Experimental Chemical Kinetics of an A+B→0 System Showing Non-Classical Effects of Initial Reactant Distribution

Abstract

AbstractWe demonstrate here the implementation of an experimental system suitable for the study of the diffusion-limited A+B→0, non-classical reaction behavior. Using a combination of a fluorescent calcium indicator and a calcium ion which is initially “caged”, a pulse of near-UV light initiates the reaction which is followed as product formation vs. time. Sensitive dependence on the initial reactant distribution is observed through patterns in the uncaging UV light profile. The reaction progress passes through two non-classical time regimes, one due to roughness originating from laser speckles, followed by one exhibiting the three-dimensional Zeldovich rate of (1/ρA − 1/ρA0) ˜ t3/4, with features matching Monte Carlo simulations on this initial distribution.