Literatura académica sobre el tema "Nanoparticules biosourcées"
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Tesis sobre el tema "Nanoparticules biosourcées"
Aouay, Mohamed. "Amélioration des performances des plastiques biodégradables via l'intégration de nanoparticules biosourcées dans le PLLA et les mélanges PBAT/amidon". Electronic Thesis or Diss., Université Grenoble Alpes, 2024. http://www.theses.fr/2024GRALI026.
Texto completoThis thesis was set in a sustainable development context and aimed at improving the properties of biodegradable polymers, focusing on the use of PLLA and PBAT as promising alternatives to traditional polymers, particularly in the short-term packaging sectors. The first part of this work addressed the limitations associated with PLLA, such as its slow crystallization and limited crystallinity. The adopted approach involved incorporating biobased nanoparticles (NPs) like cellulose and chitin nanocrystals as nucleating agents to formulate PLLA-PEG-NP nanocomposites. The results revealed a significant increase in the crystallization rate and the degree of crystallinity of PLLA, with the nucleation efficiency varying with the specific surface properties of the NPs. The second part focused on optimizing the dispersion of amino-functionalized cellulose nanocrystals (CNC-Am) in PEG-plasticized PLLA. The incorporation of CNC-Am substantially increased the tensile strength and Young's modulus of PLLA, reaching optimum performance at a 2 wt% NCC concentration. The final section dealt with the enhancement of PBAT/thermoplastic starch (TPS) blends by incorporating lignocellulosic nanofibrils (CNF-L), thereby overcoming the constraints related to the low fraction of TPS and moisture sensitivity. The water resistance and mechanical properties of the blends incorporating CNF-L were notably increased, providing a sustainable option for various applications of these polymers. This thesis highlighted the significant potential of these strategies to improve the performance of biodegradable polymers, opening new avenues for the advancement of environmentally-friendly materials
Roux-Pertus, Charles. "Investigation de la Pulvérisation Électrohydrodynamique du Chitosan". Electronic Thesis or Diss., Université de Lorraine, 2019. http://www.theses.fr/2019LORR0335.
Texto completoElectrohydrodynamic (EHD) methods enable to produce with one low cost set-up polymeric films/particles by electrospray or polymeric fibres by electrospinning. Particles or fibres produced by these methods can be very uniform in size. Therefore, electrospray and electrospinning of chitosan are appealing topics of re-search. Chitosan is a bio-based material possessing numerous qualities such as biocompati-bility, biodegradability, antibacterial activity and muco-adhesion. This thesis deals with EHD methods with a focus on chitosan electrospray whose applications are abundant in health (tissue engineering, drug delivery), food (nutrients en-capsulation, cling film), wastewater treatment and textiles. However electrospray has several limitations. First, effective electrospray depends of the grade of the chitosan, of the preparation of the solution and of used set-up. Second, particle-size distribution reported in literature are broad whereas applications such as drug delivery require monodisperse particle-size distributions. Then, the question is to know how to produce chitosan particles of monodisperse controlled size. To answer this question, a critical analysis of literature led to an experimental approach divided in four steps : (1) characterization of chitosan, (2) measurement of chitosan solution properties, (3) study of stability of electrospray process, (4) assessment of deposit morphology and particle-size distribution. Finally, as part of a biomimetic approach, imitation with chitosan of natural shapes has been studied. These shapes are part of structures that confer striking properties such as hygrochromic behavior and hydrophobicity to insects
Garg, Garima. "Solvants ioniques biosourcés et CO2 supercritique : conception des processus durables pour la synthèse de molécules cibles (BISCO2)". Thesis, Toulouse, INPT, 2019. http://www.theses.fr/2019INPT0085.
Texto completoThis Thesis represents a multi-disciplinary project where aspects going from solvent engineering to catalysis using metal-based nanoparticles, are explored. In this project, solvent engineering has been applied to bio-based deep eutectic solvents (DES) synthesized from choline tosylalaninate and glycerol in an effort to decrease the solvent viscosity by using different amounts of carbon dioxide. In this context, molecular rotors were used as an innovative method to measure the viscosity, avoiding the use of expensive instrumentation and giving the possibility to access to the microviscosity of the system. Furthermore, DES have been applied for the synthesis of palladium nanoparticles, also acting as stabilizers, which were fully characterized. The as-prepared palladium nanoparticles were then used for catalytic hydrogenations of unsaturated C-C bonds, and nitro and carbonyl groups. Sub and supercritical CO2 conditions have been applied to improve the efficiency of the palladium nanocatalysts in hydrogenation reactions and afterwards for the extraction of organic products. This work represents an effort to intensify a hydrogenation process in a highly viscous, non-volatile, biodegradable, and non-toxic DES by using CO2 in order to decrease mass transfer limitations and to extract products from the reaction media
Hinostroza, Ramos Jessica Viviana. "Synthèse de métallophosphates poreux biosourcés pour des applications environnementales et biomédicales". Thesis, Mulhouse, 2017. http://www.theses.fr/2017MULH9658/document.
