AM-FM Viscoelastic Mapping of polystyrene-polycaprolactone (PS-PCL) polymer film

AM-FM Mode images for a polystyrene-polycaprolactone (PS-PCL) polymer film on mica: elastic storage modulus (a and c), viscoelastic loss tangent (b), and indentation depth (d). Storage modulus is higher in PS regions (light brown) than PCL regions (dark brown), while PCL regions exhibit higher loss tangent than PS. The ability to capture the fine fibrillar structure of PCL (c and d) demonstrates AM-FM Mode?s high spatial resolution and gentle nature. Imaged with the Cypher S at 2 Hz scan rate with blueDrive? photothermal excitation. Scan sizes 5 µm (a and b) and 1.5 µm (c and d).