Analiza povrsine vlaken z mikroskopijo atomskih sil (AFM)

Atomic force microscopy (AFM) is one of the most modern types of microscopy enabling nanoscale imaging of both conducting and insulating surfaces. It was developed by the Nobel Prize winners in physics, Binning and Roher. Since its invention in 1986 the atomic force microscope has become useful in industry and as a very important laboratory instrument in different fields of research such as physics, chemistry, polymers and biology. This method can also be applied in textile research although the researchers working in this field are few. The structure of fibres is very complex. In most cases the morphology of the fibre surface differs from the morphology of the core. The characteristics of the fibre surface influence the processes at the interfaces which makes any surface analysis of the fibres extremely important, and the introduction of new methods valuable. AFM gives a three-dimensional nanoscale image of the surface thus revealing additional information about the fibrillar structure of the fibres. It can also be used for intermolecular and intercolloidal force measurements sensing forces even smaller than 1 nN. A sample preparation prior to imaging is much simpler compared to electron microscopy. In this paper the basic AFM operation is discussed and the topography of PA6 filament is analysed using AFM. The fibrillar structure can be seen at the fibre surface. The smallest detectable fibrils are in the range of about 10 nm in width. They are congregated in bigger fibril bundles having up to 1-2 μm in diameter. Cavities and niches vary in width (30-200 nm) and shape (round or oblong). They are oriented in the direction of the fibre. The surface of the filament is less furrowed in the direction of the fibre; the difference in height between the highest and the lowest regions alongside is only up to 30 nm and transverse up to 70 nm.