Synthesis of optically clear molecular organogels using phenol and a sulfosuccinic surfactant in various solvents with cyclic geometries

Abstract

Equal concentration mixtures of p-chlorophenol and a sulfosuccinic surfactant bis(2-ethylhexyl)sulfosuccinate (AOT) are known to form optically clear gels in cyclic organic solvents like cyclohexane, whereas turbid gels are obtained in acyclic alkanes and aromatic solvents with the same gelators. Clear organogels are necessary when emitting devices are dispersed inside the gel. As such, in this study, we employed 16 cyclic solvents including cyclic alkanes, cyclic alkenes, cycloalkanones, and chlorocyclohexane. Eventually we were to obtain clear gels in 12 cyclic alkane and cyclic alkene solvents at immediately after the gelation, while 2 of those gels turned out to be turbid in a few days. A cyclic solvent geometry was shown to be unnecessary to obtain clear gels. Transmittance spectra, drop-point temperature, and nuclear magnetic resonance were employed to characterize the organogels. The rigid structure in the π-stack caused by p-chlorophenol self-assembly brought about a higher drop point.