Thermoresponsive PNIPAm-PMMA-Functionalized PVDF Membranes with Reactive Fe-Pd Nanoparticles for PCB Degradation

Fe-Pd nanoparticles are immobilized in stimuli-responsive poly-N-isopropylacrylamide (PNIPAm)- and poly-methyl methacrylate-functionalized polyvinylidene fluoride membranes using ion exchange for 2-chlorobiphenyl (PCB-1) degradation via the reductive pathway. PNIPAm is introduced into the reactive membrane system, and its thermoresponsive behavior is leveraged to enhance PCB-1 diffusion and adsorption into the reactive domain. The surface area-normalized rate constant (k(SA)) values were determined in the convective flow mode to be 0.13, 0.28, 0.72, and 1.36 L/m(2)/g at 15, 25, 35, and 45 degrees C, respectively, with an activation energy of 60 kJ/mol (3 wt % Pd). The diffusion coefficients for PCB-1 were 6.6 x 10(-11) and 8.7 x 10(-11) m(2)/s at 25 and 35 degrees C, respectively. The adsorption of PCB-1 onto PNIPAm hydrogels also increased from 40 to 70% as the temperature was increased above its lower critical solution temperature of 32 degrees C. The batch-mode kSA values were 0.12 L/m(2)/h at 25 degrees C and 0.35 L/m(2)/h at 35 degrees C.