Multiwalled Carbon Nanotube Deposition on Model Environmental Surfaces

Deposition of multiwalled carbon nanotubes (MWNTs) on model environmental surfaces was investigated using a quartz crystal microbalance with dissipation monitoring (QCM-D). Deposition behaviors of MWNTs on positively and negatively charged surfaces were in good agreement with Derjaguin-Landau-Verwey-Overbeek (DLVO) theory, although hydrophobic interactions dominated MWNTs deposition on a hydrophobic polystyrene surface. Initial deposition rates (r(f)) and deposition attachment efficiencies (alpha(D)) depended on solution ionic strengths (IS) and surface electrostatic properties. Identical r(f) and alpha(D) values at constant IS on similar surfaces suggested that deposition was insensitive to surface morphology (i.e., bare crystal surface vs coated surface). The dissipation unit (D) was used with frequency (f) to investigate nanoparticle deposition: vertical bar Delta D/Delta f vertical bar values varied for deposition on different surfaces, indicating that the nature of MWNT association with surfaces varied despite constant r(f) and alpha(D) values.