Heterogeneous Crystal Nucleation from the Melt in Polyethylene Oxide Droplets on Graphite: Kinetics and Microscopic Structure

It is well known that the crystallization of liquids often initiates at interfaces to foreign solid surfaces. In this study, using polarized light optical microscopy, atomic force microscopy (AFM), and wide-angle X-ray scattering (WAXS), we investigate effect substrate–material interactions on nucleation in an ensemble polyethylene oxide (PEO) droplets graphite amorphous polystyrene (PS). The measurements during cooling with a constant rate explicitly evidenced substrate enhances kinetics, as occurred approximately 11 °C higher temperature than PS due changes interface. This observation allowed us conclude induces heterogeneous PEO. By employing classical theory for analysis data reference substrate, obtained results indicated crystal nuclei contact angles range 100–117° were formed Furthermore, show led preferred orientation PEO crystals graphite, whereas had isotropic orientation. difference orientations two substrates was also confirmed AFM, which showed only edge-on lamellae compared unoriented PS.