The concept of splayed, hyperthin polyelectrolyte multilayers (PEMs) is introduced in which a bulky, hydrophilic and charged pendant group is used to increase the gas permeability of a PEM without reducing its permeation selectivity. Proof of principle studies are reported using nm-thick PEMs made from poly(sodium 4-styrene sulfonate) () and poly(allylamine hydrochloride) () bearing bulky cobal...

This work continues the development of a numerical model to simulate transient tritium transport on breeder zone (BZ) level for EU helium-cooled pebble bed (HCPB) concept DEMO. The basis is open-source field operation and manipulation framework, OpenFOAM. key output quantities are concentration in purge gas coolant inventory inside BZ structure. New features briefly summarized. As first relevan...

Membranes are attractive for upgrading natural gas; however, the gas permeation processes through membranes challenging to control. The coexistence of condensable H2S and CO2 typically causes membrane performance decline under practical feed conditions, due uncontrolled penetrant competition undesired plasticization polymer matrix. In this paper, we report a strategy successfully transform thes...

The time-lag method, using a gas permeation experiment, is currently the most popular method for determining the membrane properties: diffusivity coefcient and permeability coefcient, and from which the solubility coefcient can be calculated. In this investigation, the impact of systematic, random (noise), resolution and extrapolation errors associated with gas permeatio...

Nitrogen is very difficult to remove from natural gas. Most specifications require no more than 4% nitrogen or total inerts in the interstate pipeline system. With about 15% of the raw natural gas produced in the United States having nitrogen contents over 4%, technology is needed to economically bring the gas to pipeline quality. Cryogenic distillation, the current state-of-the-art technology,...

of a paper to be present at the March 2004 meeting of American Physical Society. These abstracts can be seen at the APS web site: http://www.eps.org/aps/meet/MAR03/baps/abs/S9530.html 28) J.Bockris “Early Contributions From Workers at Texas A&M University to (So-Caled) Low Energy Nuclear Reactions.”Journal of New Energy, Vol 4, no 2, 1999, p. 40 29) J. Bockris, G. Lin, and N. Packham " A Review...

The liquid-phase epitaxy (LPE) method was effectively implemented to deliberately grow/construct ultrathin (0.5-1 μm) continuous and defect-free ZIF-8 membranes. Permeation properties of different gas pair systems (O2-N2, H2-CO2, CO2-CH4, C3H6-C3H8, CH4-n-C4H10) were studied using the time lag technique.

Water transport through gas diffusion layer of proton exchange membrane fuels cells is investigated experimentally. A filtration cell is designed and the permeation threshold and the apparent water permeability of several carbon papers are investigated. Similar carbon paper with different thicknesses and vailable online 26 February 2011

Headed for a membrane: Continuous, polycrystalline ZIF-90 membranes (picture, left) can be grown at 65 °C from methanolic precursor solutions on nanocrystal-seeded surfaces of poly(amide-imide) macroporous hollow fibers (right). The ZIF-90 membranes exhibit good separation properties for linear over cyclic hydrocarbons, as well as gas permeation selectivities higher than Knudsen values.

Swift heavy ion irradiation produces damage in polymers in the form of latent tracks. Latent tracks can be enlarged by etching it in a suitable etchant and thus nuclear track etch membrane can be formed for gas permeation / purification in particular for hydrogen where the molecular size is very small. By applying suitable and controlled etching conditions well defined tracks can be formed for ...