Gotowe bibliografie tematyczne / Silica immobilisation

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Gotowa bibliografia na temat „Silica immobilisation”

Autor: Grafiati

Data publikacji: 4 czerwca 2021

Data aktualizacji: 18 lutego 2022

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Artykuły w czasopismach na temat "Silica immobilisation"

Coradin, Thibaud, i Jacques Livage. "Mesoporous alginate/silica biocomposites for enzyme immobilisation". Comptes Rendus Chimie 6, nr 1 (styczeń 2003): 147–52. http://dx.doi.org/10.1016/s1631-0748(03)00006-7.

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Koopal, L. K., Y. Yang, A. J. Minnaard, P. L. M. Theunissen i W. H. Van Riemsdijk. "Chemical immobilisation of humic acid on silica". Colloids and Surfaces A: Physicochemical and Engineering Aspects 141, nr 3 (listopad 1998): 385–95. http://dx.doi.org/10.1016/s0927-7757(97)00170-2.

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Cesarino, Ivana, Éder T. G. Cavalheiro, Glimaldo Marino i Jivaldo R. Matos. "Functionalisation and Characterization of SBA-15 Nanostructured Silica Modified with 2-Benzothiazolethiol". Materials Science Forum 587-588 (czerwiec 2008): 458–62. http://dx.doi.org/10.4028/www.scientific.net/msf.587-588.458.

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Mesoporous silica can be modified and functionalised by immobilisation of organic substances covalently bonded to the silanol groups on the silica surface. This paper describes the modification of a SBA-15 nanostructured silica with 2-benzothiazolethiol. After derivatization the modified silica was chacacterized by elemental analysis, IR spectroscopy, thermal analysis (TG and DSC), NMR in solid phase and scanning electron microscopy.

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Moelans, Dieder, Pegie Cool, Jan Baeyens i Etienne F. Vansant. "Immobilisation behaviour of biomolecules in mesoporous silica materials". Catalysis Communications 6, nr 9 (wrzesień 2005): 591–95. http://dx.doi.org/10.1016/j.catcom.2005.05.007.

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Danil de Namor, Angela F., Jorge A. Zvietcovich-Guerra, Jose A. Villanueva Salas, Oscar E. Piro, Oliver A. Webb, Abdelaziz El Gamouz, Weam Abou Hamdan i Eduardo E. Castellano. "Calix[4]arene amine modified silica: from fundamentals to new recyclable materials for the removal of chlorophenoxy acids from water". RSC Advances 5, nr 42 (2015): 33524–35. http://dx.doi.org/10.1039/c5ra02551f.

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Hu, Jianpeng, Bingnan Yuan, Yongming Zhang i Minghui Guo. "Immobilization of laccase on magnetic silica nanoparticles and its application in the oxidation of guaiacol, a phenolic lignin model compound". RSC Advances 5, nr 120 (2015): 99439–47. http://dx.doi.org/10.1039/c5ra14982g.

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Immobilisation of Aspergillus laccase on magnetic silica nanoparticles via a facile and efficient process and its high catalytic efficiency for guaiacol as phenolic lignin model compound was investigated.

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Matsuura, Shun-ichi, Tomoya Baba, Manami Chiba i Tatsuo Tsunoda. "Nanoporous scaffold for DNA polymerase: pore-size optimisation of mesoporous silica for DNA amplification". RSC Adv. 4, nr 49 (2014): 25920–23. http://dx.doi.org/10.1039/c4ra02725f.

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The simple and selective immobilisation of a thermostable DNA polymerase on mesoporous silicas was achieved, and DNA amplification activity was retained under the pore-size regulation of the mesoporous silicas.

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Rózga-Wijas, K., J. Chojnowski, W. Fortuniak, M. Ścibiorek, Z. Michalska i Ł. Rogalski. "Branched functionalised polysiloxane–silica hybrids for immobilisation of catalysts". J. Mater. Chem. 13, nr 9 (2003): 2301–10. http://dx.doi.org/10.1039/b304134d.

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Willemin, Stephanie, Guillem Arrachart, Lollita Lecren, Joulia Larionova, Thibaud Coradin, Rodolphe Clérac, Talal Mallah, Christian Guérin i Clément Sanchez. "Immobilisation of single molecule magnets in mesoporous silica hosts". New J. Chem. 27, nr 10 (2003): 1533–39. http://dx.doi.org/10.1039/b305124b.

