Carbon nanotube addition has been shown to improve the mechanical properties of some polymers. Because of their unique adsorptive properties, carbon nanotubes may also improve the barrier performance of polymers used in contaminant containment. This study compares the barrier performance of poly(vinyl alcohol) (PVA) membranes containing single-walled carbon nanotubes (SWCNTs) to that for PVA containing powdered activated carbon (PAC). Raw and surface-functionalized versions of each sorbent were tested for their abilities to adsorb 1,2,4-trichlorobenzene and Cu2+, representing the important hydrophobic organic and heavy metal contaminant classes, as they diffused across the PVA. In both cases, PAC (for 1,2,4-trichlorobenzene) and functionalized PAC (for Cu2+) outperformed SWCNTs on a per mass basis by trapping more of the contaminants within the barrier membrane. Kinetics of sorption are important in evaluating barrier properties, and poor performance of SWCNT-containing membranes as 1,2,4-TCB barriers is attributed to kinetic limitations.
Bibliographical noteFunding Information:
This work was primarily supported by a Doctoral Dissertation Fellowship awarded to E.M.S. by the Graduate School of the University of Minnesota. Ancillary support came from the Cooperative Institute for Coastal and Estuarine Environmental Technology (CICEET) and the National Science Foundation . We also thank the research group of Professor Andreas Stein for providing training and access to their sonicator, the University of South Carolina Electron Microscopy Center for instrument use and technical assistance, the reviewers for their constructive comments, and Professor Edward Cussler for valuable discussions.
- Activated carbon
- Barrier membrane
- Carbon nanotubes
- Landfill liner
- Sediment cap