Poly(vinyl pyrrolidone) wrapped multi-walled carbon nanotube/poly(vinyl alcohol) composite hydrogels

In this work, poly(vinyl pyrrolidone) (PVP) wrapped multi-walled carbon nanotube (MWCNT) reinforced poly(vinyl alcohol) (PVA) composite hydrogel was investigated. The addition of PVP was proved to facilitate uniform distribution of nanotubes and improve the interface between nanotubes and matrix. The tensile strength, modulus, toughness, tear strength and friction coefficient of MWCNT–PVP/PVA composite hydrogels with different MWCNT contents were measured and compared. The results demonstrated that the mechanical properties of the composite hydrogel were improved significantly by adding less than 2 wt% of PVP treated MWCNTs, and the increase of mechanical properties depended on the concentration and distribution of the nanotubes. The friction coefficient of the composite hydrogel was decreased essentially due to the lubrication effect of PVP and independent of MWCNT concentration. The overall performance of the composites manifested that PVP as a nonionic surfactant played a synergistic role with MWCNTs in the production and performance of PVA composite hydrogels.