Tang Miao, Zhong Zhuoran, Ke Chenfeng
Department of Chemistry, Dartmouth College, 41 College Street, Hanover, 03755 NH, USA.
Chem Soc Rev. 2023 Mar 6;52(5):1614-1649. doi: 10.1039/d2cs01011a.
The exciting advancements in 3D-printing of soft materials are changing the landscape of materials development and fabrication. Among various 3D-printers that are designed for soft materials fabrication, the direct ink writing (DIW) system is particularly attractive for chemists and materials scientists due to the mild fabrication conditions, compatibility with a wide range of organic and inorganic materials, and the ease of multi-materials 3D-printing. Inks for DIW need to possess suitable viscoelastic properties to allow for smooth extrusion and be self-supportive after printing, but molecularly facilitating 3D printability to functional materials remains nontrivial. While supramolecular binding motifs have been increasingly used for 3D-printing, these inks are largely optimized empirically for DIW. Hence, this review aims to establish a clear connection between the molecular understanding of the supramolecularly bound motifs and their viscoelastic properties at bulk. Herein, extrudable (but not self-supportive) and 3D-printable (self-supportive) polymeric materials that utilize noncovalent interactions, including hydrogen bonding, host-guest inclusion, metal-ligand coordination, micro-crystallization, and van der Waals interaction, have been discussed in detail. In particular, the rheological distinctions between extrudable and 3D-printable inks have been discussed from a supramolecular design perspective. Examples shown in this review also highlight the exciting macroscale functions amplified from the molecular design. Challenges associated with the hierarchical control and characterization of supramolecularly designed DIW inks are also outlined. The perspective of utilizing supramolecular binding motifs in soft materials DIW printing has been discussed. This review serves to connect researchers across disciplines to develop innovative solutions that connect top-down 3D-printing and bottom-up supramolecular design to accelerate the development of 3D-print soft materials for a sustainable future.
软材料3D打印领域令人振奋的进展正在改变材料开发与制造的格局。在为软材料制造设计的各种3D打印机中，直接墨水书写（DIW）系统对化学家和材料科学家特别有吸引力，因为其制造条件温和、与多种有机和无机材料兼容，且易于进行多材料3D打印。用于DIW的墨水需要具备合适的粘弹性，以实现顺利挤出并在打印后能够自支撑，但从分子层面促进功能材料的3D可打印性仍然并非易事。虽然超分子结合基序已越来越多地用于3D打印，但这些墨水在很大程度上是通过经验对DIW进行优化的。因此，本综述旨在在对超分子结合基序的分子理解与其本体粘弹性之间建立明确的联系。本文详细讨论了利用非共价相互作用（包括氢键、主客体包合、金属-配体配位、微晶化和范德华相互作用）的可挤出（但非自支撑）和可3D打印（自支撑）的聚合材料。特别是，从超分子设计的角度讨论了可挤出墨水和可3D打印墨水之间的流变学差异。本综述中展示的例子还突出了从分子设计中放大的令人兴奋的宏观功能。还概述了与超分子设计的DIW墨水的分级控制和表征相关的挑战。讨论了在软材料DIW打印中利用超分子结合基序的前景。本综述旨在连接跨学科的研究人员，以开发创新解决方案，将自上而下的3D打印和自下而上的超分子设计联系起来，加速用于可持续未来的3D打印软材料的开发。