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Pillinger, Martyn, Carla D. Nunes, Pedro D. Vaz, Anabela A. Valente, Isabel S. Gonçalves, Paulo J. A. Ribeiro-Claro, João Rocha, Luís D. Carlos i Fritz E. Kühn. "Immobilisation of rhodium acetonitrile complexes in ordered mesoporous silica". Physical Chemistry Chemical Physics 4, nr 13 (22.05.2002): 3098–105. http://dx.doi.org/10.1039/b202537j.

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Rozprawy doktorskie na temat "Silica immobilisation"

Smith, Graham Michael. "Enzyme immobilisation and catalysis in ordered mesoporous silica /". St Andrews, 2008. http://hdl.handle.net/10023/573.

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Smith, Graham Murray. "Enzyme immobilisation and catalysis in ordered mesoporous silica". Thesis, University of St Andrews, 2008. http://hdl.handle.net/10023/573.

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A range of mesoporous materials based on SBA-15 have been prepared and characterised. The materials were templated by neutral block copolymer P123, and typically have a hexagonal (p6mm) pore structure, with high surface areas and narrow pore size distributions. The removal of the surfactant template by calcination and solvent extraction has been investigated. The aqueous stability of this material, and the hydrolysis of the surface was studied. Organic functional groups were incorporated into the silica surface by co-condensation, or by post synthesis grafting. A range of functional groups were incorporated, including amine, carboxy, allyl and thiol groups. The pore size of the materials was controlled by the addition of trimethoxybenzene during synthesis, which significantly increased the pore size and uptake capacity of the materials. The adsorption of CALB by SBA-15 was investigated, with support materials extracted by calcination or solvent extraction. Rapid uptake at high loading was observed, with a maximum loading of 450 mg g-1 measured. The leaching of the enzyme from the support was investigated, and found to be high with unfunctionalised supports. The leaching from functionalised supports incorporating sulfur groups was significantly reduced. The activity of the immobilised CALB was measured by tributyrin hydrolysis in aqueous media, and by enantioselective transesterification of (R)-1-phenylethanol in organic media. The effect of surface functionalisation for reusability and thermal stability in aqueous systems was investigated. Preliminary studies of supported CALB for dynamic kinetic resolution were carried out, with an investigation of acidic zeolites and a mesoporous supported catalyst for 1-phenylethanol racemisation. The encapsulation of immobilised CALB was investigated, and the activity and reusability of these systems studied.

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Lynch, Michele M. "Enzyme immobilisation on mesoporous silica, inspired by chaperonins". Thesis, University College London (University of London), 2018. http://discovery.ucl.ac.uk/10056498/.

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In nature, chaperonins stabilise enzymes and protect them from high temperature and unfavourable solution conditions. We are inspired by some of chaperonins’ fundamental properties when investigating materials for enzyme immobilisation. In this project, mesoporous silica SBA-15 is used as a synthetic chaperonin analogue because of its controlled mesopore diameter and its negatively charged surface. Mesoporous silica SBA-15 have been synthesised by an acidic sol-gel method. The morphologies and textural parameters of the SBA-15 have been characterised using electron microscopy, gas physisorption, and small-angle Xray scattering. The synthesised SBA-15 samples are used to immobilise several model proteins: myoglobin, lysozyme, trypsin, and pepsin. At equilibrium, protein immobilisation can be described by the Langmuir model of physical adsorption. The maximum amount of protein that can be adsorbed onto SBA-15 increases with increasing pore diameter. The kinetics of adsorption of the protein myoglobin is found to be affected by the pore size of the SBA-15, with the protein diffusing faster through a larger pore. Immobilising enzymes to SBA-15 is shown to increase their biocatalytic activity under some solution conditions. For myoglobin and lysozyme, the protective effects were strongest in solutions where the enzyme is strongly electrostatically attracted to the silica surface. Immobilised myoglobin is also found to be protected from digestion by the protease pepsin. For trypsin, the relationship between electrostatic attraction and improved activity was inconclusive. SBA-15 pore size was shown to affect the activity of the smallest enzyme, lysozyme. In summary, this thesis recommends the following prioritisations for enzyme immobilisation: strong electrostatic attraction between enzyme and material, followed by pore size just exceeding the diameter of the enzyme. By determining the relative importance of these parameters, this thesis increases the fundamental understanding of enzyme immobilisation by physical adsorption onto porous materials.

