Organogelators derived from the bisphenol A scaffold

Abstract

Bisphenol A, a common precursor molecule used in the preparation of some polymers, was investigated as a possible scaffold for the design and synthesis of small-molecule gelators. To this end, a small library of ten molecules was synthesized by appending different n-alkyl chains and aromatic moieties via the p-hydroxyl groups in a single step. Five of these served as excellent gelators of several polar solvents. All the gelators contained n-alkyl chains, while none of the aromatic moieties imparted the gelling ability to the molecules. The minimum gelation concentrations ranged between 1–3%, with the ether-linked gelators more efficient than the ester-linked ones. The gel-to-sol transition temperatures observed for these gels were in the range of 26–54 °C. Detailed characterizations of the gels for two representative gelators were carried out using techniques like FTIR, UV-vis absorption, scanning electron microscopy, rheology, powder XRD, and contact angle measurement. The gels showed good absorption profiles for two water-soluble dyes. Based on these results, we propose that ‘bisphenol A’ can be conveniently exploited as a versatile core gelating scaffold in the design of many other small-molecule gelators.