Strategy to Obtain nm Size Crystals through Precipitation in the Presence of Polyelectrolyte
Strategy to Obtain nm Size Crystals through Precipitation in the Presence of Polyelectrolyte
复制标题
在聚电解质存在下通过沉淀获得纳米尺寸晶体的策略
DOI：
10.1002/ceat.200500355
复制
发表时间：
2005
影响因子：
2.1
通讯作者：
T. Sakuma
中科院分区：
文献类型：
--
作者：
I. Hirasawa;T. Mikami;Aki Katayama;T. Sakuma
用双喷流结晶器在不同聚电解质聚合物(酸性、中性和碱性聚合物)的溶液中沉淀了硫酸铅晶体。聚乙烯亚胺(PEI)碱性聚合物同时控制成核速率和晶体生长速率，能够产生细小的单分散晶体。铅浓度变化的在线测量表明，当提供一定量的反应物N tot时，PEI失去作用。核磁共振分析发现铅离子与PEI相互作用，表明铅离子与PEI形成了某种络合物。无论进料流量和反应物浓度如何，N tot值与PEI在溶液中的重量都有很好的相关性，如关联式N tot=kW 0.49所示。结果表明，当反应物的供给量超过N-TOT时，PEI不再能控制沉淀速率。此后，发生了快速成核。用PEI沉淀可以通过在研磨溶液中加入一定量的PEI来控制，以得到单分散的细晶。这些结果为如何制备各种纳米尺寸的晶体提供了一个有效的想法。
Crystals of lead sulfate were precipitated in solutions of various polyelectrolyte polymers (acidic, neutral, and basic polymers) using a double-jet crystallizer. Polyetyleneimine (PEI) basic polymer controlled both the nucleation rate and crystal growth rate, and enabled the production of fine monodispersed crystals. The on-line measurement of the variation in the lead concentration indicated that PEI lost its effect when a certain amount of the reactants N tot was supplied. Interaction between lead ions and PEI was detected by NMR analysis, which suggested that lead ions made some kind of complex with PEI. The values of N tot correlated well with the weight of PEI in the solution, regardless of the feed flow rate and reactant concentration, as shown in the correlative equation N tot = k W 0.49 . It was suggested that PEI could no longer control the precipitation rate when the amount of reactants supplied exceeded N tot . Thereafter, rapid nucleation occurred. Precipitation with PEI could be controlled by a certain amount of PEI in a ground solution in order to produce monodispersed fine crystals. These results give an effective idea of how to create various nm size crystals.