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Ritchie, Lyndsey Kay. "Large pore mesoporous silicas for application in protein adsorption, enzyme immobilisation and drug delivery /". St Andrews, 2009. http://hdl.handle.net/10023/747.

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Hodyl, Jozef Andrew Zbigniew, i jozef hodyl@flinders edu au. "Silica Immobilised Metal Ion Activated Molecular Receptors". Flinders University. School of Chemistry, Physics and Earth Sciences, 2008. http://catalogue.flinders.edu.au./local/adt/public/adt-SFU20090301.162335.

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Immobilisation of functional entities, such as, enzymes, onto solid supports, as a means of facilitating their removal from the surrounding environment and subsequent regeneration has been in practice for many decades. This work focuses on the immobilisation and analysis of three-walled (pendant armed), cyclen based receptor complexes immobilised onto a silica surface for the purpose of sequestering aromatic anions from aqueous solution: Si-GPS-[Cd(Trac)](ClO4)2, Si-GPS-[Cd(DiPTrac)](ClO4)2, and Si-GPS-[Cd(TriPTrac)](ClO4)2 were the immobilised receptors used. Initially, synthesis of a three-walled model receptor, [Cd(TracHP12)](ClO4)2, that is not bound to silica yet mimics the properties of the silica anchored receptor complexes with a hydroxypropyl pendant arm was effected. Aromatic anion binding constant measurements were made on the model receptor using 1H NMR monitored titrations in DMSO-d6 which showed that, in comparison to the first generation four-walled receptors, the removal of one of the pendant arms did not affect the binding capability of the receptor's cavity significantly. It was shown that the binding strength correlated well with the pKa of the particular anion with, for example, p-hydroxybenzoate > m-hydroxybenzoate > o-hydroxybenzoate. The precursor to this receptor was then immobilised onto a silica surface and subjected to metal ion uptake studies to gauge its coordination properties with a number of divalent metal(II) ions: Cd(II), Pb(II), Zn(II), Cu(II) and Ca(II). The three Cd(II) coordinated receptor complexes mentioned above were then subjected to inclusion studies with a number of aromatic anions in aqueous conditions whereupon a reversal of the previously mentioned trend, i.e. o-hydroxybenzoate > m-hydroxybenzoate > p-hydroxybenzoate was observed. This indicated that the presence of water in the system changes the hydrogen bonding mode of the host-guest complexes, and was a major discovery arising from this work.

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Nasrallah, Houssein. "Immobilisation de complexes à base de ruthénium par des interactions non-covalentes pour le recyclage en métathèse des oléfines". Thesis, Université Paris-Saclay (ComUE), 2015. http://www.theses.fr/2015SACLS005.

