Study on the Inkjet Printing of Nano-fluid Inks with Anomaly Surface Tension Behavior.

采用微波辅助液相还原法制备了聚乙烯吡咯烷酮(PVP)包覆银铜纳米粒子作为喷墨印刷电子线路板(PCB)制造用导电材料油墨的分散体系。得到的乙二醇银纳米材料分散体包括直径40~60 nm的不同形状的球形纳米颗粒、200~300 nm的纳米片、长度为10~20μm、直径70~100 nm的纳米线。银表面封端剂PVP的浓度和平均相对分子质量、纳米粒子蚀刻剂的存在、氯化钠的存在以及微波反应器的升温速率等合成条件都可以控制这些形貌。用动态光散射(DLS)和紫外可见表面等离子体共振(SPR)光谱检测了银纳米材料在乙二醇中的组成，这些分散体系在几个月内都是稳定的。此外，还测量了制备的银纳米粒子分散体的粘度。为了研究银纳米材料的喷墨成型特性，测试了施加在压电喷嘴上的各种控制波形、驱动电压和频率，并通过高速的CMOS视频采集系统对喷墨成型进行了可视化。考虑了压电式喷嘴驱动的波形、频率和电压对喷墨液滴形成的影响和变化，提出了喷墨液滴形成的定性图。

Synthesis of polyvinylpyrrolidone (PVP) capped silver and copper nanoparticles dispersions as conductive material inks for ink-jet printing electronic circuit board (PCB) manufacturing process by microwave-assisted liquid phase reduction method have been investigated. Obtained ethylene glycol dispersions of silver nanomaterials contained varied shaped 40-60 nm in diameter spherical nanoparticles, 200-300 nm nanoplates, and 10-20 μm in length 70-100 nm in diameter nanowires. These shapes could be controlled by synthesis conditions such as concentrations and average molecular weight of silver surface capping reagent PVP, existence of nanoparticle etching reagent, NaCl, and temperature rising rate of microwave reactor. The compositions of silver nanomaterials in ethylene glycol were also checked by using dynamic light scattering (DLS) and UV-VIS surface plasmon resonance (SPR) spectra and these dispersions were stable for several months. Also, viscosities of prepared silver nanoparticles dispersions were measured. To investigate the silver nanomaterials inkjet formation characteristics, various control waves, driving voltages and frequencies applied to the piezoelectric ink-jet nozzle were tested and ink-jet formation were visualized by high-speed CMOS video capture system. The qualitative map of ink-jet droplet formation was proposed by considering influence and variation of shape of piezoelectric ink-jet nozzle driven waves, frequencies and voltages.