Microgel-Reinforced Hydrogel Films with High Mechanical Strength and Their Visible Mesoscale Fracture Structure
Microgel-Reinforced Hydrogel Films with High Mechanical Strength and Their Visible Mesoscale Fracture Structure
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DOI：
10.1021/ma2016248
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发表时间：
2011-10-11
期刊：
影响因子：
5.5
通讯作者：
Gong, Jian Ping
中科院分区：
文献类型：
--
作者：
Hu, Jian;Hiwatashi, Kenta;Gong, Jian Ping
机械性能差仍然是传统合成水凝胶广泛应用于组织支架等实际应用的最大障碍。在这项工作中，我们已经合成了水凝胶膜的存在下，具有不同电荷的各种化学物种的微凝胶前体。所制备的水凝胶具有新颖的两相复合结构，其中连续相是松散交联的聚丙烯酰胺（PAAm）基质，分散相几乎是双网络（DN）微凝胶。被命名为微凝胶增强（MR）水凝胶，它们表现出显着的机械强度和韧性的增强，相比，没有微凝胶的水凝胶。MR水凝胶显示出与常规双连续DN水凝胶相当的机械性能。通过在伸长之前、期间和之后观察嵌入的微凝胶，确认了微凝胶相的中尺度断裂，这将有效地钝化裂纹并增强断裂扩展阻力。因此，我们得出结论，MR凝胶的本质增强原理根源于由微凝胶贡献的牺牲键效应。该工作为从各种微凝胶合成高强度和韧性的水凝胶薄膜提供了一条新的通用途径，并可能为水凝胶在快速响应致动器、燃料电池薄膜、伤口敷料等领域的应用开辟新的途径。
The poor mechanical properties remain the largest barrier to traditional synthetic hydrogels for extensive practical applications, such as tissue scaffolds. In this work, we have synthesized the hydrogel films in the presence of microgel precursors of various chemical species with different charges. The hydrogels fabricated have a novel two-phase composite structure, where the continuous phase is a loosely cross-linked polyacrylamide (PAAm) matrix and the disperse phase is virtually double-network (DN) microgels. Named as microgel-reinforced (MR) hydrogels, they exhibited dramatic enhancement in mechanical strength and toughness, in comparison to the hydrogels with no microgels. MR hydrogels showed the comparable mechanical properties with the conventional bicontinuous DN hydrogels. By visualizing the embedded microgels before, during, and after the elongation, mesoscale fractures of the microgels phase were confirmed, which should effectively blunt the crack and enhance the fracture propagation resistance. Therefore, we conclude that the essential reinforcement principle of MR gels roots in the sacrificial bonds effect contributed by the microgels. This work provides a novel universal pathway to synthesize hydrogel thin films with high strength and toughness from various microgels and may open a new avenue for the application of hydrogels in various fields, such as fast responsive actuators, fuel cell films, wound dressings, etc.