室温下具有“内置”机制的导电油墨自烧结研究

Conductive Inks with a"Built-In"Mechanism That Enables Sintering at Room Temperature

目前，尚没有金属油墨可以在室温下只通过印刷步骤便形成导电图案的技术。例如使用纳米金属油墨在塑料电子产品上印制导电图案，必须进行额外的烧结处理，通常是通过加热至高温来实现。在烧结过程中，形成图案的纳米粒子（NPs）发生团聚以形成连续的导电层。近年来，发展了很多新型的烧结工艺，如微波、激光烧结，脉冲氙气、电子或化学烧结以及等离子烧结等，但是这些方法通常需要高成本的设备以及复杂的预处理或后处理工艺。因此，对于油墨而言，尚需研究的课题是，印制后无须额外烧结工艺即可获得高导电率。

At present there is no metallic ink that enables formation of conductive patterns at room temperature by a single printing step. Printing conductive features by metallic nanoparticle-based inks must be followed by sintering while heating to elevated temperatures, thus preventing their utilization on most plastic substrates used in plastic electronics. In this report we present a new silver nanoparticle-based conductive ink, having a built-in sintering mechanism, which is triggered during dr- ying of the printed pattern. The nanoparticles that are stabilized by a polymer undergo selfsintering spontaneously, due to the presence of a destabilizing agent, which comes into action only during drying of the printed pattern. The destabilizing agent, which contains C1 - ions, causes detachment of the anchoring groups of the stabilizer from the nanoparticles＇surface and thus enables their coalescence and sintering. It was found that the new metallic ink leads to very high conductivities, by a single printing step： up to 41% of the conductivity of bulk silver was achieved, the highest reported conductivity of a printed pattern that is obtained from nanoparticles at room temperature.