Growth Modification of Seeded Calcite by Carboxylic Acid Oligomers and Polymers: Toward an Understanding of Complex Growth Mechanisms
Growth Modification of Seeded Calcite by Carboxylic Acid Oligomers and Polymers: Toward an Understanding of Complex Growth Mechanisms
复制标题
DOI：
10.1021/cg1005105
复制
发表时间：
2010-09-01
影响因子：
3.8
通讯作者：
Bowen, Paul
中科院分区：
文献类型：
--
作者：
Aschauer, Ulrich;Ebert, Johannes;Bowen, Paul
聚羧酸分子和低聚物已被研究作为晶种方解石沉淀过程中的生长调节剂。为了更好地理解可能的分子相互作用和动力学效应，在这项工作中，具有不同结构和分子量的添加剂进行了研究。所有添加剂都显示出生长调节作用，尽管对于琥珀酸和谷氨酸不太强烈。这归因于与沉淀颗粒的相对弱的相互作用以及添加剂尺寸太小而不能影响生长机制的聚集相。另一方面，聚（丙烯酸）和聚（天冬氨酸），导致强的生长改性，与所得的颗粒是纳米结构的，由组装的纳米尺寸的初级颗粒，因此具有高的比表面积形成。在分子量和官能团浓度相近的情况下，聚天冬氨酸比聚丙烯酸具有更强的生长调节作用。这是不容易解释的，而不使用分子动力学模拟（报告在单独的文章），这表明，差异源于刚性的骨干和有利的静电之间的相互作用的骨干氮原子和表面的情况下，聚（天冬氨酸）。
Polycarboxylate molecules and oligomers have been investigated as growth modifiers during seeded calcite precipitation. To better understand possible molecular interactions and kinetic effects, additives with different structures and molecular weights have been investigated in this work. All additives show growth modifying effects, albeit less strongly for succinic acid and glutaric acid. This is attributed to a relatively weak interaction with the precipitated particles as well an additive size too small to influence the aggregation phase of the growth mechanism. Poly(acrylic acid) and poly(aspartic acid), on the other hand, led to strong growth modification, with the resulting particles being nanostructured, formed by an assembly of nanosized primary particles and consequently having a high specific surface area. Poly(aspartic acid) showed a stronger growth modifying effect than poly(acrylic acid) at a similar molecular weight and functional group concentration. This was not readily explainable without using molecular dynamics simulations (reported in a separate article), which suggests that the differences originate from the rigidity of the backbone and favorable electrostatic interactions between backbone nitrogen atoms and the surface in the case of poly(aspartic acid).