Local Thermomechanical Characterization of Phase Transitions in Polymers using Band Excitation Atomic Force Acoustic Microsco...

An approach for thermomechanical characterization of phase transitions in polymeric materials (PET) by band excitation acoustic force microscopy is developed. This methodology allows the independent measurement of resonance frequency, Q factor, and oscillation amplitude as a function of temperature of a small volume, from which the thermal evolution of tip-surface spring constant and mechanical dissipation can be extracted. We demonstrate a heating protocol which keeps the contact area and contact force constant, thus allowing for reproducible measurements and quantitative extraction of materials properties including temperature dependence of indentation-based elastic and loss moduli.

PACS: 82.35.Lr + 82.35.Jk + 68.37.Ps