(87e) Dispersion of Magnesium Hydroxide/Zeolite Nanostructures in Polymers

Zeolite / metal oxide nanocomposites have attracted attention because of their potential application in catalysis, gas sensing, ion exchange media, electrochemical capacitors, and adsorbents. It has been shown that polymer membranes with dispersed magnesium hydroxide/zeolite 4A nanocomposites exhibit enhanced gas-barrier performance for the separation of CO2 and CH4. The performance of the membrane, however, depends on improved adhesion between the zeolite and the organic polymer. We have deposited magnesium hydroxide nanopetals on zeolite 4A surfaces from an aqueous solution of magnesium chloride and ammonia at ambient conditions, and prepared membranes by dispersing these nanocomposites in polymers. We have also determined that Mg(OH)2 crystals do not adsorb on silanol or aluminol sites on the zeolite 4A surface, but instead interact with the bridging hydroxyl protons (SiOHAl). This was confirmed by adsorption experiments, FTIR spectra, and solid state 1H, 29Si, and 27Al NMR analyses. The performance of Mg(OH)2/zeolite/polymer membranes has been evaluated.