Dissertations / Theses on the topic 'Surfactants – Composition chimique – Propriétés physico-chimiques'
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Delforce, Lucie. "Nouvelles méthodologies pour la caractérisation des particules, des huiles complexes et des tensioactifs : relations entre structures chimiques, propriétés physicochimiques et propriétés applicatives." Electronic Thesis or Diss., Université de Lille (2022-....), 2022. http://www.theses.fr/2022ULILR042.
The multiple aims of this thesis fall within the implementation of a new HT-SMART-FORMU technological platform dedicated to formulation science. The focus is set on the development of reliable experimental methods, theoretical and predictive tools, so as to establish relations between chemical composition, physicochemical properties and applicative properties.The first type of systems investigated in this work consists of solid dispersions. Their stability has long been approached by the DLVO theory, but more recent studies suggest the use of Hansen Solubility Parameters to describe their stability in non-aqueous media. In the first chapter, a systematic analytical method based on zeta potential measurement and light scattering stability monitoring allows deducing a complementarity of both theories to describe the stability of TiO2 dispersions in non-aqueous solvents.The problematic of oil hydrophobicity prediction through EACN values modelling, which is a key parameter to design surfactant/oil/water (SOW) dispersed systems, is addressed in the second chapter. Two mathematical models, designed using machine-learning methods, are proposed for the rapid prediction of the EACN of oils, namely Neural Networks (NN) and Graph Machines (GM). While the GM model is implemented from the SMILES codes, the NN model is fed with σ-moments descriptors computed with the COSMOtherm software. The prediction reliability of both models is discussed based on a complex 10-molecule test set.In chapters 3 and 4, the scope of applicative properties of a nonionic glycerol-based surfactant are investigated. Firstly, chapter 3 focuses on its aggregation behavior in aqueous solutions and the formation of liquid crystals (LC) at low concentration, in comparison with the benchmark polyethoxylated fatty alcohols and alkyl polyglucosides. The influence of its physicochemical properties, in particular the air / water interface dilational viscoelasticity, is put in relation with the observed poor foamability and long-lasting foam stability.Finally, C12Gly2 properties in SOW systems are investigated in chapter 4. The Normalized Hydrophilic-Lipophilic Deviation (HLDN), a powerful theoretical tool, is regarded as a way to rationalize the characteristics of both emulsions and microemulsions. In this way, a thorough quantification of surfactants amphiphilicity, temperature sensitivity and salt-tolerance are presented. The potential use of C12Gly2 as O/W and W/O emulsifier is then investigated: the granulometry and stability of emulsions obtained by varying the oil concurs with HLDN values. A minimum is observed at HLDN = 0 and increases for negative and positive HLDN values
Sindi, Kaïs. "Imidates : synthèse de sidérophores pouvant être modifiés par des antibiotiques : étude de leurs propriétés physico-chimiques." Paris 7, 2008. http://www.theses.fr/2008PA077112.
: The synthesis of imidazolides 3a-c, benzimidazolides 4a-d and imidazo-[4,5b]-pyridines 4e-h, starting from 7V-acyl imidates 1 and 1,2-diamines 2 is described. (Chap. I)In the second part, two synthesis strategies, SEA and AES, are developed in the aim of producing antibiotic-siderophore-like conjugates. A secondary amine 13 is first prepared from spermidine 5 and 2,3-dihydroxybenzoic acid 7. In the first strategy, a C3 or C5 linker, bearing a carboxylic moiety, is grafted onto the central nitrogen atom of the amine 13. After deprotection of the catechol groups, four ligands are obtained 57-60. In the second strategy, C3 and C5 linkers are directly grafted onto the unprotected antibiotic, ampicillin 29. Even if up-today the corresponding antibiotic-siderophore-like conjugates are not obtained, the studies of their acid-base properties and of their iron(III) chelates demonstrate these molécules, LEt3H₅, LEt5H₅, LAc3H₅, et LAc5H₅ (57-60), to behave as siderophores. Practically, ail the individual pKa values have been measured for the free ligands, while for their iron(III) chelates, only the average pKa values of both ortho- and meta- catecholic protons were obtained, and the carboxylic and amine ones. Then, their affinities for Iron(III), b, and their pFes deduced from kinetic experiments show these new bis-catecholic siderophores, LEt3H₅, LEt5H₅, LAc3H₅, et LAc5H₅, can compete with natural bis-catecholic ones, such as Tait’s compound II
Bérépion, Bastien. "Incidence de la composition chimique et des propriétés physico-chimiques des gommes en acacia sur leurs propriétés en émulsion." Le Havre, 2011. http://www.theses.fr/2011LEHA0013.
