调控共轭高分子墨水的流变行为和粘弹性实现喷墨打印单一液滴稳定喷射

Ink-jet printing is one of the most important technologies in the field of defined polymer deposition in relation to the manufacturing of low-cost and large-area optoelectronic devices. Stable single droplet jetting (to eliminate the filament and satellite droplets) is the foremost problem that inkjet printing technology is applied to the preparation of organic optoelectronic devices. As for ink-jetting technology, the ink’s rheological property and viscoelasticity are the two key factors to determine the formation of droplets from non-Newtonian fluids. Therefore, the relationship between behaviors of the drop generation and ejection process with ink’s viscosity, surface tension and conformational transition of molecular chain at high shear rate of conjugated polymer inks will be researched in this project. Realize the construction of conjugated polymer inks with good printability. Further, the relationship of the molecular structure, the effective conjugate length and the molecular weight of conjugate polymer with the drop generation behavior will be found and used to provide theoretical guidance on the molecular structure design and molecular weight control of the printable conjugated polymer materials, which have important practical value for inkjet printed organic optoelectronics.

喷墨打印是在基板上定位沉积功能高分子薄膜的重要手段之一，对低成本大面积光电器件加工具有重要意义。单一液滴稳定喷射（消除液滴拖尾和卫星液滴）是喷墨打印技术应用于有机光电器件制备的首要问题。非牛顿流体墨水流变性质和粘弹性是决定喷墨打印液滴形成的核心。因此，本项目重点研究共轭高分子墨水的表面张力、粘度和高剪切速率下聚合物分子链的构象变化与液滴打印行为及打印稳定性的关系，实现单一液滴稳定喷射的共轭高分子墨水构建。在此基础上，通过对共轭高分子分子结构、有效共轭长度、分子量等对液滴形成行为的研究，对可打印共轭高分子材料的分子结构设计、分子量控制提供理论指导，对喷墨打印制备有机光电器件有重要的实践价值。

喷墨打印技术已经成为最有效的有机光电薄膜图案化方法之一。单一且体积稳定的液滴喷射是高精度图案化喷墨打印的关键。本项目针对喷墨打印共轭高分子墨水过程中出现的拖尾及卫星液滴造成的打印不稳定性这一核心问题，系统研究并确立共轭高分子墨水流变性质及粘弹性影响液滴形成行为的基本原理，发展调控共轭高分子墨水液滴打印行为的方法，为共轭高分子墨水构建提供理论基础。我们首先建立了共轭高分子墨水流变性质及打印条件与液滴打印行为的关系，在此基础上，明确了共轭高分子墨水粘弹性对高剪切速率下聚合物分子链拉伸造成细颈稳定和拖尾延后断裂对卫星液滴形成的影响规律，进一步构建了单一液滴稳定喷射的共轭高分子墨水，并将其应用于高精度高分子发光显示像素矩阵的喷墨打印加工。