Teses / dissertações sobre o tema "Nanoparticules d'oxyde de fer – Synthèse (chimie)"
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Veja os 23 melhores trabalhos (teses / dissertações) para estudos sobre o assunto "Nanoparticules d'oxyde de fer – Synthèse (chimie)".
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Girardet, Thomas. "Développement de la synthèse micro-ondes de nanoparticules d'oxyde de fer superparamagnétiques pour des applications biomédicales". Electronic Thesis or Diss., Université de Lorraine, 2022. http://www.theses.fr/2022LORR0187.
Texto completo da fonteNanomaterials are becoming more and more common in everyday life and in different fields such as the environment for water and soil decontamination, energy storage for batteries or information storage for spintronics. Among the nanomaterials, those with a magnetic character are particularly studied for applications in the biomedical field. Thus, iron oxide nanoparticles are of great scientific interest in the biomedical field because of their biocompatibility, the simplicity of their synthesis and their low cost. Their superparamagnetic properties (no magnetisation at room temperature) allow them to be used for diagnosis (MRI contrast agent), therapy (hyperthermia, vectorisation) or both. During this thesis, the first step was to develop a new method for the synthesis of superparamagnetic functionalized iron oxide nanoparticles that are stable in an aqueous solution: microwave synthesis. To allow an optimised development of this synthesis, an experimental design was carried out. The syntheses were then characterised by different techniques (TEM, DLS, XRD, FTIR, Raman spectroscopy, Mössbauer spectroscopy, TGA, magnetic measurements) to determine their physico-chemical properties as well as possible: the nanoparticles obtained with a diameter between 2.5 and 4 nm are stable in aqueous solutions. In a second step, the biological behaviour of these nanoparticles (cellular internalisation, cytotoxicity, mitochondrial activity) was studied. Then, a study of the relaxivity of the synthesised nanoparticles was carried out in order to be able to compare their effectiveness with that of commercial contrast agents such as Endorem®
Dazzazi, Anass. "Synthèse et caractérisation de nanoparticules d'oxydes métalliques par voie organométallique : vers des applications biomédicales". Toulouse 3, 2013. http://thesesups.ups-tlse.fr/1951/.
Texto completo da fonteThis manuscript describes a collaborative work between the University of Toulouse and the University of Rabat. This work is devoted to the development of metal oxide nanoparticles (gamma-Fe2O3 and ZnO) for biological applications (MRI or optical imaging). It focuses in particular on the development of methodologies for transforming hydrophobic nanoparticles prepared following organometallic chemistry to hydrophilic ones, and to study their properties. Methodologies of solvent exchange to transfer ZnO hydrophobic nanoparticles into water using Gémini ligand have been first developed. The well known "double layer" strategy turned to be much more complicated as expected. The use of amino-PEG surfactants leads to the direct formation of water-dispersible iron oxide nanoparticles. In a second step, the physical properties (optical or magnetic properties) of such nanoparticles were studied either in organic media or in water. In particular, we demonstrated that the optical properties of the ZnO nanoparticles are independent of the solvent but strongly depend on the surface state of the nanoparticles. The first example of a photocommutation of ZnO nanoparticles by a diarylethene photochromic dye has been described. Finally, ZnO nanoparticles stables in buffered solutions have been obtained and the first observation with a fluorescence microscope performed. The iron oxide nanoparticles have been tested as MRI contrast agents
Ait, Kerroum Mohamed Alae. "Synthèse et fonctionnalisation de nano-ferrites pour le traitement par hyperthermie". Thesis, Strasbourg, 2019. http://www.theses.fr/2019STRAE016/document.
