The two techniques aqueoustwo-phase partitioning and expanded bed adsorption that bothare suitable for primary protein recovery were studied. Most ofthe work was focused on partition in aqueous two-phase systemsand in particular on the possibility to effect the partitionbehaviour by fusion of short peptide tags or protein domains tothe target protein. The partitioning of fusionproteins between different variants of the domain tag Z and thenaturally occurring protein DNA Klenow polymerase were studiedin Breox/Reppal aqueous two-phase systems. Most studies wereperformed with cell homogenate. The Breox/Reppal system was infocus because if the fusion protein can be partitioned to theBreox-rich top phase the next step can be a thermoseparatingaqueous two-phase system. When the Breox phase is heated to50°C it switches from a one-phase system to a two-phasesystem resulting in an almost pure water rich top phase andhighly concentrated Breox-rich bottom phase. The Breox can thenbe reused and the protein recovered from the water phase. TheZ-domain was genetically modified in different ways to Zbasic1, Zacid2and Ztrp12and fused to the Klenow protein to try toenhance partitioning to the Breox-rich phase. From theexperiments it was not possible to observe any effects on thepartition behaviour irrespectively of tested properties of thedomain tag. Despite the absence of domain tag effects highK-values, i.e. partition to the Breox-rich top phase, wereobserved in the Breox/Reppal system. However, the proteinK-values seemed to be rather sensitive to the cell homogenateload and showed a tendency to decrease with increased cellhomogenate load. Also increased phosphate concentration reducedthe K-values. The partitioning of cell debris also seemed todependent on the cell homogenate load. At higher homogenateload (&lt;=20g DW/L) clear Breox-rich top phases were observedwith the cell debris collected in Reppal-rich bottomphases. Two different tetrapeptides,AlaTrpTrpPro and AlaIleIlePro were inserted near the C-terminusof the protein ZZT0. The Trp-rich peptide unit stronglyincreased both the partitioning of ZZT0 into the poly(ethyleneglycol) (PEG)-rich phase in a PEG/potassium phosphate aqueoustwo-phase system and its retention on PEG and propylhydrophobic interaction chromatographic columns with potassiumphosphate as eluent in isocratic systems. Both the partitioningand the retention increased with increasing number of Trp-richpeptide units inserted into ZZT0. Insertion of Ile-richtetrapeptide units affected the partitioning and retention to amuch lesser extent. Partition and modelling data also indicateda folding of inserted Trp and Ile tetrapeptide units, probablyto minimise their water contact. It was also investigated howto predict the partitioning of proteins in isoelectricPEG/phosphate aqueous two-phase systems. The capture ofß-galactosidase fromE. colicell homogentate (50g DW/L) by metal chelatexpanded bed adsorption was studied. These experiments showedthat capture, with a certain degree of selectivity, andclarification of ß-galactosidase could be achieved from acell homogenate. However, a rather low recovery of about 35 %was obtained at a capacity of 0.25mg/mL of gel. Thus, severalparameters remain to be optimised like the load buffercomposition and the cell homogenate load. <b>Keywords:</b>E. coli, aqueous two-phase systems, fusion proteins,hydrophobic interaction chromatography, expanded bedadsorption, ß-galactosidase, Klenow polymerase, Z-domain,peptide tags / NR 20140805

De nouveaux matériaux hybrides « inorganique-organique » pour le captage de polluants organiques (pesticides, HAP) ont été préparés soit par greffage sur des oxydes métalliques, soit par procédé sol-gel. Pour préparer ces matériaux nous avons développé une méthodologie catalytique pour la synthèse des motifs organiques aromatiques. Cette méthodologie repose sur la réaction de couplage de Heck palladocatalysée entre le vinylphosphonate de diéthyle avec des différents halogénures d’aryles en utilisant des catalyseurs homogènes et hétérogènes. Des bons rendements isolés ont été obtenus. En complément, nous avons étudié l’arylation du diéthylacétale de l’acroléine en milieu aqueux qui donne principalement l’ester propanoïque et le