Carbon nanotube membrane composites
- Graduate student: Matt Hotze (Environmental Engineering, Duke University)
- Primary Adviser: Dr. Mark Wiesner (Environmental Engineering, Duke University)
- PERMEANT collaboration: Dr. Jean-Christophe Remigy (UPS, Toulouse)
Carbon nanotubes exhibit characteristics such as strength and electrical conductivity that make them promising materials for use in developing new composite materials. First, the possible toxicity of nanotubes might be exploited when inserted in membranes as a basis for inhibiting bacterial growth and therefore reducing biofouling. Although there is no consensus in the literature concerning CNT toxicity, if such toxic effects towards bacteria were detected, carbon nanotubes immobilized within the membrane skin might serve as a basis for fouling produced by microbial growth. Chemical modification of membrane surfaces through the introduction of nanomaterials is another strategy to reduce fouling, or to alter the affinity of the membrane for organic solutes. Nanotubes can be functionalized to create materials of variable hydrophilicity that might be used to adjust membrane surface chemistry.
Most importantly, single-wall nanotubes (SWNT) and high-quality multi-wall nanotubes (MWNT) prepared by arc-discharge exhibit a high surface area and quite unique characteristics : their Young's moduli can reach values greater than 1 TPa and the tensile strength can be as high as 50 GPa. One premise of the current effort if that these properties might be exploited to create membrane materials of very high strength.
We are examining the properties of membranes made from carnon nanotube/polymer composites. Multi-walled carbon nanotubes are incorporated into polysulfone nanofiltration membranes, prepared according to the wet phase inversion method. The dispersion of the nanotubes and the morphology of the membranes are observed by scanning electron microscopy. The membranes are characterized for surface roughness, contact angle, permeability and mechanical properties.