Dispersion of carbon nanofibers modified with polymer colloids to enhance mechanical properties of PVA nanocomposite film

Polymer colloids have been used to modify the surface of carbon nanofibers (CNFs), to enhance the mechanical properties of polyvinyl alcohol (PVA) resin/CNF nanocomposite materials prepared by the solution casting method. However, the CNFs showed uneven dispersal within, and adhesion to, the PVA resin. In this study, the colloidal technique using polymer particles was applied to achieve more uniform dispersion of CNFs in PVA resin. This results in the polymeric particles functioning as spacers, thereby inhibiting CNF clustering; and in hydrogen bonding between PVA and polymer particles, thereby increasing surface adhesion between CNF and PVA. Polymer colloids prepared by the emulsion polymerization of styrene and N-vinylacetamide showed particularly notable enhancements of dispersion and surface adhesion in the composites. Consequently, PVA composite film containing uniformly distributed CNFs showed significantly enhanced tensile strength and modulus even at CNF mass fraction of 5.0 wt%.