cinnamaldéhyde. Nous avons mis en évidence l’influence de différents paramètres (catalyseurs, température, bases, additifs) et montré que l’ajout de cyclodextrines est bénéfique, en augmentant dans la plupart des cas la vitesse de la réaction. Dans le cadre de cette étude, nous avons montré que le remplacement de NaOAc par NH(i-Pr)2 conduisait à une inversion de la sélectivité du cinnamaldéhyde vers l’ester propanoïque. Les matériaux azotés (amine; guanidine; biguanide@oxyde métallique) ont été obtenus soit par greffage des composés bi fonctionnels [fonction azoté]/PO(OEt)2 sur les supports, soit par greffage d’un aminophosphonate suivi d’une condensation en phase solide avec le DIP.La capacités de piégeage de différents pesticides par extraction en phase solide a été évaluée et comparés à celle de deux matériaux courants (charbon actif et Si-C18) connus comme support solide universel dans ce domaine. Nous avons ainsi démontré la complémentarité des différents matériaux dans le piégeage des pesticides. / Development of new hybrid materials “inorganic-organics” for the collecting of the various organic pollutants (pesticides, PAH). These materials were prepared by two methods: grafting of metallic oxides and sol-gel method. A catalytic methodology of the aromatic organic matrix synthesis was considered. This methodology is based on the reaction of pallado-catalyzed Heck coupling between the diethyl vinylphosphonate with different aryl halogenurs by using homogeneous and heterogeneous catalysts. The good isolated yields for products were obtained. The complement, we study of the arylation reaction of the acrolein diethylacetal in aqueous medium, and the influence of various parameters (catalysts, bases, temperature, additifs) on this reaction. The addition of cyclodextrins in reaction medium is beneficial. Within the framework of this study, we showed that the replacement of NaOAc by NH (i-Pr)2 led to an inversion of the selectivity of cinnamaldéhyde towards propanoïque ester. Nitrogen material (amine, guanide, biguanide/PO-OEt)2 either by grafting of bifunctional compounds on the supports, and grafting of amiophosphonate flow condensation to DIP.The capacity of the trapping of pesticides by extraction in solid phase was evaluated and compared of two current materials (activated carbon and Si-C18) known as universal solid support. We thus showed the complementarity of various materials in the trapping of the pesticides

京都大学 / 0048 / 新制・課程博士 / 博士(理学) / 甲第18806号 / 理博第4064号 / 新制||理||1585(附属図書館) / 31757 / 京都大学大学院理学研究科地球惑星科学専攻 / (主査)教授 平島 崇男, 教授 大沢 信二, 准教授 河上 哲生 / 学位規則第4条第1項該当 / Doctor of Science / Kyoto University / DFAM

No description available.

Abstract The aim of the present study was to increase the understanding of how the cell surface properties affect the performance of unit operations used in primary protein purification. In particular, the purpose was to develop, set up and apply methods for studies of cell surface properties and cell interactions. A method for microbial cell surface fingerprinting using surface plasmon resonance (SPR) is suggested. Four different Escherichia coli strains were used as model cells. Cell surface fingerprints were generated by registration of the interaction between the cells and four different surfaces, with different physical and chemical properties, when a cell suspension was flown over the surface. Significant differences in fingerprint pattern between some of the strains were observed. The physical properties of the cell surfaces were determined using microelectrophoresis, contact angle measurements and aqueous two-phase partitioning and were compared with the SPR fingerprints. The generated cell surface fingerprints and the physical property data were evaluated with multivariate data analysis that showed that the cells were separated into individual groups in a similar way using principal component analysis plots (PCA). Studies of the behaviour of the model cells on stirred cell filtration and in an interaction test with different expanded bed adsorption (EBA) adsorbents were performed. It could be concluded that especially one of the strains behaved differently. Differences in the properties of the model cells were indicated by microelectrophoresis and aqueous