Use of phase imaging in atomic force microscopy for measurement of viscoelastic contrast in polymer nanocomposites and molecularly thick lubricant films

Probing particle structure in waterborne pressure-sensitive adhesives with atomic force microscopy

“…Unlike what is seen in our results, the contrast in both height and phase images has been found elsewhere [33,44,49] [42], is avoided. Likewise, the attractive regime at very low A sp is avoided.…”

“…Other experiments and modelling [44] has shown that contrast is accentuated in phase images when there is a low A sp and a high A o , as is the case here.…”

“…When the tip interacts with a viscoelastic region in which the elastic component is higher, however, it is expected that less energy will be dissipated, making φ smaller. [44] In the phase contrast images presented in this work, lighter areas correspond to lower values of φ, and darker areas correspond to larger values. Hence, in phase contrast images, more energy dissipative regions will appear darker.…”

“…We attribute this phase contrast to the effect of The reasons for contrast in phase images has been a subject of frequent investigation [34,34,43,44,45]. Phase contrast has been shown to be independent of variations in the elastic moduli (i.e.…”

“…[43] On the other hand, when the tip interacts with a viscous material, energy is dissipated. There is convincing evidence from experiments and modelling [44,48] that the energy dissipation in tip-sample interactions is greater in viscoelastic materials with a high viscosity. Variations in viscosity across a surface therefore lead to contrast in phase images and have indeed been observed over lateral distances of a few nm.…”