Surface and bulk properties of soft nanocomposites

The behavior of polymer grafted soft nanoparticles mixed with like homopolymers was investigated to gain some fundamental understanding of the surface wear mechanisms of these composites on a nanometer scale. The resistance to surface wear of nanocomposites composed of poly(ethyl methacrylate) (PEMA) and PEMA-grafted nanoparticles could be increased while the elastic modulus of the composite remained constant. The elevated nanowear resistivity was attributed to the increased number of entanglements with the grafted polymer brushes and is a direct consequence of the dispersion behavior of the PEMA-grafted nanoparticles in a PEMA matrix.
The dispersion of PEMA-grafted nanoparticles in a PEMA matrix was investigated by SPM and GISAXS. It was shown that theoretical models for the behavior of star polymers are also applicable for polymer-grafted nanoparticles.
The surface of nanomechanical cantilever sensors was functionalized with polymer brushes. This approach allowed deposition of thick homogeneous polymer coatings on cantilevers by Inkjet-printing. The mechanical properties of the printed films were then determined by measuring the resonance frequency of the cantilevers. This concept allows for a screening of the mechanical properties of polymers and polymer nanocomposite materials using nanomechanical cantilever sensors.