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L'objectif de cette thèse est le développement de nouvelles stratégies d'immobilisation de complexes de ruthénium sur des supports insolubles par des interactions non-covalentes pour le recyclage aisé de ces catalyseurs dans la métathèse des oléfines. Tout d'abord, un rappel bibliographie sur le développement de la métathèse des oléfines, de sa découverte jusqu'à nos jours, est présenté. Ensuite trois approches différentes d'immobilisation de catalyseurs de métathèse sont détaillées afin de réaliser le recyclage en tenant compte des défis concernant cette réaction. Une procédure d'immobilisation des catalyseurs par formation de complexes à transfert de charge (CTC) réversibles entre le catalyseur et le support est tout d'abord étudiée dans ces conditions. En se basant sur les résultats obtenus dans ces conditions, une approche plus économique a alors été développée qui consiste en l'immobilisation d'un catalyseur commercial par formation de liaisons hydrogène avec les sites silanols d'un simple support de silice. Finalement, un autre type de support à base de carbone structuré (rGO) a été employé dans l'étude de l'immobilisation de complexes de ruthénium tagués par un fragment pyrène via la formation d'interactions π- π (π-stacking).La performance des différents matériaux catalytiques a d'abord été évaluée dans la réaction test de métathèse d'oléfines (RCM du DEDAM). Ensuite, autres types de métathèses (ènyne, CM et l'homo-métathèse de l'oléate de méthyle) ont été testées pour étendre l'application de ces matériaux.Le développement de ces approches d'immobilisation est également accompagné par des études mécanistiques, en se basant sur l'effet boomerang, connu pour ces réactions.Ce travail a été réalisé dans le cadre du projet ANR CD2I CFLOW-OM, en collaboration avec des partenaires académiques (ENSC-Rennes, LGPC-Lyon, CPE-Lyon, LCMT-Caen) et industriels (ITERG, NOVANCE, OMEGA-CAT-SYSTEM)
Ruthenium complexes immobilization by non-covalent interactions for the recycling in olefin metathesisAbstractThe aim of this thesis is the development of new ruthenium complexes immobilization strategies onto insoluble supports by non-covalent interactions, for their easy recycling in olefin metathesis reactions.First, a bibliographic part is devoted to the development of the olefin metathesis from the discovery until now. Then, three different approaches of metathesis catalysts immobilization are described in order to achieve efficient recycling, considering the important challenges associated to this reaction. Firstly, an immobilization procedure of catalysts by formation of reversible charge transfer complexes (CTC) is described between the appropriated tagged catalyst and the support. Based on the results obtained in these conditions, a more economical approach involved the immobilization of a commercially available catalyst by formation of hydrogen bonds with the silanol sites present in silica. Finally, another type of support namely a structured carbon based support (rGO), was used for the pyrene tagged ruthenium complexes immobilization via formation of non-covalent π- π interactions (π-stacking).The catalytic performances of these solid materials were firstly evaluated in the benchmark reaction of olefin metathesis (RCM of DEDAM). Then, other olefin metathesis reactions were applied to extend the application of these materials (enyne, CM, self-metathesis of methyl oleate).The development of these approaches has also been accompanied by mechanistic studies, based on the boomerang effect, already known for these reactions.This work was performed as part of the ANR project CD2I CFLOW-OM, in collaboration with academic (ENSC-Rennes, LGPC Lyon, CPE Lyon-Caen LCMT) and industrial (ITERG, NOVANCE, OMEGA-CAT- SYSTEM) partners

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Engelmark, Cassimjee Karim. "Tools in biocatalysis : enzyme immobilisation on silica and synthesis of enantiopure amines". Licentiate thesis, KTH, Biochemistry, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-12936.

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This thesis presents two techniques in the field of biocatalysis:

An enzyme immobilisation method based on the His6-tag for attachment on modified silica oxide beads, and it’s employment in aqueous and organic medium for synthesis applications. The method functions as a one step extraction and immobilisation protocol.

An equilibrium displacement system which enables complete conversion in reactions with ω-transaminases where isopropylamine is the donor, a route for synthesis of pharmaceutically interesting enantiopure amines.

Biocatalysis is predicted to be a paramount technology for an environmentally sustainable chemical industry, to which every newly developed method represents a small but important step. The work done here is aimed to be a part of this development.

I denna avhandling presenteras två tekniker inom ämnet biokatalys:

En metod för immobilisering av His6-enzym på modifierad kiseloxid, och användning av detta konstrukt för kemiska synteser i vatten och organiska lösningsmedel. Detta system fungerar även som en snabb extraherings- och immobiliseringsmetod.

Ett jämviksförskjutningssystem som möjliggör fullständig omsätt-ning i reaktioner med ω-transaminaser där isopropylamin är amino-donator, en syntesväg för tillverkning av farmakologiskt intressanta kirala aminer.

Biokatalys förutspås att bli en ovärderlig teknologi i en miljömässigt hållbar kemisk industri, i vilken varje ny metod är en liten men dock viktig del. Detta arbete är menat som en del i denna utveckling.

QC 20100519

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Ritchie, Lyndsey K. "Large pore mesoporous silicas for application in protein adsorption, enzyme immobilisation and drug delivery". Thesis, University of St Andrews, 2009. http://hdl.handle.net/10023/747.

