Dhakal Ankit, Jung Sangeun, Bae Byungjoon, Arjun Ajith Mohan, Robinson Sean, Baek Yongmin, Riffe William T, Tiernan Emma M, Gunaga Shubha, Verma Prince, Phister Meagan R, Stone Madison, Stone Kevin H, Morris Amanda, Swami Nathan S, Hopkins Patrick E, Venkatesh Amrit, Lee Kyusang, Giri Gaurav
Department of Chemical Engineering, University of Virginia, Charlottesville, Virginia 22904-4746, United States.
Department of Electrical and Computer Engineering, University of Virginia, Charlottesville, Virginia 22904-4746, United States.
ACS Appl Mater Interfaces. 2025 Aug 6;17(31):44899-44909. doi: 10.1021/acsami.5c07907. Epub 2025 Jul 23.
Polymer-metal-organic framework (polymer-MOF) composites have garnered significant interest as polymers can enhance the processability and industrial applicability of MOFs. Thin films of these composites are particularly attractive for applications in sensing, separations, and flexible electronics. Solution shearing, a meniscus-guided coating technique, has emerged as a scalable process for fabricating thin films of MOFs, and can produce large-area films within minutes. In this study, we utilized solution shearing to fabricate composite thin films of a MOF UiO-66 and a piezoelectric polymer poly(vinylidene fluoride-trifluoroethylene) (P(VDF-TrFE)), investigating how polymer concentration during MOF synthesis and composite formation influences thin film properties, including crystallinity, surface coverage, and piezoelectric performance. Additionally, solid-state NMR spectroscopy was utilized to probe the interactions between P(VDF-TrFE) and UiO-66 in the composite. Evidence from solid-state NMR indicated polymer-MOF interactions, suggesting that the polymer strands are in close proximity to the UiO-66 pores, supporting a mixed surface coating and pore infiltration model. Furthermore, incorporating P(VDF-TrFE) enhanced the film's areal coverage from 70% to 100%. While the thermal conductivity remained essentially unchanged, the composite film showed an improved piezoelectric effect. The composite with 91 wt % P(VDF-TrFE) exhibited the highest output voltage of 9.1 V and a sensitivity of 0.26 V/N under applied pressure. This work demonstrates the potential of solution shearing as a scalable technique for fabricating polymer-MOF composite thin films.
聚合物-金属有机框架（polymer-MOF）复合材料已引起了广泛关注，因为聚合物可以提高MOF的可加工性和工业适用性。这些复合材料的薄膜在传感、分离和柔性电子等应用中特别有吸引力。溶液剪切是一种弯月面引导的涂层技术，已成为制造MOF薄膜的可扩展工艺，并且可以在几分钟内制备大面积薄膜。在本研究中，我们利用溶液剪切法制备了MOF UiO-66与压电聚合物聚（偏二氟乙烯-三氟乙烯）（P(VDF-TrFE)）的复合薄膜，研究了MOF合成和复合材料形成过程中聚合物浓度如何影响薄膜性能，包括结晶度、表面覆盖率和压电性能。此外，利用固态核磁共振光谱来探测复合材料中P(VDF-TrFE)与UiO-66之间的相互作用。固态核磁共振的证据表明了聚合物与MOF之间的相互作用，这表明聚合物链靠近UiO-66孔，支持混合表面涂层和孔渗透模型。此外，加入P(VDF-TrFE)使薄膜的面积覆盖率从70%提高到了100%。虽然热导率基本保持不变，但复合薄膜的压电效应有所改善。含91 wt% P(VDF-TrFE)的复合材料在施加压力下表现出最高输出电压9.1 V和灵敏度0.26 V/N。这项工作证明了溶液剪切作为一种可扩展技术用于制造聚合物-MOF复合薄膜的潜力。