Acacia gum is an exudate from Acacia senegal var senegal commonly used in food and pharmaceutical industry as emulsifier and stabilizer (E414). The aim of this thesis, in partnership with Allan & Robert, was to study the relationship between chemical composition, physic-chemical properties, functional properties and environmental conditions of acacia gums synthesis and harvest. At first, studying raw gums show the influence of geographic origin and post-harvest storage condition on the acacia gums chemical composition and physic-chemical properties. Then, we confirm the important role of AGP fraction in emulsions properties into correlating the AGP percent with the emulsifying properties, the aromatic amino acid proportion in the fraction with the emulsion stability and the aggregates negative effect on the emulsion properties. Furthermore, a relation appears between emulsions quality and protein percent in gums. Finally, we highlighted the atomization process influence on physic-chemical and functional properties of acacia gums
Klaver, Anne. "Estimation des propriétés optiques des poussières désertiques d'origines saharienne et sahélienne, à proximité de leurs zones sources d'émission, à partir de leurs propriétés physico-chimiques." Paris 7, 2012. http://www.theses.fr/2012PA077179.
By absorption and scattering of the solar and terrestrial radiations, mineral dust has a direct radiative effect. At the global scale, this direct radiative effet is currently estimated between -0. 56 and + 0. 1 W m⁻², which doesn't allow to say if the mineral dust cools or warms the Earth/Atmosphere System. The estimation of this effect still remains uncertain because of the limited knowledge concerning the optical properties of mineral dust (scattering and absorption) which are linked with their physico-chemical properties. My work is incorporated within the issues of the reduction of these uncertainties. It involved the study of the physico-chemical (mineralogical composition, size and shape) and optical (scattering, absorption and extinction coefficients, single scattering albedo and asymmetry parameter) properties of thé minéral dust coming from western Africa, observed in the framework of the African Monsoon Multidisciplinary Analysis (AMMA) program at Banizoumbou (Niger) station in winter and summer 2006. With an optical model, these observations have been used in order to perform closure studies of the optical properties. I tried to determine if it is possible to estimate the optical properties of the mineral dust based on the knowledge of their physico-chemical properties. I showed a good representation of the scattering and absorption coefficients by calculation (calculation/measurement discrepancy < 13 %). However, efforts have to be performed concerning the estimation of the absorption coefficient and single scattering albedo (calculation/measurement discrepancy up to 291 %)
Epoune, lingome Cédric. "Nouveaux agrotensioactifs glycolipidiques : synthèse, propriétés physico-chimiques et application en polymérisation." Thesis, Lyon, INSA, 2011. http://www.theses.fr/2011ISAL0150/document.
Aware of the irreversible scarcity and graving increase in oil prices, as well as large amounts of surfactants produced and disposed of each year, the chemical industry more and more focuses on resources from biomass. However in Europe, plant derived from plants only represent 20%. New strategies to produce surfactants with novel structures derived produced of the surfactants from agricultural resources are thus synthetic challenges.. As part of a research collaboration, ITERG (Pessac) and ICBMS (COB-INSA in Lyon) have joined forces to develop the synthesis of new amphiphilic glycolipids obtained by functionalization of epoxidized vegetable oils. Synthetic issues concerned the competition between the two reactive groups of epoxidized oils (ester and oxirane) and multifunctionality of sugars and other polyols used as nucleophilic substrates. Several series of novel compounds were prepared and their physicochemical properties were assessed for targeted industrial applications. Among the synthesized products, some were also evaluated as biobased monomers
Rivellini, Laura-Hélèna. "Propriétés physico-chimiques, optiques et identification des sources des aérosols en Afrique de l’Ouest." Thesis, Lille 1, 2017. http://www.theses.fr/2017LIL10177/document.
