Adequate measuring techniques for ions in liquid crystal layers

The ion contamination in twisted nematic liquid crystals should be limited to assure good electro-optical performance of AM-LCDs. Today, pure liquid crystal mixtures are produced, though little information is available on long term stability, and on the kind of ions that contaminate the liquid crystal. The first step in the determination of the ion source is the development of an appropriate measuring technique that characterizes the ions in the liquid crystal. In this article such a new method is proposed. A comparison with former techniques is made.