Study of extrudability and standoff distance effect during nanoclay-enabled direct printing
Study of extrudability and standoff distance effect during nanoclay-enabled direct printing
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DOI：
10.1007/s42242-018-0009-y
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发表时间：
2018-06-01
影响因子：
7.9
通讯作者：
Huang, Yong
中科院分区：
文献类型：
--
作者：
Jin, Yifei;Zhao, Danyang;Huang, Yong
纳米粘土使能的自支撑打印已经成为一种有前途的基于纳米粘土的挤出制造方法，用于不同的生物医学和工程应用，包括组织工程。随着纳米粘土粉末的加入，液体构建材料在挤出时可以表现出类似固体的行为，并且可以在空气中直接打印成复杂的三维结构。本研究的目的是研究纳米粘土对N-异丙基丙烯酰胺（NIPAAm）的可挤出性的影响，以及在纳米粘土使能的直接打印过程中，间隔距离对打印质量的影响。结果表明，纳米粘土的加入可以显著改善NIPAAm的挤出性能，有效地消除挤出过程中的胀模现象。此外，随着喷距的增加，沉积丝从过度沉积到轮廓分明到拉伸到断裂，丝宽减小，打印保真度变差。进一步提出了一个数学模型来确定最佳的间隔距离，以在纳米粘土支持的直接打印期间实现更好的打印保真度。基于来自该研究的可挤出性和间隔距离知识，NIPAAm-Laponite纳米粘土和NIPAAm-Laponite纳米粘土-氧化石墨烯纳米复合材料水凝胶前体被成功地印刷成三层一维响应图案，证明了在最佳印刷条件下在纳米粘土使能的印刷期间良好的可挤出性和印刷质量。
Nanoclay-enabled self-supporting printing has been emerging as a promising filament-based extrusion fabrication approach for different biomedical and engineering applications including tissue engineering. With the addition of nanoclay powders, liquid build materialsmay exhibit solid-like behavior upon extrusion and can be directly printed in air into complex three-dimensional structures. The objective of this study is to investigate the effect of nanoclay on the extrudability of N-isopropylacrylamide (NIPAAm) and the effect of standoff distance on the print quality during nanoclay-enabled direct printing. It is found that the addition of nanoclay can significantly improve the NIPAAm extrudability and effectively eliminate die swelling in material extrusion. In addition, with the increase of standoff distance, deposited filaments change from over-deposited to well-defined to stretched to broken, the filament width decreases, and the print fidelity deteriorates. A mathematical model is further proposed to determine the optimal standoff distance to achieve better print fidelity during nanoclay-enabled direct printing. Based on the extrudability and standoff distance knowledge from this study, NIPAAm-Laponite nanoclay and NIPAAm-Laponite nanoclay-graphene oxide nanocomposite hydrogel precursors are successfully printed into a three-layered one-dimensional responsive pattern, demonstrating the good extrudability and print quality during nanoclay-enabled printing under optimal printing conditions.