The formation and growth of a DDR zeolite membrane was developed on the low cost indigenous clayalumina substrate for separation of H 2 from H 2 -CO 2 mixture by selective deposition of oriented seed crystals, followed by secondary growth method with sonication mediated hydrothermal technique. The formation of free radicals by ultrasonic irradiation in the sonochemical method enhances the rate of nucleation which ultimately reduces the DDR zeolite crystallization time. Surface seeding not only accelerates the zeolite crystallization on the support surface but also enhances the formation of an homogenous zeolite membrane layer. The DDR seeds were synthesized by a sonication mediated hydrothermal technique within a short crystallization time i.e. 2 days and used to provide nucleation for the membrane growth. Accordingly DDR zeolite membranes were synthesized on seeded substrate within 5 days. The membrane thickness was found to be $26 mm. The synthesized membranes along with seed crystals were characterized by XRD, FTIR, FESEM and EDAX analysis. The performance of the membrane formed was evaluated by single gas as well as mixture gas permeation measurement for H 2 and CO 2 . The H 2 -CO 2 separation selectivity of the membrane increased up to 3.7 at room temperature which is more than the reported values. To the best of our knowledge, there is no report on the synthesis of a DDR zeolite membrane within 7 (2 days for seed crystal and 5 days for membrane synthesis) days by a secondary growth technique.

In this work, DDR zeolites were synthesized by sonochemical method without the application of any heat energy at room temperature. The synthesized zeolites were characterized by X‐ray diffraction (XRD), infrared (IR) spectral analysis, and field‐emission scanning electron microscopy (FESEM). XRD and IR results showed that phase pure DDR zeolite was started to form at room temperature after 24 h of aging and completed the formation after 5 d of aging. The Brunauer–Emmett–Teller (BET) surface area of the powder was found to be 202 m2/g. The FESEM micrograph and elemental analysis showed that desired atomic ratio of the DDR zeolite was obtained after 5 days of synthesis.

In this work, sodium aluminosilicate zeolite powder and membranes were synthesized by ultrasonic irradiation at room temperature using montmorillonite clay as precursor material. For comparison, same zeolite powder and membranes were synthesized at 100 °C also. The synthesized zeolites were characterized by X-ray diffraction (XRD), infrared (IR) spectral analysis, and field-emission scanning electron microscopy (FESEM). XRD and IR results showed that phase pure mainly LTA phase was formed after 15 days of aging at room temperature. By using the zeolite powders as seeds, membranes were synthesized on clay alumina support tubes at room temperature and also at 100 °C. In both the cases membranes were formed on support surface. The membrane thickness was found to be 15 μm. The performances of the membranes were evaluated by single gas as well as mixture gas permeation measurement for H-CO and CO-CH respectively. The H-CO and CO-CH separation selectivity for the mixture gas of the membrane was found to 16.2 and 20.9 at room temperature respectively. To the best of our knowledge, there is no report of synthesis of zeolite membrane at room temperature using clay as raw materials. For the first time we have reported the synthesis of alumino-silicate zeolite membrane on clay alumina support surface using clay as starting material by sonochemical method at room temperature.

A simple method of pore modification complied with defect removal polymer zeolite mixed matrix membrane was developed by in situ carbon (C) deposition. The C deposition was achieved by the controlled decomposition of polymer matrix by heat treatment. In this study, polyetherimide/silicoaluminophosphate‐34 mixed matrix membrane (MMM) was fabricated on clay‐alumina support tube, followed by carbonization of the polymer matrix for gas separation application. MMM without heat treatment were also synthesized for comparison by conventional method. The membranes were characterized by X‐ray diffraction, field emission scanning electron microscopy, and X‐ray photoelectron spectroscopy. Due to carbonization, in situ C nanoparticles were deposited in to the interfacial pores, and filler particles were oriented in preferable direction. The presence of CO, CN, and graphitic carbon in the matrix, may be an indication of partial carbonization and restoration of adherence of polymer with substrate. The separation factor for CO2/CH4 achieved 39.15 with a permeance value of 23.01 × 10−8mol/(m2 s Pa) for CO2 at 30 °C and 200 kPa feed pressure. For the first time, this work shows an improvement toward permeability of MMM by simple carbonization of polymer matrix with commendable values as compare to the reported literature. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 45508.

In this work, the high-quality ilmenite (FeTiO 3 ) membranes were grown on the clay-Al 2 O 3 support tube from microemulsion-derived FeTiO 3 powders by dip-coating method. FeTiO 3 powders were synthesized by reverse microemulsion method, using cyclohexane, Tween-80, Brij 30, Triton X-100, and n-butanol at different composition. The membranes as well as powders were finally characterized by removal of red dye from a simulated wastewater of textile industry in same conditions. The membrane separation process demonstrates the removal of dye coupled with permeation of water simultaneously, and the overall process may have great potential for wide industrial application.