Multilayer composites from vapor-grown carbon nano-fibers

Layer-by-layer assembled (LBL) materials from single-wall carbon nanotubes and multiwall carbon nanotubes revealed promising mechanical properties attributed to the uniform distribution of inorganic filler in the organic polyelectrolyte matrix. In this paper, we extend the family of LBL layered nanocomposites to include another important building block i.e. vapor-grown carbon nanofibers (VGCFs). Besides the advantages of low cost, mass production, and relatively small amount of impurities, VGCFs have convenient tubular morphology. Using the LBL film deposition method free-standing polymer composite films with high loadings (> 46%) of VGCFs were successfully prepared and examined by scanning electron microscopy, UV-visible spectroscopy and thermal gravimetric analysis. Combined with permeable nature of polyelectrolyte multilayers, these layered composites can be exceptionally useful for smart materials with release-on-command functionality, which requires considerable mechanical strength and thermal and/or electrical conductivity. Such applications may include biological implants, anticorrosion coatings, and thermal/electrical interface materials. Inherent versatility of LBL technology affords preparation of unique multifunctional materials by layering carbon nanofibers with other nanoscale building blocks, for instance, proteins, nanoparticles, clay sheets and others. (c) 2005 Elsevier Ltd. All rights reserved.