Neat (matrix free) assemblies of polymer-functionalized inorganic nanoparticles have gained attention for their potential applications in high performance dielectrics, ceramic green bodies, multifunctional composites, and meta materials. Combining low-graft density (<0.1 chains/nm2) with a high molecular weight polymer, chain entanglement between the hairy nanoparticle (HNP) coronas can be preserved while maximizing the hybrid's inorganic fraction. While a �grafting from� technique can provide hairy nanoparticles with a broad range of grafting density, the surface polymerization is often difficult to control, leading to different molecular weight polymers on the surface. Alternatively, a �grafting to� approach facilitates the modular synthesis of HNP. A series of solvents and catalysts for optimal nanoparticle dispersion and yield were determined for coupling azide-terminal polystyrene to alkyne functionalized silica via �click� reaction. Size exclusion chromatography (SEC) provided insight on the reaction process as well as the stability of the HNP after being subjected to extreme temperatures and shear mixing. The corona height depends on grafting density and polymer size, and has a profound effect on the morphology, processibility and thermomechanical properties of these materials. After casting thin films of neat HNP, their dielectric properties were measured and compared to polystyrene and polystyrene - HNP mixtures to understand the impact of dispersion state, volume fraction and dielectric contrast of the nanoparticle on the dielectric breakdown process of the hybrid.

Synthesis, stability, and dielectric properties of polymer-functionalized SiO<sub>2 </sub>nanoparticles

245th National Meeting (2013)

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Synthesis, stability, and dielectric properties of polymer-functionalized SiO2 nanoparticles

Synthesis, stability, and dielectric properties of polymer-functionalized SiO₂nanoparticles