A sol-gel method was applied for the development of highly permeable hydrogen separation membranes using bis(triethoxysilyl)ethane (BTESE) as a silica precursor. Hybrid showed quite high permeance (1 x 10(-5) mol m(-2) s(-1) Pa(-1)) with H(2)-to-SF(6) selectivity 1000 because loose organic-inorganic networks. were found to show hydrothermal stability due presence Si-C-C-Si bonds in

Abstract DDR‐type zeolite membranes were prepared by the secondary growth method on porous α‐alumina disk, followed on‐stream counter diffusion chemical vapor deposition modification to eliminate intercrystalline micropores. Single gas permeation of He, H 2 , CO and through this membrane before after CVD was measured in 25–500°C. Intracrystalline diffusivities for these four gases obtained from data above 300°C examine effects size molecular weight permeating rate membrane. For unmodified...

Abstract Organic/inorganic hybrid silica membranes were prepared from 1,1,3,3‐tetraethoxy‐1,3‐dimethyl disiloxane (TEDMDS) by the sol‐gel technique with firing at 300–550°C in N 2 . TEDMDS‐derived showed high H permeance (0.3–1.1 × 10 −6 mol m −2 s −1 Pa ) low /N (∼10) and /SF 6 (∼1200) perm‐selectivity, confirming successful tuning of micropore sizes larger than TEOS‐derived membranes. 550°C increased gas permeances as well pore after air exposure 450°C. TEDMDS had an advantage size...

Hybrid organically bridged silica membranes have attracted considerable attention because of their high performances in a variety applications. Development robust reverse osmosis (RO) to withstand aggressive operating conditions is still major challenge. Here, new type microporous organosilica membrane has been developed and applied osmosis. Sol-gel derived RO reject isopropanol with rejection higher than 95%, demonstrating superior molecular sieving ability for neutral solutes low weight....

Abstract Silica and cobalt‐doped silica membranes that showed a high permeance of 1.8 × 10 −7 mol m −2 s −1 Pa H 2 /N ratio ∼730, with excellent hydrothermal stability under steam pressure 300 kPa, were successfully prepared. The permeation mechanism gas molecules, focusing particularly on hydrogen water vapor, was investigated in the 300–500°C range is discussed based activation energy selectivity gaseous molecules. correlated well He/H for porous prepared by sol–gel processing, chemical...

The general mechanisms of gas separation in microporous inorganic membranes are reviewed this article. Emphasis has been placed on discussing the requirements membrane pore structure and material properties for high temperature hydrogen from other small gases involved processes production fossil fuels. recent research progresses developing crystalline zeolite membranes, amorphous silica-based critically reviewed. fundamental issues associated with silica relevant to practical applications...

Bis(triethoxysilyl)methane (BTESM), which consists of Si–C–Si bonds, was used as a membrane precursor to control the size amorphous silica networks. The single gas permeation characteristics hybrid membranes were examined determine effect precursors on Pore distribution, determined by permeation, suggested that average pore in following order: bis(triethoxysilyl)ethane (BTESE)-derived > BTESM-derived tetraethoxysilane (TEOS)-derived silica, due differences minimum units precursor. high...

MFI-type zeolite membranes were prepared by the template-free secondary growth method followed onstream counter-diffusion or one-side chemical vapor deposition (CVD) modification to eliminate intercrystalline pores. Gas permeation and separation experiments conducted on unmodified modified at 25−500 °C. For membranes, single-gas of H2, He, CO, CO2 exhibits characteristics Knudsen diffusion up 500 °C, adsorption has a strong effect ternary gas (H2, CO2) below 300 Counter-diffusion CVD is...

Catalytic decomposition of NH 3 with H 2 ‐selective microporous silica membranes for CO x ‐free hydrogen production was studied theoretically and experimentally. The simulation study shows that conversion, yield purity increase the Damköhler number ( Da ), their improvement is affected by effect extraction as well N permeation through membranes. experimental carried out in a bimodal catalytic membrane reactor BCMR consisting support layer. showed permeances 6.2–9.8 × 10 −7 mol m −2 s −1 Pa ,...

Microporous organosilica membranes with ethane, ethylene, and acetylene bridges have been developed the extensive microstructural characterization has discussed in relation separation properties of membrane. The network structure membrane performances can be controlled by adjusting flexibility, size, electronic bridging groups. A relatively narrow size distribution was obtained for novel acetylene-bridged sol optimizing synthesis. Incorporation larger rigid into networks resulted a looser...

Organosilica membranes were fabricated using bridged organoalkoxysilanes (bis(triethoxysilyl)methane (BTESM), bis(triethoxysilyl)ethane (BTESE), bis(triethoxysilyl)propane (BTESP), bis(trimethoxysilyl)hexane (BTMSH), bis(triethoxysilyl)benzene (BTESB), and bis(triethoxysilyl)octane (BTESO)) to produce highly permeable molecular sieving membranes. The effect of the on network pore size microporous structure was evaluated by examining temperature dependence gas permeance across a wide range...

We investigated the previously unexplored domain of water vapor/gas separation using graphene oxide (GO) membranes, expecting future applications, including gas dehumidifiers and superior humidity controllers. While importance manipulation GO nanosheet size surface chemistry in traditional purification has been acknowledged, their potential impact on remained until now. applied sonication hydrogen peroxide treatments to dispersions systematically evaluated each nanosheet. Both reduced...

Abstract A sol–gel method was applied for the preparation of silica membranes with different average pore sizes. Ammonia (NH 3 ) permeation/separation characteristics were examined in a wide temperature range (50–400°C) by measurement both single and binary component separation. The order gas permeance through membranes, which independent membrane size, as follows: He > H 2 NH N . These results suggest that, permeation molecular size is larger than that , despite previous reports kinetic...