two-phase partitioning which to some extent correlated with observed differences in behaviour during filtration and in an interaction test with EBA adsorbents. The impact of high-pressure homogenisation of E. coli cell extract was examined, with a lab scale and a pilot scale technique. The DNA-fragmentation, visualised with agarose gel electrophoresis, and the resulting change in viscosity was analysed. A short homogenisation time resulted in increased viscosity of the process solution that correlated with increased concentration of released non-fragmented DNA. With longer homogenisation time the viscosity decreased with increasing degree of DNA-fragmentation. The results show that strain dependant cell surface properties of E. coli may have an impact on several primary steps in downstream processing. / QC 20101129

M. Tech. (Department of Chemistry, Faculty of Applied and Computer Sciences), Vaal University of Technology. / Removal of wastewater pollutants is urgent as they are continuously defiling the limited freshwater resources, affecting the ecosystem, aquatic and terrestrial life. Carbon nanotubes-based adsorbent materials are effective for removal of wastewater pollutants owing to their large specific surface area. Surface modification of carbon nanotubes (CNTs) can mediate specific pollutant adsorption and increase CNTs colloidal stability and chemical reactivity. Heavy metal pollution of wastewater is one of the major threats, as this metals can be toxic to humans when present at certain concentrations in drinking water. This study report the synthesis of chlorine functionalized and nitrogen doped carbon nanotubes (ClNCNTs) loaded with iron oxide nanoparticles and their use as adsorbents for Pb2+ ions in aqueous solutions. Carbon nanomaterials that are functionalized with chlorine and doped with nitrogen were successfully synthesized. This was done through pyrolysis of a mixture of dichlorobenzene and acetonitrile (in a 1:1 volume ratio) over 10% Fe-Co/CaCO3 bi-metallic catalyst via chemical vapour deposition (CVD) method. Addition of chlorine and nitrogen to the CNTs was to enable defect and disorder creation on the surface of the nanotubes which is envisaged to create nucleation sites on the their surface for better adhesion of the iron oxide nanoparticles. Different loadings of magnetite (Fe3O4) nanoparticles on the surface of the ClNCNTs was achieved using a co-precipitation method. The synthesized materials were charaterized by Raman spectroscopy, Transmission electron microscopy (TEM), Powder X-ray diffraction (PXRD) spectroscopy, Thermal gravimetric analysis (TGA), Brunauer Emmett and Teller (BET) and X-ray photoelectron spectroscopy (XPS). Highly defected CNTs, some with hollow and others with bamboo-compartments due to nitrogen inclusion were obtained. The effect of metal salt concentration in wt.% (10, 20, 30 and 53 wt.%) was investigated. The increase in wt.% loading has resulted in an increase in surface area, and a decrease in thermal stability as a result of defected Fe3O4/ClNCNTs. In addition, agglomeration was observed at 30 and 53 wt.% loading, due to large amount of iron present. The identity of the Fe3O4 nanoparticles was confirmed by PXRD and XPS with two iron peaks deconvoluted at 725.6 eV and 721 eV respectively. The percentage loading of the Fe3O4 nanoparticles at the surface of the ClNCNTs was affirmed by TGA analysis, where the residual mass obtained from TGA were closely related to the mass percentages added. Different nitrogen environments namely, the quatenary, pyridinic, pyrollic and nitrogen oxides were also observed, whilst chlorine could not be deconvoluted because it was present in very limited amount probably it was masked by the iron oxide nanoparticle. Thus, a 20 wt.% Fe3O4/ClNCNTs was chosen as an optimum, due to uniform distribution of spherical nanopaticles observed along the radial length of ClNCNTs that had an average size of 10 ± 4.5 nm. The synthesized ClNCNTs and a nanocomposite made from a 20 wt.% Fe3O4/ClNCNTs were applied in the removal of Pb2+ ions from aqueous solution. The results obtained showed that a nanocomposite made from a 20 wt.% Fe3O4/ClNCNTs had a better adsorption capacity of 17.0 mg/g as compared with 14.8 mg/g for ClNCNTs.

