Université PSL

Publications

RECHERCHER

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Synthesis of benzaldehyde with high selectivity using immobilized AuNPs and AuNPs@zeolite in a catalytic microfluidic system
Laboratoire Procédés - Plasmas - Microsystèmes - Xi Rao, Ali Abou Hassan, Cédric Guyon, Stephanie Ognier , Michaël Tatoulian
ELSEVIER - 240 121974 - https://doi.org/10.1016/j.matchemphys.2019.121974 - 2020
Although solid particles assembling on substrate surface is one of the key points for developing membrane reactors, the technology of organizing nano/near 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 near-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 h’ immersion and the surface area of substrate could be improved by the deposition of zeolite.
Electrocatalytic behaviour of CeZrOx-supported Ni catalysts in plasma assisted CO2 methanation
Laboratoire Procédés - Plasmas - Microsystèmes - Maria Mikhail, Patrick Da Costa, Jacques Amouroux, Siméon Cavadias, Michael Tatoulian, Stéphanie Ognier and María Elena Gálvez
Catalys Science & Technology - 10 4532-4543 - https://doi.org/10.1039/D0CY00312C - 2020
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.
Coupling experiment and simulation analysis to investigate physical parameters of CO2 methanation in a plasma‐catalytic hybrid process
Laboratoire Procédés - Plasmas - Microsystèmes - Bo Wang Maria Mikhail Maria Elena Galvez Simeon Cavadias Michael Tatoulian Patrick Da Costa Stéphanie Ognier
FULL PAPER - 17 9 - https://doi.org/10.1002/ppap.201900261 - 2020
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.
Ni-Fe layered double hydroxide derived catalysts for non-plasma and DBD plasma-assisted CO2 methanation
Laboratoire Procédés - Plasmas - Microsystèmes - D Moreno, MV Ognier, S Motak, Grzybek, T Da Costa, P Galvez
Catalys Science & Technology - 45 17 - DOI: 10.1016/j.ijhydene.2019.06.095 - 2020
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.
Plasma‐Induced Polymerizations: A New Synthetic Entry in Liquid Crystal Elastomer Actuators
Laboratoire Procédés - Plasmas - Microsystèmes - Bin Ni Mengxue Zhang Cédric Guyon Patrick Keller Michael Tatoulian Min‐Hui Li
First published - 41 19 - https://doi.org/10.1002/marc.202000385 - 2020
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.
Fast carbonylation reaction from CO2 using plasma gas/liquid microreactors for radiolabeling applications
Laboratoire Procédés - Plasmas - Microsystèmes - Marion Gaudeau, Mengxue Zhang, Michaël Tatoulian, Camille Lescot and Stéphanie Ognier
Reaction Chemistry & Engineering - 5 1981-1991 - doi.org/10.1039/D0RE00289E. - 2020
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.
A new injection system for spraying liquid nitrates in a low power plasma reactor: Application to local repair of damaged thermal barrier coating
Laboratoire Procédés - Plasmas - Microsystèmes - F.Rousseau A.Quinsac D.Morvan M.-P.Bacos O.Lavigne C.Rio C.Guinard B.Chevillard
ELSEVIER - 357 195-203 - https://doi.org/10.1016/j.surfcoat.2018.09.069 - 2019
In addition to the search for new Thermal Barrier Coating (TBCs) systems with increased reliability over very long time periods, the repair of current systems is a technological and economic issue for both civilian and military engine end-users. This paper describes the latest version of the deposition process known as the Low-Power Plasma Reactor (LPPR) process, specially developed to repair locally damaged TBCs. The LPPR process enables micro/nanostructured TBCs to be made from nitrate salts in aqueous solutions, which are sprayed in an Ar/O2 plasma discharge at low power (240 W) and transformed into oxide coatings. A new injection device was designed to produce a fairly homogenous and reproducible spray to repair partially spalled APS and EB-PVD TBCs deposited on small flat coupons. The microstructure and the stability of the LPPR TBCs were assessed, in particular using SEM observations, during ageing tests under various time/temperature conditions. The Particle Image Velocimetry (PIV) technique and associated modeling have proved that the nitrates impact the substrate in a liquid state even in the presence of plasma and a vacuum. Due to the liquid state of the precursors, the new LPPR TBC seals the damaged areas and deeply infiltrates all porosities and failure cracks in the original coatings. This research has enabled the new version of the LPPR process to be validated as a simple, efficient, cheap and promising way to repair locally damaged TBCs
