Plasma-catalytic and thermo-catalytic methanation were assayed in the presence of a CeZrOx-supported Ni catalyst, proving that high CO2 conversions and high methane yields can be obtained under dielectric barrier discharge (DBD) plasma conditions and that they are maintained with time-on-stream over 100 h operating time. The characterization of the spent catalysts through TPD-MS, ATR-FTIR, TEM and HR-TEM and XRD evidenced the coexistence of a Ni0/NiO phase together with an increased presence of Ce3+ cations and oxygen vacancies, on the surface of the catalyst submitted to plasma catalytic operation. The different facts collected through physicochemical characterization point to our catalyst behaving like a PN junction, or like a fuel cell, with a P-side, the anode, i.e. the Ni-side releasing electrodes, while the CeZrOx support, N-side and cathode, acts as an acceptor. The DBD plasma, rich in ionic species and free electrodes, acts as the electrolyte, conducting the electrodes in the right direction. Oxygen accumulation on the surface of the catalyst during thermo-catalytic methanation leads to the formation of non-reactive adsorbed species, whereas Ni-sintering is favored. Under DBD plasma conditions, electron transfer is guaranteed and the adsorption–desorption of reactants and products is favored.

This study focuses on the use of a heterogeneous catalyst Ni/Ce0.58Zr0.42O2 to study the Sabatier reaction in conventional catalytic thermal heating and the dielectric barrier discharge plasma‐catalytic process. Its aim is to study the threshold temperature of the Sabatier reaction in plasma conditions. A set of experiments with different inlet flow rates is carried out in a plasma reactor to investigate the steady‐state temperature of the reaction. To estimate the threshold temperature of the Sabatier reaction more accurately, the temperature difference between the catalytic bed and the external surface of the reactor is calculated and simulated in COMSOL Multiphysics® software. Finally, the threshold temperature of the Sabatier reaction during plasma processing is assumed to be 116°C, based on the experimental data and simulation analysis.

A series of bi-metallic layered double hydroxide derived materials, containing a fixed amount of Ni promoted with various amounts of Fe were obtained by co-precipitation. The synthesized materials were characterized by X-ray diffraction (XRD), temperature-programmed reduction (H 2-TPR), temperature-programmed desorption of CO 2 (CO 2-TPD), elemental analysis and low temperature N 2 sorption and tested as catalysts in CO 2 methanation at atmospheric pressure. The obtained results confirmed the formation of mixed nano-oxides after thermal decomposition of the precursor and suggest successful introduction of both nickel and iron into the layers of Layered Double Hydroxides (LDHs). The introduction of Fe into the layered double hydroxides changed the interaction between Ni and supports matrix as proven by temperature programmed reduction (H 2-TPR). The introduction of low amount of iron influenced positively the catalytic activity in CO 2 methanation at 250 C, with CO 2 conversion increasing from 21% to 72% with CH 4 selec-tivity ranging from 97 to 99% at 250 C. No other products, except CH 4 and CO were registered during the experiments. In order to enhance the catalytic activity a non-thermal plasma created by dielectric barrier discharge was applied. The obtained results prove that * Corresponding author.

The research on soft actuators including liquid crystal elastomers (LCEs) becomes more and more appealing at a time when the expansion of artificial systems is blooming. Among the various LCE actuators, the bending deformation is often in the origin of many actuation modes. Here, a new strategy with plasma technology is developed to prepare single‐layer main‐chain LCEs with thermally actuated bending and contraction deformations. Two distinct reactions, plasma polymerization and plasma‐induced photopolymerization, are used to polymerize in one step the nematic monomer mixture aligned by magnetic field. The plasma polymerization forms cross‐linked but disoriented structures at the surface of the LCE film, while the plasma‐induced photopolymerization produces aligned LCE structure in the bulk. The actuation behaviors (bending and/or contraction) of LCE films can be adjusted by plasma power, reaction time, and sample thickness. Soft robots like crawling walker and flower mimic are built by LCE films with bending actuation.

Carbon-11 is undoubtedly an attractive PET radiolabeling synthon because carbon is present in all biological molecules. It is mainly found under 11CO2, but the latter being not very reactive, it is necessary to convert it into a secondary precursor. 11CO is an attractive precursor for labeling the carbonyl position through transition-metal mediated carbonylation because of its access to a wide range of functional groups (e.g., amides, ureas, ketones, esters, and carboxylic acids) present in most PET tracer molecules. However, the main limitations of 11CO labeling are the very short half-life of the radioisotope carbon-11 and its low concentration, and the low reactivity and poor solubility of 11CO in commonly used organic solvents. In this work, we show that a possible solution to these limitations is to use microfluidic reactor technology to perform carbonylation reactions, whilst a novel approach to generate CO from CO2 by plasma is described. The methodology consists of the decomposition of CO2 into CO by non-thermal DBD plasma at room temperature and atmospheric pressure, followed by the total incorporation of CO thus formed in the gas phase by carbonylation reaction, in less than 2 min of residence time. This “proof of principle” developed in carbon-12 would be further applied in carbon-11. Although considerable advances in 11CO chemistry have been reported in recent years, its application in PET tracer development is still an area of work in progress, because of the lack of commercially available synthesis instruments designed for 11C-carbonylations. To the best of our knowledge, such an innovative and efficient process, combining microfluidics and plasma, allowing the very fast organic synthesis of carbonyl molecules from CO2 with high yield, in mild conditions, has never been studied.

