Journal: JACS | https://doi.org/10.1021/jacs.5c03875

This paper presents an autonomous synthesis platform that combines droplet-flow microreactors with real-time X-ray scattering (SAXS/WAXS) and machine learning optimization to synthesize gold nanoparticles with precise control over their properties. Through 365 experiments exploring ~19,000 synthesis recipes, the system achieved targeted control of particle size (4–60 nm) and polydispersity across an unprecedented range of citrate/gold ratios. The research revealed that crystallite size and particle size follow a linear relationship with a universal slope, but the intercept can be independently tuned through synthesis parameters like chloride, gold precursor, citrate, and pH. This discovery enables independent control of internal crystalline domain structure at fixed particle sizes, confirmed by electron microscopy showing polycrystalline domains within single particles. The platform demonstrated excellent reproducibility and stability, establishing a robust framework for autonomous nanomaterial synthesis with multiscale structural control.

Read the article: https://doi.org/10.1021/jacs.5c03875