Highly Deformable Rigid Glassy Conjugated Polymeric Thin Films
Highly Deformable Rigid Glassy Conjugated Polymeric Thin Films
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DOI：
10.1002/adfm.202306576
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发表时间：
2023-08
影响因子：
19
通讯作者：
Yunfei Wang;Song Zhang;Guillaume Freychet;Zhaofan Li;Kai‐Lin Chen;Chih-Ting Liu;Zhiqiang Cao;Y. Chiu;W. Xia;X. Gu
中科院分区：
文献类型：
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作者：
Yunfei Wang;Song Zhang;Guillaume Freychet;Zhaofan Li;Kai‐Lin Chen;Chih-Ting Liu;Zhiqiang Cao;Y. Chiu;W. Xia;X. Gu
可穿戴设备受益于可拉伸共轭聚合物 (CP) 的使用。传统上，可拉伸 CP 的设计基于这样的假设：低弹性模量 (E) 对于实现高拉伸性至关重要。然而，这项分析 65 CP 薄膜机械性能的研究挑战了这一观点。人们发现，柔软度本身并不能决定拉伸性；相反，关键的是纠缠的程度。这意味着刚性 CP 也可以表现出高拉伸性，这与传统观点相矛盾。为了进一步研究，研究了两种模型CP的机械行为、电性能和变形机制：E为2.2 GPa的玻璃态聚(3-丁基噻吩-2,5-二基)(P3BT)和E为86 MPa的粘弹性聚(3-辛基噻吩-2,5-二基)(P3OT)。非原位透射 X 射线散射和偏振紫外可见光谱表明，只有初始应变（即 <20%）在两种聚合物之间表现出不同的链排列机制，而刚性和软质 P3AT 在较大应变下表现出类似的行为。通过挑战低 E 的传统设计指标以实现高拉伸性并强调缠结的重要性，希望能够扩大可用于可穿戴设备的 CP 的范围。
Wearable devices benefit from the use of stretchable conjugated polymers (CPs). Traditionally, the design of stretchable CPs is based on the assumption that a low elastic modulus (E) is crucial for achieving high stretchability. However, this research, which analyzes the mechanical properties of 65 CP thin films, challenges this notion. It is discovered that softness alone does not determine stretchability; rather, it is the degree of entanglement that is critical. This means that rigid CPs can also exhibit high stretchability, contradicting conventional wisdom. To inverstigate further, the mechanical behavior, electrical properties, and deformation mechanism of two model CPs: a glassy poly(3‐butylthiophene‐2,5‐diyl) (P3BT) with an E of 2.2 GPa and a viscoelastic poly(3‐octylthiophene‐2,5‐diyl) (P3OT) with an E of 86 MPa, are studied. Ex situ transmission X‐ray scattering and polarized UV–vis spectroscopy revealed that only the initial strain (i.e., <20%) exhibits different chain alignment mechanisms between two polymers, while both rigid and soft P3ATs showed similarly behavior at larger strains. By challenging the conventional design metric of low E for high stretchability and highlighting the importance of entanglement, it is hoped to broaden the range of CPs available for use in wearable devices.