Colloidal Stability of TiO2 Nanoparticles: The Roles of Phosphonate Ligand Length and Solution Temperature
Colloidal Stability of TiO2 Nanoparticles: The Roles of Phosphonate Ligand Length and Solution Temperature
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DOI：
10.1002/chem.202201560
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发表时间：
2022-08-03
影响因子：
4.3
通讯作者：
Okada, Yohei
中科院分区：
文献类型：
--
作者：
Yamashita, Shohei;Sudo, Tatsuya;Okada, Yohei
表面配体是使胶体纳米颗粒（NPs）在溶剂中稳定的重要工具。然而，关于配体壳层，特别是配体长度的影响的知识是不足的和有争议的。在这里，我们展示了基于溶液的实验，N-烷基膦酸酯封端的二氧化钛纳米粒子，研究配体长度和溶液温度对胶体稳定性的影响。实现了稳健的配体交换过程，其将游离配体和杂质从胶体溶液中抽出。在甲苯中的8 nm的NPs的情况下，十二烷基膦酸酯配体提供比所有其他的n-烷基膦酸酯配体更好的胶体稳定性。此外，弛豫研究表明，在分散/团聚转变中存在动力学滞后。所提出的方法适用于广泛的表面配体，旨在最大限度地提高纳米粒子的胶体稳定性。
Surface ligands are essential tools for the stabilization of colloidal nanoparticles (NPs) in solvents. However, knowledge regarding the effects of the ligand shell, especially the ligand length, is insufficient and controversial. Here we demonstrate solution-based experiments on n-alkylphosphonate-capped TiO2 NPs to investigate the effects of ligand length and solution temperature on colloidal stability. A robust ligand-exchange process is achieved that draws free ligands and impurities away from the colloidal solution. In the case of 8 nm anatase NPs in toluene, the dodecylphosphonate ligand provided better colloidal stability than all the other n-alkylphosphonate ligands. In addition, relaxation studies suggested there is kinetic hysteresis in the dispersion/agglomeration transition. The proposed method is applicable to a wide range of surface ligands designed to maximize the colloidal stability of NPs.