Interfacial Nanocomposite Characterization by Nanoparticle Debonding

Heated tip AFM (HT-AFM) is an emerging scanning probe technique that can provide local transition behavior in polymer materials. We demonstrate here, that the tool also provides direct access to the interfacial interaction (debonding) strength in reverse selective nanocomposites of poly(trimethyl silyl propyne) (PTMSP) and silica. Local nano thermomechanical analysis identified a transition at 330 degrees C, which subsequent imaging confirmed as degradation. By thermally inducing debonding of the silica particles, interfacial polymer mobility and debonding energy were simultaneously probed. Using a torsional stiffness calibrated thermal AFM probe, probe-particle impact force was continuously monitored to reveal a debonding force of 450 nN and an impact force transition 30 degrees C below the degradation temperature in the neat polymer, confirming the presence of enhanced polymer mobility at the PTMSP-silica interface.