Cross coupling of alkylsilicates with acyl chlorides via photoredox/nickel dual catalysis: a new synthesis method for ketones
Laboratoire Procédés - Plasmas - Microsystèmes - Etienne Levernier, Vincent Corcé, Louise-Marie Rakotoarison, Adrien Smith, Mengxue Zhang, Stephanie Ognier, Michael Tatoulian, Cyril Ollivier and Louis Fensterbank
Organic Chemistry Frontiers - 6 1378-1382 - https://doi.org/10.1039/C9QO00092E - 2019
Photoredox/nickel dual catalysis using easily oxidized bis-catecholato hypercoordinated silicon derivatives as radical sources and acyl chlorides as electrophiles allows a new method of formation of dialkyl and alkyl-aryl ketones as well as dibenzyl ketones which are less easily accessed. Flow chemistry can be used.
Plasma-catalytic hybrid process for CO2 methanation: optimization of operation parameters
Laboratoire Procédés - Plasmas - Microsystèmes - M. Mikhail, B. Wang, R. Jalain, S. Cavadias, M. Tatoulian, S. Ognier, M. E. Gálvez & P. Da Costa
Reaction Kinetics, Mechanisms and Catalysis - 126 629–643 - doi.org/10.1007/s11144-018-1508-8 - 2019
The present study focuses on the hybrid plasma catalytic process for CO2 methanation. This plasma-catalytic process, based on the combination of a DBD plasma and Ni/CeZrO2 catalyst, has several advantages over conventional catalysis: it operates at ambient conditions and requires no external heating. An optimization of the process considering the effect of the different operational parameters such as voltage, GHSV, catalyst mass, flow rate, discharge length, is herein presented. Moreover, a spectroscopic study, aiming to understand the mechanism of the reaction, is also showed. At temperatures around 270 °C and under adiabatic conditions, CO2 conversion rates of about 80% were measured, with a CH4 selectivity greater than 95%.
Surface functionalization of cyclic olefin copolymer by plasma‐enhanced chemical vapor deposition using atmospheric pressure plasma jet for microfluidic applications
Laboratoire Procédés - Plasmas - Microsystèmes - Samantha Bourg Sophie Griveau Fanny d'Orlyé Michael Tatoulian Fethi Bedioui Cédric Guyon Anne Varenne
FULL PAPER - 16 6 - doi.org/10.1002/ppap.201800195 - 2019
Lab‐On‐A‐Chips promise solutions for high throughput and specific analysis for environmental and health applications, with the challenge to develop materials allowing fast, easy, and cheap microfabrication and efficient surface treatment. Cyclic olefin copolymer (COC) is a promising thermoplastic, easily microfabricated for both rapid prototyping and low‐cost mass production of microfluidic devices but still needing efficient surface modification strategies. This study reports for the first time the optimization of an easy COC silica coating process by plasma‐enhanced chemical vapor deposition at atmospheric pressure with plasma jet and tetraethylorthosilicate as precursor, leading to a 158 ± 7 nm thickness and a 14‐day‐stability of hydrophilic properties for a COC‐embedded microchannel (100 µm), paving the way for a simplified and controlled COC surface modification.
Synthesis of benzaldehyde with high selectivity using immobilized AuNPs and AuNPs@zeolite in a catalytic microfluidic system
Laboratoire Procédés - Plasmas - Microsystèmes - Xi Rao, Ali Abou Hassan, Cédric Guyon, Erick Osvaldo Martinez Ruiz, Michaël Tatoulian and Stephanie Ognier
Lab. Chip - 19 2866-2873 - https://doi.org/10.1039/C9LC00386J - 2019
In the present work, gold based catalysts were synthesized and immobilized on the surface of cyclic olefin copolymer (COC) microreactors. The microreactors were subsequently applied in a homemade microfluidic system for synthesizing benzaldehyde by oxidation of benzyl alcohol in water medium. The Au nanoparticles (NPs) immobilized on the inner surface of the microchannel showed a very high selectivity (94%) for benzaldehyde, while zeolite NPs exhibited only an adsorption feature to this reaction. Moreover, the results showed that the AuNP catalytic activity was maintained for at least 9 hours. However, the obtained conversion with AuNPs was only 20%, indicating a relatively low productivity. In comparison, AuNPs assembled on the surface of zeolite NPs (AuNPs@zeolite) and immobilized in the microchannel showed the best catalytic performance, as the highest benzaldehyde selectivity (>99%) with a relatively high benzyl alcohol conversion of 42.4% was achieved under the same conditions. To the best of our knowledge, this is the first example demonstrating the use of AuNP or AuNP@zeolite catalysts in a microsystem performing such high selectivity for benzaldehyde in water medium.

