REPOVSKÝ Daniel Comenius University in Bratislava

Formation Mechanism and Thermal-Solvation Dynamics of Complex Films: Atomic Force Microscopy

Co-authors JÁNÉ Eduard, VELIČ Dušan

A complex film formation, based on silane film and PVA/PVAc (polyvinyl alcohol/polyvinyl acetate) microspheres on glass fiber surface is determined by using atomic force microscopy (AFM). Silane strongly binds through the Si-O-Si bond to the glass surface providing the attachment mechanism as a coupling agent. The silane film then vertically penetrates in a honeycomb fashion from the glass surface through the deposited PVA/PVAc microspheres forming a hexagonal close pack structure. The silane film not only penetrates, but also deforms the spheres from a dispersion to a ellipsoidal shape on the surface. The silane film also moves PVA/PVAc microspheres in the process the complex film formation from the low silane concentration areas into the complex film area providing enough silane to stabilize the structure. Silane – PVA/PVAc complex film on glass fiber surface is studied also during thermal curing and water re-exposure by using AFM. The water re-exposure after 15 minutes 200 °C curing leads a re-containing water but without restored microsphere structure, due to the intramixing, leaving the silane – PVA/PVAc film not complex anymore. ACKNOWLEDGEMENTS: The work was supported by meta-QUTE., Johns Manville Slovakia, a.s. This research is also sponsored by NATO's Public Diplomacy Division in the framework of "Science for Peace," project Nr. SfP984698.