Cette étude porte sur le broyage en voie humide (nanobroyage) de produits organiques à usage pharmaceutique dans un broyeur à billes agité. L'objectif des travaux réalisés était d'analyser la faisabilité de l'opération de nanobroyage et d'améliorer la compréhension des processus de réduction de taille dans le cas de produits organiques cristallins. Dans un premier temps, des expériences préliminaires ont été menées pour le choix d'agents mouillants et dispersants adéquats pour les matériaux choisis (ciclopirox, ibuprofène) et pour la mise au point du mode de fonctionnement du procédé de broyage. Nous avons également testé différentes techniques comme la spectroscopie acoustique et la diffusion dynamique de la lumière pour caractériser la distribution de taille des particules broyées, en se basant sur une étude expérimentale conduite sur la calcite, utilisée dans cette étude comme matériau de référence. La seconde partie a été consacrée au broyage par microbilles appliqué aux différents matériaux choisis. Nous avons étudié l'influence des paramètres opératoires tels que le débit de suspension, la vitesse de rotation de l'agitateur, la taille des billes de broyage et la concentration en solide sur l'efficacité énergétique du procédé et la qualité des produits broyés. Les critères de qualité pris en compte dans cette étude sont la distribution de taille des particules, la stabilité et le comportement rhéologique des suspensions broyées ainsi que les propriétés structurales du produit. L'effet du broyage sur les changements microstructuraux des différents produits a enfin été analysé. Une attention particulière a également été portée sur l'effet de la température sur le procédé de réduction de taille et les propriétés de l'ibuprofène broyé. / This work focuses on wet grinding (nanogrinding) of organic materials for pharmaceuticals using a stirred media mill. The aim of the work was to examine the feasibility of nanogrinding process and to improve the understanding of size reduction processes applied on crystalline organic products. Firstly, preliminary investigations were conducted to make a choice of appropriate wetting agents and dispersants for the selected materials (ciclopirox, ibuprofen), and for the development of the operation mode of the grinding process. We also tested different techniques such as acoustic attenuation spectroscopy and dynamic light scattering to characterize the ground particle size distribution, based on an experimental study conducted on calcite, used in this study as reference material. The second part was devoted to the milling process by grinding beads applied to the selected materials. The influence of operating parameters such as suspension flow rate, stirrer tip speed, grinding media diameter and solid mass concentration on grinding process efficiency and ground products quality were investigated. The quality criteria considered in this study are particle size distribution, stability and rheological behaviour of the products, as well as their structural properties. The effect of grinding process on the microstructural change of different materials was finally analysed. Particular attention was also focused on the effect of temperature on size reduction process and ground ibuprofen properties.

Résumé : Cette étude examine l'impact de la taille et de la gradation de particules sur les corrélations théoriques et empiriques existantes les plus connues entre la résistance au cisaillement et le comportement dilatatant des matériaux granulaires en condition de déformation plane et en compression triaxiale drainée. À cette fin, 276 tests de cisaillements symétriques directs et 35 tests de compressions triaxiales drainées ont été menés sur des échantillons composés de billes de basalte (particules rondes), et de sables constitués de particules angulaires (sable de Péribonka et sable d'Eastmain) sur une échelle de 63 µm à 2000 µm afin d'évaluer leur résistance au cisaillement et leur comportement de dilatance sur une vaste échelle de pressions normales et de densités relatives initiales. Premièrement, la fiabilité et l'applicabilité des limites de mesure à l’aide de tests physiques de cisaillements symétriques directs dans l'interprétation de la résistance au cisaillement frictionnel en déformation plane des matériaux granulaires ont été discutées et confirmées par l'usage du code informatique DEM, SiGran. L'accent a été particulièrement mis sur la validation du modèle DEM au moyen de comparaison des résultats des simulations DEM avec leurs équivalents physiques à une échelle macro. Les résultats virtuels DSA sont abordés du point de vue de la coaxialité entre les principales tensions et les principales directions des paliers de pression ainsi que de la déviation de la direction d'extension nulle à partir de la direction horizontale. Les résultats numériques fournissent également des données quantitatives sur les différentes formes d'énergie consommées durant le cisaillement confirmées par d'autres résultats physiques et numériques publiés. Sur la base des postulats précédents, un examen minutieux des résultats des essais de cisaillements directs et de données issues de la littérature a été accompli afin d'évaluer la fiabilité des formules empiriques bien connues de Bolton et Collins et al. avec leurs constantes couramment employées en condition de déformation plane. L'étude montre qu'une application des relations empiriques de force-dilatation de cisaillement avec les constantes proposées par Bolton (1986) et Collins et al. (1992) aux sables ayant une distribution de taille de particules différente peut conduire à surestimer leurs valeurs en terme de force de cisaillement. Dans cette étude, les coefficients des équations de Bolton et Collins et al. ont donc été ajustée afin de prendre en compte les caractéristiques des particules, en particulier le diamètre médian, D50. De manière analogue, les effets microstructuraux imposés par la géométrie interne des particules (par exemple la taille, la forme et la gradation des particules) sur la relation tension-dilatation très connue, celle de Rowe (1962), et son ajustement empirique en condition triaxiale drainée ont été examinés dans cette étude. Une comparaison des prédictions des formules proposées avec les données de force de cisaillement issues de la littérature fournit de nombreuses preuves en faveur des contraintes mises en place au sein des