BACKGROUND
Only a few studies were reported on the ALD modified inorganic membranes for desalination. Alam et al. grew TiO2 ALD on polyethersulphone (PES) membrane. It was shown that the TiO2-film deposited PES membrane exhibited >90% NaCl rejection (4 times higher than uncoated membranes) in a pressurized desalination at feed pressure of 8 atm and room temperature. However, deposition of TiO2 resulted in marginal decrease in water flux from 60 to 47 L m-2 h-1 because of pore size reduction caused by nanolayer deposition. Song et al. used molecular layer deposition (MLD) as a novel and highly controllable method to prepare TiO2 nanofiltration membranes with ~1nm pore size for water purification. Membrane pre sizes were controlled by number of deposition cycles and precursor species. Optimized TiO2 nanofiltration membrane had water permeability of ~40 L m-2 h-1 for pressurized desalination. Membrane showed moderate rejection for Na2SO4 (43%), and MgSO4 (35%) and high rejection of methylene blue (96%).
SUMMARY OF TECHNOLOGY
The proposed invention is an inorganic membranes for the efficient desalination. ZnO was deposited on alumina membrane via atomic layer deposition (ALD) which helped in enhancing the hydrophilicity of the membrane. A vacuum-assisted ‘flow-through’ evaporation method was used for testing membranes. Membrane exhibited exceptional purification performance with excellent salt rejection rate (>99.9%) with maintaining high water flux (~170 m-2 h-1
POTENTIAL AREAS OF APPLICATION
MAIN ADVANTAGES
STAGE OF DEVELOPMENT