The adsorption conformations of three comb-shaped polycarboxylate (PCE) with different numbers of grafted side-chains on the tricalcium aluminate (C3A) and ettringite surface is studied by all-atom molecular dynamics (MD) simulations with INTERFACE-PCFF forcefield. The similarity of absorbed PCEs on both surfaces is backbones of PCEs absorbed on the surface and the side-chains extended to liquid phase. The difference is that side-chains of PCEs keep a tilt angle with the C3A crystal but maintain parallel and closer to ettringite crystals. The absolute value of adsorption energy of PCEs on C3A surface is greater than that on ettringite surface, which indicate the stronger interaction between PCEs and C3A than ettringite. PCE with less side chains is favorable for the adsorption due to stronger electrostatic interaction with surface. Adsorption capacity and water-reducing ability of PCEs are contradictory. Density of water near the solid–liquid interface is more severely decreased by PCE with more side chains. Correlation of the adsorption conformation of PCEs with the flow behaviors of fresh cement paste is summarized.

中文翻译：

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梳状聚羧酸盐在铝酸三钙 (100) 和钙矾石 (100) 表面的吸附构象比较：分子动力学研究

通过使用 INTERFACE-PCFF 力场的全原子分子动力学 (MD) 模拟，研究了具有不同数量接枝侧链的三种梳状聚羧酸盐 (PCE) 在铝酸三钙 (C3A) 和钙矾石表面上的吸附构象。两个表面上吸收的 PCE 的相似性是吸收在表面上的 PCE 的主链和延伸到液相的侧链。不同之处在于 PCE 的侧链与 C3A 晶体保持倾斜角，但保持平行并更接近钙矾石晶体。PCEs在C3A表面的吸附能绝对值大于钙矾石表面，表明PCEs与C3A的相互作用强于钙矾石。由于与表面更强的静电相互作用，具有较少侧链的 PCE 有利于吸附。四氯乙烯的吸附能力和减水能力是矛盾的。具有更多侧链的 PCE 会更严重地降低固液界面附近的水密度。总结了 PCE 的吸附构象与新水泥浆体流动行为的相关性。