relations existantes de force-dilatation de cisaillement en condition de déformation plane et triaxiale. Ces comparaisons prouvent également que la prise en compte de la taille des grains conduit à des résultats plus tangibles que lorsque la taille de la particule n'est pas considérée. Les formules de force-dilatation ajustées peuvent se révéler avantageuses pour évaluer indépendamment la cohérence des forces de cisaillement déterminées expérimentalement et pour introduire des lois d’écoulement plus précises dans les analyses géotechniques analytiques et numériques. / Abstract : The present study examines more closely the potential impact of particle size and gradation on the most famous existing theoretical and empirical correlations between the shear strength and the dilation behavior of granular materials in plane strain and drained triaxial compression conditions. For this purpose, 276 symmetrical direct shear and 35 drained triaxial compression tests have been carried out on samples made up of basalt beads (rounded particles), and sands consisting of angular particles (Péribonka sand and Eastmain sand) in the range of 63 µm to 2000 µm to evaluate their shear resistance and dilation behavior over a wide range of normal pressures and initial relative densities. First, the reliability and applicability of boundary measurements in physical symmetrical direct shear tests to interpret the plane strain frictional shearing resistance of granular material have been discussed and confirmed using DEM computer code SiGran. Particular emphasis is placed on the validation of the DEM model by comparing the results of DEM simulations with their physical counterparts at the macro-scale. The virtual DSA results are discussed in terms of the coaxiality between the principal stresses and the principal strains increments directions as well as the deviation of the zero extension direction from the horizontal direction. The numerical results also provide quantitative data on different forms of energy consumed during shearing confirming other published physical and numerical results found in the literature. Following the assumptions above, a close scrutiny of symmetrical direct shear test results and strength and dilation data from the literature have been done to evaluate the reliability of well-known empirical Bolton’s and Collins et al.’s formulations with their commonly used constants in plane strain condition. The study shows that an application of empirical shear strength-dilation relationships with the constants proposed by Bolton (1986) and Collins et al. (1992) to sands with different particle-size distribution may strongly over-predict their shear strength values. In this study, the coefficients of Bolton’s and Collins et al.’s equations have been, therefore, adjusted to account for particle characteristics, in particular for D50. Similarly, the microstructural effects imposed by internal particle geometry (e.g. particle-size, particle shape, and particle gradation) on most popular stress-dilatancy relationship of Rowe (1962), and its empirical adjustment in drained triaxial condition have been investigated in this study. A comparison of the predictions by the proposed formulas with shear strength data from the literature provides evidences in support of the implemented constraints into existing shear strength-dilation relations in plane strain and drained triaxial conditions. These comparisons also proves that accounting for the grain size yields more authentic results than when particle size is not considered. The adjusted strength-dilation formulas may be beneficial for independently assessing the consistency of the experimentally-determined shear strengths, and introducing more refined flow rules into analytical and numerical geotechnical analyses.

Abstract : Although concrete is a relatively green material, the astronomical volume of concrete produced worldwide annually places the concrete construction sector among the noticeable contributors to the global warming. The most polluting constituent of concrete is cement due to its production process which releases, on average, 0.83 kg CO[subscript 2] per kg of cement. Self-consolidating concrete (SCC), a type of concrete that can fill in the formwork without external vibration, is a technology that can offer a solution to the sustainability issues of concrete industry. However, all of the workability requirements of SCC originate from a higher powder content (compared to conventional concrete) which can increase both the cost of construction and the environmental impact of SCC for some applications. Ecological SCC, Eco-SCC, is a recent development combing the advantages of SCC and a significantly lower powder content. The maximum powder content of this concrete, intended for building and commercial construction, is limited to 315 kg/m[superscript 3]. Nevertheless, designing Eco-SCC can be challenging since a delicate balance between different ingredients of this concrete is required to secure a satisfactory mixture. In this Ph.D. program, the principal objective is to develop a systematic design method to produce Eco-SCC. Since the particle lattice effect (PLE) is a key parameter to design stable Eco-SCC mixtures and is not well understood, in the first phase of this research, this phenomenon is studied. The focus in this phase is on the effect of particle-size distribution (PSD) on the PLE and stability of model mixtures as well as SCC. In the second phase, the design protocol is developed, and the properties of obtained Eco-SCC mixtures in both fresh and hardened states are evaluated. Since the assessment of robustness is crucial for successful production of concrete on large-scale, in the final phase of this work, the robustness of one the best-performing mixtures of Phase II is examined. It was found that increasing the volume fraction of a stable size-class results in an increase in the stability of that class, which in turn contributes to a higher PLE of the granular skeleton and better stability of the system. It was shown that a continuous PSD in which the volume fraction of each size class is larger than the consecutive coarser class can increase the PLE. Using such PSD was shown to allow for a substantial increase in the fluidity of SCC mixture without compromising the segregation resistance. An index to predict the segregation potential of a suspension of particles