Degradation of glucocorticoids in aqueous solution by dielectric barrier discharge: Kinetics, mechanisms, and degradation pathways
Laboratoire Procédés - Plasmas - Microsystèmes - Liu YN, Wang CH, Shen X, Zhang A, Yan SW, Li X, Miruka AC, Wu SM, Guo Y, Ognier S
Chemical Engineering Journal - 374 412-428 - DOI10.1016/j.cej.2019.05.154 - 2019
Performance and mechanism of non-thermal plasma (NTP) technology in removing glucocorticoids (GCs) was investigated using a dielectric barrier discharge (DBD) reactor with fluocinolone acetonide (FA), triamcinolone acetonide (TA) and clobetasol propionate (CP) as representative compounds. Effects of discharge power, plasma-working gases, initial pH, coexistence of ions, and various water matrices (ultrapure water, lake water, drinking water, wastewater effluent) on GC removal and energy yield were evaluated. The results confirm that DBD treatment could efficiently remove FA, TA, and CP, achieving efficiency of 72% (k = 0.0126 min(-1)), 71% (k = 0.0096 min(-1)), and 74% (k = 0.0116 min(-1)), respectively in air-DBD system at 45.2 W, with the process following the first order kinetics and energy yield of 6 mg kW(-1) h(-1). The removal efficiency decreased when adding radical scavengers, indicating that hydroxyl radicals played an important role in GC degradation, while other active species (such as solvated electrons (e(aq)(-)), ozone (O-3), hydrogen peroxide (H2O2) and ultraviolet photolysis (UV)) also contribute to GC degradation. The intermediates generated during the process were analyzed using quadrupole time-of-flight mass spectrometry (QTOF-MS). A total of 23 transformation products of FA, TA and CP were identified, and it was noted that substitution of halogen atoms with center dot OH, oxidation of hydroxyl group to keto acid, decarboxylation of the keto acid, addition of center dot OH, intramolecular cyclization, and hydrolysis of esters occurred during GC degradation by DBD treatment.
Synthesis of benzaldehyde with high selectivity using immobilized AuNPs and AuNPs@zeolite in a catalytic microfluidic system
Laboratoire Procédés - Plasmas - Microsystèmes - Xi Rao, ORCID logo, Ali Abou Hassan, Cédric Guyon, Erick Osvaldo Martinez Ruiz, Michaël Tatoulianb and Stephanie Ognier
Lab. Chip - 17 - DOI: 10.1039/c9lc00386j - 2019
In the present work, gold based catalysts were synthesized and immobilized on the surface of cyclic olefin copolymer (COC) microreactors. The microreactors were subsequently applied in a homemade microfluidic system for synthesizing benzaldehyde by oxidation of benzyl alcohol in water medium. The Au nanoparticles (NPs) immobilized on the inner surface of the microchannel showed a very high selectivity (94%) for benzaldehyde, while zeolite NPs exhibited only an adsorption feature to this reaction. Moreover, the results showed that the AuNP catalytic activity was maintained for at least 9 hours. However, the obtained conversion with AuNPs was only 20%, indicating a relatively low productivity. In comparison, AuNPs assembled on the surface of zeolite NPs (AuNPs@zeolite) and immobilized in the microchannel showed the best catalytic performance, as the highest benzaldehyde selectivity (>99%) with a relatively high benzyl alcohol conversion of 42.4% was achieved under the same conditions. To the best of our knowledge, this is the first example demonstrating the use of AuNP or AuNP@zeolite catalysts in a microsystem performing such high selectivity for benzaldehyde in water medium.

