Stretchable calix[4]arene-based gels by induction of water

This study focused on controlling the stretching property of gels. This resilience is dependent on the water content in the calix[4]arene-based gel solvent system, where the stretching property of gels could be controlled upon the addition of water. The storage (G ') and loss (G '') moduli of the calix[4]arene-based gels prepared in solvent systems with different water contents were investigated via rheological measurements. By the strain sweeps, the values of G ' decreased, while tan-delta increased with water content in the solvent system. In addition, a significant changes in the G ' and G '' values were observed upon the addition of water by frequency sweeps. In particular, the decrease in the G '' value of the gel prepared from the 1,3-alternated calix[4]arene derivative (HC4) and diisocyanate linker (HDI) in DMSO/H2O mixed solvent (8:2 v/v) was approximately 5-fold larger than that of the gel prepared in 100% DMSO. Thus, this novel approach would useful for the development of new soft materials with finely controllable mechanical properties.