in a yield stress fluid was proposed. In the second phase of the dissertation, a five-step design method for Eco-SCC was established. The design protocol started with the determination of powder and water contents followed by the optimization of sand and coarse aggregate volume fractions according to an ideal PSD model (Funk and Dinger). The powder composition was optimized in the third step to minimize the water demand while securing adequate performance in the hardened state. The superplasticizer (SP) content of the mixtures was determined in next step. The last step dealt with the assessment of the global warming potential of the formulated Eco-SCC mixtures. The optimized Eco-SCC mixtures met all the requirements of self-consolidation in the fresh state. The 28-day compressive strength of such mixtures complied with the target range of 25 to 35 MPa. In addition, the mixtures showed sufficient performance in terms of drying shrinkage, electrical resistivity, and frost durability for the intended applications. The eco-performance of the developed mixtures was satisfactory as well. It was demonstrated in the last phase that the robustness of Eco-SCC is generally good with regards to water content variations and coarse aggregate characteristics alterations. Special attention must be paid to the dosage of SP during batching. / Résumé : Même si le béton est un matériau relativement vert, le volume astronomique de béton produit à travers le monde chaque année met le secteur de la construction en béton parmi les contributeurs important au réchauffement climatique. Le constituant le plus polluant du béton est le ciment en raison de son processus de production qui dégage, en moyenne, 0,83 kg de CO[indice inférieur 2] par kg de ciment. Le béton autoplaçant (BAP), un type de béton qui peut remplir le coffrage sans vibration externe, est une technologie qui peut offrir une solution aux problèmes de développement durable de l'industrie du béton. Cependant, toutes les exigences de la maniabilité du BAP proviennent d'une teneur en poudre plus élevé (par rapport au béton conventionnel), ce qui peut augmenter le coût de la construction et de l'impact environnemental du BAP pour certaines applications. Le BAP écologique, Éco-BAP, est un développement récent combinant les avantages du BAP tout en ayant une teneur en poudre significativement plus faible. La teneur en poudre maximale de ce béton, destinée à la construction du bâtiment et aux applications commerciales, est limitée à 315 kg/m[indice supérieur 3]. Néanmoins, la conception de l’Éco-BAP peut être difficile, car un équilibre délicat entre les différents ingrédients de ce béton est nécessaire pour garantir un mélange satisfaisant. Dans ce programme de doctorat, l'objectif principal est de développer une méthode systématique pour la formulation de l’Éco-BAP. Puisque l'effet de groupe des particules (EGP) est un paramètre clé pour la conception des mélanges l’Éco-BAP stables, et que ce phénomène est peu connu, dans la première phase de cette recherche, l’EGP est étudié. Cette partie se concentre sur l'influence de la granulométrie sur l’EGP et la stabilité des mélanges de modèle ainsi que des BAPs. Dans la deuxième phase, le protocole de formulation est développé, et les propriétés des mélanges obtenus, à l’état frais ainsi que l’état durcis, sont évaluées. Étant donné que l'évaluation de la robustesse est cruciale pour la production du béton à grande échelle, dans la dernière phase de ce travail, la robustesse d'un des mélanges les plus performants de la Phase II est examinée. Basé sur les résultats obtenus, nous constatons que l'augmentation de la fraction volumique d'une classe mène à une meilleure stabilité de cette classe. Cela contribue également à une EGP supérieure du squelette granulaire et à une stabilité plus élevée du système. Il a été montré qu'une granulométrie continue dans lequel la fraction volumique de chaque classe est plus grande que la classe consécutive plus grossière peut augmenter l’EGP. En utilisant une telle granulométrie, la fluidité d’un mélange du BAP pourrait être augmentée sans compromettre la résistance à la ségrégation. Un indice de prédiction du potentiel de la ségrégation de particules suspendues dans un fluide à seuil a été proposé. Dans la deuxième phase de la thèse, une méthode de conception en cinq étapes pour l’Éco-BAP a été développée. Le protocole de formulation commence par la détermination des teneurs en poudre et de l'eau, suivie par l'optimisation des fractions volumiques du sable et des gros granulats selon un modèle idéal de granulométrie (Funk et Dinger). La composition de poudre est optimisée dans la troisième étape afin de minimiser la demande en eau tout en garantissant une performance adéquate à l'état durci. Le dosage du superplastifiant (SP) est déterminé dans l’étape suivante. La dernière étape s’agit d’évaluer le potentiel du réchauffement climatique des mélanges développés. Les mélanges de l’Éco-BAP optimisés répondent à toutes les exigences à l'état frais pour le BAP. La résistance à la compression à 28 jours de ces mélanges est dans la fourchette cible de 25 à 35 MPa. En outre, les mélanges montrent des performances suffisantes en termes de retrait de séchage, la résistivité électrique, et la résistance contre gel-dégel pour les applications visées. La performance écologique des Éco-BAPs produis a été satisfaisante. Il a été démontré dans la dernière phase que la robustesse de l'Éco-BAP est généralement bonne en ce qui concerne les variations de teneur en eau et les changements de propriétés des gros granulats. Une attention particulière doit être accordée au dosage du SP pendant le malaxage.

