To investigate the dispersion of montmorillonite (MMT) nanosheets in cement, MMT was modified with three organic surfactants of various alkyl chain lengths (C1-OMMT, C10-OMMT and C16-OMMT) and then compounded with cement. Of all nanocomposites, the one containing 0.5 wt% of C10-OMMT exhibited the most significant enhancement in compressive strength by 11.2% and in the hydration degree by 11% with low porosity, corresponding to the improved microstructure and durability. The high performance is determined by two factors: (i) the filling effect – the surfactants promote the dispersion of MMT nanosheets in cement and (ii) the reinforcement by the modified nanosheets, which may be compromised by the unnecessarily high fraction of long-chain surfactants. These two conflicting factors can be balanced by selecting an appropriate surfactant chain length, which is key to the resulting composite morphology and thus high mechanical performance and durability in terms of resistance to water penetration.

为了研究蒙脱土（MMT）纳米片在水泥中的分散性，将MMT用三种烷基链长不同的有机表面活性剂（C1-OMMT，C10-OMMT和C16-OMMT）进行了改性，然后与水泥混合。在所有纳米复合材料中，含有0.5 wt％的C10-OMMT的复合材料在低孔隙率下的抗压强度提高了11.2％，水合度提高了11％，这与微结构和耐久性的提高相对应。高性能取决于两个因素：（i）填充效果–表面活性剂促进MMT纳米片材在水泥中的分散，以及（ii）改性纳米片材的增强作用，这可能会受到不必要的长链高比例的损害表面活性剂。可以通过选择适当的表面活性剂链长来平衡这两个矛盾的因素，