Texto completo da fonteThe superparamagnetic iron oxide nanoparticles (NPs) are a class of nanomaterials with a high interest in the nanomedicine field. Their magnetic properties and biocompatibility recommend them as potential candidates for diagnostics purposes (MRI, optical or nuclear Imaging ...) and therapy (hyperthermia, nanovectorization...). The aim of this thesis was to study the influence of the synthesis parameters on the final properties of magnetic zinc doped iron oxide nanoparticles. Two synthesis methods were considered, the co-precipitation and the thermal decomposition. The characterization of the obtained nanoparticles by complementary techniques allowed us to propose a consistent relationship between the size, shape and chemical composition on the one hand, and the magnetic properties of the nanoparticles on the other hand. The functionalization of NPs, that is a crucial step for ensuring their biocompatibility and use in magnetic hyperthermia, was also realised and the hyperthermia properties were measured on some typical nanoparticles
Zheng, Ce. "Synthèse de nano-amas d'oxyde métallique par implantation ionique dans un alliage Fe10Cr de haute pureté". Thesis, Université Paris-Saclay (ComUE), 2015. http://www.theses.fr/2015SACLS091/document.
Texto completo da fonteODS (Oxide Dispersed Strengthened) steels, which are reinforced with metal dispersions of nano-oxides (based on Y, Ti and O elements), are promising materials for future nuclear reactors. The detailed understanding of the mechanisms involved in the precipitation of these nano-oxides would improve manufacturing and mechanical properties of these ODS steels, with a strong economic impact for their industrialization. To experimentally study these mechanisms, an analytical approach by ion implantation is used, to control various parameters of synthesis of these precipitates as the temperature and concentration. This study demonstrated the feasibility of this method and concerned the behaviour of alloys models (based on aluminium oxide) under thermal annealing. High purity Fe-10Cr alloys were implanted with Al and O ions at room temperature. Transmission electron microscopy observations showed that the nano-oxides appear in the Fe-10Cr matrix upon ion implantation at room temperature without subsequent annealing. The mobility of implanted elements is caused by the defects created during ion implantation, allowing the nucleation of these nanoparticles, of a few nm in diameter. These nanoparticles are composed of aluminium and oxygen, and also chromium. The high-resolution experiments show that their crystallographic structure is that of a non-equilibrium compound of aluminium oxide (cubic γ-Al₂O₃ type). The heat treatment performed after implantation induces the growth of the nano-sized oxides, and a phase change that tends to balance to the equilibrium structure (hexagonal α-Al₂O₃ type). These results on model alloys are fully applicable to industrial materials: indeed ion implantation reproduces the conditions of milling and heat treatments are at equivalent temperatures to those of thermo-mechanical treatments. A mechanism involving the precipitation of nano-oxide dispersed in ODS alloys is proposed in this manuscript based on the obtained experimental results, and the existing literature
Kombaya, Touckia Linin Erland Modeste. "Conception, élaboration et caractérisation d’emballages actifs absorbeurs d’O2". Thesis, Montpellier, 2019. http://www.theses.fr/2019MONTG006.
Texto completo da fonteCurrently, we are seeing the development of new materials, namely active materials, through various processes and applications. Among these active materials, the use of O2 scavenging iron nanoparticles (NanoFe) as required knowledge of several parameters for efficient application in the field of food packaging such as knowledge about oxidation mechanism and O2 consumption rate. These parameters are necessary to be able to quantify the absorption capacity and absorption rate of O2. Although necessary, these two parameters have so far been little characterized and even less related to the morphological (size, specific surface, etc.) and physico-chemical properties (such as the iron speciation) of iron nanoparticles implemented.In order to tailor nanocomposite film with O2 scavenging properties, this work aims to combine a passive barrier, related to the phenomenon of tortuosity induced by the presence of clay platelets dispersed in a polymeric matrix and an