Streaming potential characterization of LBL membranes on porous ceramic supports



An in-situ characterization of the growth of the self-assembled polyelectrolyte membranes on the porous support was conducted by applying transmembrane streaming potential measurement via surface charge monitoring. The membranes were prepared by layer-by-layer alternative deposition of poly (allylamine hydrochloride) and poly (styrenesulfonate) on porous ceramic supports. The surface charge variations of membranes as functions of different top-assembled materials and numbers of deposited cycles were investigated. Different top-assembled materials make isoelectric points of the as-prepared membranes drift in opposite directions and also lead to symmetrical signal changes of zeta-potential in salt solutions at the isoelectric points of the supports. Ex-situ characterizations, including scanning electron microscopy, atomic force microscopy, and energy dispersive X-ray spectroscopy, also confirm the alternative deposition of polyelectrolytes. It is demonstrated that the transmembrane streaming potential measurement is effective in studying the growth of layer-by-layer membranes on porous support. © 2007 American Institute of Chemical Engineers AIChE J, 2007