(244f) Pnipam Functionalized Temperature Responsive Membranes and Pollutant Adsorption

Authors: 
Saad, A., University of Kentucky
Wan, H., University of Kentucky
Bhattacharyya, D., University of Kentucky
This study is aimed at evaluating the effect of temperature on the degradation of chlorinated organics in water streams. PVDF microfiltration membranes are functionalized with poly-N-isopropylacrylamide (PNIPAm), and its temperature responsive behavior is studied as it relates to water flux and partitioning of toxic pollutants. Effective pore size can be predicted based on the swelling extent of the temperature-responsive PNIPAm polymer around its LCST. PNIPAm is known to show a sharp transition to a hydrophobic state at its lower critical solution temperature (LCST) at around 32oC, making PNIPAM attractive for industrial applications. The entrapment of reactive Fe/Pd nanoparticles in a poly-acrylic acid (PAA) polymer domain has been reported for the effective degradation of chlorinated organic compounds. The NPs are also entrapped in the temperature responsive PNIPAm-co-PAA polymer network for dechlorination and contaminant degradation of PCBs and TCEs. This study aims to evaluate PCB and TCE degradation by reactive immobilized nanoparticles in a PNIPAm functionalized PVDF MF membrane. The ability of PNIPAm particles to selectively adsorb various contaminants, specifically PCBs, TCEs, and PFOA, at various temperatures is also studied, as well as adsorption kinetics and ability to desorb through temperature changes. Increasing the surrounding temperature affects inter-particle spacing, solute adsorption and diffusion because of the changing PNIPAm conformation, as well as the intrinsic rate constant for the reaction. These effects are predicted, and studied by experimental degradation results. This research is supported by the NIEHS-SRP grant P42ES007380, and by the NSF KY EPSCOR program. Full-scale PVDF membranes were developed through collaborative work with Nanostone-Sepro (Oceanside, CA, USA).