The dust particles generated due to mechanical wear of iron ore pellets and clusters formed in molten stainless steel alloyed with rare earth metals (REM) are considered in this study. Firstly, the influence of the characteristics of iron ore pellets, applied load on a pellet bed and partial reduction of the pellets on the size distribution of the generated dust was investigated. Secondly, REM clusters are investigated to evaluate the size distribution of the clusters. Also, an extreme value distribution (EVD) analysis has been applied for the observed REM clusters. The large sized pellets showed 10-20% higher wear rate than small sized pellets during wear in a planetary mill. Moreover, an increase of ~67% was observed in the friction and dust generation in the pellet bed as the applied load increased from 1 to 3 kg. Also, it was observed that a higher friction in the pellet bed can lead to an increased amount of airborne particles. The mechanical wear experiments of pellets reduced at 500 °C (P500) and 850 °C (P850) showed that P500 pellets exhibit ~16-35% higher wear rate than unreduced pellets. For the P850 pellets, the wear is inhibited by formation of a metallic layer at the outer surface of the pellets. The mechanism of dust generation has been explained using the obtained results. A reliable cluster size distribution of REM clusters was obtained by improving the observation method and it was used to explicate the formation and growth mechanism of REM clusters. The results show that the growth of clusters is governed by different types of collisions depending on the size of the clusters. For EVD analysis three different size parameters were considered. Moreover, using the maximum length of clusters results in a better correlation of EVD regression lines compared to other size parameters. Moreover, a comparison of predicted and observed maximum lengths of clusters showed that further work is required for the application of EVD analyses for REM clusters. / Studien fokuserar på två olika typer av mikropartiklar som är valda från olika delar av järn- och ståltillverkningsprocessen. Dessa partiklar är dels stoft som genereras på grund av mekanisk nötning av partiklar och dels klusters som bildas i flytande rostfria stål legerade med sällsynta jordartsmetaller (REM). Inledningsvis så undersöktes inverkan av tre faktorer på storleksfördelningen hos stoft som bildas vid hantering av järnoxidpellets. De undersökta faktorerna inkluderade karakteristiken hos järnoxidpellets, det applicerade trycket på pelletsbädden och den partiella reduktionen av järnoxidpellets. Därefter så utfördes tredimensionella undersökningar av REM kluster som extraherats med hjälp av elektrolytisk extraction för att bestämma storleksfördelningen hos klustren. Dessutom så utfördes en extremvärdesdistribution (EVD) studie för de studerade klustren. En planetkvarn användes för att undersöka inverkan of karakeristiken hos pellets på stoftbildningen. Resultaten visade att storleken på pellets kan påverka nötningshastigheten under dessa försöksförhållanden. Pellets som hade en större storlek (13.5&lt; Deq &lt;15.0 mm) uppvisade en 10 till 20% högre nötningshastighet i jämförelse med mindre pellets (9.5&lt; Deq &lt;12.5 mm). Baserat på analyserna av stoftet som genererades under nötningsexperimenten så konstaterades att nötningsmekanismerna för dessa pellets var abrasions- och kollisionsnötning. En pelletsbädd skapades för att möjliggöra studier av inverkan av ett applicerat tryck på stoftbildningen och friktionskrafterna i en pelletsbädd. Ett varierat tryck på mellan 1 till 3 kg applicerades på pelletsbädden. Resultaten visade att en ökning på ~67% av friktionskraften och stoftbildningen ägde rum när det applicerade trycket ökades från 1 till 3kg. Dessutom så visade resultaten att en högre friktionskraft i pelletsbädden kan resultera in en ökad mängd luftburna partiklar. Den mekaniska nötningen av pellets som reducerats vid 500 °C (P500) och 850 °C (P850) studerades också genom användande av en planetkvarn. Resultaten visade att P500 pellets uppvisade en ~ 16 till 35% högre nötningshastighet i jämförelse med oreducerade referenspellets.  Resultaten för P850 pellets visade att den mekaniska nötningen motverkades genom bildningen av ett metalliskt skikt på den yttre delen av pelletsen. Resultaten visade också att stoftet som bildats pga mekanisk nötning av reducerade pellets innehöll 3 till 6 gånger mer grova partiklar  (&gt;20µm) i jämförelse med stoft som bildats från oreducerade pellets. Slutligen så diskuterades hur dessa resultat kan relateras till industriella förhållanden med avseende på mekanismerna som är involverade i den mekaniska nötningen av pellets samt med avseende på relationen mellan hastigheten av de utgående gaserna och storlken och morfologin hos stoftpartiklarna. Klusters innehållande REM-oxider som extraherats från en 253MA rostfri stålsort undersöktes med användande av en tredimensionell teknik. En trovärdig storleksfördelning av klusters (CSD) erhölls genom att förbättra undersökningsmetoden och denna användes för att studera bildningen och tillväxten av REM oxider. Dessutom så användes cirkularitetsfaktorn hos klusters för att dela in klustren i två olika grupper, vilka bildas och tillväxer enligt olika mekanismer. Resultaten visade också att tillväxten av klusters gynnas av olika typer av kollisioner som beror av av storleken på klusters. För REM-klusters så drogs slutsatsen att turbulenta kollisioner är den huvudsakliga mekanismen som påverkar tillväxten. Avhandlingen behandlar även problemet om hur det är möjligt att hantera synfält där det inte förekommer kluster vid en extremvärdesdistribution (EVD) analys. Tre olika parametrar undersöktes i EVD analysen. Resultaten visar att om den maximala längden på kluster (LC) används i analysen så erhålls den bästa korrelationen gällande regressionslinjen för en EVD analys. Specifikt så var R2 värdet upp till 0.9876 i jämförelse med de andra storleksparametrarna som har värden i intervallet 0.9656 – 0.9774. Slutligen så visar resultaten från en jämförelse mellan beräknade och observerade maximala klusterlängder att EVD analyser för studier av REM kluster behöver undersökas ytterligare i framtiden. / <p>QC 20161128</p>

