Controlled phase behavior of polymer-grafted nanoparticles (PGNP) blend thin films.

Polymer blend thin films are essential materials for emerging technologies and applications such as optoelectronics, energy storage, and coatings. The microstructure and molecular interactions of polymer thin films influence their properties and suitability for various applications. This study reveals how the presence of grafted nanoparticles influences the morphology and properties of blends of polymethylmethacrylate grafted nanoparticle silica (PMMA-SiO2) and polymers of different chemical classes. A comprehensive investigation of the phase separation at the nanoscale was done using Atomic force microscopy (AFM), Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS), and Grazing-Incidence Wide-Angle X-ray Scattering (GIWAXS) to characterize the surface topography, morphology and structure of the thin films of various thicknesses at different temperatures, and processing pathways including thermal annealing (TA) and direct immersion annealing (DIA). The measurement results combined show the lateral phase separation kinetics and the vertical phase separation in the polymer blend thin films. The changes in mechanical and thermal properties will also be discussed.