Electrochemical Studies in Liquid Crystals.
Abstract
The electrochemical characterization of room temperature nematic phase liquid crystals has been performed in order to identify suitable candidates that will serve as solvents in electrochemical systems. In acentonitrile solvent, we find that the working potential ranges for 4-methoxybenzylidene-4'-n-butylaniline (MBBA), 4-methoxy-4'-butylazoxybenzene (MBAB) and 4-pentyl-4'-cyanobiphenyl (K-15) are +1.2 - -1.8 V (vs. SSCE), +1.4 --1.5 V and +1.6 --1.8 V, respectively. Similar results are obtained in the neat phases used as solvents, however, in order to maintain a liquid crystalline phase, the electrolyte concentration needs to be kept under 40 millimolar. The electrochemical response of tetracyanoethylene (TCNE), tetracyanoquinodimethane (TCNQ), Ru(bpy)3(2+), ferrocene and other redox systems has been investigated in these phases. In general, we find large ohmic drops due to the very high resistance of these materials and in order to mitigate these effects, we are exploring the use of microelectrodes. The effect of orientation on the electrochemical behavior of TCNE has been investigated and the preliminary results seem to indicate a difference in the formal potentials for parallel and perpendicular orientation. In order to better quantify these results, we are developing reference electrodes that will be compatible with these materials.
Document Details
- Document Type
- Technical Report
- Publication Date
- Apr 10, 1985
- Accession Number
- ADA154317
Entities
People
- A. Serra
- Héctor D. Abruña
- R. D. Mariani
Organizations
- Cornell University Department of Chemistry and Chemical Biology