active barrier, related to oxygen uptake by synthesized NanoFe. Nano-Fe were synthesized by chemical reduction with sodium borohydride on Montmorillonite clay (MMT) support. The TEM characterization revealed the formation of iron nanoparticle aggregates with an average size of 57 ± 17 nm scattered on the MMT surface. The Mössbauer kinetics on the MMT-Fe powder confirms that the different iron phases (Fe0 and FeII) in the iron nanoparticles do not oxidize at the same speed. This allowed to adjust the mathematical model of O2 absorption properties prediction. The study of O2 absorption properties on powders has shown that the reaction constant (k), the proportionality coefficient (n) and the O2 absorption capacities are of the same order of magnitude for the wet, dried and stored powders. The nanocomposite films prepared from the synthesized MMT-Fe dried powders incorporated in a LLDPE polymer showed good absorption capacity, but lower than that of the fresh powder, related to the advanced oxidation of iron in these films, confirmed by Mössbauer spectroscopy (films are 60% oxidized versus 30% for powders). A numerical model using the second law of Fick coupled to the system of chemical kinetics equations obtained on the powder, made it possible to predict the phenomenon of diffusion and reaction of oxygen in films produced. This model was compared with experimental data obtained by measuring O2 absorption by films. In parallel, a study of the absorption kinetics of commercial O2 scavengers, commonly used in modified atmosphere packaging, was carried out. On these commercial systems, absorption kinetics has also been described by a second-order kinetic reaction with Arrhenius-like behavior for the effect of temperature. Mössbauer spectroscopy revealed that, in this case, only the Fe0 species were predominant to describe the kinetics (that of FeII being negligible as it was fast). We have shown for the first time that Mössbauer spectroscopy can be successfully coupled to the measurement of oxygen in order to characterize iron oxidation, speciation and O2 absorption capacity in situ. This configuration associating Mössbauer spectroscopy and oxygen measurement provided valuable information on the reaction mechanisms governing the O2 absorbers. All of these results will have important implications for understanding oxygen uptake in the active O2 absorber system
Bergeron, Benjamin. "Synthèse de nanoparticules à structure coeur-coquille d'oxyde de fer et d'or". Master's thesis, Université Laval, 2014. http://hdl.handle.net/20.500.11794/25564.
Texto completo da fonteDaou, Toufic Jean. "Synthèse et fonctionnalisation de nanoparticules d’oxydes de fer magnétiques". Université Louis Pasteur (Strasbourg) (1971-2008), 2007. https://publication-theses.unistra.fr/public/theses_doctorat/2007/DAOU_Toufic_Jean_2007.pdf.
Texto completo da fonteIn the first part, magnetite nanoparticles with controlled size have been synthesized by co-precipitation followed by hydrothermal treatment. By varying different parameters like the pH, the nature of the bases and the Base/Fe ratio, we were able to obtain, nanoparticles with an average size of 12 (± 2) nm but especially of 39 (± 5) nm with global composition: Fe2. 95O4 which can be described by a core-shell system with stoechiometric magnetite as core and oxidized layer as shell. In the second part, we report, our results on the direct and strong bonding of functional organic molecules onto the surface of this nanoparticles using either phosphate, phosphonate or carboxylate groups as coupling agents. These studies have shown that the nanoparticles functionalised by a phosphate or phosphonate groups allowed stronger bonding on the surface of the nanoparticles, higher grafting rate than the carboxylate groups and especially the conservation of the magnetic properties. The grafting occurs mainly by interaction with the Fe3+ in octahedral sites present in the (111) denser plane. The magnetic properties are not modified with phosphonate and phosphate, whereas the carboxylate induce a canting of spin in the oxidized layer decreasing magnetization. Optimisation of grafting conditions has conducted to very stable suspensions in water and THF
Vichery, Charlotte. "Procédé de recuit protégé appliqué à des nanoparticules d'oxyde de fer : étude des relations structure / propriétés magnétiques". Phd thesis, Palaiseau, Ecole polytechnique, 2012. https://pastel.hal.science/docs/00/75/65/67/PDF/VICHERY_these.pdf.