Plasma Polymer Layers with Primary Amino Groups for Immobilization of Nano- and Microparticles
Laboratoire Procédés - Plasmas - Microsystèmes - Xi Rao; Ali Abou Hassan; Cédric Guyon; Mengxue Zhang; Stephanie Ognier; Michaël Tatoulian
Plasma Chemistry and Plasma Processing - 2 178 - DOI: 10.1007/s11090-019-10056-z - 2019
The assembly of nano- and micro-scale building blocks on surface has been the focus of intense interest in materials science for years. In this work, (3-aminopropyl)triethoxysilane (APTES) carrying one primary amino group was deposited on various substrate surfaces using the plasma polymerization method. The key plasma parameters i.e. pressure and power were varied to obtained the highest density of primary amino groups. The influence of such parameters on the characteristics of deposited layers (e.g. chemical structure, adhesion strength, growth rate, etc.) was systemically investigated using various characterization methods such as XPS, FTIR, ellipsometry and so on. Meanwhile, three types of particles (AuNPs, zeolites and gold@zeolites) with sizes from nano- to submicro-range were synthesized and further used as model building blocks. Subsequently, the prepared particles were deposited onto cyclic olefin copolymer (COC) substrate surfaces, which were pre-functionalized by deposition of the plasma polymer layer using the parameters of pressure = 1.0 mbar and power = 30 W. The results confirmed the formation of membrane structures consisting of highly packed particles on the COC surface, and such immobilized structures showed high stability against flowing water, evidencing the good immobilization ability of deposited APTES layers with amino groups.
Thermo-mechanical and photo-luminescence properties of micro-actuators made of liquid crystal elastomers with cyano-oligo(p-phenylene vinylene) crosslinking bridges
Laboratoire Procédés - Plasmas - Microsystèmes - Bin Ni, Hui Chen, Mengxue Zhang, Patrick Keller, Michael Tatoulian and Min-Hui Li
Materials Chemisty Frontiers - 3 2499-2506 - https://doi.org/10.1039/C9QM00480G - 2019
Nematic liquid crystal elastomer (LCE) micropillars with reversible thermomechanical deformations and photo luminescence (PL) intensity variations were successfully fabricated by introducing a cyano-oligo(p-phenylene vinylene) dye as a chemical crosslinker. The PL intensity of the micropillars decreased and increased reversibly during the thermal-deformation process. We studied in detail the possible factors that influence the PL intensity variations of the micropillars, including temperature variation, contraction/extension and phase transition. The dye molecules mainly kept the “monomer” state in the micropillars during the thermo-activated deformation. It was found that the phase transition from nematic to isotropic of the LCEs played the major role in the PL intensity variations. This kind of micropillar may have potential application in fluorescent soft sensors and actuators.

High density gold nanoparticles immobilized on surface via plasma deposited APTES film for decomposing organic compounds in microchannels
Laboratoire Procédés - Plasmas - Microsystèmes - XiRao, CédricGuyo, StephanieOgnier, Bradley Da Silva, Chenglin Chu, MichaëlTatoulian, Ali AbouHassan
Applied Surface Science - 439 272-281 - https://doi.org/10.1016/j.apsusc.2018.01.009 - 2018
Immobilization of colloidal particles (e.g. gold nanoparticles (AuNps)) on the inner surface of micro-/nano- channels has received a great interest for catalysis. A novel catalytic ozonation setup using a gold-immobilized microchannel reactor was developed in this work. To anchor AuNps, (3-aminopropyl) triethoxysilane (APTES) with functional amine groups was deposited using plasma enhanced chemical vapor deposition (PECVD) process. The results clearly evidenced that PECVD processing exhibited relatively high efficiency for grafting amine groups and further immobilizing AuNPs. The catalytic activity of gold immobilized microchannel was evaluated by pyruvic acid ozonation. The decomposition rate calculated from High Performance Liquid Chromatography (HPLC) indicated a much better catalytic performance of gold in microchannel than that in batch. The results confirmed immobilizing gold nanoparticles on plasma deposited APTES for preparing catalytic microreactors is promising for the wastewater treatment in the future.