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A range of mesoporous materials based on SBA-15, KIT-6 and FDU-12 have been prepared using neutral block copolymers Pluronic P123 and F127 and characterised using methods including electron microscopy and nitrogen adsorption. Typically the materials have a hexagonal (p6mm) or cubic (Fm3m and Ia-3d) symmetry and pore geometry and are rendered porous by either calcination or solvent extraction. Organic functional groups were incorporated into the silica walls of the materials by co-condensation in the form of propyl thiols and additives in the form of alkanes were added to control pore size and geometry. The effects of temperature, additives, organic functionalisation, synthesis time and sol-gel composition were investigated and the resulting materials were tested as supports for protein adsorption, enzyme immobilisation, and drug delivery. Two FDU-12 materials of differing entrance and cavity sizes were used to adsorb a range of proteins with molecular weight 17 to 160 kDa to determine if there was a size exclusion effect. It was seen that the larger pore material was able to adsorb proteins of a larger size (molecular weight 105 kDa) and an exclusion effect was observed when the dimension of the proteins became too great (larger than 130 kDa). There was no clear trend for the smaller pore material where each protein was adsorbed to some extent by the material but apart from the smallest protein, myoglobin, mainly on the surface and not within the pores. The adsorption of the lipase B from Candida Antartica, CALB, was studied on a range of mesoporous supports with their templates removed by either calcination or extraction. The effect of pore size and functionalisation was investigated in terms of maximum loading and rate of loading. By functionalising the KIT-6 material the maximum loading of CALB was reduced from 45.5 to 32 mg/g whereas functionalising the FDU-12 material increased the maximum from 33 to 42.5 mg/g. The activity of the immobilised CALB was measured by enantioselective transesterification of (R)-1-phenylethanol in methyltetrabutyl ether (MTBE). The effect of loading, surface functionalisation and reusability in organic media were investigated. Functionalisation with propyl thiol was seen to increase the rate of conversion after 30 minutes for both KIT-6 and FDU-12 materials. Selected FDU-12 and KIT-6 materials with window sizes from 6 to 12 nm and with and without functionalisation were used to carry out a drug release study using Bovine serum albumin (BSA). BSA was loaded onto the material and the uptake quantified using nitrogen adsorption, elemental analysis, and thermogravimetric analysis. The release of BSA into simulated body fluid at 37 ºC was measured using HPLC. Functionalisation was seen to have little effect. The type of cubic morphology controlled the rate at which the BSA was released. The KIT-6 3D channel material exhibited a burst release initially followed by a steady release of BSA whereas the mesocage FDU-12 material had a slower and more linear release profile, closer to that desired.

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Launez, Rémy. "Immobilisation d'organocatalyseurs sur supports inorganiques et évaluation de leur activité en condition de flux continu". Thesis, Université Paris-Saclay (ComUE), 2015. http://www.theses.fr/2015SACLS212/document.