Texto completoThis thesis work focuses on the biosourced synthesis of metal phosphates in order to find solutions to the depletion of the natural phosphorus resources that are usually used for the preparation of the phosphorus-containing inorganic reagents (i.e., H3PO4). Hydrothermal synthesis of metal phosphates involved them for example. Porous metal phosphates have important properties in catalysis, adsorption and separation fields. However, there are also less explored domains such as biomedical and environmental ones where they are further used. During this thesis, the synthesis of biosourced porous zinc phosphates and aluminum phosphates has been carried out using different biomolecules (casein and nucleotides) by hydrothermal method. Many synthesis parameters were studied (pH, synthesis temperature, reagents concentration, influence of calcination conditions ...). Solids were characterized using different techniques (XRD, SEM, 31P NMR, N2 adsorption, spectrofluorimetry ...). The antibacterial and cytotoxic properties of zinc phosphates optionally enriched in silver nanoparticles synthetized with casein were evaluated on the bacterial strain Escherichia coli K 12 and STRO1A+ osteoprogenitor cells respectively. This work at the interface of materials chemistry and biology makes possible to consider the application of the prepared new metal phosphates for emerging biomedical and environment fields
Fumagalli, Matthieu. "Elaboration et caractérisation de nanocomposites à base de renforts biosourcés". Phd thesis, Université de Grenoble, 2013. http://tel.archives-ouvertes.fr/tel-01053815.
Texto completoDelacroix, Sébastien. "Synthèse de liquides ioniques biosourcés à partir d'acides aminés et d'oses : études de leur immobilisation sur silice et quelques applications". Amiens, 2013. http://www.theses.fr/2013AMIE0112.
Texto completoThis PhD work deals with the synthesis and applications of some family of ILs, which is newly studied in the laboratory. Four areas of ILs chemistry were chosen giving rise to the four chapters of this report. Chapter 1 and 2 are devoted to the preparation and applications of ILs prepared from amino acids in homogenous phases. On the one hand, new Brønsted acid ionic liquids (BAILs) derived from amino acids and also from tetrazoles were developed. Their syntheses, characterizations and applications in aqueous glycosylation reactions are displayed. On the other hand, new ILs derived from L-Proline esters were synthesized and their electrochemical properties were studied. The last two chapters deal with ILs and supported ILs. Relying on our background experience in electrochemical studies of ILs made starting from L-Pro, the synthesis, characterization and applications in electrochemistry of SILPs (Supported Ionic Liquids Phases) derived from imidazolium salts were performed. Finally, with our experience in preparing supported ILs phases, we decided to use derivatives of imidazolium halides, mainly substituted by sugars. These ILs allowed to generate chiral N-heterocyclic carbene (NHCs) of palladium supported by silica nanoparticules and to study their applications in asymmetric catalysis
Lancien, Antoine. "Synthèse d’amines bio-sourcées à l’aide de procédés hybrides combinant des nanoparticules métalliques supportées et des transaminases". Thesis, Université de Lille (2018-2021), 2021. https://pepite-depot.univ-lille.fr/ToutIDP/EDSMRE/2021/2021LILUR059.pdf.
Texto completoThe objective of hybrid catalysis is to exploit the advantages of biological and chemical catalysts to access new synthetic routes that cannot be performed independently or to perform transformations that have shown low yields with conventional approaches. 5-Hydroxymethylfurfural (HMF) is a versatile platform (or building block) molecule that can be used in many industrial applications. In particular, the synthesis of biosourced amino polymers represents a promising method for its valorization. To date, very few studies have described the production of these amino derivatives and their polymers. Finding an efficient methodology to directly convert HMF to 5-aminomethyl-2-furancarboxylic acid (AMFC) is therefore a significant challenge. After selecting the best oxidation catalyst for the conversion of HMF to 5-aldehyde-2-furancarboxylic acid and immobilizing a transaminase on a solid support, we were able to implement the first "one-pot two-step" hybrid catalytic process to produce FMCA (77% yield). With 2,5-furandicarboxylic acid (FDCA, 23% yield) as the sole by-product, this represents the most efficient direct catalytic production method of FMCA from HMF reported to date. In addition, a hybrid "one-pot one-step" process for integrated production of FMCA from HMF was also developed with a maximum yield of 20%, this represents a first breakthrough for this platform molecule, and a first achievement for French hybrid catalysis. Finally, the synthesis of a hybrid multi-catalytic material combining palladium nanoparticles and a transaminase, on an EziGTMOPAL support, was achieved and its application led to a final yield of 10% in FMCA. Finally, this concept was also applied to the conversion of a panel of bio-sourced molecules, with in particular the transformation of myrtenol into its amino equivalent according to a "one-pot two-step" process with a yield higher than 99%
Pinem, Mekro Permana. "Nanofluid engineering of chitosan-based edible packaging". Thesis, Compiègne, 2021. http://www.theses.fr/2021COMP2585.
Texto completoThe requirements in terms of quality and safety during the processing and distribution of food products require the use of suitable packaging to prevent their degradation and extend their shelf life as well as to preserve their organoleptic qualities while respecting safety and ecological constraints. However, currently, most of these packagings are made from oil-based plastic which has defective consequences on waste generation and ecosystem pollution. One approach to overcome this issue is to replace conventional plastics with bio-based materials which can be produced from natural substances and degraded in nature. Among the various existing biopolymers, chitosan appears to be a good candidate due to its known antimicrobial and filmforming properties which are favorable for packaging purposes. However, the mechanical properties of chitosan-based plastic films are not sufficient and it is often necessary to add other components such as cellulose to them to improve their mechanical properties. Moreover, recently it has also been described that the utilization of these biopolymers in their nanoforms could greatly enhance their properties. However, the extraction of these biopolymers and their transformation into nanomaterials involve procedures that do not always comply with the principles of green chemistry and processes. In this work, we propose the development of ecological protocols based on microwaves and ultrasound to produce nanocellulose from bacterial cellulose as well as chitosan from chitin. Furthermore, we prepared bioplastic films from chitosan and cellulose and evaluated the properties of the film when using nanoforms of these polymers. To improve the water resistanceof the film, emulsions with beeswax were prepared and the impact of their formulations on the properties of the film was studied. Finally, the impact dynamics of the droplets of the latter formulation was evaluated to study the potentiality of its use for application by spraying