Yu Yadong, Kong Kangren, Tang Ruikang, Liu Zhaoming
Department of Chemistry, Zhejiang University, Hangzhou, Zhejiang 310027, China.
ZJU-Hangzhou Global Scientific and Technological Innovation Center, Hangzhou, Zhejiang 311215, China.
ACS Nano. 2022 May 24;16(5):7926-7936. doi: 10.1021/acsnano.2c00663. Epub 2022 Apr 28.
The nacre-inspired laminates are promising materials for their excellent mechanics. However, the interfacial defects between organic-inorganic phases commonly lead to the crack propagation and fracture failure of these materials under stress. A natural biomineral, bone, has much higher bending toughness than the nacre. The small size of inorganic building units in bone improves the organic-inorganic interaction, which optimizes the material toughness. Inspired by these biological structures, here, an ultratough nanocomposite laminate is prepared by the integration of ultrasmall calcium phosphate oligomers (CPO, 1 nm in diameter) within poly(vinyl alcohol) (PVA) and sodium alginate (Alg) networks through a simple three-step strategy. Owing to the small size of inorganic building units, strong multiple molecular interactions within integrated organic-inorganic hierarchical structure are built. The resulting laminates exhibit ultrahigh bending strain (>50% without fracture) and toughness (21.5-31.0 MJ m), which surpass natural nacre and almost all of the synthetic laminate materials that have been reported so far. Moreover, the mechanics of this laminate is tunable by changing the water content within the bulk structure. This work provides a way for the development of organic-inorganic nanocomposites with ultrahigh bending toughness by using inorganic ionic oligomers, which can be useful in the fields of tough protective materials and energy absorbing materials.
受珍珠母启发的层压板因其出色的力学性能而成为很有前景的材料。然而，有机-无机相之间的界面缺陷通常会导致这些材料在应力作用下裂纹扩展和断裂失效。一种天然生物矿物——骨骼，其弯曲韧性比珍珠母高得多。骨骼中无机结构单元的小尺寸改善了有机-无机相互作用，从而优化了材料的韧性。受这些生物结构的启发，在此，通过一个简单的三步策略，将超小的磷酸钙低聚物（CPO，直径1纳米）整合到聚乙烯醇（PVA）和海藻酸钠（Alg）网络中，制备了一种超韧性纳米复合层压板。由于无机结构单元尺寸小，在整合的有机-无机层次结构中建立了强大的多重分子相互作用。所得层压板表现出超高的弯曲应变（>50%且无断裂）和韧性（21.5 - 31.0 MJ/m³），超过了天然珍珠母以及迄今为止报道的几乎所有合成层压材料。此外，这种层压板的力学性能可通过改变整体结构中的含水量来调节。这项工作为通过使用无机离子低聚物开发具有超高弯曲韧性的有机-无机纳米复合材料提供了一种方法，这在坚韧防护材料和能量吸收材料领域可能会很有用。
