(541a) Preparation and Characterization of Functional Polyamide RO Membrane Via Spin Assisted Layer-By-Layer Assembly

Layer by layer assembly is an attractive method for preparing ultrathin layer of composite membranes. In this work, spin assisted layer by layer (SA-LbL) assembly was used to prepare and modify polyamide membranes for water desalination. The polyamide membranes was prepared by two methods:1) conventional Interfacial polymerization of MPD and TMC, 2) Spin assisted layer by layer of MPD and TMC. The prepared membranes were functionalized by two different sets of poly-electrolytes: Poly (ethylene imine) (PEI)/ poly (allylamine hydrochloride) (PAH), poly sodium styrene sulfonate (PSS)/Poly(acrylic acid) (PAA). Membrane characterization will be performed using atomic force microscope (AFM), Scanning Electron microscopy (SEM), Fourier transform infra-red (FTIR), and contact angle. It was found that the thickness of the membranes prepared by conventional interfacial polymerization is larger than that prepared by SA-LbL. On the other hand, functionalized membranes were found to have lower roughness and higher hydrophilicity. A model was developed to describe the effect of number of layers, polyelectrolyte concentration, and pH on contact angle, roughness, and membrane thickness via statistical models derived from the design of experiment.

Membrane performance is currently being investigated to assess the permeabilty, salt rejection, and fouling behavior under brackish water conditions.