The aim of this thesis consists in studying the chemical nature, the origins as well as the optical properties of aerosols in West Africa. We focused on establishing the links between the chemical composition of fine particles at surface and aerosols optical properties. Our study is based on measurements acquired during the SHADOW field campaign, implemented on the M’Bour (Senegal) site during two intensive observation periods: March to June 2015 (IOP-1) and November 2015 to January 2016 (IOP-2). For this purpose, an instrumentation allowing online chemical characterization of surface PM1 (ACSM, TEOM-FDMS, aethalometer), at high time resolution, was implemented in parallel with instruments measuring aerosols optical properties at surface (aethalometer, nephelometer) and along the atmospheric column by remote sensing (Lidar, photometer). The coupling of meteorological data with statistical tools allowed determining the local and/or regional contribution of the different species, and identifying the source areas responsible for the high concentrations observed on site. The source receptor model (PM) allowed to further investigate the submicronic organic fraction, highlighting a fast photochemistry and the influence of specific anthropogenic activities (waste burning, fish smoking). We were also able to characterize, per season, the type of aerosols contributing to the fine particle extinction measured at surface, as well as to show links/differences between remote sensing and surface chemical/optical properties of fines particles during the two IOP
Laubé, Florian. "Compréhension des phénomènes physicochimiques régissant l’adhésion et la formulation de vernis à ongles à base de résines biosourcées : approches in silico et in vitro." Electronic Thesis or Diss., Université de Lille (2018-2021), 2019. http://www.theses.fr/2019LILUR014.
Several billion nail polishes are sold every year throughout the world, and the market is still fast-growing. Despite a tightening of regulations over the past twenty years, the composition of varnishes remains problematic from an environmental point of view. The main obstacle to reach a 100% bio-based varnish is the secondary film-forming agent, or resin, which provides the additional adhesion, the gloss and the stability that nitrocellulose lacks. In this context, we have focused on understanding the physicochemistry of these complex systems in order to assist the design of new compatible biosourced resins through the establishment of structures-properties relationships. First, complete physicochemical characterizations (surface aspect and surface energy, composition, permeability) were carried out on native nails and two semi-synthetic models. An adhesion test was developed to evaluate the adhesion of formulations onto substrates. Correlated to physicochemical characterizations, these results allowed to identify the best model of the native nail and highlighted the adhesion mechanisms at the varnish-nail interface. In parallel, the "benchmarks" resins were characterized in order to define precise specifications according to their application performances. Thanks to the adaptation of prediction tools to polymers, we managed to link structural modifications to solubility and was validated using synthesized model oligoesters. The impact of some structural features on the gloss or the hardness of resins has been highlighted and the identified structures-properties relationships were confirmed through the evaluation of the performances of new bio-based polyester resins
Ben, Hassine Habib. "Etude de l'évolution des propriétés chimiques et physico-hydriques des principaux types de sols céréaliers du Nord-Ouest tunisien : effets sur les productions céréalières." Aix-Marseille 1, 2002. http://www.theses.fr/2002AIX11038.
Gumez, Laurie. "Caractérisation des propriétés physico-chimiques du tendon altéré par l'absence du facteur de transcription TIEG1 (TGFβ inducible Early Gene 1)." Compiègne, 2010. http://www.theses.fr/2010COMP1917.