Texto completo da fonteBecause of their promising applications, particularly in the field of biomedicine, many research activities are currently focused in understanding and improving the magnetic properties of iron oxide nanoparticles. The large surface/volume ratio, inherent to the size reduction at the nanometer scale, and crystalline defects have a significant influence on the magnetic properties of these particles, because they give rise to weakly coupled and misaligned spins, which are responsible for low saturation magnetization values. In the course of this PhD project, a strategy of protected annealing was investigated to improve the crystallinity and/or to change the local composition of maghemite and cobalt ferrite nanoparticles, without agglomeration or grain growth. A diamagnetic, refractory and inert sol-gel silica matrix was selected. The high-temperature annealing of the composite samples was first used to study the impact of various structural defects on the magnetic properties. We showed that for maghemite nanoparticles, ordering of Fe vacancies and changes in the surface state, as a result of dehydration, had opposite effects. Vacancy ordering predominates for particles of 14 nm and tends to increase magnetization values, while the removal of surface hydroxyl groups, predominant for particles of 7 nm, induces the propagation of the outer shell made of misaligned spins toward the center of the particles, thus decreasing magnetization values. In the case of cobalt ferrite, the Co-Fe ions distribution may also have an impact on spin misalignment. However, an 800°C annealing did not induced a large increase in inversion degree, probably because of the refractory nature of CoFe2O4. This strategy of protected annealing also allowed modulating the magnetic properties of maghemite particles upon cobalt doping. A progressive increase of the anisotropy constant, up to 3. 5 times, was observed as a result of the diffusion of Co2+ ions into the spinel structure
Vichery, Charlotte. "Procédé de recuit protégé appliqué à des nanoparticules d'oxyde de fer : étude des relations structure / propriétés magnétiques". Phd thesis, Ecole Polytechnique X, 2012. http://pastel.archives-ouvertes.fr/pastel-00756567.
Texto completo da fonteKovalenko, Artem. "Stabilisation de microbulles de gaz par des tensioactifs semi-fluorés et des nanoparticules d'oxyde de fer". Phd thesis, Université de Strasbourg, 2013. http://tel.archives-ouvertes.fr/tel-01037952.
Texto completo da fonteAyadi, Sondra. "Nouveaux nanomatériaux hybrides métal/hydroxyde de fer. Synthèse, caractérisation et application à la catalyse chimique et électrochimique". Thesis, Evry-Val d'Essonne, 2015. http://www.theses.fr/2015EVRY0011/document.
Texto completo da fonteWe developed simple, fast and "green" synthesis of new nanohybrids, composed of metal nanoparticles supported on inorganic matrix of iron hydroxide. Their synthesis in suspension involves first, the formation of the FeII-bearing inorganic solid matrix, then the reaction with metal salt solution, in the same reactor. Three inorganic matrices (carbonated or sulfated green rusts (GRc or GRs) and chukanovite Chu) and three metals (Au, Ag and Pt) were studied. The nanohybrids, noted metal-exMatrix, were characterized by XRD, FTIR, SEM, TEM and voltammetry. The matrix acts as a reducing agent supplying electrons by solid state oxidation, and also as the support of metal nanoparticles. Two reaction mechanisms with intra- or inter-particle electron transfer are proposed. Nanoparticles sizes vary between 20 and 200 nm. The first application involves the building of amperometric H2O2 sensors. Carbon ink electrodes incorporating silver-based nanohybrids, particularly Ag-exRVs, or platinum, Pt-exChu, provide electrochemical catalytic properties, enabling us to quantify the peroxide by its electrochemical response in reduction or oxidation. For the second application, the reduction reaction of 4-nitrophenol by borohydride, we showed that our nanohybrids were more efficient catalysts than the best current materials, with similar metal load and temperature
Sodreau, Alexandre. "Design de précurseurs organométalliques et synthèse contrôlée de nano-objets de germaniure de fer". Thesis, Toulouse 3, 2018. http://www.theses.fr/2018TOU30290/document.
