Carbon nanotube immobilized polar membranes for enhanced extraction of polar analytes

We demonstrate for the first time that carbon nanotubes (CNTs) can be readily immobilized on the surface of a solid polymeric membrane which can lead to enhanced enrichment factor and extraction efficiency. The effectiveness of the CNT mediated process is demonstrated by micro-scale membrane extraction via direct solvent enrichment of polar and nonpolar organics. The enrichment factor measured as the ratio of concentrations in the acceptor to the donor phases was as high as 282 and the enhancement over the unmodified membrane was as much as 92%. In addition, the solvent retention in the carbon nanotube immobilized membrane (CNIM) increased by as much as 29%. Overall, the CNT incorporation provided enhanced solute transport and thus led to overall performance enhancement.