Bio-inspired functionalization of very fine aggregates for better performance of cementitious materials
Bio-inspired functionalization of very fine aggregates for better performance of cementitious materials
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DOI：
10.1016/j.conbuildmat.2020.118104
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发表时间：
2020-04
影响因子：
7.4
通讯作者：
Yi Fang;Jialai Wang;Xin Qian;Liang Wang;Guangping Lin;Zhongqi Liu
中科院分区：
文献类型：
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作者：
Yi Fang;Jialai Wang;Xin Qian;Liang Wang;Guangping Lin;Zhongqi Liu
由于许多地区天然骨料的储备和供应短缺和枯竭，通常使用人工砂和沙丘砂等替代砂。这些替代砂通常具有比天然砂多得多的极细颗粒（VFP）。为了促进这些VFP在混凝土中的应用，本研究采用多巴胺功能化这些VFP的表面，以实现更好的VFP和水泥净浆之间的粘附。这项研究是生物学的灵感来自贻贝，这显示出非凡的能力，坚持使用粘性蛋白L-3，4-二羟基苯丙氨酸（DOPA）在贻贝足丝的水下基板。多巴胺作为DOPA的模拟物，通过共价和非共价相互作用与不同表面具有类似的强结合能力，其可以修饰VFP的表面并活化惰性的极细砂。为此，将VFP以不同的持续时间（1小时、6小时和24小时）和浓度（1 g/L、2 g/L和3 g/L）浸入具有10 mM tris缓冲液（pH 8.5）的多巴胺水溶液中，以在VFP表面上产生聚多巴胺涂层。通过使用功能化的VFP，混凝土的抗压强度已经实现了显着的改善。
Alternative sands such as manufactured sands and dune sands are commonly used due to the shortage and depletion of reserve and supply of natural aggregates in many areas. These alternative sands usually have much more very fine particles (VFPs) than the natural sands. To promote applications of these VFPs in concrete, this study employs dopamine to functionalize the surface of these VFPs to achieve better adhesion between the VFPs and the cement paste. This study is biologically inspired by mussels, which display an extraordinary ability to adhere to underwater substrates using adhesive proteins L-3,4-dihydroxyphenylalanine (DOPA) in the mussel byssus. Dopamine, as a mimic of the DOPA, has similar strong binding ability to diverse surfaces through covalent and non-covalent interactions, which can modify the surface of VFPs and activate the inert very fine sand. To this end, the VFPs were immersed in an aqueous solution of dopamine at different durations (1 h, 6 h and 24 h) and concentrations (1 g/L, 2 g/L, and 3 g/L) with 10 mM tris buffer (pH 8.5) to produce a polydopamine coating on the surface of the VFPs. A significant improvement of the compressive strength of the concrete has been achieved by using the functionalized VFPs.