Ligaments are unique wet biological tissues with high tensile modulus and fracture stress, combined with high bending flexibility. Developing synthetic materials with these properties is a significant challenge. Hydrogel composites made from high stiffness fabrics is a strategy to develop such unique materials; however, the ability to produce these materials has proven difficult, since common hydrogels swell in water and interact poorly with solid components, limiting the transfer of force from the fabric to the hydrogel matrix. In this work, for the first time, we successfully produce extraordinarily tough hydrogel composites by strategically selecting a recently developed tough hydrogel that de-swells in water. The new composites, consisting of polyampholyte hydrogels and glass fiber woven fabrics, exhibit extremely high effective toughness (250 000 J m(-2)), high tear strength (similar to 65 N mm(-1)), high tensile modulus (606 MPa), and low bending modulus (4.7 MPa). Even though these composites are composed of water-containing, biocompatible materials, their mechanical properties are comparable to high toughness Kevlar/polyurethane blends and fiber-reinforced polymers. Importantly, the mechanical properties of these composites greatly outperform the properties of either individual component. A mechanism is proposed based on established fabric tearing theory, which will enable the development of a new generation of mechanically robust composites based on fabrics. These results will be important towards developing soft biological prosthetics, and more generally for commercial applications such as tear-resistant gloves and bulletproof vests.
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机译:韧带是独特的湿生物组织,具有高拉伸模量和断裂应力,并具有高弯曲挠性。开发具有这些特性的合成材料是一项重大挑战。由高硬度织物制成的水凝胶复合材料是开发这种独特材料的一种策略。然而,事实证明生产这些材料的能力很困难,因为普通的水凝胶在水中会膨胀并且与固体成分的相互作用较弱,从而限制了从织物到水凝胶基质的力传递。在这项工作中,我们首次通过战略性地选择了最近开发的可在水中溶胀的坚硬水凝胶,成功地生产了极坚韧的水凝胶复合材料。由聚两性电解质水凝胶和玻璃纤维机织织物组成的新复合材料具有极高的有效韧性(250 000 J m(-2)),高撕裂强度(类似于65 N mm(-1)),高拉伸模量(606) MPa)和低弯曲模量(4.7 MPa)。即使这些复合材料由含水的生物相容性材料组成,其机械性能仍可与高韧性凯夫拉尔/聚氨酯共混物和纤维增强聚合物相媲美。重要的是,这些复合材料的机械性能大大优于任何一种单独组分的性能。根据已建立的织物撕裂理论提出了一种机制,该机制将使新一代基于织物的机械坚固复合材料的开发成为可能。这些结果对于开发柔软的生物假体将是重要的,并且更广泛地用于商业应用,例如抗撕裂手套和防弹背心。
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