The purpose of this study is to characterize the physico-chemical properties of tendon altered by TIEG1 gene (TGF-β Inducible Early Gene 1). The effect of this gene was analyzed at the cellular and molecular levels for the dorsal tail tendon and Achilles tendon extracted from WT and TIEG1 KO female mice C57BL/6. The molecular organization of collagen inside tendon fibers was analyzed with synchrotron and the collagen amount was determined from hydroxyproline assays. In parallel, expression analysis of genes involved in the development of tendon extracellular matrix was performed by qRT-PCR on 1, 3 and 8 months old fibroblasts. Then, molecular and chemical compositions were determined with FTIR (Fourier Transform Infrared Spectroscopy) and XPS (X-ray photoelectron spectroscopy) techniques on tendon surface. In addition, the internal molecular composition was quantified by FTIRM (Fourier Transform Infrared Microspectroscopy) technique, requiring the development of experimental protocols. The results revealed that the absence of TIEG1 gene induced a disorganization of the collagen structure, a significant decrease in the amount of collagen as well as differences in gene expression. Moreover, the comparison of the internal and external molecular composition is different according to the type of tendon (tail tendon vs Achilles tendon) and genotype (WT vs TIEG1 KO). These data allow us to characterize the role of TIEG1 on tendon structure in order to design new therapeutics
Laubé, Florian. "Compréhension des phénomènes physicochimiques régissant l’adhésion et la formulation de vernis à ongles à base de résines biosourcées : approches in silico et in vitro." Thesis, Lille 1, 2019. http://www.theses.fr/2019LIL1R014.
Several billion nail polishes are sold every year throughout the world, and the market is still fast-growing. Despite a tightening of regulations over the past twenty years, the composition of varnishes remains problematic from an environmental point of view. The main obstacle to reach a 100% bio-based varnish is the secondary film-forming agent, or resin, which provides the additional adhesion, the gloss and the stability that nitrocellulose lacks. In this context, we have focused on understanding the physicochemistry of these complex systems in order to assist the design of new compatible biosourced resins through the establishment of structures-properties relationships. First, complete physicochemical characterizations (surface aspect and surface energy, composition, permeability) were carried out on native nails and two semi-synthetic models. An adhesion test was developed to evaluate the adhesion of formulations onto substrates. Correlated to physicochemical characterizations, these results allowed to identify the best model of the native nail and highlighted the adhesion mechanisms at the varnish-nail interface. In parallel, the "benchmarks" resins were characterized in order to define precise specifications according to their application performances. Thanks to the adaptation of prediction tools to polymers, we managed to link structural modifications to solubility and was validated using synthesized model oligoesters. The impact of some structural features on the gloss or the hardness of resins has been highlighted and the identified structures-properties relationships were confirmed through the evaluation of the performances of new bio-based polyester resins
Ducel, Jean-François. "Nouveaux verres borophosphates de sodium et de calcium. Corrélation structure-propriétés physico-chimiques. Application dans le domaine biomédical." Phd thesis, Université Sciences et Technologies - Bordeaux I, 1993. http://tel.archives-ouvertes.fr/tel-00134062.
Leproux, Anne. "Etude des polyosides de deux chlorophycées botryococcus braunii et enteromorpha intestinalis." Paris 6, 1986. http://www.theses.fr/1986PA066119.
Daoudi, Mouad. "Développement de diagnostics optiques et chimiques pour caractériser et contrôler les émissions particulaires et gazeuses des systèmes de combustion." Electronic Thesis or Diss., Université de Lille (2022-....), 2022. http://www.theses.fr/2022ULILR062.
Combustion is one of the main contributors to both particulate matter (PM) and several gaseous pollutants which may have harmful effects on human health, environment, and climate. The main goal of this PhD is to develop a measurement procedure based on optical extinction to monitor PM and/or some gaseous pollutants emissions produced by a combustion system (e.g., internal combustion engine, turbine or industrial burner). This work also aims to shed the light on the relationship between the chemical composition and the optical extinction coefficient measured for these emissions. To succeed in this measurement challenge and avoid the complexity of a real powertrain setup, a modular combustion bench has been built in which gaseous pollutants and PM can be monitored independently. This experimental setup was equipped with a version of the miniCAST soot generator that has