Silva Lívia Oliveira Xavier, Bernardino Kalil
Laboratório de Química Computacional, Departamento de Química, Universidade Federal de São Carlos, Rod. Washington Luiz S/n, 13565-905 São Carlos, Brazil.
ACS Nanosci Au. 2025 May 8;5(4):262-268. doi: 10.1021/acsnanoscienceau.5c00003. eCollection 2025 Aug 20.
Ionic liquids have aroused great interest as solvents for the synthesis and stabilization of nanomaterials. The segregation between polar and apolar domains in ionic liquids with long alkyl groups provides kinetic stability for nanoparticle dispersions by rendering multiple free energy barriers for the aggregation. Similar effects also modulate the adsorption of nanoparticles over both liquid-vapor and liquid/solid interfaces. In this work, molecular dynamics simulations were performed to compute the potential of the mean force for the adsorption of spherical nanoparticles over solid substrates through films of imidazolium-based ionic liquids with different alkyl group lengths. While liquids with small alkyl groups produce simple profiles with barriers only close to the substrate, complex oscillatory forces arise between the nanoparticle and the substrate for ionic liquids with significant domain segregation. In addition, long-range solvent-mediated repulsive forces were also noted for liquids with an alkyl group long enough to display a smectic liquid crystal phase.
离子液体作为纳米材料合成和稳定化的溶剂引起了极大的兴趣。具有长烷基的离子液体中极性和非极性区域之间的分离，通过为聚集提供多个自由能垒，为纳米颗粒分散体提供了动力学稳定性。类似的效应也调节了纳米颗粒在液-气和液/固界面上的吸附。在这项工作中，进行了分子动力学模拟，以计算球形纳米颗粒通过不同烷基长度的咪唑基离子液体薄膜在固体基质上吸附的平均力势。虽然具有小烷基的液体产生简单的轮廓，仅在靠近基质处有势垒，但对于具有明显区域分离的离子液体，纳米颗粒和基质之间会出现复杂的振荡力。此外，对于具有足够长烷基以显示近晶液晶相的液体，还注意到了远程溶剂介导的排斥力。
