Lay-by-Layer Assembled Membranes on a Hollow Fiber Porous Support
Over the past decade the versatile layer-by-layer (LbL) assembly method has been widely used for assembling organic or organic/inorganic hybrid thin film. Till now, such films are typically prepared by the consecutive deposition of oppositely charged polyelectrolytes (PEs) from bulk solutions onto a planar or tubular solid support. Few works have dealt with the assembly of PEs on a porous hollow fiber support. In this work, a dynamic LbL adsorption technique was proposed to accomplish the assembly of PEs on the inner surface of hollow fibers. The assembly process was successfully accomplished by alternatively dynamically filtrating polyacrylic acid (PAA) and polyethyleneimine (PEI) on a hydrolyzed hollow fiber polyacrylonitrile (PAN) membrane under a negative pressure condition. The influences of dynamic conditions, such as bilayer number, negative pressure and recycling velocity, packing density, fiber length on the formation of non-porous selective layer and pervporation performance were investigated.
