Selective Transport of Aromatic Molecules across Ultrathin Separation Membranes of p-Sulfonato-calix[n]arenas and Cationic Polyelectrolytes

Abstract

Ultrathin separation membranes were prepared upon alternate electro-static layer-by-layer (lbl) adsorption of anionic p-sulfonatocalix-[arenes (calix8 and calix6) and cationic Polyvinylamine (PVA) polyelectrolytes on porous polyacrylonitrile/polyethylene terephthalate (PAN/PET) substrates. The permeation rates (PR) of a variety of neutral and charged aromatic compounds across calix8/PVA and calix6/PVA membranes are investigated. The solutes were aniline (An), phenol (Ph), naphthalene (Np), alkali metal salts of benzene sulfonate (BS), naphthalene 2-sulfonate (NS) and benzene disulfonate (1, 3-BDS). For the neutral compounds, a size-selective transport was found. For charged aromatic compounds, the transport was both size-and charge-selective. Size and charge-selectivity lead to a separation factor α (Ph/1, 3-BDS) of 333.