Per- and polyfluoroalkyl substances (PFASs) are a group of artificial chemicals which have been used in a wide area of applications such as surface protection agents in cloths and different industrial applications. It has been found that PFASs are potentially toxic and are frequently found in the environment due to their persistent and mobile properties. Effluents from wastewater treatment plants (WWTPs) have been identified as an important point source of PFASs. Bark, by-product from the paper and wood industry, is a low-cost adsorbent and has the potential to be used as a filter material for PFASs in WWTPs. In this study, the removal of PFASs in wastewater has been investigated using granulated active carbon (GAC) (n = 2) and bark (n = 2) in a pilot scale experiment at Kungsängsverket, Uppsala over a period of five weeks. The specific objects included: i) investigate the influence of flow-rate (10, 30 40 and 60 Ld-1 ) on the removal efficiency of PFASs in the GAC and bark filters, ii) investigate the influence of particle size of bark on the removal efficiency of PFASs and iii) establish what circumstances that potentially promotes removal of PFASs in GAC and bark filters. The results showed that GAC was the most effective method compared to bark, with a reduction of 73-93%, with increasing efficiency under low flow (10-30 L d-1 ) conditions. The removal efficiency of bark was 45% with a particle size of 2-5 mm and under low flow conditions (10-30 L d-1 ), while under high flow conditions (60 L d-1 ) with the same particle size the removal of PFASs was not efficient, instead the total PFAS concentration increased with 40%. In contrast, bark with a particle size of 5-7 mm proved to be not efficient in removing PFASs (removal efficiency = 0%). In general, the removal efficiency increased with smaller particle size of the adsorbent and lower flow rate. The results indicate that bark may be a low-cost alternative in reducing PFASs from wastewater, under certain conditions. / Per- och polyfluroalkyla ämnen (PFAS) är en familj av artificiella fluorerade organiska föreningar som har använts sedan 1950-talet i en rad olika applikationer, såsom impregnering i kläder. Studier har visat att PFAS är potentiellt toxiska och att de förekommer globalt på grund av deras persistenta och mobila egenskaper. Spillvatten från avloppsreningsverk etablerats som en betydande källa för PFAS. Bark, vilket är en biprodukt från pappers- och träindustrin, är ett poröst material vilket möjligen kan användas som adsorbent av PFAS. Denna studie har jämfört effektiviteten hos granulerat aktivt kol (GAC) och bark för att minska PFAS i avloppsvatten. Experimentet var utformat som ett småskaligt kolonn-experiment vid Kungsängsängsverket, Uppsala, och pågick under en fem veckors period. Frågeställningen var att i) studera vilka effekter flödes-hastigheten (10, 30, 40 och 60 L d-1 ) har på reduktionen av PFAS hos GAC och barkfiltren, ii) studera vilka effekter partikelstorleken hos bark har på reduktion av PFAS och iii) redogöra vilka förhållanden som potentiellt gynnar reduktionen av PFAS i GAC och bark filtren. Resultaten visade att GAC var det mest effektiva av de två materialen, med en total reduktion på 73- 93% av PFAS, med ökande effektivitet under låga flödesförhållanden (10-30 L d-1 ). Bark minskade den totala mängden av PFAS med 45% då partikelstorleken var 2-5 mm och under låga flödesförhållanden (10-30 L d-1 ) medan bark med samma partikelstorlek under ökade flödesförhållanden (60 L d-1 ) visade en ökning på 40% av PFAS i det utgående vattnet. Bark med en partikelstorlek på 5-7 mm visade ingen reduktion av PFAS. Generellt visade resultaten att reduktionen av PFAS ökar under låga flödesförhållanden och minskad partikelstorlek. Resultaten visade att bark kan vara ett alternativt material för att minska PFAS i avloppsvatten förutsatt att gynnsamma förhållanden upprätthålls.

Ce projet porte sur l’étude de plusieurs plantes d’intérêt de la Lorraine afin d’extraire par voie sèche et d’analyser des substances bioactives pour une valorisation de la flore locale. Un procédé de broyage et de tamisage de matériel végétal en de fines particules est utilisé afin de concentrer les composés bioactifs dans les poudres résultantes. Les poudres présentent des tailles de particules allant de 20 µm à 500 µm. Les propriétés phytochimiques de chaque classe granulométrique sont comparées à celle des parties de plantes non tamisées. Ces activités sont liées aux métabolites secondaires notamment les polyphénols et les dérivés terpéniques, qui sont caractérisés et quantifiés par des analyses LC-MS et GC-MS. Au cours de ce travail ont été développés : - la validation d’une nouvelle technique de séparation différentielle en fonction de la granulométrie des poudres par comparaison avec des extraits de plantes non tamisées ; - le dosage des différents constituants chimiques par des méthodes spectrométriques (UV/Visible), la caractérisation par des techniques analytiques telles que la LC-MS et GC-MS ; - l’évaluation du potentiel antioxydant/anti-radicalaire et anti-acétylcholinestérase réalisée par voie chimique in vitro en fonction des classes granulométriques. Cette étude démontre l’intérêt que présente ce nouveau procédé d’extraction différentiel des composés bioactifs issue de matrices végétales. Un enrichissement en produits actifs est observé au niveau de certaines classes granulométriques. Au niveau des activités antioxydantes pour toutes les plantes et de l’activité anti-acétylcholinestérase dans le cas du saule blanc, on observe des variations significatives en fonction de la taille de particules des échantillons des poudres superfines. L’étude de l’activité anti-acétylcholinestérase a été complétée par une modélisation in silico afin de mettre en évidence l’interaction entre les composés et les sites actifs de l’enzyme acétylcholinestérase / This project focuses on the study of 12 plants coming from Lorraine region. The study aims to improve the exploitation of local flora using a dry extraction process. A milling and a sieving process up to fine particles of plant material is used to concentrate the bioactive compounds in the resulting powders. The powders were classified according to the particle size which were ranging from 20 µm to 500 µm. The phytochemical properties of each particle size fraction are compared to non-sieved plant parts. These activities are linked to secondary metabolites including polyphenols and terpene derivatives, which are characterized and quantified by LC-MS and GC-MS analyses. It was developed in this work a new validation technique of differential separation depending on the particle size of the powders compared with extracts of non-sieved plant parts. The quantification of chemical compound classes was done by UV-Visible methods and their identification was conducted using LC-PDA/MS and GC-MS characterization technics. The evaluations of the antioxidant activity and anti-acetylcholinesterase activity is carried out in vitro according to the particle sizes. This study demonstrates the usefulness of this new differential extraction process of bioactive compounds from vegetal matrices. The Enhancing of the concentration of the active products is observed according to the particle sizes. In silico modeling study of anti-acetylcholinesterase activity is employed to highlight the interactions between the active sites and some anticipated active compounds in the extract

