Soft Materials Laboratory, Institute of Materials, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, 1015, Switzerland.
Macromol Rapid Commun. 2022 Aug;43(15):e2200196. doi: 10.1002/marc.202200196. Epub 2022 May 1.
Rapid advances in the biomedical field increasingly often demand soft materials that can be processed into complex 3D shapes while being able to reliably bear significant loads. Granular hydrogels have the potential to serve as artificial tissues because they can be 3D printed into complex shapes and their composition can be tuned over short length scales. Unfortunately, granular hydrogels are typically soft such that they cannot be used for load-bearing applications. To address this shortcoming, individual microgels can be connected through a percolating network, such that they introduce the double network toughening mechanism into granular hydrogels. However, the influence of the microgel size and concentration on the processing and toughness of microgel-reinforced hydrogels (MRHs) remains to be elucidated. Here, it is demonstrated that processing and toughness depend on the inter-microgel connectivity, while the stress at break is solely dependent on the microgel size. These findings offer an in-depth understanding of how liquid- and paste-like precursors containing soft, deformable microgels can be processed into bulk microstructured soft materials and how the size and concentration of these microgels influence the mechanical properties of microgel-reinforced hydrogels.
生物医学领域的快速发展越来越需要能够加工成复杂 3D 形状且能够可靠承受显著载荷的软材料。颗粒水凝胶具有作为人工组织的潜力，因为它们可以 3D 打印成复杂的形状，并且它们的组成可以在短长度尺度上进行调整。不幸的是，颗粒水凝胶通常很软，因此不能用于承重应用。为了解决这个缺点，可以通过渗透网络将单个微凝胶连接起来，从而将双网络增韧机制引入颗粒水凝胶中。然而，微凝胶尺寸和浓度对微凝胶增强水凝胶（MRH）的加工和韧性的影响仍有待阐明。在这里，证明了加工和韧性取决于微凝胶之间的连接性，而断裂应力仅取决于微凝胶的尺寸。这些发现深入了解了如何将含有柔软可变形微凝胶的液态和糊状前体加工成块状微结构软材料，以及这些微凝胶的尺寸和浓度如何影响微凝胶增强水凝胶的机械性能。
