Effect of Surfactant Molecules on the Electrooptical Properties of Nematic Emulsions

Switchable nematic emulsions can be obtained by fast cooling of isotropic mixtures of nematic liquid crystal and monomers. Films obtained with this procedure show very low saturation fields but rather long relaxation times. In this paper, we doped nematic emulsions with different percentages of surfactant agents to obtain a good compromise between low saturation fields and fast relaxation times. The decay time decreases in a significant way, and the saturation field is slightly affected by the additional small amounts of surfactant. Experimental results are shown to be in rather good agreement with a phenomenological model.