyl radical. Almost all semiquinone radicals disproportionate to AQ and AQH 2 . Copper ions are reduced to catalytic nuclei by AQH 2 as well as by hydroxy-alkyl radicals. Hydroxyalkyl radicals that are not consumed for reduction recombine to form a cross-linked polymer.