(Invited) Nanoporous Membranes by Self-Assembly of “Hairy” Nanoparticles

Abstract

We developed a novel approach to the preparation of nanoporous membranes by the assembly of polymer brush-modified colloidal nanoparticles. Membranes made of uncharged HNPs carrying PHEMA brushes were stable in water, disassembled in organic solvents and could withstand multiple cycles of assemblydisassembly. Their filtration cut-off could be controlled by varying the silica sphere diameter and depends on the polymer brush structure. These membranes can also be recycled and washed from contaminants. Charged HNP membranes containing PSPM-r-PEEMA brushes can be prepared through layered deposition of bare silica and hairy particles. The flux through these membranes responds to the changes in electrolyte concentration. The salt rejection by these membranes is in the moderate to high range (65-80%) and depends on the composition of the polymer brushes and salt concentration.