Photoluminescent lyotropic liquid crystals formed by Tyloxapol and n-dodecyl tetraethylene monoether

Photoluminescent lytropic liquid crystals (LLCs) were prepared in aqueous solutions from n-dodecyl tetraethylene monoether (C12E4) and Tyloxapol, which is an oligomer of polyoxyethylene tert-octylphenyl ether (TX-100) with a polymerization degree below 7. The close packing of the seven benzene rings in Tyloxapol induces a strong p-p interaction, which makes Tyloxapol fluorescent. The Tyloxapol/C12E4 mixed system were characterized by polarized optical microscopy (POM) observations, small-angle X-ray scattering (SAXS), rheological and fluorescence measurements with close comparison to the TX-100/C12E4 mixture. It was found that the type of LLCs transfered gradually from lamellar phase to hexagonal phase with increasing mass ratio of Tyloxapol to C12E4, during which an enhanced photoluminescence was observed. Our results showed that encapsulation of fluorescent molecules into the matrix of traditional surfactants could be an effective way for the preparation of photoluminescent LLCs.