Porous polymer monolith templated by small polymer molecules

Porous poly(ethylene glycol) diacrylate (PEGDA) monoliths have been prepared by UV‐initiated polymerization of PEGDA oligomer (M_n = 700 g/mol). In the mean time, the addition of hydrophobic poly(propylene oxide) (PPO, M_n = 725 g/mol) as porogen into an ethanol solution of PEGDA oligomer to form a homogenous mixture, causes a phase separation between PPO and PEGDA following removal of ethanol by UV heating. Porous PEGDA monolith was prepared by immediate heating at 300°C to remove PPO molecules from the as‐synthesized PEGDA/PPO hybrid. The micrometer pores of the PEGDA monolith have relatively concentrated pore size distribution according to the mercury intrusion porosimetry results and field emission scanning electron microscopy (FE‐SEM).     

Einsatz von perowskitischen Hohlfasermembranen in einem Mikrowellenplasma

For the first time the combination of a separation process with a plasma process was successfully tested. In this case, a mixed‐conducting perovskite membrane separates the oxygen. At 1 kW a permeation of 2.24 mL min^?1cm^?2 could be achieved. Corresponding perovskite membranes have been manufactured as hollow fibers with a very good CO₂ stability. The hollow fibers showed a constant permeation over more than 200 h. Furthermore, a spinning process with a sulphur‐free polymer binder has been established.     

Liquid chromatography/quadrupole ion trap/time-of-flight determination of the efficacy of drug test kits for rapid screening of food

The goal of this study was to evaluate the plausibility and accuracy of commercially available on-site immunoassay urinalysis kits for the screening of compounds of interest within food matrices. In conjunction with this study, a sensitive, robust, and reproducible analytical method, utilizing solid-phase extraction liquid chromatography/quadrupole ion trap/time-of-flight mass spectrometry for confirmation analysis, was developed. The food matrices analyzed were tomato juice, apple juice, milk, beer, white wine, ground beef, powdered milk, and all-purpose flour. Compounds fortified into the food matrices included heroin, phencyclidine, cocaine, benzoylecgonine, methadone, 2-ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine, imipramine, doxepin, nitrazepam, diazepam, oxazepam, temazepam, alprazolam, flunitrazepam, clonazepam, and lorazepam. Standard curves were prepared for each matrix from 10 to 500 ng/ml for each analyzed compound. All liquid chromatography/tandem mass spectrometry samples were fortified with 20 microl of deuterated internal standard at 90 ng/ml. Quality control standards were prepared at 20 and 400 ng/ml, and > 90% were within 2 SD of the mean for each analyte. The test kits were found to produce up to 85% of the expected results based on concentration levels of adulterants (i-Screen in milk). This study shows that lateral-flow immunoassay test kits are plausible as a rapid, accurate, and reliable screening method in the event of adulteration of the food supply.     

Evaluation of small-scale combustion of an insensitive high explosive formulation containing 3-nitro-1,2,4-triazol-5-one (NTO), 2,4-dinitroanisole (DNAN), and 1,3,5-trinitroperhydro-1,3,5-triazine (RDX)

ABSTRACT

Energetic materials are often disposed by open-burning or open-detonation as it is a cost-effective and efficient means of destroying explosive material, and often minimizes the need to transport hazardous explosives to treatment facilities. This practice is often scrutinized for the negative environmental impact of the odorous and unsightly toxic gaseous emissions as well as the resulting deposition residues, which often contain unburned energetic materials. With the increasing use of Insensitive High Explosive compositions in munitions, it is essential that the potential environmental impact of their disposal is assessed before their extensive use to prevent the kind of contamination incidents experienced with legacy explosives. Therefore, the aim of this work was to develop a controlled laboratory experiment to identify the gaseous emissions and the energetic material residues that are generated through the combustion of the IHE components 3-nitro-1,2,4-triazol-5-one (NTO), 2,4-dinitroanisole (DNAN), and 1,3,5-trinitroperhydro-1,3,5-triazine (RDX). A sealed vial containing small (mg) quantities of energetic material was heated until the energetic material combusted. Gas chromatography/mass spectrometry (GCMS) was used to calculate the oxygen consumption and to identify the gases that were generated. The solid residues were analyzed by high-performance liquid chromatography (HPLC) to quantify unburned energetic material. Results showed that DNAN was the most resistant to burning, thus leaving significant quantities of unreacted starting material in the vial. An interesting observation for the IHE formulation was that DNAN also inhibited the combustion of NTO and RDX. The gases emitted during the open burning of IHE components and mixtures included CO, CO₂, and N₂O as expected, but the proportions differed when the components and mixture were compared, reflecting the influence of DNAN on the burning behavior. From our data, we concluded that open-burning DNAN-based formulations is an environmentally unfavorable waste-management practice for the disposal of IHEs mainly due to generation of solid residues as well as unburnt DNAN.     

High‐Pressure High‐Temperature Transparent Fixed‐Bed Reactor for Operando Gas‐Liquid Reaction Follow‐up

A 3‐MPa, 350 °C fixed‐bed reactor was designed to follow‐up gas‐liquid‐solid reactions on a millimetric size heterogeneous catalyst with Raman spectroscopy. The transparent reactor is a quartz cylinder enclosed in a Joule effect heated stainless‐steel tube. A methodology to determine how to focus the microscope for liquid and solid phase characterization is presented. The setup was validated by performing diesel hydrodesulfurization on a CoMo/alumina extrudate catalyst with a conversion very close to expected values along with the acquisition of Raman spectra of the solid catalyst showing an evolution of the catalyst phase during sulfidation.     

Stress corrosion cracking susceptibility of P285NH and API 5L X65 steel grades in the high-level radioactive waste repository cell concept

Since 2014, the concept developed for the disposal of high-level radioactive waste in the French deep geological repository project Cigéo includes a cement-based grout material. This cement-based grout material will be injected between the casing and the claystone to neutralize the potential acidity resulting from the claystone oxidation induced by the drilling process of the disposal cell. In these conditions of pH (around 10.5) and temperature (90°C, maximum expected during the disposal), the metallic materials could be sensitive to stress corrosion cracking (SCC). In this project, different environments (aerated or deaerated, at room temperature or at 90°C) and synthetic solutions are considered to reproduce the different periods expected during the long life repository. The project is based on electrochemical measurements (polarization curves to define the SCC critical domain of potentials), slow strain rate tensile tests, and long-term immersion for crack initiation and propagation tests.     

Intercomparison exercise of high pressure gas flow test facilities within GERG

Ten of the main European gas Companies decided to carry out the second intercomparison exercise of high pressure test facilities within GERG (Groupe Européen de Recherches Gazières). The survey has compared the performances of 8 high pressure gas flow laboratories in the period autumn 1998–autumn 1999.

The aim was to check to what extent results obtained at the various laboratories are comparable and to reveal possible ways of improving the performances. Tests have been carried out using three transfer standard packages of three different diameters. The considered performance parameters have been: (1) agreement of results between laboratories, (2) short term stability and (3) day to day reproducibility of the reference flow.

The following main conclusions have been drawn:

• The majority of the laboratories involved in the intercomparison produced very accurate results. Despite the involvement of five independent traceability chains, 92.5% of the test results are within a band of ±0.25%.

• For most facilities the short term fluctuations are of the order of ±0.1%. Individual facilities may perform even better.

• This exercise allowed us to confirm the good results of the previous campaign and to identify some items to improve future intercomparisons.