Professor James Economy's Group
Advanced Membranes for Desalination and Wastewater Treatment
The objective of this project is to develop low fouling, cost effective, durable reverse osmosis (RO) and nanofiltration (NF) membranes for desalination and wastewater treatment which greatly outperform current state-of-the-art RO and NF membranes. We are currently preparing and screening a series of new membrane materials including aromatic liquid crystalline, non-liquid crystalline thermosetting polyesters, hyperbranched poly(imide-ester)s and poly(imide-silsesquioxane)s, hyperbranched aromatic poly(amide-silsesquioxane)s and poly(amide-urea)s, cross-linked functional poly(etheretherketone)s, selected high temperature polymers including polyquinoline, polyquinoxaline, polybenzthiazole, polybenzoxazole, polybenzimidazole, and ladder polymers based on some of these structures, etc. These membrane materials will be used to develop dense and thin-film composite (TFC) membranes. At the same time we will determine the efficiency of such membranes for desalination and wastewater treatment. The most promising systems will be modified further to control the membrane properties. A variation on the above theme will involve taking advantage of work currently underway in the microelectronics industry to prepare dielectric films with closed micropores to determine any possible advantages to that kind of morphology.
Thin-film composite membranes as shown above for desalination will be developed by spin-coating or dip-coating the as-synthesized materials (material A) on the surface of the porous support (material B) such as polysulfone or ceramic membrane.
Evaluation of the prepared membranes for desalination will be carried out using the above filtration cell housing. The membrane will be placed on a support screen and sealed in filter holder using an O-ring assembly. This filtration cell will be used for initial proof-of-concept demonstrations and will be incorporated into an in-house built system.
Activated Microporous Membranes
These membranes will have continuous pore structures on the order of 10 angstroms with carefully controlled pore chemistry (acidic vs. basic character) analogous to activated carbon materials currently produced by this group. When pore size and surface chemistry is optimized this should allow polar water molecules to pass but not ionic molecules. It is believed that this technology will compete with reveres osmosis (RO) membranes for desalination and microporous membranes for other water purification applications such as organics removal. These activated membranes should have numerous advantages over RO such as lowered pressure drop, increased flow rate, greater strength and fouling resistance.