The Mars Organic Molecule Analyzer (MOMA) and Sample Analysis at Mars (SAM) instruments onboard the Exomars 2022 and Mars Science Laboratory rovers, respectively, are capable of organic matter detection and differentiating potentially biogenic from abiotic organics in martian samples. To identify organics, both these instruments utilize pyrolysis-gas chromatography coupled to mass spectrometry, and the thermochemolysis agent tetramethylammonium hydroxide (TMAH) is also used to increase organic volatility. However, the reactivity and efficiency of TMAH thermochemolysis are affected by the presence of calcium perchlorate on the martian surface. In this study, we determined the products of TMAH pyrolysis in the presence and absence of calcium perchlorate at different heating rates (flash pyrolysis and SAM-like ramp pyrolysis with a 35°C$min -1 heating rate). The decomposition mechanism of TMAH pyrolysis in the presence of calcium perchlorate was studied by using stepped pyrolysis. Moreover, the effect of calcium perchlorate (at Mars-relevant concentrations) on the recovery rate of fatty acids with TMAH thermochemolysis was studied. Results demonstrate that flash pyrolysis yields more diversity and greater abundances of TMAH thermochemolysis products than does the SAM-like ramp pyrolysis method. There is no obvious effect of calcium perchlorate on TMAH degradation when the [ClO 4 -] is lower than 10 weight percent (wt %). Most importantly, the presence of calcium perchlorate does not significantly impact the recovery rate of fatty acids with TMAH thermochemolysis under laboratory conditions, which is promising for the detection of fatty acids via TMAH thermochemolysis with the SAM and MOMA instruments on Mars.

International audienceSurfactants are extensively used in household and industrial products. Several processes exist to treat industrial wastewaters, including membrane filtration such as ultrafiltration, nanofiltration and reverse osmosis (RO). We studied fouling of RO membranes during filtration of aqueous anionic surfactant solutions under different conditions. The aim was to describe the local organisation of the surfactant at the membrane interface. To this end, the typical surfactant sodium dodecyl sulfate (SDS) and a polyamide membrane (SG, GE Water & Process Technologies) were selected. A marked surfactant mass loss was experimentally quantified and attributed to the accumulation of surfactants on the membrane surface and adsorption on the non-membrane materials in the filtration system. The concentration of surfactant in the polarisation layer compared with the SDS phase diagram, combined with contact angle measurements and flux decline analysis, enabled us to deduce a structure for the fouling. The fouling layer presented different structures according to the surfactant concentration: from a dense hydrophobic layer at very low concentration to a lamellar hexagonal phase in the gel layer at concentrations above 35 wt% in wate

The main limitations of current methods for synthesizing perovskite oxide (ABO 3 ) nanoparticles (NPs), e.g., the high reagent costs and sophisticated equipment, the long time and high-temperature processing, or multiple post-processing and thermal treatment steps, hamper their full study and potential application.Here, we use a facile low temperature (50 °C) chemical bath synthesis and only one annealing step to successfully produce high phase purity and crystalline quality nano-shaped rare-earth-based REMO 3 NPs (RE = La, Nd, Sm, Gd; M = Fe, Mn, Al). We also show the versatility of this approach by fabricating La 0.7 Sr 0.3 MnO 3 solid solution and non-RE-based BiFeO 3 perovskite. To assess the potential of the as-prepared REFeO 3 and REMnO 3 NPs, they are used for photocatalytic degradation of the norfloxacin antibiotic and show high efficiency. We believe this easy, robust, versatile, and general route for synthesizing ABO 3 -based NPs can be further explored in the vast perovskite family and beyond.