Texto completo da fonteControlled synthesis of nano-alloys of iron germanide has gained a renewed interest thanks to the recent discovery of new applications in the field of information storage. However, the chemistry of the iron-germanium pair is a complex chemistry that remains little studied. The work presented in this thesis combines molecular chemistry and nano-object chemistry to explore the potential of single-source precursors for solution synthesis, in soft conditions, of iron germanium NPs. First, we focused on the formation of new complexes with an amidinatogermylene-type architecture offering a balance between the stabilization of complexes and their decomposition temperatures, for example mono-germylene iron complexes {[iPrNC(tBu)NiPr]GeCl}Fe(CO)4 and {[iPrNC(tBu)NiPr]GeHMDS}Fe(CO)4 or the bis-germylene iron complex {[iPrNC(tBu)NiPr]GeCl}2Fe(CO)3. In a second step, we show that this method represents a path of choice to reach the formation of nano-alloys of iron germanide and that the architecture of the mono-source precursors allows to control the final nanoparticles. In particular, the decomposition at 200°C. of the {[iPrNC(tBu)NiPr]GeHMDS}Fe(CO)4 complex leads to the formation of Fe3,2Ge2 spherical nanoparticles, with a mean diameter of 6.5 ± 0.8 nm, exhibiting a ferromagnetic behavior
Vecco-Garda, Clément. "Vers une chimie de surface de nanoparticules d'oxyde de fer magnétiques plus adaptée pour de meilleures performances en diagnostic et thérapie par hyperthermie magnéto-induite". Thesis, Bordeaux, 2020. http://www.theses.fr/2020BORD0308.
Texto completo da fonteThis work focuses on the development of methods for the chemical modification of the surface of injectable nanoparticles (NPs) for diagnostic or therapeutic purposes. Hybrid NPs,consisting of an inorganic core and a macromolecular polyethylene glycol (PEG) corona with well established physico-chemical surface characteristics (grafting densities, surface charge, corona thickness) have been synthesized as part of a study of their pharmacokinetic (PK) performance. The results showed in particular that it was possible to modulate the circulation times as well as the tumor accumulation levels of these NPs according to their surface physico-chemical properties. The addition of surface biomolecules was studied to observe the role of active targeting on pharmacokinetics and tumor accumulation. This method of covalent chemical modification was subsequently applied to magnetic iron oxide nanoparticles in order to develop new negative (T2) and positive (T1) contrast agents in MRI. The surface chemistry of iron oxide NPs was studied to improve their thermogenicityand efficiency in magnetic hyperthermia. The direct effect of the temperature dissipated under magnetic induction of NPs could be studied in vivo (thermo-ablation or thermo-stimulation of the microenvironment) while avoiding the toxic effects due to the presence of NPs. The development of a biocompatible oily ferrofluid based on iron oxide NPs modified by chemisorption of phospholipids on their surface allowed to increase tenfold their thermogenic power. The efficiency of these oils under an alternating magnetic field was evaluated in vivo in the context of their application
Luo, Ming. "Synthèse et caractérisation de nanoparticules d'or greffées par le glutathion réduit en vue de l'obtention de réservoirs d'oxyde nitrique". Thesis, Université de Lorraine, 2015. http://www.theses.fr/2015LORR0179.
Texto completo da fonteNitric oxide (NO) is a gaseous messenger playing numerous physiological roles, especially in the cardiovascular system. However, its bioavailability is limited due to a short half-life. The combination to thiols increases its stability and facilitates its storage and transport. Thus NO donor drugs represent a promising therapeutic approach in such diseases. The present study aimed at developing NO reservoirs. Firstly, serum albumin (SA) was S-nitrosated through three chemical pathways to prepare SA-SNO. Then, potential NO reservoirs with high loading capacity were developed by anchoring reduced glutathione (GSH) to dihydrolipoic acid capped gold nanoparticles, AuNP@DHLA. The obtained AuNP@DHLA-(GSH)n showed stronger antioxidant power and they will be able not to disturb the cell homeostasis. Its further poly-S-nitrosation will benefit from the S-nitrosation of SA as both macromolecular possess free thiols. In parallel, citrate ions stabilized AuNP were entrapped in multilayer polyelectrolyte films using layer-by-layer (LbL) assemblies, providing proof-of-concept of multilayer films as a useful tool to protect AuNP from degradation and increase the cyto/hemocompatibility toward biological elements. The present work opens the window to S-nitrosate AuNP@DHLA-(GSH)n either as a colloidal solution or immobilized in the multilayer system, which is expected to be applied into developing of NO eluting stent for the treatment of cardiovascular diseases
Ferjaoui, Zied. "Synthèse et caractérisation de nanoparticules magnétiques répondantes pour des applications en thérapie cancéreuse". Electronic Thesis or Diss., Université de Lorraine, 2020. http://www.theses.fr/2020LORR0013.
