Nanocomposites based on low density polyethylene filled with carbon nanotubes prepared by high energy ball milling and their potential antibacterial activity

Low density polyethylene, LDPE, based nanocomposites containing multi-walled carbon nanotubes, MWCNT, were prepared by a two-step process consisting in a pre-mixture using high energy ball milling, HEBM, and subsequent hot pressing. The effects of HEBM and presence of MWCNT on some physical properties of the LDPE based materials and antimicrobial efficiency against DH5α Escherichia coli were studied. FTIR revealed the polymer structure did not change in the final materials after the addition of MWCNT. Differential scanning calorimetry showed small differences in the LDPE thermal behavior as a function of the type of material due to small changes in the polymer crystallization. This result was mainly ascribed to the milling process rather than to the incorporation of the MWCNT. The presence of 1% by weight of the nanofiller increased the rigidity and hydrophobicity of the nanocomposites respect to the neat LDPE. This effect was explained considering certain presence of the MWCNT in the surface of the material as the main factor of decreasing the polar contribution to the surface free energy. A correlation between hydrophobicity, biofilm development, shape and size of DH5α E. coli was observed, indicating that the presence of MWCNT leads to biocide effect by decreasing cell adhesion and changing its metabolism.

Nanocomposites based on low density polyethylene filled with carbon nanotubes prepared by high energy ball milling and their potential antibacterial activity Articles