the ability to burn liquid fuels, thus allowing the study of the impact of the chemical composition of the fuel on the physico-chemical properties of PM. A total of 34 operating points were characterized, spanning a wide range of flame overall equivalence ratio (i.e., 0.104 - 1.673) using two different fuels (diesel B7 and dodecane). The soot particles produced by this burner were characterized in terms of morphological key parameters, size distributions, mass concentrations, and optical extinction coefficients. All these data were then used to evaluate and intercompare the soot volume fraction using three different methods: granulometric (combining size measurement and morphology), mass, and optical.Furthermore, the chemical composition of the combustion products of the miniCAST was studied in order to characterize the organic content of the gas-phase and the particulate-phase. This study was carried out by combining gas chromatography (GC), to examine low mass polycyclic aromatic hydrocarbons (PAHs) in the gas-phase, and time-of-flight secondary ion mass spectrometry (ToF-SIMS), to characterize the heavy PAHs in both the gas- and particle-phases. These experiments allowed to identified the operating points associated with the highest content of organic compounds. Then, a correlation was observed between the presence of that organic content (mostly attributed to organic PAHs) and the optical extinction coefficient. The use of an oxidation catalyst (catalytic stripper) on the burner exhaust gases allowed to evaluate the impact of this thermal treatment at 350 °C on the chemical composition of the exhaust gases, on the size and morphology characteristics of soot aggregates, and consequently on the measurement of the optical extinction coefficient. Finally, the measurement of the optical extinction coefficient for PM and gaseous pollutants such as NO, NO2 and/or NH3 injected first separately and then simultaneously was performed to evaluate the interference of gaseous pollutants with PM and to propose a procedure allowing their simultaneous control.In conclusion, this thesis provides for a soot generator's PM emissions a detailed description of soot particles sizes, morphologies, soot volume fractions and optical extinction coefficient, as well as a detailed characterization of the chemical composition of the gas- and particulate-phase produced by this generator, under different operating conditions. Thanks to the experimental database obtained, this thesis proposes a methodology of measurement and analysis for optical extinction coefficients and for ToF-SIMS mass spectra which can be transposed to the study of bio-fuels or synthetic fuels (e-fuels) in the near future
Lemaire, Romain. "Étude de l'impact de la combustion de différents types de carburants sur les caractéristiques physico-chimiques des particules de suie par couplage de l'incandescence et de la fluorescence induite par laser." Electronic Thesis or Diss., Lille 1, 2008. http://www.theses.fr/2008LIL10138.
Soot particles generated in combustion processes are strongly linked to various environmental and health problems. As a consequence, regulations regarding particulate emissions are becoming more and more stringent. To reduce the quantities of soot emitted into the atmosphere, fundamental studies have to be undertaken in order to better understand the mechanisms involved in the formation of soot particles. The objective of this work is to study the impact of the combustion of different types of fuels on the physical-chemical properties of soot. To this end, a hybrid bumer has been specially designed in order to generate a series of liquid fuel diffusion flames whose hydrodynamic behaviour is similar and independent of the physical properties of the tested fuels. Quantitative mappings of soot and soot precursors have been carried out in flames of kerosene, Diesel, gasoline, biofuels and various kerosene and Diesel surrogates by coupling Laser Induced Incandescence and Laser Induced Fluorescence (Lll/LIF). By comparing the LII signaIs obtained for different excitation wavelengths, it has been possible to determine the evolution of the optical properties of soot as a function of the wavelength. The evolution of the physical properties of soot particles (density, specific heat, refractive index, diameter) during the combustion process have been derived from the analysis of the LII fluence curves and time decays obtained at different heights in the flames. Finally, a microprobe sampling system has been developed in order to obtain soot samples which have then been analysed using laser desorption/laser ionization/time-of- tlight mass spectrometry to determine the nature of the chemicals adsorbed on the soot surface
Dupeux, Tristan. "Integrated in silico and in vitro approaches to investigate the physicochemical phenomena induced by fragrances in micellar aqueous solutions and foams." Electronic Thesis or Diss., Université de Lille (2018-2021), 2021. http://www.theses.fr/2021LILUR053.
