Transient Electrofluorescence of Dye-Tagged Polytetrafluoroethylene Latexes

Changes in the intensity of the fluorescence of suspensions of emulsion-grade polytetrafluoroethylene have been measured under the influence of pulsed electric fields. Two types of polymer sample were studied. The first consisted of suspensions of the usual lozenge-shaped particles, and the second had some 16% of elongated rod-like particles in addition to the lozenges. When tagged severally with four different dyes to give variable coloured emission under polarized ultraviolet light, significant electrofluorescent effects were recorded. The study indicates that suitably oriented tagged-rod particles exhibit extremely high contrast between perpendicularly polarized fluorescent states and are a potential medium for display devices. The data are consistent with the model that, within the rod particles, the polymer molecules are aligned essentially parallel to the rod axes and that the lozenges consist of folded rod structures.