TY - JOUR
T1 - Enhancing the performance of nanofiltration membranes by modifying the active layer with aramide dendrimers
AU - Saenz De Jubera, Ana M.
AU - Gao, Yuan
AU - Moore, Jeffrey S.
AU - Cahill, David G.
AU - Mariñas, Benito J.
PY - 2012/9/4
Y1 - 2012/9/4
N2 - The fully aromatic polyamide active layer of a commercial nanofiltration membrane was modified with three generations (G1, G2, and G3) of aramide dendrimers, all with oligoethylene glycol chains on their peripheries. Permeation experiments revealed that the rejection of Rhodamine WT, used as a surrogate for organic contaminants, improved 1-2 orders of magnitude for membranes modified with G2 and G3 dendrimers at loadings of 0.7-3.5 μg/cm2 (dendrimer layer thicknesses of ∼1-6 nm) compared to the performance of unmodified membranes. In contrast, the corresponding water permeability of dendrimer-modified membranes decreased by only ∼30%. Although an enhancement in the rejection of H3AsO3, NaCl, and BaCl2 was also observed for dendritic membranes, the effect was less pronounced than that for rhodamine WT. Characterization of membranes modified with 3.5 μg/cm2 dendrimers G2 and G3 by Rutherford backscattering spectrometry with the aid of heavy ion probes (Ag+ and Ba2+) revealed that accessibility of the larger Ba2+ probe to carboxylate groups on the active layer decreased for the membranes modified with dendrimers.
AB - The fully aromatic polyamide active layer of a commercial nanofiltration membrane was modified with three generations (G1, G2, and G3) of aramide dendrimers, all with oligoethylene glycol chains on their peripheries. Permeation experiments revealed that the rejection of Rhodamine WT, used as a surrogate for organic contaminants, improved 1-2 orders of magnitude for membranes modified with G2 and G3 dendrimers at loadings of 0.7-3.5 μg/cm2 (dendrimer layer thicknesses of ∼1-6 nm) compared to the performance of unmodified membranes. In contrast, the corresponding water permeability of dendrimer-modified membranes decreased by only ∼30%. Although an enhancement in the rejection of H3AsO3, NaCl, and BaCl2 was also observed for dendritic membranes, the effect was less pronounced than that for rhodamine WT. Characterization of membranes modified with 3.5 μg/cm2 dendrimers G2 and G3 by Rutherford backscattering spectrometry with the aid of heavy ion probes (Ag+ and Ba2+) revealed that accessibility of the larger Ba2+ probe to carboxylate groups on the active layer decreased for the membranes modified with dendrimers.
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U2 - 10.1021/es301392w
DO - 10.1021/es301392w
M3 - Article
C2 - 22831486
AN - SCOPUS:84865725538
SN - 0013-936X
VL - 46
SP - 9592
EP - 9599
JO - Environmental Science and Technology
JF - Environmental Science and Technology
IS - 17
ER -