Polymer thin films have recently become one of the most emerging research areas due to their profuse applications in energy storage, flexible electronics, and photonics. The mechanical response of polymer thin films is crucial in defining a high-performance device encompassing the film’s durability, bond ability, and flexibility. In the past few decades, the mechanical properties of nanoparticle-filled polymer thin films have been studied rigorously, suggesting that the inclusion of nanoparticles in the polymer matrix enhances the elastic modulus of thin films. However, there’s still a window of opportunity for an intensive study of the process-morphology-property (PMP) relationship for polymer-grafted nanoparticle (PGNP) thin films based on the particle size, loading percentage, the molecular weight of the grafted polymer, and the film thickness. This research investigates the elastic modulus of polymethyl methacrylate grafted silica nanoparticle (PMMA-g-SiO2) thin films as a function of thickness and processing conditions. PGNPs of 15nm core diameter with grafted PMMA chains of different molecular mass at high grafting density were dispersed in tetrahydrofuran (THF) solution to produce thin films of varying thickness ranging from 50nm to 150nm. The nanoparticle distribution throughout the film thickness and surface roughness were studied using atomic force microscopy. The PMMA films with similar thickness ranges were analyzed to compare the effect of PGNPs on the elastic modulus for both as-cast and thermally annealed conditions, evaluated through strain-induced elastic buckling instability for mechanical measurements (SIEBIMM) technique. The effects on the mechanical properties due to confinement, molecular mass, and film surface for as-cast and thermally annealed samples were studied.
