Controllable transformation from sensitive and reversible heat-set organogel to stable gel induced by sodium acetate

Reversible sol–gel transition and different phenomena caused by adding carboxylates. The reversible heat-set organogel system composed of (-CD, phenolphthalein and lithium chloride in N,N-dimethylformamide could transform to stable gel as the temperature decreased. This controllable transformation is realized by the addition of proper amount of sodium acetate into the reversible gel system. [Display omitted] ► The heat-set organogel is prepared by β-CD, phenolphthalein and LiCl in DMF. ► The heat-set organogel could transform to stable gel with decreasing temperature. ► The transformation could be controlled effectively by the amount of sodium acetate. ► Other analogous acetates with K+ and Mg2+ do not possess this controllable property. This paper describes the first example of controllable transformation from sensitive and reversible heat-set organogel to stable gel induced by sodium acetate. Upon the addition of proper amount of acetate sodium into the reversible heat-set organogel system composed of β-CD, phenolphthalein (PP) and lithium chloride in N,N-dimethylformamide, the reversible gel could transform to stable gel as the temperature decreased. Further studies showed that other analogous acetates with K+ and Mg2+ do not possess this property. The gel was characterized by SEM, XRD and FT-IR. This work may pave the way for the design of smart materials with multi-responsiveness.