Department of Applied Chemistry, National Chiao Tung University, 1001 Ta Hsueh Road, Hsinchu, 30029, Taiwan.
Key Laboratory of Bio-Inspired Smart Interfacial Science and Technology of Ministry of Education, School of Chemistry, Beihang University, 37 Xueyuan Road, Haidian District, Beijing, 100191, China.
Adv Mater. 2017 Sep;29(34). doi: 10.1002/adma.201606987. Epub 2017 Jul 10.
Directional solution coating by the Chinese brush provides a facile approach to fabricate highly oriented polymer thin films by finely controlling the wetting and dewetting processes under directional stress. The biggest advantage of the Chinese brush over the normal western brush is the freshly emergent hairs used, whose unique tapered structure renders a dynamic balance of the liquid within the brush by multiple forces when interacting with the liquid. Consequently, the liquid is steadily held within the brush without any unexpected leakage, making the liquid transfer proceed in a well-controllable manner. It is demonstrated that the Chinese brush coating enables the crystallization of the polymer and the self-assembly of conjugated backbones to proceed in a quasi-steady state via a certain direction, which is attributed to the controllable receding of the three-phase contact line during the dewetting process by the multiple parallel freshly emergent hairs. The as-prepared polymer thin films exhibit over six times higher charge-carrier mobility compared to the spin-coated films, which therefore provides a general approach for high-performance organic thin-film transistors.
定向溶液刷涂通过精细控制定向应力下的润湿和去湿过程，为制备高度取向聚合物薄膜提供了一种简便的方法。与普通的西式刷子相比，中国毛笔的最大优势在于使用了新出现的毛发，其独特的锥形结构在与液体相互作用时通过多种力使刷子内的液体保持动态平衡。因此，液体可以稳定地保持在刷子内，不会发生任何意外泄漏，从而使液体以可控的方式转移。研究表明，通过中国毛笔涂层可以使聚合物结晶和共轭主链自组装在一个准稳定状态下沿着某个方向进行，这归因于在去湿过程中通过多个平行的新出现的毛发控制三相接触线的后退。与旋涂薄膜相比，所制备的聚合物薄膜的载流子迁移率提高了 6 倍以上，因此为高性能有机薄膜晶体管提供了一种通用方法。