Texto completo da fonteIn the frame of this PhD project, smart superparamagnetic nanoparticles (SPIONs) have been developed for a further use as a drug platform for cancer therapy. These nanoparticles of core / shell type are obtained from the functionalization of a core based on Fe3-δO4 by a co- polymer obtained from the surface-initiated polymerization of a mixture xMEO2MA and yOEGMA (x + y = 1). Once their structures and their colloidal behavior in water and in-vitro perfectly characterized as well as the demonstration of their thermo-responsive properties, studies of encapsulation and release of an anti-cancer drug, the doxorubicin (DOX) at physiological temperatures were successfully obtained. In-vitro studies showed the non- cytotoxicity of the nanoparticles, but when the cancer cells were in contact the DOX-loaded NPs, the cytotoxicity was increased. To induce the targeting of ovarian cancer (SKOV3 cells) and the enhancement of the internalization of nanoparticles in cells, we have functionalized the previous nanoparticles with folic acid as these last cells over-express receptors that bind folate α (FR-α ). The combination of different macroscopic and nanometric scale characterization techniques allowed us to conclude that our systems are capable of encapsulating DOX, releasing it in a specific manner and at a controlled rate and that they exhibit hyperthermia properties. We have then contributed to successfully develop new third generation vectors for cancer therapy
Ménard, Mathilde. "Synthèse de nanoparticules hybrides de type coeur-coquille à visées théranostiques". Thesis, Strasbourg, 2017. http://www.theses.fr/2017STRAE050/document.
Texto completo da fonteThe aim of this PhD work was to synthesize and test new nano-objects for the diagnosis and treatment of cancer. For this purpose, we developed hybrid nanoparticles made of an inorganic core surrounded by a human serum albumin (HSA) organic coating. The inorganic core is a composite by itself as it is made of an iron oxide core (IO) surrounded by a mesoporous silica (MS) shell. The IO core ensures, through its magnetic properties, diagnosis by magnetic resonance imaging (MRI) and therapy by magnetic hyperthermia, whereas the MS shell allows the loading of anticancer drugs for chemotherapy within its porosities. The pore sizes of the silica shell were modulated to enhance the drug loading content and the IO core size was also tuned to improve magnetic hyperthermia as well as T2 MRI imaging properties of the final core-shell system. The use of a thick shell of HSA as gatekeeper for controlled drug delivery triggered by its degradation with proteases was also studied. In parallel the synthesis of drug loaded HSA nanocapsules using MS as sacrificial template was performed. Finally, the biological activities of these nanoparticles were tested on various cancer cell lines
Laanaiya, Majdouline. "Amélioration des propriétés du ciment par insertion des nanoparticules nano-Fe2O3". Thesis, Lille 1, 2020. http://www.theses.fr/2020LIL1I007.
