Abstract In the present study, we demonstrate a simple technique to synthesize calcium carbonate chain-like nanoparticles with high aspect ratios; we introduced CO2 gas into aqueous slurry of calcium hydroxide (lime milk) with addition of a small amount of lime milk during the reaction. Primary particle structures and agglomeration states of the chain-like particles were analyzed in detail and compared with those of spheroidal particles synthesized by a carbonation reaction without lime milk addition. The technique to fabricate anisotropic nanoparticles will broaden the applications of calcium carbonate. On the other hand, chain-like particles entangled with each other to form larger and fluffier agglomerates with sporadic pores. It was found that the slurry of chain-like particles showed much higher dewaterability (solid-liquid separation efficiency). Several properties of the filtered and dried cakes were investigated to decipher the mechanism of dewaterability. The novel technique to increase dewaterability without using any additives, such as surfactants, may expand the designing of nanoparticle manufacturing processes.

中文翻译：

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碳酸钙链状纳米粒子：合成、结构表征和脱水性

摘要 在本研究中，我们展示了一种合成高纵横比碳酸钙链状纳米粒子的简单技术；我们将二氧化碳气体引入氢氧化钙（石灰乳）的水浆中，并在反应过程中加入了少量的石灰乳。详细分析了链状颗粒的初级颗粒结构和团聚状态，并与不添加石灰乳的碳酸化反应合成的球状颗粒进行了比较。制备各向异性纳米粒子的技术将拓宽碳酸钙的应用。另一方面，链状颗粒相互缠结形成更大、更蓬松的团块，并带有零星的孔隙。发现链状颗粒的浆料表现出更高的脱水能力（固液分离效率）。研究了过滤和干燥的滤饼的几种特性，以破译脱水的机制。在不使用任何添加剂（如表面活性剂）的情况下提高脱水能力的新技术可能会扩展纳米颗粒制造工艺的设计。