Student Summer Scholars






An interesting class of materials is polymer nanocomposites (PNC). Essentially, PNC’s are polymer matrices with nanoparticles dispersed within it. These nanoparticles provide a surface for attachment within the polymer, potentially resulting in alterations of macroscopic properties, such as conductivity, hardness, and flame-retardence. This change in attachment can also alter microscopic properties, such as voids in the polymer. Since it has been well studied, an ideal model system for studying polymer attachment to silica nanoparticles (15-20 nm in diameter for this study) is diglycidyl ether bisphenol A (DGEBA) with 4,4’-diaminodiphenyl sulfone (DDS) hardener. Using Positronium Annihilation Lifetime Spectroscopy (PALS), we can study these voids by analyzing the lifetime of positronium (the bound state of an electron and its antiparticle, a positron) which tends to localize in the voids of the polymer matrix. Preliminary results will be discussed, as will the PNC fabrication process.