Starting from experimental evidence of the goodness of poly(ethylene glycol-bl-propylene sulfide), PEG-PPS, to disperse single-walled carbon nanotubes (SWCNTs), atomistic molecular dynamics (MD) simulations have been performed to study SWCNTs/polymer systems in the presence of water molecules in solution. Comparison between block copolymer (PEG PPS) and homopolymer (PEG) and between single and double chains system is presented. Results show that the hydrophobic nature of PPS systematically ensures a higher SWCNT surface coverage, a higher interstitial water depletion and a much lower degree of water ordering when compared to the PEG homopolymer.