V. Smuleac

Nanostructured Membranes for Enzyme Catalysis and Green Synthesis of Nanoparticles

Macroporous membranes functionalized with ionizable macromolecules provide promising applications in high capacity toxic metal capture, nanoparticle syntheses, and catalysis. Our low-pressure membrane approach has good reaction and separation selectivities, which are tunable by varying pH, ionic strength, or pressure. The sustainable green chemistry approach under ambient conditions and the evaluation of a reactive poly(acrylic acid) (PAA)-modified polyvinylidene fluoride (PVDF) membrane is described. Two distinct membrane types were obtained through different methods: 1) a stacked membrane through layer-by-layer assembly for the incorporation of enzymes (catalase and glucose oxidase), providing tunable product yields and 2) Fe/Pd nanoparticles for degradation of pollutants, obtained through an in situ green synthesis. Bioreactor-nanodomain interactions and mixed matrix nanocomposite membranes provide remarkable versatility compared to conventional membranes.

Functionalized Membranes for Sorption, Separation, and Reaction: An Overview

Functionalized membrane processes are finding wide applications ranging from water treatment to reactors to advanced bioseparations. In this chapter, applications of functionalized membranes in the area of sorption, separation, and reaction are discussed with specific examples. Selected examples for sorption applications include ethoxylated nonionic surfactants sorption from hydrophobic solvent and metal sorption from aqueous solutions. Membranes functionalized with either single layer or layer-by-layer assembly of charged polyelectrolytes have been discussed for separation applications of various ionic and neutral solutes. Charge-based ion exclusion with highly open geometries and high permeabilities is a distinct advantage of the ionizable polyelectrolyte functionalized membranes. Applications of functionalized membranes in the area of reaction by providing alternative support for catalyst immobilization are discussed with reference to catalytic dechlorination of chloro-organics. It was demonstrated that in situ formation of membrane immobilized structured bimetallic nanoparticles offers an efficient way for complete dechlorination of toxic chloro-organics at room temperature.