Anisotropic-to-isotropic change in lateral force at the surface of single-crystal lamellae of high-density polyethylene during low-temperature annealing

The low-temperature annealing effect was directly investigated for isolated single-crystal lamellae of HDPE, using small-angle x-ray scattering, in-situ Atomic force microscopy (AFM), and lateral force microscopic (LFM) measurements. The anisotropic-to-isotropic change was observed in lateral force at the surface of the single-crystal lamellae during the low-temperature annealing. The results confirm that the sharp loop at the lamellar surface changes into the loose loop during the low-temperature annealing. The results also show that an increase in the magnitude of the lateral force is due to an increase in the contact area between the microtip and the lamellar surface.