Elemental analysis was performed for the palladium foil through which the hydrogen gas penetrated. We analyzed sample surface by Time-of-Flight secondary ion mass spectroscopy and searched for newly produced elements during the gas permeation process. Significant increase of the counts for Cr, Fe, Cu and Ag were found after the permeation. These elements could have been produced by nuclear tran...

In this work a new resistance model has been presented based on that of Henis-Tripodi which can be used for interpretation of gas permeation data in composite and asymmetric membranes. In contrast to the previous works, in this model the fraction of the support layer surface that includes the pores filled with coating material has been taken into account. The influences of the filled pores on s...

Membranes offer remarkable attributes such as possessing small equipment footprints, having high efficiency and are environmentally friendly, with carbon membranes progressively investigated for gas separation applications. In this study, carbon tubular membranes for CO2 separationare prepared via the dip-coating method with P84 co-polyimide as the carbon precursor. The prepared membranes were ...

A theoretical model of gas permeation in polydimethylsiloxane (PDMS) is conducted for two prior works involving MEMS sensors and actuators. The issue for modeling a sensor is about using PDMS slabs to replace Pyrex glass as the packaging substrate for bulk-micromachined pressure sensors. The leakage pressure due to gas permeation in PDMS reveals the time-varying behavior of exponential decay. T...

Permeation tubes are convenient analyte sources for generating standard gas mixtures (containing, in particular, volatile organic compounds) used in the calibration of analytical instruments. For small permeation rates, corresponding to trace levels of analytes, the calibration of permeation tubes is time-consuming. The use of thermogravimetry as a means to measure rapidly the weight loss at co...

Using of nanocomposite membranes composed of polymer and inorganic nanoparticles is a novel method to enhance gas separation performance. In this study, membranes were fabricated from polyester (PE) containing silica (SiO2) nanoparticles and gas permeation properties of the resulting membranes were investigated. Morphology of the membranes, SiO2 distribution a...

Palladium doped silica membranes were synthesized by the sol-gel method using two different procedures. The first palladium-doped silica membrane (M1) was synthesized with a coating of four layers of silica-palladium sol. The second membrane (M2) was synthesized with a coating of two silica layers followed by a coating of two silica-palladium layers. Scanning electron microscopy (SEM) proved th...

As kerogen is the main organic component in shale, the adsorption capacity, diffusion and permeability of the gas in kerogen plays an important role in shale gas production. Based on the molecular model of type II kerogen, an organic nanoporous structure was established. The Grand Canonical Monte Carlo (GCMC) and Molecular Dynamics (MD) methods were used to study the adsorption and diffusion ca...

The novel concept of a microfluidic chip with an integrated three-dimensional fractal geometry with nanopores, acting as a gas transport membrane, is presented. The method of engineering the 3D fractal structure is based on a combination of anisotropic etching of silicon and corner lithography. The permeation of oxygen and carbon dioxide through the fractal membrane is measured and validated th...