Joshua A Hammons
Lawrence Livermore National Laboratory, USA
Title: Particle Growth, Assembly and Extended Particle-Solvent Interactions in Deep Eutectic Solvents
Biography
Biography: Joshua A Hammons
Abstract
Deep eutectic solvents are two component solutions that are: cost-effective, environmentally safe (some) and easy to synthesize. These solutions have a high concentration of ions, as well as a complex hydrogen bond network that results in unique physio-chemical properties. Many different nanoparticle assemblies have been achieved with DESs. Given the wide range of DESs that are known and the many more that have not been realized, it may be possible to tune the DES to achieve a particle assembly. In this work, nanoparticle, assembly and particle-solvent interactions are studied using small angle X-ray scattering as the primary technique. The high flux of X-rays that were provided by synchrotron sources allowed for these systems to be studied in-situ. From SAXS experiments, particle aggregation and assembly is observed immediately following nucleation by electrodeposition. The aggregation time is slow and occurs over several minutes. In some cases, particle assembly can occur in place of aggregation by changing the DES composition. In most cases, there are measurable deviations in the DES species concentration that extend far from the particle surface. The in-situ SAXS measurements reveal that these phenomena also depend on the DES and the nanoparticles. The extended perturbations are also observed in colloidal systems, where deviations exist hundreds of nanometers from the particle surface. These results demonstrate how DESs are unique as they are applied toward nanoparticle assembly and synthesis and how they differ from aqueous solutions and room temperature ionic liquids.