Genipin-enhanced nacre-inspired montmorillonite-chitosan film with superior mechanical and UV-blocking properties
Genipin-enhanced nacre-inspired montmorillonite-chitosan film with superior mechanical and UV-blocking properties
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京尼平增强珍珠母蒙脱石壳聚糖薄膜，具有优异的机械和紫外线阻挡性能
DOI：
10.1016/j.compscitech.2019.107747
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发表时间：
2019-09-29
影响因子：
9.1
通讯作者：
Yin, Penggang
中科院分区：
文献类型：
--
作者：
Liang, Benliang;Shu, Yingqi;Yin, Penggang
壳聚糖作为一种功能材料，具有独特的生物相容性、生物降解性和可杀菌性能，适合于许多领域的应用。然而，这种材料的力学性能较差，限制了其应用。本文从天然珍珠层的层次化结构和力学性能之间的关系出发，选择单层蒙脱石片作为增强纳米片材，与壳聚糖共同构建仿珍珠层状结构。通过引入天然交联剂Genipin，在碱性条件下对壳聚糖骨架的氨基进行化学交联，进一步强化了模拟珍珠层的能力。系统研究了蒙脱土含量、GP交联度和pH值对杂化薄膜微观结构和界面相互作用的影响。结果表明，氢键和共价键的协同效应改善了仿生复合材料的力学性能，拉伸强度达到226.3 MJ/m~3，韧性达到5.1MJ/m~3。同时，由于壳聚糖与GP发生自发反应生成深蓝色颜料，杂化膜具有良好的紫外光阻挡能力(365 nm透过率为10.0%)。这种具有生物灵感的杂化薄膜具有更好的机械性能和优异的紫外线阻隔能力，在航空航天、组织再生和建筑等领域具有广阔的应用前景。
Chitosan, as a functional material, has special characteristics: biocompatibility, biodegradability and sterilizable properties, suitable for use in many fields. However, the weak mechanical properties of this material limit its applications. Herein, inspired by the relationship between the hierarchical "brick-and-mortar" structure and excellent mechanical properties of natural nacre, monolayer montmorillonite sheet was selected as reinforcement nanoplatelet to construct nacre-mimetic layered structure with chitosan together. Genipin, a naturally occurring cross-linking agent, was introduced to further strengthen the nacre-mimetics through chemically cross-linking the amino group of chitosan matrix under alkaline condition. The effects of MMT content, GP crosslinking, and pH on the microstructure and interfacial interactions of the hybrid films were studied systematically. It is proved that the synergistic effect originating from hydrogen and covalent bonds improves the mechanical property of the bioinspired composites, generating a tensile strength of 226.3 MPa and a toughness of 5.1 MJ/m(3). Meanwhile, the hybrid film has excellent UV-blocking ability (the transmittance is 10.0% at 365 nm) because the spontaneous reaction between GP and CS forms dark blue pigments. Such bioinspired hybrid films with improved mechanical properties and excellent UV-blocking ability has promising applications in aerospace, tissue regeneration, and construction.