Similar to Fig. 3 with the same time cuts, but in the presence of dust grains. The dashed lines show the size distribution of adsorbec PAH clusters. Initially, the density of PAHs is high enough that clustering is faster than adsorption. Over time, PAHs get adsorbed on dus grains until adsorption and clustering act on similar timescales. Ther growth is halted, and clusters will be stuck on grains. Most PAHs an adsorbed as large clusters.