Peak Force Tapping Atomic Force Microscopy (PFT-AFM) was
performed on samples with concentrations of 0.5e8.0 mg/mL using
a Dimension Icon (Bruker Nano Inc: Santa Barbara, CA, USA) driven
by a Nanoscope V control unit [32,33]. The microscope was operated
in air, at room temperature and at atmospheric pressure; using
a sharp silicon nitride probe (SNL, Bruker, Santa Barbara, CA, USA)
with a spring constant (k) of 0.35 N m1. The force distance curves
were recorded at an operating frequency of 2 kHz. The samples of
different nanocomposites were from microtomed injection molded
bars.