Experimental studies of polymer-silicate nanocomposites using an atomic force microscope

The study of the relief and local mechanical properties of the polymer-silicate nanocomposites performed by atomic force microscopy. Polyethylene PE 107-02K, full ultra-thin layered particles of the modified clay Cloisite 20A, was selected as the main object of study. The original technique of sample surface preparation to the AFM scan was developed. In the first place melting polyethylene crystallites, and then restore them (recrystallization) occurred in polyethylene by special heat treatment. Thus, the crystallite formations on the surface became more visible, and the micro damages caused in the sample manufacture disappeared. As a result, the surface of nanostructure of such materials was studied. AFM scans of topography, hardness and adhesion were built. It is established that the highest stiffness and almost zero adhesion are characteristic for nanofiller particles. Amorphous phase was the least stiff, but had the greatest adhesion. Stiffness and adhesion characteristics of the crystallites were somewhere in between. Crystallites, leaving the surface of the sample, represent formation of several packs of slightly curved parallel plates with a thickness of 30–60 nm with a soft amorphous phase in the gaps. The number of these layers varied from 10 to 20 pieces.