Advanced Functional Materials, Vol.18, No.18, 2733-2744, 2008
Hierarchical Inorganic-Organic Nanocomposites Possessing Amphiphilic and Morphological Complexities: Influence of Nanofiller Dispersion on Mechanical Performance
Novel nanocomposites possessing ternary compositions and complex morphologies have been prepared from amphiphilic crosslinked hyperbranched fluoropolymer-poly(ethylene glycol) (HBFP-PEG) in the presence of pristine and chemically functionalized nanoscopic fillers, single-walled carbon nanotubes (SWNTs) and silica nanoparticles (SiO2). Both SWNTs and SiO2 Were engineered specifically to become phase-designated reinforcing functional materials, SWNT-g-PEG and SiO2-g-HBFP, which (1) improved the dispersion of fillers, nanotubes, or spherical nanoparticles in the amphiphilic matrices, (2) enhanced the non-covalent interactions between nanofillers; and polymers, and more importantly, (3) maintained reactive functionalities to be further covalently integrated into the complex networks. Tensile moduli (E-dry) for these as-prepared SWNT-containing composites increased by up to 430% relative to the unfilled material, while those incorporated with SiO2 had a 420% increase of E-dry. After swelling in water, the water absorption within the micro- and nanochannels of PEG-rich domains rigidified or Softened the entire crosslinked network, as determined by the amount of PEG.