The microstructure and properties of calcium-silicate-hydrate (C-S-H) gels are largely controlled by the physicochemical environment during their precipitation. However, the role of the steric repulsive environment induced by the pore solution chemistry on the kinetics, structure, and properties of C-S-H gels remains unclear. Here, we develop two potential formalisms, namely sinusoidal and polynomial, to simulate the role of steric repulsions in C-S-H. The results show excellent agreement with experimental observations of precipitation kinetics and elastic properties. We demonstrate that the repulsive interactions result in delayed precipitation and percolation, and an open and branched microstructure. Interestingly, the elastic properties (which are equilibrium properties) are also significantly affected by these second-neighbor interactions. Overall, the present study demonstrates that the kinetics, structure, and equilibrium properties of colloidal gels are controlled by the steric repulsions induced by the chemical environment.

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空间排斥对沉淀动力学和硅酸钙水合物凝胶结构的作用

水合硅酸钙 (CSH) 凝胶的微观结构和性质在很大程度上受其沉淀过程中的物理化学环境控制。然而，由孔溶液化学诱导的空间排斥环境对 CSH 凝胶的动力学、结构和性质的作用仍不清楚。在这里，我们开发了两种潜在的形式，即正弦和多项式，以模拟空间排斥在 CSH 中的作用。结果显示与沉淀动力学和弹性性质的实验观察非常一致。我们证明了排斥相互作用导致延迟沉淀和渗透，以及开放和分支的微观结构。有趣的是，这些第二邻域相互作用也显着影响了弹性特性（即平衡特性）。