TY - JOUR
T1 - Nafion-Based Low-Hydration Polyelectrolyte Multilayer Membranes for Enhanced Water Purification
AU - Reurink, Dennis M.
AU - te Brinke, Esra
AU - Achterhuis, Iske
AU - Roesink, Hendrik D. W.
AU - de Vos, Wiebe M.
N1 - ACS deal
PY - 2019/9/13
Y1 - 2019/9/13
N2 - The increase of micropollutant concentration in both surface and groundwater is an emerging concern for the environment and human health. Most of such small organic molecules (medicines, hormones, and plasticizers) enter the environment via our wastewater, because they are not sufficiently removed by the current techniques applied in wastewater treatment plants. A possible solution to remove micropollutants is the usage of polyelectrolyte multilayer (PEM) based membranes. PEM membranes have received a growing interest in the past decade due to their high chemical and physical stability and their high permeability and selectivity. A popular polyelectrolyte pair to make dense PEM membranes with high salt retentions is the combination of poly(allylamine hydrochloride) (PAH) and poly(sodium 4-styrenesulfonate) (PSS). Unfortunately, smaller micropollutants (such as bisphenol A, sulfamethoxazole, naproxen, and bezafibrate) still show significant permeation through this membrane. In this study, for the first time, a single final layer of Nafion is applied on the PEM to increase the density of the PEM membrane. It is shown that when terminating with Nafion, the swelling of the multilayer decreases by 50%. These pronounced changes in layer structure are reflected by changes in membrane performance, such as a lower molecular weight cutoff (MWCO) and an increasing hydraulic membrane resistance. Furthermore, we show that the Nafion content of the multilayer can be increased by constructing a Nafion/PAH multilayer on top of the existing PSS/PAH multilayer, thereby lowering the MWCO. Although hydraulic resistance increases, these PSS/PAH/Nafion-based multilayers show excellent performance in rejecting difficult-to-remove micropollutants that have low molecular weight (200–650 Da) and different charges. Overall, a cocktail of eight small micropollutants can be removed up to 97% by these membranes, allowing strongly enhanced water purification.
AB - The increase of micropollutant concentration in both surface and groundwater is an emerging concern for the environment and human health. Most of such small organic molecules (medicines, hormones, and plasticizers) enter the environment via our wastewater, because they are not sufficiently removed by the current techniques applied in wastewater treatment plants. A possible solution to remove micropollutants is the usage of polyelectrolyte multilayer (PEM) based membranes. PEM membranes have received a growing interest in the past decade due to their high chemical and physical stability and their high permeability and selectivity. A popular polyelectrolyte pair to make dense PEM membranes with high salt retentions is the combination of poly(allylamine hydrochloride) (PAH) and poly(sodium 4-styrenesulfonate) (PSS). Unfortunately, smaller micropollutants (such as bisphenol A, sulfamethoxazole, naproxen, and bezafibrate) still show significant permeation through this membrane. In this study, for the first time, a single final layer of Nafion is applied on the PEM to increase the density of the PEM membrane. It is shown that when terminating with Nafion, the swelling of the multilayer decreases by 50%. These pronounced changes in layer structure are reflected by changes in membrane performance, such as a lower molecular weight cutoff (MWCO) and an increasing hydraulic membrane resistance. Furthermore, we show that the Nafion content of the multilayer can be increased by constructing a Nafion/PAH multilayer on top of the existing PSS/PAH multilayer, thereby lowering the MWCO. Although hydraulic resistance increases, these PSS/PAH/Nafion-based multilayers show excellent performance in rejecting difficult-to-remove micropollutants that have low molecular weight (200–650 Da) and different charges. Overall, a cocktail of eight small micropollutants can be removed up to 97% by these membranes, allowing strongly enhanced water purification.
KW - UT-Hybrid-D
KW - nanofiltration
KW - Nafion
KW - swelling
KW - micropollutants
KW - polyelectrolyte multilayers
U2 - 10.1021/acsapm.9b00689
DO - 10.1021/acsapm.9b00689
M3 - Article
SN - 2637-6105
VL - 1
SP - 2543
EP - 2551
JO - ACS Applied Polymer Materials
JF - ACS Applied Polymer Materials
IS - 9
ER -
