β-Thioester-Based Low-Molecular-Weight Organogelator for Highly Efficient Gelation of Perfluorocarbons

Abstract

Thermally reversible supramolecular perfluorocarbon (PFC) gels are unique soft materials and have been gaining significant interest in many applications. Developing efficient low-molecular-weight organogelators for PFCs is an attractive field, but it remains challenging. This paper reports a highly efficient β-thioester-based gelator for the gelation of PFCs. The gelators are synthesized through click chemistry, using alkyl thiols and acrylates containing perfluoroalkyl chains, and have a diblock molecular structure that incorporates thioether and ester groups. In four typical PFCs (perfluorooctane, perfluorotributylamine, perfluoropropylene trimers, and perfluorodecalin), the gel properties of β-thioester-based gelators have been studied, achieving a low critical gel concentration (CGC) of only 0.3%–0.7% w/w. Comparative studies have shown that the high gelation efficiency arises from the formation of a fine fibrous structure in which the thioether group plays a crucial role, supported by the synergistic contribution of the ester group. In addition to the functional groups, the effect of alkyl chain length is also studied, revealing that the optimal chain length is n = 12. The achieved PFC gels are thermally reversible and have a storage modulus of 10³–10⁴ Pa in the 0.5–1.5% (w/w) concentration range. As we have demonstrated, these PFC gels are promising candidate materials for constructing temperature-responsive films that can switch the transmission of visible light.