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Le but de notre projet était de mettre au point un procédé éco-compatible d’organocatalyse asymétrique hétérogène en flux continu. Pour réaliser ce procédé, nous avons choisi d’utiliser la cupréine, un alcaloïde dérivé de la quinine comme organocatalyseur bifonctionnel. La silice (un matériau inorganique mésoporeux) a été choisie comme support pour l’hétérogénéisation du catalyseur. La cupréine immobilisée sur silice a ensuite été testée comme organocatalyseur de la réaction d’addition de Michael asymétrique entre le trans-β-nitrostyrène (accepteur de Michael) et le diméthyl malonate (donneur de Michael) en condition de flux continu.Nous avons tout d’abord immobilisé la cupréine sur deux types de silice selon trois stratégies différentes. Chaque stratégie nous a permis d’obtenir le support greffé avec des quantités de cupréine allant de 0,2 à 0,4 mmol par gramme de silice, ainsi que des silices greffées possédant des caractéristiques différentes selon les stratégies envisagées.L’évaluation de l’activité catalytique de la cupréine greffée sur silice a ensuite été réalisée en milieu hétérogène en batch. Différents solvants biosourcés ont alors été testés comme solvants alternatifs pour la réaction d’addition de Michael. Le 2-MeTHF s’est révélé être un bon solvant et a été choisi pour les expériences de catalyse en flux continu. Les résultats obtenus en catalyse avec la cupréine greffée sur silice sont comparables à ceux en milieu homogène (excès énantiomériques supérieur ou égale à 85 % et conversion supérieure à 96 %) exceptés pour la fréquence de rotation (TOF, mol de substrat converti/mol de catalyseur/durée de réaction) qui est trois fois plus faible en milieu hétérogène (0,2 h-1 pour 0,6 h-1 en milieu homogène).Enfin, cette réaction d’addition de Michael a été réalisée en flux continu avec les différentes silices greffées. La fréquence de rotation de la cupréine a été multipliée par deux (0,4 h-1) et le nombre de rotation (TON, mol de substrat converti/mol de catalyseur) a lui aussi été augmenté, passant de 16 en milieu hétérogène en batch à 63 en condition de flux continu. Finalement, différents dérivés du trans-β-nitrostyrène (Chloré, phénolique et méthoxy en position 4) ont été testés avec succès.Ainsi, à notre connaissance, nous avons réalisé la première réaction d’addition de Michael entre le trans-β-nitrostyrène et le diméthyl malonate, organocatalysée en milieu hétérogène en batch et en flux continu par la cupréine immobilisée sur silice, en utilisant un solvant biosourcé. Nous avons réussi à mettre au point le procédé de catalyse hétérogène en flux continu permettant de recycler facilement le catalyseur et aussi d’augmenter la productivité de la cupréine immobilisée par rapport au milieu hétérogène en batch, tout en conservant une conversion et une énantiosélectivité équivalente à celles en milieu homogène
The aim of our project was to develop an eco-friendly process based on heterogeneous asymmetric organocataysis in continuous flow conditions. To succeed in this development, we chose to use a quinine-derived bifunctional organocatalyst: cupreine. Silica, a mesoporous inorganic material, was chosen as the support to immobilize this organocatalyst. The grafted cupreine was then tested as catalyst for the asymmetric Michael addition between the trans-β-nitrostyrene (Michael acceptor) and the dimethyl malonate (Michael donor) in continuous flow condition.First, we immobilized the catalyst on two types of silica, following three different strategies. The various cupreine-grafted silicas we obtained were functionnalized with 0.2 to 0.4 mmol of cuprein per gram of silica. Each one of them possessed specific characteristics depending of the followed strategy.The assessment of the catalytic activity of immobilized silica was then performed in batch condition. Different bio-based solvents were used for the Michael addition. 2-MeTHF was chosen as the best solvent among those tested and used in continuous flow. Immobilized cupreine proved to be as efficient in heterogenous condition as in homogenous (enantiomeric excess was superior or equal to 85 % and conversion better than 96 %), except for turn over frequency (TOF, mol of converted substrate/mol of catalyst/reaction time) which is three times lower in hetereogeneous condition (0.2h-1 to 0.6 h-1 in homogenous condition).Michael addition of trans-β-nitrostyrene to dimethyl malonate was then realized in continuous flow condition, using the various silica-supported catalysts. Turn over frequency of cupreine was doubled (0.4 h-1) and the turn over number (mol of converted substrate/mol of catalyst) increased from 16 to 63 in continuous flow condition. Derivatives of trans-β-nitrostyrene (chlorinated, phenolic and methoxylated in position 4) were successfully tested in continuous flow.To the best of our knowledge, we realized the first asymmetric Michael addition between trans-β-nitrostyrene and the dimethyl malonate, catalysed by silica-supported cupreine in batch and in continuous flow, using a bio-based solvent.We successfully developed an eco-friendly process based on heterogeneous organocatalysis in continuous flow. This process favorited an efficient recycling of the supported catalyst, and increased the productivity of grafted cupreine compare to the heterogeneous condition in batch. The enantioselectivity of the cupreine for this reaction was similar in both homogeneous and heterogeneous conditions

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Riachy, Philippe. "Hierarchically Porous Silica Materials for the Encapsulation of Molecules of Interest". Thesis, Université de Lorraine, 2016. http://www.theses.fr/2016LORR0013/document.

