Abstract Polydiphenylacetylene derivatives with different alkyl side chains (methyl, ethyl, and n-propyl groups) via a silylene linkage (PDPA-C1, PDPA-C2, PDPA-C3) were prepared. The polymer films were examined as a solid-state sensor for measuring the viscosity of silicone oils based on the diffusion rate in the films. When the films were brought into contact with silicone oils, the fluorescence (FL) emission increased with time to reach an FL enhancing equilibrium. PDPA-C1 showed faster and more significant FL enhancement because of the larger free volume and higher degree of side phenyl stacking. The relationship between the time to reach FL enhancing equilibrium (teq) and silicone oil viscosity (η) was well expressed by a modified Forster-Hoffmann equation: log teq = C + x log η, where x is the probe-dependent constant. The slope x values, which indicate viscosity sensitivity, were 0.37 for PDPA-C1, 0.35 for PDPA-C2, and 0.36 for PDPA-C3 in thin films and 1.15 for PDPA-C1 in a thick film, indicating high viscosity sensitivity depending on film thickness. The relationship between probe FL intensity and fluid viscosity, typically expressed by the Forster-Hoffmann equation, was never established in this system. The viscosity determination method using the modified Forster-Hoffmann equation proved very useful for identifying unknown viscosities of commercial silicone oils.

中文翻译：

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基于聚二苯乙炔薄膜中扩散速率的硅油粘度测量

摘要 制备了通过亚甲硅烷键连接不同烷基侧链（甲基、乙基和正丙基）的聚二苯乙炔衍生物（PDPA-C1、PDPA-C2、PDPA-C3）。聚合物薄膜作为固态传感器被检查，用于根据薄膜中的扩散速率测量硅油的粘度。当薄膜与硅油接触时，荧光 (FL) 发射随时间增加，以达到 FL 增强平衡。由于更大的自由体积和更高的侧苯基堆积程度，PDPA-C1 显示出更快和更显着的 FL 增强。达到 FL 增强平衡的时间 (teq) 和硅油粘度 (η) 之间的关系可以通过修改后的 Forster-Hoffmann 方程很好地表达：log teq = C + x log η，其中 x 是探针相关常数。斜率 x 值，表示粘度敏感性，PDPA-C1 为 0.37，PDPA-C2 为 0.35，薄膜中的 PDPA-C3 为 0.36，厚膜中的 PDPA-C1 为 1.15，表明取决于膜厚度的高粘度敏感性。探针 FL 强度和流体粘度之间的关系（通常由 Forster-Hoffmann 方程表示）从未在该系统中建立。使用改进的 Forster-Hoffmann 方程的粘度测定方法证明对于识别商业硅油的未知粘度非常有用。通常由 Forster-Hoffmann 方程表示的 ，从未在该系统中成立。使用改进的 Forster-Hoffmann 方程的粘度测定方法证明对于识别商业硅油的未知粘度非常有用。通常由 Forster-Hoffmann 方程表示的 ，从未在该系统中成立。使用改进的 Forster-Hoffmann 方程的粘度测定方法证明对于识别商业硅油的未知粘度非常有用。