We systematically studied the lamellar orientation of polyamide 6 (PA6) thin films on solid substrates.Figure 1 displays the morphologies characterized using atomic force microscopy(AFM)for films with different thickness.Typical 2D-like spherulites can be observed in the relatively thick films.On hydrophilic substrate(Si-OH),decreasing film thickness to below~100 nm causes the morphology change to sheaf-like structure resembling the baby PA6 spherulites.The morphology becomes combination of sheaf-like structure and microfibrils for PA6 films thinner than~50 nm.If the substrate is hydrophobic(Si-OTCS),dewetting occurred when the films was thinner than~100 nm,which can result in droplets sitting on the substrate.