Abstract Copper complex conductive inks inevitably contains water which is derived from chemicals and humid air. The dual effects of water on the performance of copper complex conductive inks with amines as ligands were investigated for the first time. On one hand, excess water caused the deterioration of copper complexes by interacting with amines to produce high concentration of OH−, yielding basic salt, hydroxide or oxide precipitate, which shortened the shelf life of copper inks. The degree of deterioration was related to the amine’s coordination ability and alkalinity. On the other hand, trace water could accelerate the thermal decomposition of copper complexes, promote the nucleation of copper, and yield smaller particles to form copper films with denser structure and lower resistivity. The blending of 2-ethylhexylamine (EtHex) and 2-amino-2-methyl-1-propanol (AMP) as ligands to copper formate (Cuf) could balance the dual effects of water on copper complex conductive inks. It was found that Cuf-EtHex-AMP (with 95 mol% EtHex in blended ligands) ink showed strong water resistance. The shelf life of the blended complex ink with additional 2 wt% water was still more than 2 months. The additional water enabled the formation of highly conductive copper films at low heating temperature. The resistivity of the copper film from the blended complex ink with additional 2 wt% water stored for 2 months only increased a little compared to that from the newly prepared ink (from 9.70 μΩ·cm to 14.42 μΩ·cm), which could meet the general requirements of printed electronics.

中文翻译：

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水对印刷电子用铜络合物导电油墨性能的双重影响

摘要 铜络合物导电油墨不可避免地含有来自化学品和潮湿空气的水分。首次研究了水对以胺为配体的铜络合物导电油墨性能的双重影响。一方面，过量的水通过与胺相互作用产生高浓度的 OH−，导致铜配合物变质，产生碱性盐、氢氧化物或氧化物沉淀，从而缩短铜油墨的保质期。劣化程度与胺的配位能力和碱度有关。另一方面，微量水可以加速铜配合物的热分解，促进铜的成核，产生更小的颗粒，形成结构更致密、电阻率更低的铜膜。2-乙基己胺（EtHex）和2-氨基-2-甲基-1-丙醇（AMP）作为甲酸铜（Cuf）的配体的混合可以平衡水对铜复合导电油墨的双重影响。发现 Cuf-EtHex-AMP（在混合配体中含有 95 mol% EtHex）墨水显示出很强的耐水性。与额外的 2 wt% 水混合的复合油墨的保质期仍然超过 2 个月。额外的水能够在低加热温度下形成高导电铜膜。与新制备的油墨（从 9.70 μΩ·cm 到 14.42 μΩ·cm）相比，添加 2 wt% 水的混合复合油墨的铜膜电阻率仅增加了 2 个月，可以满足印刷电子产品的一般要求。