Thermotropic liquid crystals are usually doped with external impurities to tune new kind of LC phases for various applications. However, very few reports are available on such dispersions in the lyotropic liquid crystalline (LLC) phases. Hence, this study is carried out to investigate the effect of doping on the LLC phases and also, to study their self-assembly at the lyotropic interface. Such a study will open new pathways for the development of advanced functional soft materials. LLC phases are derived from two different surfactants viz. sodium dodecyl sulphate (SDS) and cetylpyridinium chloride (CPC) via dissolving them in the aqueous and non-aqueous medium. These mixtures are characterized via polarizing optical microscopy and UV-Visible spectroscopy. Binary mixtures exhibit hexagonal and lamellar phases in aqueous [1] and non-aqueous medium [2-3]. Further, lyotropic phases are doped with extrinsic impurities (dye, metal salts, acid) [1-3]. The prepared systems are also exposed to UV light to study their further applications. The LLC systems show high dye sequestration/degradation efficiency in the range of 87 to 99 % for the aqueous and non-aqueous medium of CPC and SDS at basic pH (7-9) within 60 minutes. The electrostatic interaction between the dye molecule and LLC phase in different solvents is responsible for dye sequestration/degradation. All the prepared LLC system shows high conductivity in the range of 4.0–40.0 mS/cm at room temperature without any toxic dopant and thereby potentially present their candidature for electrolytic applications [1-4]. These LLC systems are good and cost-effective prominent materials for dye sequestration/degradation and could also have applications in photoluminescence, ion-conducting membranes and water treatment process, etc. [4].

Keywords: Lyotropic Liquid Crystals, dye degradation, UV light, water treatment.

References:

[1] Duklan N., et al., Inorg. Chem. Commun., 2020, 116, 107924.

[2] Duklan N., et al., Surf. Interfaces, 2022, 28, 101629.

[3] Duklan N., et al., J. Mater. Sci.: Mater. Electron., 2022, 33, 4237- 4254.

[4] Shen Y., and Dierking I., Appl. Sci. 2019, 9(12), 2512.