Nanopartículas de prata (AgNPs) vêm ganhando grande importância na prevenção contra infecções, principalmente pela sua incorporação em dispositivos médicos, tecidos entre outros produtos relacionados. Estudos prévios indicaram que partículas de menores tamanhos têm ação biocida mais efetiva. Nesse contexto, a separação granulométrica pode ser explorada para se obter partículas com as dimensões desejadas. A centrifugação foi escolhida, entre outros métodos de separação granulométrica, por sua possibilidade de ressuspensão das AgNPs após a separação, pela facilidade do aumento de escala e baixa complexidade. Um modelo do perfil de concentração (em uma cela centrífuga) de AgNPs em função do tempo e intensidade de centrifugação foi proposto a partir da Equação de Lamm, considerando a difusividade Browniana e o coeficiente de Svedberg calculado a partir do balanço de forças. A equação foi resolvida com a solução semi-analítica proposta inicialmente por Fujita (1962) e melhorada pelos alemães Joachim Behlke e Otto Ristau (2001). O desempenho da centrifugação de AgNPs sintetizadas pelo Método Turkevich foi avaliado analisando-se as partículas sobrenadantes por DLS, UV-Vis e microscopia eletrônica e comparando com o modelo proposto. O modelo previu razoavelmente a concentração total de partículas e a sua distribuição de tamanhos em diferentes tempos de centrifugação para forças de campo baixas (força centrífuga relativa até 1480). Para maiores forças de campo, houve uma sedimentação mais acelerada que a prevista pelo modelo. / Silver nanoparticles (AgNPs) have gained great importance in preventing infections, especially by their incorporation into medical devices, tissues and related products. Previous studies indicated that particles of smaller sizes have more effective biocidal action. In this context, granulometric separation may be explored to deliver nanoparticles of desired size. Centrifugation was chosen, among other particle size separation methods, for their ability to resuspend the AgNPs after separation, for the ease of scale-up and low complexity. A profile concentration model (in the centrifuge cell) of AgNPs as a function of time and intensity of centrifugation has been proposed from the Lamm equation, considering the Svedberg and Brownian diffusivity coefficients calculated from a force balance. The equation was solved with the semi-analytical solution proposed initially by Fujita (1962) and improved by the Germans Joachim Behlke and Otto Ristau (2001). The centrifugation performance of AgNPs synthesized by the Turkevich method was evaluated by analyzing the supernatant particles by DLS, UV-Vis and electron microscopy and comparing to the proposed model. The model reasonably predicted the total concentration of particles and their size distribution at different centrifugation times at low field strengths (1480 RCF). For higher field strengths, the sedimentation was faster than expected by the model.

Alguns dos mais freqüentes parâmetros utilizados como indicadores de qualidade do solo são: resistência tênsil de agregados (RT); densidade do solo (Ds); textura e curva de retenção de água do solo (CRAS). O objetivo deste estudo foi avaliar e desenvolver métodos para a determinação destes parâmetros e testar o uso de condicionadores químicos na redução do caráter coeso de solos, propondo alterações que tornem esses parâmetros mais precisos. Para RT foi proposto o uso do dinamômetro IMPAC, como equipamento alternativo ao KALATEC. Foram utilizados agregados (diâmetro 22,2 mm) do horizonte diagnóstico de um ARGISSOLO ACINZENTADO coeso, localizados em Pacajus-CE. Na determinação da Ds, avaliou-se a viabilidade do uso de um verniz automotivo como revestimento, substituto à resina saran na impermeabilização de agregados. Foram realizados ensaios preliminares para estabilidade desses agregados, número de imersões no verniz e tempo de secagem. Para validação da metodologia foram utilizados, além dos solos coesos e não coesos de Pacajus-CE, outros cinco solos, coletados em Piracicaba-SP. Na seleção da metodologia para análise granulométrica (AG) foram testados seis métodos: hidrômetro (com uma e quatro leituras); pipeta; micro-pipeta; método rápido e o do IAC, em 20 amostras de TFSA dos horizontes A e/ou B provenientes de 16 perfis de solos representativos dos estados de Santa Catarina e Rio Grande do Sul, com teores de argila entre 6 e 81 %. A comparação entre os métodos supracitados foi realizada com base em: ajuste por regressão linear entre as frações granulométricas determinadas pelo método da pipeta versus os demais; mudanças na classe textural indicadas no triângulo textural; e o melhor ajuste entre a fração argila e a umidade do solo retida na tensão 1500 kPa. Dados de retenção da água no solo, obtidos a partir do equipamento WP4-T, foram ajustados pelo modelo proposto em Genuchten (1980). Para avaliar o uso de condicionadores químicos na redução do caráter coeso de solos, a partir de medidas da RT, foram testados dois polímeros aniônicos (PAM). No Brasil, utilizaram-se os agregados coesos de Pacajus-CE, nos quais aplicou-se PAM por capilaridade. Na Austrália, usaram-se agregados de um solo hardsetting e o PAM foi aplicado com spray (líquido) ou a lanço (sólido), combinado com condicionadores a base de cálcio (sulfato e cloreto). Os valores da RT determinados por ambos os equipamentos (IMPAC e KALATEC) não diferiram entre si. No entanto, o IMPAC reduziu em quase 50 % o tempo de análise, com exatidão e precisão satisfatórias, o que reitera sua viabilidade em substituir o KALATEC. Os resultados da Ds demonstraram que o verniz automotivo Lazzudur é uma excelente alternativa à resina saran, além de reduzir o custo e o tempo de análise. Com relação à escolha do método para AG, a comparação entre os métodos mostrou que o do hidrômetro com uma leitura como uma alternativa viável, devido a sua simplicidade nos procedimentos de análises. A aplicação de PAM nos agregados dos solos coesos de Pacajus-CE não diminuiu a sua RT, sugerindo-se a redução das taxas aplicadas. A aplicação de PAM combinado com gesso refletiu na melhoria da qualidade física dos solos coesos da Austrália, reduzindo os valores da RT desses solos. / Some of the most common parameters used as indicators of