Die vorliegende Arbeit konzentriert sich auf die Synthese von neuartigen hohlen MoSx-Nanomaterialien mit kontrollierbarer Größe und Form durch die kolloidale Template Methode. Ihre möglichen Anwendungen in wässrigen Energiespeichersystemen, einschließlich Superkondensatoren und Li-Ionen-Batterien (LIBs), wurden untersucht. Im ersten Teil wurde eine neue Nanostruktur aus hohlen Kohlenstoff-MoS2-Kohlenstoff-nanoplättchen erfolgreich durch eine L-Cystein unterstützte hydrothermale Methode unter Verwendung von Gibbsit als Templat und Polydopamin (PDA) als Kohlenstoffvorläufer synthetisiert. Nach dem Kalzinieren und Ätzen des Gibbsit Templates wurden gleichförmige Hohlplättchen erhalten, die aus einer sandwichartigen Anordnung von teilweise graphitischem Kohlenstoff und zweidimensional geschichteten MoS2 Flocken bestehen. Die Plättchen haben eine ausgezeichnete Dispergierbarkeit und Stabilität in Wasser sowie eine gute elektrische Leitfähigkeit aufgrund des durch die Kalzinierung von Polydopaminbeschichtungen erzeugten Kohlenstoffs gezeigt. Das Material wird dann in einem symmetrischen Superkondensator mit 1 M Li2SO4 als Elektrolyt aufgebracht, der eine spezifische Kapazität von 248 F/g (0.12 F/cm2) bei einer konstanten Stromdichte von 0.1 A/g und eine ausgezeichnete elektrochemische Stabilität über 3000 Zyklen aufweist, was darauf hindeutet, dass hohle Kohlenstoff-MoS2-Kohlenstoffnanoplättchen vielversprechende Materialien als Kandidaten für Superkondensatoren sind. Im zweiten Teil wurde 21 molare LiTFSI, das sogenannte "Wasser-in-Salz" (WIS) Elektrolyt, in Superkondensatoren mit hohlen Kohlenstoffnanoplättchen als Elektrodenmaterial untersucht. Im Vergleich zu dem im ersten Teil verwendeten 1 molaren Li2SO4-Elektrolyten wurden bei dem vorliegenden WIS Elektrolyt signifikante Verbesserungen in einem breiteren und stabilen Potentialfenster festgestellt, das durch die geringere Leitfähigkeit mit dem Gegenstück leicht beeinflusst wird. Die elektrochemische Impedanzspektroskopie (EIS) wurde ausgiebig eingesetzt, um einen Einblick in die Reaktionsmechanismen der WIS-Superkondensatoren zu erhalten. Zusätzlich wurde auch der Einfluss der Temperatur auf die elektrochemische Leistung im Temperaturbereich zwischen 15 und 55 °C untersucht, was eine hervorragende spezifische Kapazität von 128 F/g bei dem optimierten Zustand von 55 °C ergab. Die EIS-Messungen deckten die Abnahme der angepassten Widerstände mit der Temperaturerhöhung und umgekehrt auf und beleuchteten direkt die Beziehung zwischen elektrochemischer Leistung und Arbeitstemperatur von Superkondensatoren für zuverlässige praktische Anwendungen. Im dritten Teil wurde MoS3, ein amorphes, kettenförmig strukturiertes Übergangsmetall Trichalcogenid, als vielversprechende Anode in "Wasser-in-Salz" Li-Ionen-Batterien (WIS-LIBs) nachgewiesen. Die in diesem Teil verwendeten hohlen MoS3-Nanosphären wurden mittels einer skalierbaren Säurefällungsmethode bei Raumtemperatur synthetisiert, wobei sphärische Polyelektrolytbürsten (SPB) als Schablonen verwendet wurden. Beim Einsatz in WIS-LIBs mit LiMn2O4 als Kathodenmaterial erreicht das präparierte MoS3 eine hohe spezifische Kapazität von 127 mAh/g bei einer Stromdichte von 0.1 A/g und eine gute Stabilität über 1000 Zyklen sowohl in Knopf- als auch in Pouch-Zellen. Der Arbeitsmechanismus von MoS3 in WIS-LIBs wurde auch durch Ex-situ-Röntgenbeugungsmessungen (XRD) untersucht. Während des Betriebs wird MoS3 während der anfänglichen Li-Ionen-Aufnahme irreversibel in Li2MoO4 umgewandelt und dann allmählich in eine stabilere und reversible LixMoOy-Phase (2≤y≤4)) entlang der Zyklen umgewandelt. Amorphes Li-defizientes Lix-mMoOy/MoOz wird bei der Delithiierung gebildet. Die Ergebnisse der vorliegenden Studie zeigen einfache Ansätze zur Synthese hohler MoSx-Nanomaterialien mit kontrollierbarer Morphologie unter Verwendung einer Template-basierten Methode, die auf die vielversprechende Leistung