Mechanically tunable organogels from highly charged polyoxometalate clusters loaded with fluorescent dyes

Inorganic nanowires-based organogel, a class of emerging organogel with convenient preparation, recyclability, and excellent mechanical properties, is in its infancy. Solidifying and functionalizing nanowires-based organogels by designing the gelator structure remains challenging. Here, we fabricate Ca₂-P₂W₁₆ and Ca₂-P₂W₁₅M nanowires utilizing highly charged [Ca₂P₂W₁₆O₆₀]^10- and [Ca₂P₂W₁₅MO₆₀]^14-/13- cluster units, respectively, which are then employed for preparing organogels. The mechanical performance and stability of prepared organogels are improved due to the enhanced interactions between nanowires and locked organic molecules. Compressive stress and tensile stress of Ca₂-P₂W₁₆ nanowires-based organogel reach 34.5 and 29.0 kPa, respectively. The critical gel concentration of Ca₂-P₂W₁₆ nanowires is as low as 0.28%. Single-molecule force spectroscopy confirms that the connections between cluster units and linkers can regulate the flexibility of nanowires. Furthermore, the incorporation of fluorophores into the organogels adds fluorescence properties. This work reveals the relationships between the microstructures of inorganic gelators and the properties of organogels, guiding the synthesis of high-performance and functional organogels.