Novel Tri-Cholesteryl Derivatives-Based Low Molecular Mass Organic Gelators with Multi-Stimuli Responsive Properties

Abstract

Two novel tri-cholesteryl derivatives 1 and 2 have been designed and prepared. Gelation tests in 30 liquids revealed that 1 is a more efficient gelator than 2. Interestingly, the gel of 1/cyclohexane shows a reversible sol–gel phase transition in response to a variety of disparate stimuli such as temperature, stress, and HCl gas. In particular, a fully reversible thixotropic property was observed, which has been rarely reported before. Fourier transform infrared spectroscopy and 1H NMR measurements revealed that hydrogen bonding is an important driving force for the formation of the gel networks. The network structures of 1 and 2 in their cyclohexane gels were studied by scanning electron microscopy and X-ray diffraction analyses, and possible packing models were proposed accordingly. The findings demonstrated in the present work suggest that there is a big potential for developing tri-cholesteryl derivatives into extraordinary low molecular mass gelators.