soil quality are tensile strength of aggregates (TS), bulk density (Bd), texture and soil water retention curve (SWRC). The aims of this work were to: (i) evaluate and develop methods for determining these parameters; (ii) test the use of the chemical conditioners in reducing the character of cohesive soil. The less expensive IMPAC dynamometer was proposed to TS analysis, as alternative equipment to KALATEC. Aggregates (22.2 mm diameter) from cohesive soil Ultisol, located in northeast of Brazil were used. The feasibility of using automotive varnish to coat soil clods for bulk density measurement was evaluated for replacing SARAN resin. Preliminary tests were conducted to determine the clod stability, the number of immersions of clod in the varnish and drying time of the varnish. To confirm this methodology, clods of the cohesive and not cohesive Ultisol soil from northeast of Brazil and the other five soils from southern of Brazil were used. Six methods were evaluated for measuring particle size analysis (PSA): Hydrometer (with one and four readings); pipette, micro-pipette, \"rapid method\" and IAC method (Brazilian institute) using 20 samples of the A and/or B horizons of air dried soil from 16 soil profiles more significant of Santa Catarina and Rio Grande do Sul States, with clay range from 6 to 81 %. The comparison among these methods was conducted by: fitting linear regression between the pipette method versus the other; changing in textural class in the textural triangle; and the best fitting between fraction clay and soil moisture hold in 1500 kPa tension. Soil water retention data by WP4-T equipment were fitted by the model proposed in Genuchten (1980). Changes of TS of the cohesive soil after treatment with two kinds of anionic polymer (PAM) were investigated. In Brazil, clods from northeast were used and the PAM was applied by capillarity in the laboratory. In Australia, clods of a hardsetting soil were used and the PAM was applied by spray (liquid) or spread (solid), besides of conditioners based calcium (chloride and sulfate). No significant difference was detected at TS values determined by both of equipments tested. However, IMPAC equipment reduced time of analysis by almost 50%, with high accuracy, as a result it can replace the KALATEC equipment. Bulk density data showed that the automotive varnish is an excellent alternative to SARAN resin. The simpler procedure for determination of PSA was the hydrometer method (one reading), consequently, it was preferred than the other. The application of PAM at cohesive soils, from northeast of Brazil, did not reduce TS due to the high PAM concentration used in this study. This result suggests to need to reduce PAM rates. Gypsum an

Emulsões são sistemas formados quando dois componentes imiscíveis são misturados, na forma de gotículas dispersas numa fase contínua, estabilizados pela ação de emulsificantes, compostos anfifílicos, com afinidades por ambas as fases do sistema. No caso de emulsões de Pickering, o sistema é estabilizado por partículas coloidais sólidas, que adsorvem à interface das gotículas da emulsão. O objetivo desta dissertação foi produzir e caracterizar suspensões de celulose cristalina (CC), celulose amorfa (CA) e de partículas de quitosana (PQ) e avaliar seu potencial de aplicação como únicos compostos estabilizantes em emulsões óleo-em-água. As CC e CA foram produzidas por tratamentos térmico e ácido de celulose microcristalina, respectivamente, enquanto que as PQs foram produzidas por tratamento ácido de quitosana de média massa molecular. Em todos esses casos, os tratamentos foram seguidos de ultra-agitação: 0 (ST), 10000 (UT10), 15000 (UT15) ou 20000 rpm (UT20) por 3 minutos. As suspensões de CC, CA e PQ foram caracterizadas para determinação da distribuição do tamanho de partículas, do potencial zeta e da estabilidade física, e por microscopia eletrônica de varredura e/ou de força atômica. As partículas em pó, produzidas por liofilização, foram submetidas a análises de difração de raios-X, espectroscopia de infravermelho com Transformada de Fourier (FTIR) e de colorimetria instrumental. Em função dessas caracterizações, foi estudado o efeito do tipo de partícula estabilizadora (CC, CA ou PQ) sobre o tamanho de gotas, colorimetria instrumental e estabilidade física de emulsões com 20% (v/v) de óleo de soja, sem e com &beta;-caroteno. Observou-se que os tratamentos UT10, UT15 e UT20 provocaram importantes alterações na distribuição de tamanho de partículas, com redução do tamanho médio das partículas, sem efeito significativo da velocidade de agitação. Em relação à PQ, os tratamentos por ultra-agitação não influenciaram o tamanho de partículas, nem quando comparado com suspensões ST. A CC apresentou-se em fragmentos de fibras celulósicas e altamente instáveis em suspensão, com índices de instabilidade próximos a 0,78. A CA apresentou-se em partículas coloidais e agregados irregulares, com estabilidade física razoável em suspensão (0,26). As suspensões de PQ apresentaram grandes estruturas cristalinas de acetato de sódio, junto a partículas coloidais de quitosana, mas altamente estáveis em suspensão aquosa (0,04). De forma geral, o potencial &zeta; e a estabilidade física das suspensões de CC, CA e PQ não variaram com o tratamento (ST, UT10, UT15 e UT20). Na caracterização das partículas liofilizadas, constatou-se alto índice de cristalinidade da CC (81%), e baixa cristalinidade da CA (42%) e da PQ (40%). Os tratamentos não provocaram modificações consideráveis na estrutura química, analisada por FTIR, e nem na cor instrumental da CC, CA e PQ. Por fim, apenas a PQ foi capaz de produzir e estabilizar emulsões óleo-em-água, não havendo formação de fase creme durante o armazenamento. A adição de 0,005% de &beta;-caroteno à fase lipídica deixou as emulsões estabilizadas por PQ ligeiramente alaranjadas e aumentou sua estabilidade física, sem afetar o tamanho médio de suas gotas (29-32 &micro;m). Portanto, apenas a PQ demonstrou potencial para estabilizar emulsões óleo-em-água, com ou sem &beta;-caroteno. / Emulsions are systems formed when two immiscible components are mixed, presenting dispersed droplets in a continuous phase, stabilized by emulsifiers, amphiphilic compounds, with affinities for both phases of the system. In the case of Pickering emulsions, the system is stabilized by solid colloidal particles, which adsorb at the interface