†Center for Molecular and Engineering Thermodynamics, Department of Chemical and Biomolecular Engineering, University of Delaware, Newark, Delaware 19716, United States.
‡Central Research and Development, DuPont Company, Wilmington, Delaware 19880, United States.
ACS Nano. 2015 Mar 24;9(3):3243-53. doi: 10.1021/acsnano.5b00354. Epub 2015 Mar 13.
The critical role of solvation forces in dispersing and stabilizing nanoparticles and colloids in 1-butyl-3-methylimidazolium tetrafluoroborate [C4mim][BF4] is demonstrated. Stable silica nanoparticle suspensions over 60 wt % solids are achieved by particle surface chemical functionalization with a fluorinated alcohol. A combination of techniques including rheology, dynamic light scattering (DLS), transmission electron microscopy (TEM), and small angle neutron scattering (SANS) are employed to determine the mechanism of colloidal stability. Solvation layers of ∼5 nm at room temperature are measured by multiple techniques and are thought to be initiated by hydrogen bonds between the anion BF4 and the fluorinated group on the surface coating. Inducing structured solvation layering at particle surfaces through hydrogen bonding is demonstrated as a method to stabilize particles in ionic liquids.
证明了溶剂化力在分散和稳定纳米粒子和胶体在 1-丁基-3-甲基咪唑四氟硼酸盐[C4mim][BF4]中的关键作用。通过用氟化醇对粒子表面进行化学功能化，实现了高达 60wt%固体的稳定二氧化硅纳米粒子悬浮液。流变学、动态光散射（DLS）、透射电子显微镜（TEM）和小角中子散射（SANS）等多种技术的结合被用来确定胶体稳定性的机制。通过多种技术测量了室温下约 5nm 的溶剂化层，据认为这是由阴离子BF4和表面涂层上的氟化基团之间的氢键引起的。通过氢键在粒子表面诱导结构溶剂化层被证明是一种在离子液体中稳定粒子的方法。
