Encapsulation of multi-walled carbon nanotubes with copolymer to disperse in aqueous media

Abstract

An emulsion-like polymerization technique called admicellar polymerization (AP) was used to encapsulate a thin film of copolymer on the surface of multi-walled carbon nanotubes (MWCNTs). A water-soluble component sodium acrylate and a non-water soluble component methyl methacrylate were used to form thin films of copolymer on multi-walled carbon nanotubes. Various ratios of polymer combinations were formulated on MWCNT’s to understand the stability of polymer composition and surface heterogeneity on MWCNT’s. Encapsulated MWCNTs were characterized using SEM, energy dispersive spectroscopy (EDS), thermal analysis and FT-IR. Analytical studies indicate the formation of copolymer on MWCNTs. Monomer conversion rate and copolymer reactivity ratios were analyzed using high performance liquid chromatography (HPLC) by Fineman-Ross and Kelen-Tudos methods. The copolymer combination showed an alternating tendency and azeotropic composition at 0.6 acrylate monomer. The encapsulated MWCNTs were stable in aqueous media with onset of aggregate formation beginning at 40 days for the copolymer.