Publications by authors named "Delmotte L"

Mobile health diagnostics have demonstrated effectiveness in detecting and managing chronic diseases. This method comparison study aims to assess the accuracy and precision of the previously evaluated OptiBP™ technology over a four-week study period. This device uses optical signals recorded by placing a patient's fingertip on a smartphone's camera to estimate blood pressure (BP).

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The porosity of differently wetted carbonaceous material with disordered mesoporosity was investigated using low-field 1H NMR relaxometry. Spin−spin relaxation (relaxation time T2) was measured using the CPMG pulse sequence. We present a non-linear optimization method for the conversion of relaxation curves to the distribution of relaxation times by using non-specialized software.

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Almost regular hexagonal arrays of microscopic pyramids consisting of soot nanoparticles are formed on the surface of graphitized hollow filaments, which are resistively heated to ∼1800-2400 °C under an Ar atmosphere containing trace amounts of oxygen (∼300 ppm). At higher temperatures ( > 2300 °C, approximately) the soot particles are represented mainly by multishell carbon nano-onions. The height and width of the pyramids are strongly dependent on the temperature of the resistive heating, diminishing from 5 to 10 μm at ≈ 1800 °C to ∼1 μm at 2300-2400 °C.

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Mostly biosourced non-isocyanate polyurethanes (NIPU) were prepared from mono- and disaccharides, namely glucose and sucrose, reacted with dimethyl carbonate and hexamethylene diamine. The main aim of this research was to show that NIPU can be prepared from mono- and disaccharides, this just being an initial exploratory work and its sole main aim. The oligomers obtained were detected by MALDI-ToF, CP-MAS C NMR, and FTIR spectrometries.

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The reaction of citric acid with wood veneers was studied by Cross Polarization Magic Angle Spinning Nuclear Magnetic Resonance (CP MAS C NMR) and matrix assisted laser desorption ionization time of flight (MALDI ToF) mass spectrometry. The analysis showed that reactions of citric acid occurred with both lignin and carbohydrate constituents of wood. The reactions occurring are esterifications between the carboxylic acid functions of citric acid and the numerous aromatic and aliphatic hydroxyl groups of the main wood constituents.

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The reaction of condensation and cross-linking of desulfurized kraft lignin with triethyl phosphate (TEP) was explored. Catechol, a simple model of the aromatic ring of lignin, and glycerol, a model compound of the aliphatic hydroyl groups of the side chain of lignin, were employed under similar reaction conditions. Solid state cross-polarisation/magic-angle spinning (CP-MAS) C NMR and matrix assisted laser desorption ionization time-of-flight (MALDI-TOF) spectroscopy studies showed that polycondensation occurs on phenolic hydroxyl groups of lignin, as well as on aliphatic hydroxyls groups of its side chain.

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Reaction of a condensed flavonoid tannin, namely mimosa tannin extract with a hexamethylene diamine, has been investigated. For that purpose, catechin was also used as a flavonoid model compound and treated in similar conditions. Solid-state cross-polarisation/magic-angle spinning (CP-MAS) carbon 13 nuclear magnetic resonance (C NMR) and matrix assisted laser desorption ionisation time of flight (MALDI-ToF) mass spectroscopy studies revealed that polycondensation compounds leading to resins were obtained by the reaction of the amines with the phenolic hydroxy groups of the tannin.

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The design of mesoporous carbon materials with controlled textural and structural features by rapid, cost-effective and eco-friendly means is highly demanded for many fields of applications. We report herein on the fast and tailored synthesis of mesoporous carbon by UV and IR laser assisted irradiations of a solution consisting of green phenolic resins and surfactant agent. By tailoring the UV laser parameters such as energy, pulse repetition rate or exposure time carbon materials with different pore size, architecture and wall thickness were obtained.

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Complementary analytical methods have been used to study the effect of potassium on the pyrolysis mechanisms of cellulose and lignocellulosic biomasses. Thermogravimetry, calorimetry, high-temperature (1) H NMR spectroscopy (in situ and real-time analysis of the fluid phase formed during pyrolysis), and water extraction of quenched char followed by size-exclusion chromatography coupled with mass spectrometry have been combined. Potassium impregnated in cellulose suppresses the formation of anhydrosugars, reduces the formation of mobile protons, and gives rise to a mainly exothermic signal.

