Mohammadi Erfan, Zhao Chuankai, Zhang Fengjiao, Qu Ge, Jung Seok-Heon, Zhao Qiujie, Evans Christopher M, Lee Jin-Kyun, Shukla Diwakar, Diao Ying
Department of Polymer Science & Engineering , Inha University , Incheon 402-751 , South Korea.
ACS Appl Mater Interfaces. 2019 Jun 26;11(25):22561-22574. doi: 10.1021/acsami.9b02923. Epub 2019 Jun 13.
Dynamic surfaces play a critical role in templating highly ordered complex structures in living systems but are rarely employed for directing assembly of synthetic functional materials. We design ion gel templates with widely tunable dynamics ( T) to template solution-coated conjugated polymers. We hypothesize that the ion gel expedites polymer nucleation by reconfiguring its surface to facilitate cooperative multivalent interactions with the conjugated polymer, validated using both experimental and computational approaches. Varying ion gel dynamics enables large modulation of alignment, molecular orientation, and crystallinity in templated polymer thin films. At the optimal conditions, ion-gel-templated films exhibit 55 times higher dichroic ratio (grazing incidence X-ray diffraction) and 49% increase in the relative degree of crystallinity compared to those templated by the neat polymer matrix. As a result, the maximum hole mobilities increase by factors of 4 and 11 along the π-π stacking and the backbone directions. Intriguingly, we observe a synergistic effect between the gel matrix and the ionic liquid that produces markedly enhanced templating effect than either component alone. Molecular dynamics simulations suggest that complementary multivalent interactions facilitated by template reconfigurability underlie the observed synergy. We further demonstrate field-effect transistors both templated and gated by ion gels with average mobility exceeding 7 cm V s.
动态表面在生物系统中高度有序的复杂结构模板化过程中起着关键作用，但很少用于指导合成功能材料的组装。我们设计了具有广泛可调动力学（T）的离子凝胶模板，用于模板化溶液涂覆的共轭聚合物。我们假设离子凝胶通过重新配置其表面来促进与共轭聚合物的多价协同相互作用，从而加速聚合物成核，这一假设通过实验和计算方法均得到了验证。改变离子凝胶动力学能够对模板化聚合物薄膜的排列、分子取向和结晶度进行大幅度调制。在最佳条件下，与由纯聚合物基质模板化的薄膜相比，离子凝胶模板化薄膜的二向色比（掠入射X射线衍射）高55倍，相对结晶度提高49%。结果，沿π-π堆积和主链方向的最大空穴迁移率分别提高了4倍和11倍。有趣的是，我们观察到凝胶基质和离子液体之间存在协同效应，这种协同效应产生的模板化效果明显优于单独的任何一种组分。分子动力学模拟表明，模板可重构性促进的互补多价相互作用是观察到的协同效应的基础。我们进一步展示了由离子凝胶模板化和栅控的场效应晶体管，其平均迁移率超过7 cm V s。