Fragrance is a major component of personal care product formulations, whose perception and intensity have a strong impact on the consumer's opinion of their effectiveness and appreciation. Depositing a fragrance on the hair in a durable way or controlling its release during in-use are serious technological and scientific challenges for the formulator and the physicochemist. Long-term release can be effectively ensured by perfume capsules which have provided a reliable technological solution, but the desired scent burst during the product use is not yet sufficiently mastered. In this context, we focused on understanding the behavior of fragrance molecules in a complex matrix, such as those found in shampoos, from the surfactant-rich aqueous micellar solution to the formation of foam after dilution, in order to identify the physicochemical levers to exalt the release of fragrance. By combining analytical and predictive approaches, we studied the interactions of fragrance molecules with surfactants and salts. Headspace gas chromatography (HS-GC), DOSY NMR and COSMOmic software were useful tools to correlate the concentration of fragrance molecules in air with the solubilized fraction and their positioning in the micellar system. The addition of salts completely modifies the properties of the solution at the level of the micelles as well as the perfume. The release of the latter depends mainly on the nature of the ions and the concentration of the perfume in the water while remaining independent of the viscosity of the system. The COSMO-RS-ES (adapted to salt solutions) and COSMOplex (adapted to micelles) methods provided reasonable predictions of the experimentally measured fragrance partition in such systems. Finally, a feasibility analysis was performed to investigate the importance of foam properties and structure in enhancing airborne fragrance diffusion
Lemaire, Romain. "Étude de l'impact de la combustion de différents types de carburants sur les caractéristiques physico-chimiques des particules de suie par couplage de l'incandescence et de la fluorescence induite par laser." Thesis, Lille 1, 2008. http://www.theses.fr/2008LIL10138.
Soot particles generated in combustion processes are strongly linked to various environmental and health problems. As a consequence, regulations regarding particulate emissions are becoming more and more stringent. To reduce the quantities of soot emitted into the atmosphere, fundamental studies have to be undertaken in order to better understand the mechanisms involved in the formation of soot particles. The objective of this work is to study the impact of the combustion of different types of fuels on the physical-chemical properties of soot. To this end, a hybrid bumer has been specially designed in order to generate a series of liquid fuel diffusion flames whose hydrodynamic behaviour is similar and independent of the physical properties of the tested fuels. Quantitative mappings of soot and soot precursors have been carried out in flames of kerosene, Diesel, gasoline, biofuels and various kerosene and Diesel surrogates by coupling Laser Induced Incandescence and Laser Induced Fluorescence (Lll/LIF). By comparing the LII signaIs obtained for different excitation wavelengths, it has been possible to determine the evolution of the optical properties of soot as a function of the wavelength. The evolution of the physical properties of soot particles (density, specific heat, refractive index, diameter) during the combustion process have been derived from the analysis of the LII fluence curves and time decays obtained at different heights in the flames. Finally, a microprobe sampling system has been developed in order to obtain soot samples which have then been analysed using laser desorption/laser ionization/time-of- tlight mass spectrometry to determine the nature of the chemicals adsorbed on the soot surface
Freville, Vianney. "Caractérisation et évaluation des performances de nouveaux solvants synthétisés à partir d'agroressources." Compiègne, 2011. http://www.theses.fr/2011COMP1964.
Solvents are essential products in many fields of applications. However, their use is now prohibited because they mostly derive from petroleum and they are toxic to health and the environment. Therefore, currently, eco-responsible technologies are developed to replace these compounds. Among these alternatives, agrosolvents represent one of the most important ways to substitute petrochemical solvents. They are produced by at least one part of renewable raw materials and they are eco-friendly (non-VOC, biodegradable, non-toxic and non eco-toxic). In this context, this thesis is part of the AGROSOLVANT project, supported by the Region Picardie and the Region Champagne-Ardenne and accredited by the world-scale competitive cluster Industries and Agro-Resssources (IAR). The objective of the project is to substitute solvents derived from petroleum by new green solvents derived from renewable resources, in order to use them in two different applications: degreasing and agrochemical formulations. This work is dealing with the evaluation of properties and performances of agrosolvents synthesized from agricultural products which allow the valorization of biofuels co-products (glycerol, amyl alcohols) and the fermentative succinic acid production. The study is structured around a substitution process in order to examine the physico-chemical properties, the solvent power and the application performances of the molecules. At each step, a comparison is made with petrochemical solvents. In the context of substitution, the last part concerns agrosurfactant aqueous solutions and focuses on the physico-chemical mechanisms involved in aqueous degreasing processes
Fournaise, Tristan. "Étude multiéchelle des phénomènes de reconstitution de poudres issues d'agroressources." Electronic Thesis or Diss., Université de Lorraine, 2022. http://docnum.univ-lorraine.fr/public/DDOC_T_2022_0100_FOURNAISE.pdf.