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A novel one-pot laser-assisted approach is reported herein for the synthesis of ordered carbons with embedded cobalt nanoparticles. The process is based on a UV pulsed laser exposure of an ethanolic solution consisting of green carbon precursors, a structure directing agent and a cobalt salt. Very short irradiation times (5 to 30 min) are only required to polymerize and cross-link carbon precursors (i.

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Solid state NMR methods are required to analyze biomass as a function of its chemical or biological treatment for biofuels, chemicals, or biochar production. The native polymers network in lignocellulosic biomass and other solid materials, such as coal, coke, or biochar, can hardly be analyzed by liquid state NMR due to their poor swelling ability without chemical modification. A (1)H-(13)C two-dimensional heteronuclear correlation (HETCOR) experiment with frequency-switched Lee-Goldburg (FSLG) irradiation is performed on a high field spectrometer (750 MHz).

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Time-series hydrothermal syntheses from two organic-cation-free gels with different compositions were employed to study the factors that control the final size of zeolite L crystals. The first gel had a starting K/Al ratio of 10, whereas in the second one it was three times lower. The relatively simple chemical composition of the starting gels and the combination of complementary characterization methods allowed us to track down the different stages of transformation of the initial amorphous gels into zeolite crystals and the factors that control the nucleation and growth processes.

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All industrially available zeolites are obtained from hydrogel systems. Unfortunately the level of understanding of the events preceding zeolite crystallization is far from satisfactory. In this respect, revealing the nature of the processes taking place in the precursor gel is of paramount importance to understanding zeolite nucleation.

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As biomass feedstock, wood and lactic acid biopolymers have been used as constituents of an innovative biocomposite material possessing remarkable properties. Three different systems were made by soaking lactic acid oligomers into solid wood and then oven heating to induce in situ polymerisation, confirmed by Fourier transformed infrared spectroscopy (FTIR) and gel permeation chromatography (GPC) analysis. Combinations of treatment systems and heating durations, implying structural wood modification, led to different physical behaviours of the composites.

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Long live lubricants: The selective capture of water from lubricants using nanosized microporous aluminophosphate (AEI) and aluminosilicate materials was studied. Nearly 98 % of the moisture was removed from the lubricating oil under ambient conditions, resulting in a significant improvement in the lubricating service lifetime. Moreover, both the lubricant and the microporous sorbents can be recovered and reused.

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A series of intercalated and exfoliated nanocomposites montmorillonite-ulvan was prepared. Ulvan, extracted from the green algae, is a water-soluble polysaccharide biopolymer. Depending on the drying process, air or freeze drying, ulvan were inserted in the interlayer space or adsorbed on the both sides of inorganic layers.

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Interactions of two homopolypeptides (polylysine and polyglutamic acid) with a synthetic montmorillonite were studied by 1H MAS, 1H-27Al HETCOR and 1H-13C CP-MAS NMR experiments. 1H-27Al HETCOR with 1H spin-diffusion NMR appears to be a powerful probe for the identification of the polypeptide fragments, which interact with the montmorillonite interlayer surfaces. In particular, selective interactions were observed between the polypeptide side-chains and the montmorillonite octahedral aluminum atoms.

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19F/29Si Hartmann-Hahn continuous wave cross-polarization (CP) has been applied under fast magic-angle spinning (MAS) to a powder sample of octadecasil. Strong oscillations occur during CP on a sideband matching condition between the isolated 29Si-19F spin pairs formed by the silicons in the D4R units and the fluoride anions. The magnitude of the dipolar coupling constant was deduced directly from the line-splitting between the intense singularities of the Pake-like patterns obtained by Fourier transformation of the oscillatory polarization transfer.

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Wide-band (1 MHz) 27Al magic-angle spinning nuclear magnetic resonance (MAS NMR) spectra were recorded for zeolite Y (Si/Al approximately 2.7) and high-silica (Si/Al approximately 3.8) FAU, EMT and mixed FAU-EMT structure-type zeolites synthesized using 15-crown-5 and/or 18-crown-6 ethers as templating agents.

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The synthesis of gallophosphate cloverite in the presence of aluminium leads to a partial substitution of Ga by Al. 27Al and 19F magic-angle spinning nuclear magnetic resonance (MAS NMR) studies on this material confirm this substitution. 27Al MAS NMR shows a broad line at 30 ppm which can be attributed to tetrahedrally coordinated Al in the solid.

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