Texto completo da fonteNano-engineering of cement through adding nanosized particles such as nanofibers, nanotubes and nanoparticles offers a great potential for developing new generations of cement based materials with ultra-high performance, superior strength and novel functionalities for smart and durable structural materials. The hybridization of hydrated cement phases by incorporating nano-structured materials in a bottom-up approach allows the manipulation of structural features of cement at the nano-scale that ultimately affect the performance and durability properties at the macro-scale. In particular, the addition of Fe2O3 nanoparticles have been shown to provide cement based materials with intrinsic self-sensing properties. The thesis presents an atomic scale study of nano-modified Calcium-Silicate-Hydrate (C-S-H), the primary binding material in cement based materials, by embedding Fe2O3 nanoparticles. In order to get more insights into the Portland cement main phases (alite and belite) that react with water to form C-S-H, ab initio calculations were performed to investigate the structural, mechanical and electronic properties along with the reactive sites of alite and belite. After examining the C-S-H structure at the atomic scale using molecular dynamics methods, Fe2O3 nanoparticles were inserted and the resulting hybrid material was studied. Different insertion modes of nanoparticles inside the C-S-H matrix were considered in order to elucidate how nanoparticles distribution affects the mechanical response of the hybrid composite Fe2O3/C-S-H. The structure with “well-dispersed” nanoparticles exhibits enhanced mechanical performance in both elastic and plastic regimes. Mechanical properties were enhanced with at least 24% increase compared to pure C-S-H. In addition, the “group effect” of inserted nanoparticles gives rise to a remarkable ductility and great resistance to the crack propagation in response to tensile loading. The necking phenomenon and structural hardening were both observed in response to tensile loading, indicating a ductile failure mode of Fe2O3-reinforced C-S-H. Ultimately, this work reveals the striking potential of Fe2O3 nanoparticles for developing high performance cement based materials with superior mechanical properties and self-sensing abilities
Moulet, Lucie. "Designs rationnel et exploratoire de nanoparticules à transition de spin". Thesis, Bordeaux, 2015. http://www.theses.fr/2015BORD0160/document.
Texto completo da fonteThe spin-crossover (SCO) materials based on iron (II) and triazole ligands canchange their spin state under an external perturbation like temperature, pressure or lightirradiation. If these aspects are well known, it is only in the recent years that the SCO-particledesign has attracted attention of the scientific community with increasing interests notablyfocusing on the access to wide ranges of sizes and shapes of nanoparticles. In this context,we rationalized the reverse micellar synthesis, thanks to a scrupulous study of all experimentalparameters, to produce SCO particles with controlled size and shape. For example, underwell-defined experimental conditions, we can now offer rod-shaped particles with sizes rangingfrom 30 to 1000 nm for [Fe(Htrz)2(trz)](BF4). In parallel, we drove the first exploration byspray-drying for SCO materials. Spherical-micrometric particles with different properties, fromthose observed usually, were obtained. Within the design of SCO particles, one of the currentchallenges concerns the grafting of gold particles. In contrast to existing literature results, wepropose a method to graft directly gold nanoparticles on SCO particles leading to hybridparticles denoted SCO@Au. This grafting seems to be more effective than previous resultsand shows itself relevant for a wide range of size of gold particles
Nguyen, Thi Thanh Thuy. "Poly(oxyde d'éthylène)s fonctionnels à extrémité acide phosphonique et à fonctionnalité réversible pour la stabilisation de nanoparticules magnétiques". Phd thesis, Université du Maine, 2013. http://tel.archives-ouvertes.fr/tel-00844750.
Texto completo da fonteRodrigues, Guimarães Thiago. "Synthesis of magnetic polymer latex particles by reversible addition-fragmentation chain transfer (RAFT) polymerization in aqueous dispersed media". Thesis, Lyon, 2017. http://www.theses.fr/2017LYSE1107/document.
Texto completo da fonteIn this work reversible addition-fragmentation chain transfer (RAFT) polymerization was exploited to synthesize magnetic latex particles decorated with stimuli-responsive polymer brushes. First, five hydrophilic (co)polymers with various compositions were successfully prepared by RAFT solution (co)polymerization of acrylic acid (AA) and 2-dimethylaminoethyl methacrylate (DMAEMA) for different AA to DMAEMA molar ratios. The obtained macromolecular RAFT agents (macroRAFTs), PAA or PDMAEMA homopolymers and P(AA-co-DMAEMA) copolymers, displayed interesting pH- and thermo-responsive properties. These hydrophilic macroRAFTs were then chain extended with styrene leading to the formation of well-defined amphiphilic block copolymers. An aqueous dispersion of iron oxide clusters was next prepared using a strategy based on emulsification/solvent evaporation in which the block copolymers were used as stabilizers. By varying the experimental conditions (sonication power, macroRAFT concentration and pH of the medium), the cluster size could be controlled from 45 up to 300 nm. These clusters were then used as seeds in styrene emulsion polymerization in the presence of a crosslinker. The iron oxide clusters were individually encapsulated into a polymer shell generating latex particles, stabilized by the hydrophilic segment of the block copolymers, and displaying interesting magnetic properties. At last, these magnetic beads were evaluated as carriers in the magnetic separation of bacteria. The magnetic latex particles decorated with P(AA-co-DMAEMA) copolymers were successfully employed for the capture and trigger release of bacteria, allowing their concentration in a biological sample
Nepotu, Palamarciuc Tatiana. "Synthèse et étude de matériaux moléculaires à transition de spin". Phd thesis, Université Sciences et Technologies - Bordeaux I, 2012. http://tel.archives-ouvertes.fr/tel-00925840.
