Electrospun Membrane Adsorbers for Radiochemical Separations

Microfiltration membrane adsorbers are microporous membranes that contain ligands or binding groups which can be used in a multitude of chemical separations. An exciting new area of research is to apply these materials to purify radioactive species for use in emerging radiotherapies for cancer treatment. Radiochemical separations require high throughput and membrane materials that are resistant to strong acids and radiation. A common method for synthesizing membrane adsorbers is to graft functional polymer brushes onto the surface of commercially available ultra- and microfiltration membranes. These commercial membranes, however, do not exhibit acid- and radiation-stability needed for radiochemical separations.

In this work, acid-stable membrane adsorbers are synthesized by electrospinning styrene nanofiber mats. First, a home-built electrospinning apparatus was constructed using a 60 kV power supply, syringe pump, and grounded aluminum plate. The goal of this research is to optimize the electrospinning conditions to synthesize an electrospun membrane with high surface area, porosity, and permeability. Polymer solutions with varying polystyrene content (10-20wt%) were prepared by dissolving polystyrene polymer chip in tetrahydrofuran. The effect of solution conductivity on fiber formation was explored by adding 0.5wt% sodium dodecyl sulfate, sodium chloride or lithium chloride to the polymer solution. Additionally, the applied voltage was varied to observe its effects on fiber formation. Result of this research will lay the groundwork for a new class of radiochromatography materials.