Department of Chemical Engineering and Materials Science, Stevens Institute of Technology, Hoboken, New Jersey 07030, USA.
ACS Appl Mater Interfaces. 2012 Sep 26;4(9):4691-9. doi: 10.1021/am301050n. Epub 2012 Sep 5.
Inkjet printing offers a low-cost, high-throughput avenue for producing functional organic materials through rapid translation of desktop discoveries to industrial roll-to-roll processes. Here, we report a simple, but effective strategy to control droplet coalescence during inkjet printing, as a major variable, to tailor the nanoscale morphology of organic composite materials produced upon evaporation of all-liquid inks. During deposition, the spacing between ink droplets was controlled to systematically vary the extent of droplet coalescence. Our results show that decreasing coalescence increased the solvent evaporation rate, supersaturation of the solutes, and nucleation density of the precipitating organic crystals. This phenomenon was utilized to tailor the average size of pentaerythritol tetranitrate (PETN) crystals dispersed in an adhesive binder matrix from ~0.2 to upwards of 100 μm. The results suggest that controlling the extent of droplet coalescence can be used as an effective means to tailor the composite morphology of printed organic materials at the nanoscale.
喷墨打印为通过快速将桌面发现转化为工业卷对卷工艺，来生产功能性有机材料提供了一种低成本、高通量的途径。在这里，我们报告了一种简单但有效的策略，可控制喷墨打印过程中的液滴聚结，这是一个主要变量，可以调整所有液体油墨蒸发后产生的有机复合材料的纳米级形态。在沉积过程中，控制液滴之间的间隔以系统地改变液滴聚结的程度。我们的结果表明，减少聚结会增加溶剂蒸发率、溶质过饱和度和沉淀有机晶体的成核密度。这种现象可用于调整分散在粘合剂基质中的季戊四醇四硝酸酯（PETN）晶体的平均尺寸，范围从~0.2 微米到 100 微米以上。结果表明，控制液滴聚结的程度可作为一种有效手段，用于调整打印有机材料的纳米级复合形态。
