Clean drinking water is necessary to human life and secures a reasonable standard of living for populations. Current fresh water supplies are under great pressure with increasing demand and decreasing supply. Oceans and wastewater are excellent candidates for new water supplies. Available osmotic processes have great potential for effective water recovery. However, current commercially available polyamide membranes degrade quickly with exposure to chlorine.
This presentation will focus on a new design of mixed matrix membranes with high chemical resistance and high rejection for small molecules . In our mixed matrix membranes, a liquid-barrier chemical-resistant polymer matrix binds a layer of selective molecular sieve particles into a versatile composite film.
The main distinguishing characteristics of our new membrane design compared with current mixed matrix membranes include: (1) we use an impermeable polymer matrix enabling a broader range of chemical resistant polymers; (2) we use latex dispersions as the polymer matrix source. Latexes are environmentally friendly water based-solutions, sharing the qualities of low volatile organic compound (VOC), low cost, and non- toxicity.
We anchored 500–600 nm diameter zeolite particles on porous alumina supports by using silane covalent linkers to prevent forming an impermeable polymer layer between the molecular sieves particles and porous substrates. Then, we formed 400-500 μm thick PVDC films via dip-coating onto the substrate with the anchored molecular sieves. Next, we performed oxygen plasma to remove impermeable PVDC film from the surfaces of the molecular sieves. We report on flux and sodium chloride rejection of brackish water at 24 °C. We also will present a variety of characterizations of mixed matrix membrane morphology.