This thesis work focused on a better understanding of powder reconstitution phenomena and the development of descriptive and predictive models applicable to powder reconstitution. The first objective was to discriminate powders by principal component analysis according to their physicochemical and structural characteristics, as well as their manufacturing process. Then, the second objective was to determine the main factors involved in the reconstitution of powders and their impacts on the wetting and the reconstitutability. Powders were classified according to their reconstitution behavior into four categories: good (fast wetting and short reconstitution), correct (slow wetting and short reconstitution), mediocre (fast wetting and long reconstitution), and poor (slow wetting and long reconstitution). The third objective was to study the impact of surface properties on wettability, a whey protein isolate powder for which wetting is the limiting reconstitution step (correct reconstitution category: slow wetting and short reconstitution) has been selected. Its surface has been modified by coating with different sugars (sucrose, lactose, glucose, fructose, and galactose) to improve its wettability and understand the mechanisms of interaction between water and particle surface. The fourth objective was to develop a semi-empirical model allowing the description of the kinetics of reconstitution followed by laser granulometry. It consisted in representing the evolution of the median particle size during the main stages of reconstitution (from swelling to solubilization) in the form of first-order indicial responses, which made it possible to access kinetic information on each step of the reconstitution. The development of this descriptive modelling method has made it possible to respond to three aims: develop a model that is applicable to powders with varied reconstitution behaviors, describing the entire reconstitution with a single equation, and whose model parameters have a physical meaning linked to the kinetics of the reconstitution steps. The obtained semi-empirical descriptive model made it possible, using statistical methods (Pearson coefficients), to identify the impact of the physicochemical parameters of eight powders (the kinetics obtained for the other powders could not be modeled given their instantaneity or complexity) on the durations and rates of the various stages of reconstitution. Finally, a model aiming at predicting, from the most influential physicochemical properties, the reconstitution time of the powders under the reference conditions used in the experiments carried out during the first part of the PhD work was developed using empirical models of classical form (multilinear regression, monomial model) or improvements to these (models based on normalized values of physicochemical properties, hybrid model combining power and exponential laws). The difficulty of this study resided in the relevant choice of the physicochemical characteristics taken into account for the large panel made up of the thirty-six powders considered
Irimiea, Cornelia. "Characterization of soot particles and their precursors by coupling laser-based techniques." Thesis, Lille 1, 2017. http://www.theses.fr/2017LIL10066.
Combustion impacts many important aspects of our life like the air quality, the local and global climate and the use of energy sources. In the last decades, an outstanding progress towards cleaner combustion has been achieved. However, the reaction pathways leading to the formation of some pollutants, especially particulate matter (soot) resulting from incomplete combustion, are still elusive. In this work, we aim to investigate specific aspects of soot and its precursors formation in laboratory flames for a fundamental understanding of the mechanisms leading from the gas phase up to the mature particulate found in the exhausts. This objective is also pursued in field-campaigns to assess the potential impact of soot surface properties on the environment. Following this approach, experimental techniques like in-situ laser induced incandescence and fluorescence, and ex-situ laser desorption and secondary ion mass spectrometry are used to target specific properties of soot and its precursors. Notably, the evolution of the complex refractive index of soot is measured as a function of soot maturity, and the implications on both the flame physico-chemistry and the analytical techniques applicability are discussed. Additionally, a new detection method for soot and precursors based on simultaneous excitation at one wavelength is developed. In parallel, two campaigns are dedicated to the analysis of the surface chemistry of soot sampled from airplane and car exhausts. Statistical methods as multivariate analysis are used to identify patterns and differences within sets of samples by assessing the influence of the combustion parameters or the role of the fuel
Millon, Eric. "Étude des mécanismes d'adhérence des émaux sur les aciers." Nancy 1, 1987. http://www.theses.fr/1987NAN10099.
Connolly, Siobhan. "Etude biochimique et physicochimique de gommes végétales exsudées par Acacia senegal et Combretum nigricans." Rouen, 1988. http://www.theses.fr/1988ROUES005.