The use of atomic force microscopy for imaging the surfaces of polyamide, 6

The surface morphologies of PA 6 resulting from the use of various processing methods were studied by tapping mode atomic force microscopy. Three PA 6 samples: (1) a thin film, spin coated on a silicon wafer, (2) a freestanding film, i.e. a foil and (3) a monofilament, show definite morphological differences revealing typical supramolecular structures, The thin film having thickness of app. 35 nm is a good example of the initial step of spherulite formation where the sheaf development is still prominent. In an area of 100 mum(2) 1-4 spherulites can be detected which are typical of crystallization from the solution. The annealing (vacuum, 195degreesC, 3.5h) causes additional crystallization, which leads to a radial coordination and enlargement of spherulites to app. 50% in diameter and up to 40% in height. The morphology of foil (thickness of 100 mum) can be interpreted as a system of spherulites formed from the melt, and a typical fibrillar structure is observed on the surface of monofilament.