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Ce travail porte sur la préparation de matériaux silicatés à porosité hiérarchisée pour l'encapsulation de molécules d'intérêt dans le domaine de la pharmacie et en tant que biocatalyseur. Afin d’atteindre cet objectif, les nano-émulsions sont choisies comme empreinte pour créer les macropores du matériau en raison de la taille homogène et réduite des gouttelettes de l’émulsion (inférieure à 100 nm). Pour cela le système Remcopal 4/décane/eau est investi en déterminant les conditions les plus optimales de formation de nano-émulsion, via les méthodes d'inversion de phases. L’ajout de micelles aux nano-émulsions ne déstabilise pas les émulsions et permet la formation d’un réseau de mésopores organisés selon une symétrie hexagonale. Les matériaux hybrides issus des matériaux poreux contenant encore la phase organique sont dopés par le ketoprofène en vue d’étudier la libération de ce dernier. Celle-ci se révèle sensible au pH. De plus, cette étude de la libération du kétoprofène à partir du matériau méso-macroporeux indique qu'elle est assistée par les micelles qui sont solubilisées dans la solution réceptrice. Le deuxième objectif de ce travail est d'utiliser ces matériaux poreux en tant que biocatalyseur pour la synthèse de biodiesel à partir d'huile de colza. Pour cette application, il est nécessaire que les matériaux résistent à l’immersion dans des milieux aqueux. L’étude de la stabilité hydrothermale a montré que le matériau calciné présente la meilleure stabilité dans l’eau bouillante. Par ailleurs, le matériau peut résister jusqu’à 550°C, la structure ne subissant que des dégradations mineures. Nous avons également utilisé un matériau silicaté à double mésoporosité préparé à partir de micelles fluorées et hydrogénées coexistant dans une même solution. L'évaluation thermique et hydrothermale indique que ces matériaux présentent deux cinétiques de déstructuration qui correspondent à chacune des deux matrices ayant deux tailles de pores différents. L’immobilisation de la lipase Mml est étudiée sur le matériau méso-macroporeux calciné et sur le matériau à double mésoporosité. Les isothermes d'adsorption ont permis de mettre en évidence que le matériau à double mésoporosité peut encapsuler plus d’enzymes que son homologue méso-macroporeux. L’activité enzymatique, au regard des réactions de transestérification, est de façon inverse plus importante avec le matériau méso-macroporeux calciné
This work concerns the preparation of silica materials with hierarchical porosity for the encapsulation of molecules of interest in the field of drug delivery and as biocatalysts. In order to reach this goal, the nano-emulsions were chosen as templates for the macropores of the material because of the homogeneous and small size of the emulsion droplets (less than 100 nm). The system Remcopal 4/decane/water was investigated and the optimal conditions for which nano-emulsion is formed via the phase inversion methods were determined. Adding micelles to the nano-emulsions does not affect its stability and can form a network of mesopores organized with a hexagonal symmetry. Hybrid materials which are hierarchically porous materials where the organic phase is still present, were doped with ketoprofen to study its release, which proved to be pH sensitive. Moreover, the study of the release of ketoprofen from the meso-macroporous material indicates that it is assisted by the micelles which are solubilized in the release medium. The second objective of this work was to use these porous materials as a biocatalyst for biodiesel synthesis from colza oil. For this application it was necessary that the materials are resistant to immersion in aqueous media. The study of the hydrothermal stability shows that the calcined material has the best stability in boiling water. Moreover, the material can withstand up to 550 ° C, the structure undergoes only minor damages. We also used a dual-mesoporous silica material prepared from hydrogenated and fluorinated micelles coexisting in the same solution. Thermal and hydrothermal evaluation indicates that these materials have two different decay kinetics corresponding to each of the two matrices having different pore sizes. The immobilization of lipase Mml was studied on the meso-macroporous calcined material and the dual-mesoporous material. The adsorption isotherms were used to demonstrate that the dual-mesoporous material can encapsulate more enzymes than its meso-macroporous counterpart. On the other hand, the enzyme activity, evaluated by the transesterification reactions, is more important for the calcined meso-macroporous material

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Części książek na temat "Silica immobilisation"

Forsyth, Claire, i Siddharth V. Patwardhan. "Bioinspired Silica for Enzyme Immobilisation: A Comparison with Traditional Methods". W Advances in Silicon Science, 39–62. Dordrecht: Springer Netherlands, 2014. http://dx.doi.org/10.1007/978-94-017-9439-8_4.

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Dugas, V., Y. Chevalier, G. Depret, X. Nesme i É. Souteyr. "The immobilisation of DNA strands on silica surface by means of chemical grafting". W Trends in Colloid and Interface Science XVI, 275–79. Berlin, Heidelberg: Springer Berlin Heidelberg, 2004. http://dx.doi.org/10.1007/b11958.

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Wilson, Natalie G., i Tom McCreedy. "Microporous Silica Structures for the Immobilisation of Catalysts and Enhancement of Electroosmotic Flow (EOF) in Micro-Reactors". W Microreaction Technology: Industrial Prospects, 346–52. Berlin, Heidelberg: Springer Berlin Heidelberg, 2000. http://dx.doi.org/10.1007/978-3-642-59738-1_36.