Isothermal crystallization of glycine in semi-continuous mode by anti-solvent addition
Laboratoire Procédés - Plasmas - Microsystèmes - Wail El Bazi, Marie-Thérèse Moufarej Abou Jaoude, Catherine Porte, Isabelle Mabille
Journal of Crystal Growth - 3 498 - DOI: 10.1016/j.jcrysgro.2018.06.013 - 2018
This article focuses on the isothermal semi-continuous crystallization of glycine aqueous solution by adding an anti-solvent, ethanol. The effect of the ethanol concentration on solubility and the impact of the ethanol flow rate on the metastable zone width and on the size distribution of the crystals were investigated. The study showed that increasing the ethanol concentration in the medium decreases solubility for the studied temperatures and that increasing the ethanol flow rate causes a widening of the metastable zone without inducing any noticeable effect on the crystals’ size distribution. In addition, nucleation kinetic models were determined for two temperatures (30 and 56 °C).
Microfluidic chips for plasma flow chemistry: application to controlled oxidative processes
Laboratoire Procédés - Plasmas - Microsystèmes - Julien Wengler, Stéphanie Ognier, Mengxue Zhang, Etienne Levernier, Cedric Guyon, Cyril Ollivier, Louis Fensterbank and Michael Tatoulian
Reaction Chemistry & Engineering - 3 930-941 - https://doi.org/10.1039/C8RE00122G - 2018
The present paper reports the integration of nonthermal plasma into a biphasic gas–liquid microfluidic chip. It evaluates the potential of plasma activation to become a synthetic tool in organic chemistry, operating under mild conditions (room temperature, atmospheric pressure) and without a catalyst. Few preceding works on plasma chemistry involved a liquid phase and none of them was able to handle the high reactivity of plasma to achieve both high conversion rates and selective reactions. We fabricated a glass-polymer microfluidic chip comprising a one metre long serpentine channel, in which a parallel gas–liquid flow was stabilized thanks to a specific step-like cross-sectional shape. Transparent ITO electrodes, deposited on both sides of the chip and linked to an AC high voltage source, produced a dielectric barrier discharge along the channel. We assessed the behaviour of the flow through optical observations and characterized the discharge through electrical measurements and real time intensified-CCD monitoring. We report the successful treatment of liquid cyclohexane with oxygen plasma inside our chip. The GC analysis of the outflowing liquid revealed only a partial oxidation of cyclohexane into a mixture of cyclohexanol and cyclohexanone (industrially known as “KA oil”), and cyclohexyl hydroperoxide, with a total selectivity above 70% and conversion up to 30%. This indicates that alkanes can be activated and functionalized by means of plasma discharges, in a controlled way. In that respect, we claim to have successfully overcome some of the barriers to industrially relevant plasma chemistry. We believe that the combined use of plasma and microfluidic technologies is essential to the development of this new field of research.
Cover Picture: Plasma Process. Polym
Laboratoire Procédés - Plasmas - Microsystèmes - Fatemeh Rezaei Yury Gorbanev Michael Chys Anton Nikiforov Stijn W. H. Van Hulle Paul Cos Annemie Bogaerts Nathalie De Geyter
First published - 15 6 - doi.org/10.1002/ppap.201870013 - 2018
Front Cover: Electrospinning solutions of polylactic acid in chloroform and 5,5‐N‐dimethylformamide were subjected to preelectrospinning plasma treatment (PEPT). A broad range of spectroscopic analytical techniques, mainly EEM and EPR, were performed to investigate the plasma‐induced chemistry in the organic solutions. The enhanced conductivity of the solutions was ascribed to the formation of plasma‐induced acids during PEPT. The synergistic effect of chemical changes leads to poly lactic acid nanofibers with uniform morphology.

Further details can be found in the article by Fatemeh Rezaei et al. (e1700226).
A plasma/liquid microreactor for radical reaction chemistry: An experimental and numerical investigation by EPR spin trapping
Laboratoire Procédés - Plasmas - Microsystèmes - Mengxue Zhang Stéphanie Ognier Nadia Touati Ines Hauner Cedric Guyon Laurent Binet Michael Tatoulian
FULL PAPER - 15 - https://doi.org/10.1002/ppap.201700188 - 2017
In this paper, a novel plasma/liquid microreactor has been developed to generate and inject radical species with the aim to perform chemical synthesis reactions in liquid phase. Plasma has always been considered as a source of reactive species, such as radicals, atoms, electrons, etc., with applications mostly dedicated to surface modifications of materials. By injecting reactive species created by the plasma to the liquid phase, it is possible to initiate liquid phase synthesis reactions. In addition, gas/liquid interactions can be enhanced with a high surface‐area‐to‐volume ratio by confining the plasma and the liquid in diphasic micro‐structured systems. Herein is reported a novel plasma/liquid microreactor for liquid phase radical reactions. Radicals are generated in the gas phase in a steady flow microreactor and then transported to the liquid phase. The spin trapping reaction and the electron paramagnetic resonance (EPR) spectroscopy have been used to identify and quantify the radical species generated in the microreactor. Hydroxyl radicals and hydrogen atoms have been detected and measured in the liquid phase, indicating the huge potential of the microreactor as a handful tool for chemical synthesis.

34 publications.