Speaker
Description
Recent scientific and technological efforts have increasingly focused on developing novel multifunctional materials whose properties can be dynamically tuned by external stimuli such as light, pressure, and electric or magnetic fields. Among these, organic-inorganic hybrid structures synthesized via simple wet-chemistry processes have emerged as promising candidates. Notably, materials exhibiting metal-to-metal charge transfer (MMCT) demonstrate inherent bistability and responsiveness, making them highly attractive for applications in molecular switches and sensors.
To enhance the processability and stability of these materials for practical integration into devices, a promising approach involves embedding functional frameworks within polymer matrices. This strategy transforms brittle crystalline materials into flexible polymeric composites while preserving their molecular functionality.
In our recent study, we investigated the multi-responsive, chain-like coordination compound {NH$_4$[Ni(cyclam)][Fe(CN)$_6$]$\cdot$5H$_2$O}$_n$ (where cyclam=$1$,$4$,$7$,$11$-tetraazacyclotetradecane). Although this compound exhibits limited stability, it undergoes a reversible thermal MMCT phase transition with bistability at room temperature, characterized by a sharp and broad thermal hysteresis loop [1]. By employing electrospinning, we successfully incorporated sub-micro and nanoparticles of this bistable material into poly($\varepsilon$-lactone) (PCL) and poly($2$-vinylpyridine-co-styrene) (P$2$VP-PS) fibers. Remarkably, the switchable properties were retained in the composite materials, as confirmed by optical observations and magnetic measurements. Moreover, the polymer matrix significantly enhanced the stability of the compound, broadening its potential applications as a temperature or pressure sensor.
Acknowledgements
This work was supported by the NCN within OPUS No. 2021/43/B/ST5/02216.
References
[1] M. Reczyński et al., “Room‐Temperature Bistability in a Ni–Fe Chain: Electron Transfer Controlled by Temperature, Pressure, Light, and Humidity,” Angewandte Chemie International Edition, vol. 60, no. 5. Wiley, pp. 2330–2338, Dec. 15, 2020. https://doi.org/10.1002/anie.202012876