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Tits, J., X. Gaona, N. Macé, D. Kulik, T. Stumpf, C. Walther, G. Geipel i E. Wieland. "Immobilisation of Uraniumvi in Cementitious Materials: Evidence for Structural Incorporation in Calcium–Silicate–Hydrates and Solid Solution Formation". W Proceedings of the 10th International Congress for Applied Mineralogy (ICAM), 699–706. Berlin, Heidelberg: Springer Berlin Heidelberg, 2012. http://dx.doi.org/10.1007/978-3-642-27682-8_84.

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Geysen, D., C. Vandecasteele, M. Jaspers i G. Wauters. "Cement and Micro Silica Based Immobilisation of Different Flue Gas Cleaning Residues from MSW Incineration". W Sustainable Waste Management, 63–72. Thomas Telford Publishing, 2003. http://dx.doi.org/10.1680/swm.32514.0007.

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Riddel, S. A., W. P. Hems, A. Chesney i S. R. Watson. "Synthesis of functionalised silicas for immobilisation of homogeneous catalysts". W Nanotechnology in Mesostructured Materials, Proceedings of the 3rd International Materials Symposium, 799–801. Elsevier, 2003. http://dx.doi.org/10.1016/s0167-2991(03)80504-9.

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Streszczenia konferencji na temat "Silica immobilisation"

Sharma, K., A. P. Srivastav, M. Goswami i Madangopal Krishnan. "Calcium titanium silicate based glass-ceramic for nuclear waste immobilisation". W DAE SOLID STATE PHYSICS SYMPOSIUM 2017. Author(s), 2018. http://dx.doi.org/10.1063/1.5028805.

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Saby, Martelet, Jaffrezic, Colin, Charles, Delaire i Mandrand. "Methods Of Immobilisation Of Biomolecules On A Silicon Based Transducer." W Proceedings of the Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE, 1992. http://dx.doi.org/10.1109/iembs.1992.589579.

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Saby, C., C. Martelet, N. Jaffrezic, B. Colfn, M.-H. Charles, T. Delaire i B. Mandrand. "Methods of immobilisation of biomolecules on a silicon based transducer". W 1992 14th Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE, 1992. http://dx.doi.org/10.1109/iembs.1992.5760898.

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Sharp, J. H., J. Hill, N. B. Milestone i E. W. Miller. "Cementitious Systems for Encapsualation of Intermediate Level Waste". W ASME 2003 9th International Conference on Radioactive Waste Management and Environmental Remediation. ASMEDC, 2003. http://dx.doi.org/10.1115/icem2003-4554.

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Encapsulation in cement is the favoured method in the UK for disposal of intermediate and low level radioactive wastes. It is usual to use composite cement systems incorporating blast furnace slag (BFS) or pulverised fuel ash (PFA) as these offer several advantages over Portland cement, notably a lower heat of hydration. The use of these mineral additions utilises a waste product which would itself need a disposal route and, because of the decreased amount of Portland cement used, provides a reduction in cost and energy consumption. Cementitious systems have many attributes which make them suitable for encapsulation and immobilisation, including: • Inexpensive and readily available; • Assist immobilisation of radionuclides by: a) acting as a diffusion barrier, b) providing sorption and reaction sites, c) maintaining a high pH which in turn decreases radionuclide solubility; • Provide radiation shielding which is not degraded by the radiation; • Controllable permeation and diffusion characteristics over a wide range via selection of constituents and components. Where physical adsorption is a significant factor for immobilisation, the calcium silicate hydrate gel (C-S-H) formed on hydration of a Portland cement is advantageous as it has a high surface area and large micropore volume. Composite cements based on blast furnace slag will produce a higher proportion of C-S-H than ordinary Portland cement increasing the sorption capacity, and reducing the capillary porosity so that the diffusion resistance is increased. Intermediate level waste covers a wide range of materials, for example, metals and ion exchangers, each with differing chemical properties. It is, therefore, necessary to access the ability of the cementitious system to immobilise different wastes and to characterise the products formed. It is also necessary that alternative encapsulant materials be considered for immobilising wastes not suited to the composite cements already being used. The techniques employed to do this include x-ray diffraction (XRD), to identify standard and non-standard hydration products, isothermal conduction calorimetry (ICC) and scanning electron microscopy (SEM).

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