Graphene oxide membranes with narrow inter-sheet galleries for enhanced hydrogen separation.

This paper reports synthesis of graphene oxide (GO) membranes with narrow interlayer free spacing on scalable polyester substrates using GO sheets prepared by Brodie's method. The GO membranes show interlayer free spacing of ∼3.2 Šwith significantly improved hydrogen perm-selectivity than the GO membranes with the large inter-sheet spacing reported in literature.

Template-Free Synthesis of Highly b-Oriented MFI-Type Zeolite Thin Films by Seeded Secondary Growth.

Highly b-oriented, closely packed, MFI zeolite films are prepared on seeded stainless-steel plates using organic template-free, secondary growth solutions, containing aluminum sulfate as a crystallization agent. The number of a-oriented twin crystals is significantly reduced, and even eliminated, simply by restricting the pH value of the secondary growth solution to the narrow range of 11.1-11.3. Values of pH can be adjusted through the controlled addition of (NH4 )2 SO4 or H2 SO4 to secondary growth solutions of the composition (1 SiO2 :0.57 NaOH:137.5 H2 O:0.0050 (Al2 (SO4 )3 ⋅18 H2 O)) or by simply decreasing the molar composition of NaOH with no extra additives.