Monte Carlo Aggregation Code (MCAC) Part 2: Application to soot agglomeration, highlighting the importance of primary particles

JOURNAL OF COLLOID AND INTERFACE SCIENCE

卷:575

Article

Moran, J.¹  Yon, J.¹  Poux, A.¹  Corbin, F.¹  Ouf, F. X.²  Simeon, A.³ 

[1] Normandie Univ, CNRS, UNIROUEN, INSA Rouen,CORIA, F-76000 Rouen, France

[2] Inst Radioprotect & Surete Nuceaire IRSN, PSN RES, SCA, F-91192 Gif Sur Yvette, France

[3] Univ Lille, CNRS, UMR 8518, LOA Lab Opt Atmospher, F-59000 Lille, France

关键词: Diffusive and ballistic agglomeration;    Primary particles;    Flow regime;    Fractal dimension;    Soot;   

DOI  :  10.1016/j.jcis.2020.04.085

来源: Elsevier

【 摘 要 】

During the agglomeration of nanoparticles and in particular, soot, a change in both the flow regime (from free molecular to near continuum) as well as the change of agglomeration regime (from ballistic to diffusive) is expected. However, these effects are rarely taken into account in numerical simulations of particle agglomeration and yet, they are suspected to have an important impact on the agglomeration kinetics, particle morphologies, and size distributions. This work intends to study these properties by using the Monte Carlo Aggregation Code (MCAC) presented in the preceding work (part 1), focusing on the physical impacts of varying the particle volume fraction and monomers size and polydispersity. The results show an important sensitivity of the kinetics of agglomeration, coagulation homogeneity, and agglomerate morphology to the size of monomers. First, for smaller monomer diameters, the agglomeration kinetic is enhanced and agglomerates are characterized by larger fractal dimensions. Second, for large monomer diameters, fractal dimensions down to 1.67 can be found being smaller than the classical 1.78 for Diffusion Limited Cluster Agglomeration (DLCA) mechanism. One important conclusion is that variation in time of both regimes has to be considered for a more accurate simulation of the agglomerate size distribution and morphology. (C) 2020 Elsevier Inc. All rights reserved.

【 授权许可】

Free