Fast and Reliable Metamodeling of Complex Reaction Spaces Using Universal Kriging

We
report the application of metamodeling algorithms based on Universal
Kriging for the controlled synthesis of compound semiconductor nanoparticles.
Application of such a metamodel allows the prediction of reaction
outcomes at arbitrary points within sparsely sampled parameter spaces
as a function of reaction conditions. To demonstrate the applicability
of Universal Kriging to chemical reaction screening within microfluidic
reaction systems CdSe and CdSeTe quantum dots were synthesized by
using a segmented flow capillary reactor. Variation of input reagent
flows (to control reagent concentrations and reaction residence times)
and online spectroscopic monitoring of product characteristics was
achieved in a fully automated manner. The resulting fluorescence spectra
are analyzed to extract the fwhm, wavelength maximum, and intensity
of the band-edge emission. These values are subsequently used as inputs
for the Universal Kriging metamodeling algorithm to predict the reactor
output at arbitrary points within accessible parameter space. Results
demonstrate that the algorithm can predict reaction outcomes with
high accuracy and reliability.