Dichroism of Dyes in the Stretched PVA Sheet. II. The Relation between the Optical Density Ratio and the Stretch Ratio, and an Attempt to Analyse Relative Directions of Absorption Bands

Abstract 1) An expression for the optical density ratio was derived as a function of the stretch ratio. 2) Dichroism of the crystal violet and auramine yellow ion in stretched PVA sheets was observed, and the relation of the optical density ratio to the stretch ratio was plotted. It was shown that the theoretical expression derived here could explain rather well the experimental relation between these two quantities. 3) The analytical results were as follows. The main absorption band and the shoulder of the crystal violet ion did not orginate from the two isomers but were perhaps due to one species. For the auramine yellow ion the angle between the transition directions corresponding to the first and the second band might be approximately a right angle provided that the absorption-planes were in a same plane.