MSE & ME Joint Seminar Series: Dr. Matthew Jones

About this event

Flyer : Developing a Mechanistic Picture of the Synthesis and Assembly of Inorganic Nanomaterials

Abstract : Technical progress in chemistry can often be attributed to an understanding of the fundamental mechanisms by which chemical processes occur, enabling the rational design of molecules and materials for a host of applications. Nanochemistry, on the other hand, being a comparatively younger field, has progressed primarily through trial-and-error experimentation due to challenges associated with characterizing structures and processes at the 1-10 nm length scale and the outsized influence of surface effects which remain difficult to quantify. In this talk, I will discuss recent efforts by my group to address these shortcomings to develop a more predictive synthesis of nanoparticle-based materials with novel properties. First, I will report on our finding that the “seed” nanoparticle that has been widely used as a precursor in anisotropic gold particle syntheses over the last two decades is, in fact, an atomically-precise inorganic cluster consisting of a 32 atom Au core with 8 halide ligands and 12 neutral ligands constituting a bound ion pair between a halide and the cationic surfactant: Au 32 X 8 [AQA + •X - ] 12 (X = Cl, Br; AQA = alkyl quaternary ammonium). This result establishes a molecular precursor with well-defined surface ligands as the progenitor to larger nanostructures and is a critical first step in understanding particle growth mechanisms. Next, I will show how control over the surface chemistry of anisotropic nanoparticles facilitates their assembly into novel superlattices with chiral and quasicrystalline order. These materials will form the basis for future optical and/or mechanical metamaterials, highlighting the power afforded by mechanistic insights to control the structure and organization of matter.