Liu Cheng, Chen Xu-Yong, Cao Xiao-Jie, Zhang Wenmin, Cao Li-Hui
Shaanxi Key Laboratory of Chemical Additives for Industry, College of Chemistry and Chemical Engineering, Shaanxi University of Science and Technology, Xi'an 710021, P. R. China.
Department of Chemical Engineering and Food Science, Zhengzhou University of Technology, Zhengzhou 450044, Henan Province, China.
Precis Chem. 2025 Feb 20;3(4):221-230. doi: 10.1021/prechem.4c00102. eCollection 2025 Apr 28.
Stimuli-responsive smart materials, as an emerging material, can fulfill reversible transformation of chemical/physical properties under external stimuli such as mechanical stress, light, and electricity, which has the highlights of rapid response, designable structure, and function. Two ionic hydrogen-bonded organic frameworks () were synthesized by self-assembly of bis(benzene-/-sulfonic acid)-naphthalenediimide (/-HBSNDI) and two basic ligands. The naphthalenediimide (NDI) was introduced into the material to equip with radical-driven photochromic behavior. The proton conductivity of demonstrated a maximum of 6.50 × 10 S·cm at 98% RH and 100 °C, and it increased to 9.10 × 10 S·cm due to dual free radical synergism following UV irradiation (NDI and viologen), which represents a significant 14-fold enhancement. Furthermore, the incorporation of into the chitosan (CS) matrix forms photochromic composite membranes. The proton conductivity of the composite membrane reached up to 5.70 × 10 S·cm at 98% RH and 90 °C, and reached 8.08 × 10 S·cm after UV irradiation. This work reveals the dual radicals generated by NDI and viologen derivatives, whose synergistic action plays a significant role in enhancing the proton conductivity in iHOFs and composite membranes, rendering the rational design of stimuli-responsive smart materials feasible.
刺激响应型智能材料作为一种新兴材料，能够在机械应力、光和电等外部刺激下实现化学/物理性质的可逆转变，具有响应迅速、结构可设计和功能多样的特点。通过双（苯-1,3-二磺酸）-萘二酰亚胺（HBSNDI）与两种碱性配体的自组装合成了两种离子氢键有机框架（iHOFs）。将萘二酰亚胺（NDI）引入材料中，使其具备自由基驱动的光致变色行为。iHOFs在98%相对湿度和100°C下的质子电导率最高可达6.50×10⁻³ S·cm⁻¹，在紫外线照射（NDI和紫精）后由于双自由基协同作用，质子电导率提高到9.10×10⁻³ S·cm⁻¹，提高了14倍。此外，将iHOFs掺入壳聚糖（CS）基质中形成光致变色复合膜。iHOFs复合膜在98%相对湿度和90°C下的质子电导率高达5.70×10⁻⁴ S·cm⁻¹，紫外线照射后达到8.08×10⁻⁴ S·cm⁻¹。这项工作揭示了由NDI和紫精衍生物产生的双自由基，它们的协同作用在提高iHOFs和复合膜的质子电导率方面起着重要作用，使得刺激响应型智能材料的合理设计成为可能。
