Yasukawa Ikuto, Manyuan Nichayanan, Ikeda Junko, Kawasaki Hideya
Department of Chemistry and Materials Engineering, Kansai University, 3-3-35 Yamate-cho, Suita, Osaka 564-8680, Japan.
Mageleka Japan Co., Ltd., Tokatsu Techno Plaza, 5-4-6 Kashiwanoha, Kashiwa-shi, Chiba 277-0882, Japan; Institute of Multidisciplinary Research for Advanced Materials (IMRAM), Tohoku University, Katahira 2-1-1, Aoba-ku, Sendai 980-8577, Japan.
J Colloid Interface Sci. 2025 Feb;679(Pt A):900-909. doi: 10.1016/j.jcis.2024.10.031. Epub 2024 Oct 10.
The dispersion of apolar-ligand-protected nanoparticles (NPs) in alkanes is a complex process diverging from the "like dissolves like" principle, making its prediction beyond the capability of the Hansen solubility parameter (HSP) sphere method. This necessitates experimental investigation at the molecular level to understand dispersion behavior, particularly the role of solvent-ligand interactions.
Solvent relaxation NMR was applied for the first time to investigate solvent-ligand interactions in the dispersion/agglomeration of hexadecylamine-protected silver nanoparticles (C16-Ag NPs) in alkanes. The dispersibilities in different alkanes were determined from the localized surface plasmon resonance (LSPR) and compared with those predicted from the HSPs.
The colloidal behavior of C16-Ag NPs in alkanes was notably affected by the length of the solvent chain. LSPR analysis demonstrated that while C16-Ag NPs remained dispersed in pentane, hexane, and octane, they exhibited agglomeration in decane, dodecane, and tetradecane, contradicting the HSP theory predictions. Solvent relaxation NMR revealed that this unexpected agglomeration stems from the strong bonding of longer-chain solvents to surface C16 ligands, leading to significant interaction. In contrast, shorter-chain solvents exhibited weaker bonding, promoting better dispersion. These findings emphasize the importance of solvent choice in NP applications and offer valuable insights into ligand-shell dynamics, furthering the development of NP technologies.
非极性配体保护的纳米颗粒（NPs）在烷烃中的分散是一个复杂的过程，与“相似相溶”原理不同，这使得用汉森溶解度参数（HSP）球方法进行预测超出了其能力范围。因此需要在分子水平上进行实验研究，以了解分散行为，特别是溶剂 - 配体相互作用的作用。
首次应用溶剂弛豫核磁共振来研究十六烷基胺保护的银纳米颗粒（C16 - Ag NPs）在烷烃中的分散/团聚过程中的溶剂 - 配体相互作用。通过局域表面等离子体共振（LSPR）测定了在不同烷烃中的分散性，并与根据HSP预测的结果进行了比较。
C16 - Ag NPs在烷烃中的胶体行为受到溶剂链长度的显著影响。LSPR分析表明，虽然C16 - Ag NPs在戊烷、己烷和辛烷中保持分散，但在癸烷、十二烷和十四烷中出现团聚，这与HSP理论预测相矛盾。溶剂弛豫核磁共振显示，这种意外的团聚源于长链溶剂与表面C16配体的强键合，导致显著的相互作用。相比之下，短链溶剂表现出较弱的键合，促进了更好的分散。这些发现强调了溶剂选择在NP应用中的重要性，并为配体壳层动力学提供了有价值的见解，推动了NP技术的发展。
