Fig. 4.

Minimal mechanism for aggregation of monomer to form amorphous irregular structures in the bulk phase corresponding to Eq. 5. Depending on the values selected for the second-order rate constants governing the initial, $k_{n{\left(I\right)}_B}$, and later, $k_{g{\left(I\right)}_B}$, monomer incorporation steps the system may/may not exhibit nucleated growth type behavior. Amorphous aggregate growth may also occur by aggregate accretion/joining governed by a second-order rate constant, $k_{j{\left(I\right)}_B}$. Amorphous aggregate shrinkage is considered to occur solely via monomer loss governed by a first-order rate constant $k_{S°{\left(I\right)}_B}$. Statistical factors relating to greater chances for monomer loss as the amorphous aggregate surface area increases are specified in Eq. 5. (Translated and reprinted with full permission from Hirota and Hall (2019), CMC Publishing Corporation)