Closure systems for personnel protection applications, such as protective clothing or respirator face seals, should provide effective permeation barrier to toxic gases. Currently available mechanical closure systems based on the hook and loop types (example, Velcro) do not provide adequate barrier to gas permeation. To achieve hermetic sealing, we propose a nonmechanical, nanoscopic molecular c...

A simplified procedure for the identification and measurement of single-ring aromatic products of lignin acidolysis is described. The procedure employed a 6-h hydrolysis of spruce milled wood lignin in acidic dioxane at 87 degrees C, followed by a series of organic extractions to recover acidolysis products which were quantified by gas chromatography of trimethylsilyl derivatives. Complex gel p...

Until now, the leading polymer of intrinsic microporosity PIM-1 has become quite famous for its high membrane permeability for many gases in gas separation, linked, however, to a rather moderate selectivity. The combination with the hydrophilic and low permeable poly(ethylene glycol) (PEG) and poly(ethylene oxides) (PEO) should on the one hand reduce permeability, while on the other hand enhanc...

The aim of this study was to measure permeation of the herbicide dichlobenil in Casoron 4G through disposable and chemically protective nitrile gloves using an American Society for Testing and Materials-type permeation cell and a closed-loop system employing two different solvents (hexane and water) and two different challenge situations (aqueous emulsion and solid formulation). Capillary gas c...

The absorption and permeation of hydrogen in metals occurs in a variety of technological processes and systems, and in some cases the results are extremely detrimental (e. g., hydrogen embrittlement, stress corrosion, degradation of electrical and magnetic properties, undesired loss (or gain) of hydrogen, etc.). In an increasing number of applications the hydrogen pressure, p, is extremely low,...

ZIF-8 films were successfully prepared on a flexible nylon substrate with a contra-diffusion synthesis method, and gas permeation experiments indicated that the films were continuous and compact.

In this work heat and mass transfer in tubular asymmetric ceramic membranes suitable for applications in membrane reactors have been investigated. An experimental matrix has been employed to quantify the heat and mass transfer in the membrane, which leads to the identification and validation of respective parameters in a comprehensive and consistent manner. Two types of membranes have been inve...

Hydrogen permeation membranes are a key element in improving the energy conversion efficiency and decreasing the greenhouse gas emissions from energy generation. The scientific community faces the challenge of identifying and optimizing stable and effective ceramic materials for H2 separation membranes at elevated temperature (400-800 °C) for industrial separations and intensified catalytic rea...