Texto completo da fonteIranzo, Audrey. "Electrosynthèse assistée par ultrasons de nanoparticules de fer à valence zéro : étude de la croissance de dépôts et de leur dispersion par ondes acoustiques". Thesis, Toulouse 3, 2016. http://www.theses.fr/2016TOU30317/document.
Texto completo da fonteThis study concerns the coupling of the ultrasounds with the electrodeposition process for the synthesis of zero-valent iron nanoparticles; it is structured in two sections. The first focuses on the electrode substrate used for the iron electrodeposition and aims to determine its influence on both the deposit growth and its dispersion by ultrasonication. The interfacial and the adhesion energies of the deposit on the substrate (Y_(Fe/substrate) and W_(Fe/substrate) respectively) being related to the surface energy and the roughness of the substrate, a particular focus is put on the influence of these two properties. Thus, two materials of different surface energies, gold (Au) and vitreous carbon (VC), as well as various roughnesses, are tested. Considering only the Van der Waals interactions, a theoretical development has enabled to determine that Y_(Fe/VC)>Y_(Fe/Au) which suggests a better affinity of the iron deposit with the gold than with the VC substrate. This difference impacts the deposit morphology (2D growth on the gold and 3D growth on the VC substrate) but also the deposit adhesion. Indeed, experiments performed to study the effect of ultrasounds on the iron electrodeposit reveal its progressive and complete dispersion for the vitreous carbon case while no dispersion (no removal of the deposit from the electrode) is obtained with the gold substrate. The second section of the present study deals with the synthesis of iron nanoparticles; to this end, the electrodeposition of branched deposits has been investigated in a Hele-Shaw cell integrating a vibrating element (piezoelectric diaphragm), expected to allow both the deposit formation and its fragmentation. Experiments reveal that the hydrogen bubbles, formed by the co-reduction of free protons during the iron electrodeposition, strongly influence the fragmentation process. Using high vibration frequencies and high amplitudes, the bubbles oscillate with surface deformations, inducing interface velocity sufficiently high (˜ 4 m/s) to allow the fragmentation of the deposit into particles of sizes ranging between 1 µm and 100 nm and showing a high specific surface due to their dendritic morphology. Thus this work opens the way for a new particles manufacturing technology
Nguyen, Vo Thu An. "Magnetic polyion complex micelles as therapy and diagnostic agents". Thesis, Bordeaux, 2015. http://www.theses.fr/2015BORD0138/document.
Texto completo da fonteThis Ph.D. dissertation describes the synthesis of superparamagnetic iron oxide nanoparticles (SPIONs) designed to serve as magnetic resonance imaging (MRI) contrast agents and for heat generation in cellular radiofrequency magnetic field hyperthermia (MFH) treatment. Control over the size and size distribution of the iron oxide nanoparticles (NPs), and thus over their magnetic properties, was achieved using a G1 arborescent copolymer (comb-branched (G0) polystyrene substrate grafted with poly(2-vinylpyridine) side chains, or G0PS-g-P2VP) as a template. Good colloidal stability and biocompatibility of the SPIONs were achieved via the formation of polyion complex (PIC) micelles with a poly(acrylic acid)-block-poly(2-hydroxyethyl acrylate) (PAA-b-PHEA) double-hydrophilic block copolymer