Langevin dynamics simulation and collision frequency modification in population balance model of nanoparticle coagulation during simultaneous agglomeration and sintering.

Coagulation of nanoparticles from the free-molecular to the transition regime under a high-temperature environment is investigated by coupling Langevin Dynamics (LD) model with agglomeration and finite-rate sintering. The effect of temperature on the evolution of particle size and structure is investigated, variations in agglomeration-sintering dynamics are obtained. The fractal dimension of agglomerates at different temperatures can be expressed as a function of the ratio between the characteristic collision time and sintering time. The overall collision frequency (β) is enhanced by the polydispersity and fractal properties of agglomerates compared to the monodisperse collision kernel functions. Finally, the classic function of β is modified based on the LD simulations and used in a one-dimensional population balance equation, which reproduces a better prediction of the evolution of particle size distribution during particle coagulation with agglomeration and sintering. [Display omitted] • Langevin Dynamics model is coupled with agglomeration and sintering. • Effect of temperature on particle-to-agglomerate evolution is discussed. • Evolution of nanoparticle morphology depends on ratio of characteristic times. • Collision frequency is enhanced by polydispersity and fractal dimension. • Modified collision frequency function is used in a simple population balance model. [ABSTRACT FROM AUTHOR]