Although solid particles assembling on substrate surface is one of the key points for
developing membrane reactors, the technology of organizing nano/sub nanometer building
blocks into complex structures is still a challenge to scientists in years. In this work, amine
functional groups were deposited on the surface of different substrates via plasma enhanced
chemical vapor deposition (PECVD) technology and (3-aminopropyl)triethoxysilane
monomers were used as precursors. The influence of active gas, substrates, as well as
deposition time on the physico-chemical features of as-deposited film were investigated,
respectively. The highest density of amine of 5.5% on surface was obtained when Ar was
utilized as active gas and deposition time was 40 s. Furthermore, Y type zeolite particles at
sub-nano size were synthesized and subsequently used as a model material for testing the
immobilizing ability of plasma treated surface. The results clearly confirmed that a dense
mono or multi-layer of closely packed zeolite particles could be formed on the APTES as-
deposited surface after 24 hours’ immersion and the surface area of substrate could be
improved by the deposition of zeolite.

A miniaturized flow device has been developed to combine microfluidics technology and plasma process. In this microreactor, atmospheric pressure dielectric barrier discharges are generated in a gas in contact with a liquid phase. This study was conducted with plasma generated in ammonia in contact with a flow of liquid cyclohexane. Cyclohexylamine was synthesized with a good selectivity, and the process can be implemented to improve conversion and effectiveness. Numerical simulations confirmed that NH2 radicals are generated in the plasma and react with cyclohexyls radicals to achieve the reaction, giving a selectivity of 50% and a total molar conversion of 20% of cyclohexane. The effects of voltage and frequency on the selectivity and the experimental conversion rate were studied and discussed.

A new dismountable and reusable microchip for electrophoretic separation coupled to amperometric detection was developed. For this purpose, a new home made three-microbands electrode system was developed and microfabricated based on screen-printing for the inclusion of graphite/polydimethylsiloxane (C-PDMS) composite in microchannels down to 30 μm width. The composition of the composite as well as the fabrication methodology were optimized for an easy handling and an optimized electrochemical behavior. The electrochemical characterization of this composite material was first performed in bulk format (disc-shaped electrode, 6 mm diameter). It was then transposed to the micrometric scale for its integration in an original glass-NOA81®-PDMS microfluidic device allowing for reversible sealing. The microband electrodes were characterized by scanning electron microcopy and cyclic voltammetry, illustrating a good control of the microelectrode width. Then, the analytical performances of the C-PDMS composite microelectrodes were evaluated using Ru(NH3)63+ and FcMeOH as model electroactive molecules. The electrophoretic separation and quantitation of Ru(NH3)63+ were then performed in a background electrolyte made of hydrochloric acid and sodium chloride, leading to a LOD and a LOQ of 3.4 μmol L−1 and 11.3 μmol L−1, respectively. The re-openable NOA-based microdevice permits to regenerate the electrode surface by simply repositioning the microband on a new spot, allowing for robust analysis in a reusable system.

Driven by the growing concern about the release of untreated emerging pollutants and the need for determining small amounts of these pollutants present in the environment, novel biosensors dedicated to molecular recognition are developed. We have designed biosensors using a novel class of grafted polymers, surface-attached hydrogel thin films, on conductive transducers as a biocompatible matrix for biomolecule immobilization. We showed that they can be dedicated to the molecular recognition of diclofenac (DCL). The immobilization of the aptamer onto surface-attached hydrogel thin films by covalent attachment provides a biodegradable shelter, providing the aptamer with excellent environments to preserve its active and functional structure while allowing the detection of DCL. The grafting of the aptamer is obtained using the formation of amide bonds via the activation of carboxylic acid groups of the poly(acrylic acid) hydrogel thin film. For improved sensitivity and higher stability of the sensor, a high density of the immobilized aptamer is enabled. The aptamer-modified electrode was then incubated with DCL solutions at different concentrations. The performances of the aptasensor were investigated by electrochemical impedance spectroscopy. The change in charge-transfer resistance was found to be linear with DCL concentration in the 30 pM to 1 μM range. The detection limit was calculated to be 0.02 nM. The improvement of the limit of detection can be mainly attributed to the three-dimensional environment of the hydrogel matrix which improves the grafting density of the aptamer and the affinity of the aptamer to DCL.

Waste printed circuit boards are a major source of strategic materials such as platinum group metals since they are used for the fabrication of technological devices, such as hard drive discs, capacitors, and diodes. Because of the high cost of platinum, palladium, and gold (> 25 k€/kg), an economic and environmental challenge is their recycling from printed circuit boards that represent around 2% weight of electronic equipment. Hydrometallurgical treatments allow the recovery of these metals in solution, with a high recovery rate for a leaching liquor made of thiourea in hydrochloric acid. So as to develop an efficient recycling process from this leach liquor, one requires the speciation of these strategic metals, as well as their extraction and quantitation in the mixture. For this purpose, platinum, palladium, and gold were dissolved in model leach liquors made of hydrochloric acid and thiourea at low concentration. The identification of metal complexes was determined as a function of thiourea concentration (between 10 μmol/L and 10 mmol/L) by the combination of UV-visible spectrometry, cyclic voltammetry, and for the first time capillary electrophoresis. The electrokinetic method was then applied for the quantitation of trace metal analyses in leach samples from waste printed circuit boards reprocessing, demonstrating its applicability for industrializable recycling applications.