A chitosan based pH-responsive hydrogel for encapsulation of bacteria for self-sealing concrete
A chitosan based pH-responsive hydrogel for encapsulation of bacteria for self-sealing concrete
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DOI：
10.1016/j.cemconcomp.2018.08.007
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发表时间：
2018-10
影响因子：
10.5
通讯作者：
Jianyun Wang;A. Mignon;Gilles Trenson;S. Vlierberghe;N. Boon;N. Belie
中科院分区：
文献类型：
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作者：
Jianyun Wang;A. Mignon;Gilles Trenson;S. Vlierberghe;N. Boon;N. Belie
混凝土裂缝是建筑工程中的主要问题之一。细菌自修复混凝土已被证明是解决这一问题的一种有前途的方法。为了保护细菌免受混凝土中的恶劣条件的影响，优选将细菌包封。在这项研究中，pH响应水凝胶合成封装细菌孢子的自密封混凝土裂缝。研究了pH响应性和水凝胶对力学性能的影响。然后检查包封孢子的活力和水凝胶的细胞截留能力。通过减少水流量和裂缝封闭率来评价自封闭效率。结果表明，壳聚糖基水凝胶具有合适的pH响应性。在7和11之间的pH范围内，溶胀能力保持稳定，当溶胀在38.5 ± 0.5和42.9 ± 1.5g水/g水凝胶之间变化时没有显著差异。在骨水泥滤液中，溶胀大大降低至约12.8 ± 0.9 g水/g水凝胶。加入1 m%的水凝胶，压缩强度仅降低约5%。具有水凝胶包封的孢子的试样显示出最高的水流减少（81-90%）和最高的裂缝密封效率。超过30%的裂纹位置被完全桥接。而在其他试样中，只有2-12%的裂纹位置被完全封闭。
Cracks in concrete remain one of the major issues in constructions. Self-healing concrete by bacteria has already proven to be a promising way to solve this problem. In order to protect bacteria from the harsh condition in concrete, encapsulation of bacteria is preferable. In this study, a pH responsive hydrogel was synthesized to encapsulate bacterial spores for self-sealing concrete cracks. The pH responsiveness and the influence of the hydrogel on the mechanical properties were investigated. The viability of the encapsulated spores and the cell-entrapping capacity of the hydrogel were then examined. The self-sealing efficiency was evaluated by the reduction of water flow and crack sealing ratio. The results indicated that the chitosan based hydrogel had a suitable pH responsiveness. Within the pH range between 7 and 11, the swelling capacity remained stable, with no significant differences as the swelling varied between 38.5 ± 0.5 and 42.9 ± 1.5 g water/g hydrogel. The swelling greatly decreased to around 12.8 ± 0.9 g water/g hydrogel in cement filtrate. The compressive strength only decreased around 5% with the addition of 1 m% of hydrogel. The specimens with hydrogel encapsulated spores showed the highest reduction in water flow (81–90%) and highest crack sealing efficiency. More than 30% of the crack locations was completely bridged. While in other specimens, only 2–12% of the crack locations was completely sealed.