Kinetics of the formation of core–shell structures under transient external conditions

Journal article, 2024

The kinetics of absorption of molecules by particles are analyzed using the core–shell model provided the concentration of molecules outside increases continuously from zero up to fixed value. In the kinetically limited case, the dependence of the uptake on time is found to be of the S shape. In the diffusion-limited case, the uptake is proportional to t1/2 in the beginning and then exhibits slowdown. These features are qualitatively different compared to those predicted by the conventional model implying the concentration of molecules outside to be constant.