of the emulsion droplets. The objective of this dissertation was to produce and characterize suspensions of crystalline cellulose (CC), amorphous cellulose (CA) and chitosan particles (PQ) and to evaluate its potential as single stabilizing compounds in oil-in-water emulsions. CC and CA were produced by heat and acidic treatments of microcrystalline cellulose, respectively, whereas PQs were produced by acidic treatment of medium molecular weight chitosan, also followed by ultra-stirring treatment. In all cases, the treatments were followed by ultra-stirring: 0 (ST); 10,000 (UT10); 15,000 (UT15) or 20,000 rpm (UT20) for 3 minutes. The suspensions of CC, CA and PQ were characterized for determination of particle size distribution, zeta potential and physical stability, and by scanning electron microscopy and/or atomic force microscopy. The powder particles, produced by freeze-drying, were subjected to analysis by X-ray diffraction, Fourier Transform infrared spectroscopy (FTIR) and instrumental colorimetry. As a function of these characterizations, the effect of the stabilizing particle type (CC, CA or PQ) on droplet size, instrumental colorimetry and physical stability of emulsions with 20% (v/v) soybean oil, without and with &beta;-carotene was studied. It was observed that the treatments UT10, UT15 and UT20 caused important changes in the particle size distribution, with reduction of the mean particle size, without significant effect of the agitation speed. Regarding chitosan particles, ultra-stirring treatments did not influence particle size, neither when compared to suspensions without pretreatment. CC was presented as highly unstable cellulosic fiber fragments in suspension, with instability indexes close to 0.78. CA was presented in colloidal particles and irregular aggregates, with reasonable physical stability in suspension (0.26). The suspensions of PQ showed large crystalline structures of sodium acetate, together with colloidal chitosan particles, but highly stable in aqueous suspension (0.04). In general, the potential &zeta; and the physical stability of CC, CA and PQ suspensions did not change with the treatment (ST, UT10, UT15 and UT20). In the characterization of the freezedried particles, a high crystallinity index of CC (81%) was observed, whereas CA (42%) and PQ (40%) showed low crystallinities. The treatments neither caused significant changes in the chemical structure, analyzed by FTIR, nor in the instrumental color of CC, CA and PQ. Finally, only PQ was able to produce and stabilize oil-in-water emulsions, with no cream phase formation during storage. Addition of 0.005% &beta;-carotene to the oil phase left the emulsions stabilized by PQ slightly orange and increased the physical stability of the emulsions, without affecting the droplet size of the emulsions (29-32 &micro;m). Therefore, only PQ demonstrated the potential to stabilize oil-in-water emulsions, with or without &beta;-carotene.

Cerâmicas elétricas de Ba2In2O5 foram preparadas pelo método convencional de mistura de óxidos, e pela mistura e cristalização dos nitratos metálicos, para verificar o efeito do tamanho inicial das partículas na transição de fase ordemdesordem e na condutividade elétrica. Foram feitas substituições utilizando os cátions Gd3+ e Er3+, para verificar o efeito destes cátions na condutividade elétrica do indato de bário. Foi também preparado o óxido de índio pela técnica de complexação de cátions, e as nanopartículas obtidas foram caracterizadas por diversas técnicas. As principais técnicas de caracterização utilizadas foram: análise térmica, espectroscopia de absorção na região do infravermelho com transformada de Fourier, microscopia eletrônica de varredura, microscopia eletrônica de transmissão, difração de raios X convencional e utilizando radiação síncrotron, espalhamento de raios X a baixos ângulos, espectroscopia de energia dispersiva, espectroscopia Raman e medida da condutividade elétrica por espectroscopia de impedância. Os principais resultados mostraram que os tratamentos térmicos de calcinação e sinterização exercem forte influência na obtenção da fase Ba2In2O5. Fases espúrias são facilmente formadas no Ba2In2O5 também decorrentes da interação deste com a umidade. Um menor tamanho inicial de partículas favorece a redução na temperatura de transição de fase de segunda ordem. A introdução do Er, em teores relativamente baixos, produziu aumento na condutividade elétrica e simultânea redução na temperatura de transição de fase. Altos teores de Er e Gd dão origem a múltiplas fases. Na decomposição térmica do citrato de índio é formado um composto intermediário. A calcinação do citrato de índio produziu um material particulado com tamanho nanométrico, mesmo para temperaturas de até 900 ºC. / The Ba2In2O5 conducting ceramic was prepared by the conventional powder mixing technique and by the crystallization of a mixture of metallic nitrates. The main purpose of this work was to verify the particle size effect on the electrical conductivity and phase transition temperature of sintered ceramics. Gd3+ and Er3+ were used to study the effect of dopant cations in the electrical conductivity behavior of Ba2In2O5. Finally, indium oxide was prepared by the cation complexation technique, and the obtained nanoparticles were characterized by several techniques. The main characterization techniques used in this work were: thermal analyses, Fourier transform infrared spectroscopy, scanning and transmission electron microscopy, energy dispersive X-ray analysis, conventional X-ray diffraction and non-conventional X-ray diffraction using síncroton radiation, small angle X-ray diffraction, Raman spectroscopy and electrical conductivity by impedance spectroscopy. The main results show that special care should be taken in order to obtain single phase Ba2In2O5 powders, especially with thermal treatments of calcination and sintering of powders and compacts. The temperature for the second order phase transition decreased with reduction of the initial particle size. An increase of the electrical conductivity along with decrease in the temperature for phase transition was observed for small amounts of Er. Large contents of both Gd and Er give rise to more complexes phases. An intermediate compound was formed during the thermal decomposition of indium citrate. Calcination of this precursor up to 900 ºC gave rise to nanosized particles.