SURFACE ENERGY CHARACTERIZATION OF A SINGLE MICROSPHERE PARTICLE USING PEAKFORCE QUANTITATIVE NANOMECHANICAL MAPPING MODE OF ATOMIC FORCE MICROSCOPE

The composites are typically created by embedding functional fillers in polymeric matrices. The key indicators of reliable performance include homogeneous filler dispersion and optimal interfacial properties between the fillers and matrix. Poor dispersion causes stress concentration, premature failure, and increased filler requirement for achieving functional properties like conductivity. Additionally, interfacial characteristics are governed by surface energy differences and significantly influence the mechanical properties like elongation and rupture stress. Conventional methods for measuring surface energy, such as contact angle or Washburn adsorption, have limitations when applied to microscale powders, including issuers with accurate size handling and bulk material requirements. To overcome these challenges, the PeakForce QNM (quantitative nanomechanical mapping) mode of atomic force microscopy (AFM) was used to measure the surface energy on the surface of the powder microspheres. This method was used to characterize the surface energies of 2–5 μm carbonyl iron powders with various surface coatings. Differences in the surface energies corresponded to variations in the dispersibility and mechanical performances of these powder-based composites. The proposed nanoscale approach provides critical insights into the interfacial mechanisms, enabling enhanced design and optimization of stetchable composites for advanced electronic applications.