Morphology of polyethylene nanolayers: a study by evanescent light microscopy

Thin films morphology investigation of polyethylene by the differential evanescent light intensity (DELI) imaging method has been performed. The films of nanometer thickness were obtained by the matrix-assisted pulsed laser evaporation (MAPLE) technique. MAPLE was demonstrated to be suitable for the synthesis of organic materials in form of nanostructures. To prepare targets, 3% polyethylene powder was dissolved in toluene and frozen at liquid nitrogen temperature. In MAPLE, the organic material is protected by the frozen solvent against the direct laser and plasma action. Polyethylene thin films of various thicknesses, below 200 nm, were thus fabricated by varying the deposition conditions. We applied the DELI microscopy technique for fast and low cost morphology investigation of large polyethylene nanolayer zones. A phenomenological model for the interaction between the evanescent waves and the deposited material is presented.