von MoSx für wässrige Energiespeicheranwendungen zurückzuführen sind. Die elektrochemischen Untersuchungen von hohlen MoSx-Nanomaterialien in wässrigen Elektrolyten geben Einblick in die Reaktionsmechanismen von wässrigen Energiespeichersystemen und treiben die Entwicklung von Metallsulfiden für wässrige Energiespeicheranwendungen voran. / The present thesis focuses on the synthesis of novel hollow MoSx nanomaterials with controllable size and shape through the colloidal template method. Their possible applications in aqueous energy storage systems, including supercapacitors and Li-ion batteries (LIBs), have been studied. In the first part, hollow carbon-MoS2-carbon nanoplates have been successfully synthesized through an L-cysteine-assisted hydrothermal method by using gibbsite as the template and polydopamine (PDA) as the carbon precursor. After calcination and etching of the gibbsite template, uniform hollow platelets, which are made of a sandwich-like assembly of partial graphitic carbon and two-dimensional layered MoS2 flakes, have been obtained. The platelets have shown excellent dispersibility and stability in water, and good electrical conductivity due to carbon coating generated by the calcination of polydopamine. The material is then applied in a symmetric supercapacitor using 1 M Li2SO4 as the electrolyte, which exhibits a specific capacitance of 248 F/g (0.12 F/cm2) at a constant current density of 0.1 A/g and an excellent electrochemical stability over 3000 cycles, suggesting that hollow carbon-MoS2-carbon nanoplates are promising candidate materials for supercapacitors. In the second part, 21 m LiTFSI, so-called “water-in-salt” (WIS) electrolyte, has been studied in supercapacitors with hollow carbon nanoplates as electrode materials. In comparison with 1 M Li2SO4 electrolyte used in the first part, significant improvements on a broader and stable potential window have been revealed in the present WISE, which is slightly influenced by the lower conductivity with the counterpart. The electrochemical impedance spectroscopy (EIS) has been extensively employed to provide an insight look on the formation of solid electrolyte interphase in the WIS-supercapacitors. Additionally, the effect of temperature on the electrochemical performance has also been investigated in the temperature range between 15 and 55 °C, yielding eminent specific capacitance of 128 F/g at the optimized condition of 55 °C. The EIS measurements disclosed the decrease of fitted resistances with the increase of temperature and vise versa, directly illuminating the relationship between electrochemical output and working temperature of supercapacitors for reliable practical applications. In the third part, MoS3, an amorphous chain-like structured transitional metal trichalcogenide, has been demonstrated as a promising anode in the “water-in-salt” Li-ion batteries (WIS-LIBs). Hollow MoS3 nanospheres used in this part have been synthesized via a scalable room-temperature acid precipitation method using spherical polyelectrolyte brushes (SPB) as the template. When applied in WIS-LIBs with LiMn2O4 as the cathode material, the prepared MoS3 achieves a high specific capacity of 127 mAh/g at the current density of 0.1 A/g and good stability over 1000 cycles in both coin cells and pouch cells. The working mechanism of MoS3 in WIS-LIBs has also been studied by ex-situ X-ray diffraction (XRD) measurements. During operation, MoS3 undergoes irreversible conversion to Li2MoO4 during the initial Li ion uptake, and is then gradually converted to a more stable and reversible LixMoOy (2≤y≤4)) phase along cycling. Amorphous Li-deficient Lix-mMoOy/MoOz is formed upon delithiation. The results in the present thesis demonstrate facile approaches for synthesizing hollow MoSx nanomaterials with controllable morphologies using a template-based method, which attribute to the promising performance of MoSx for aqueous energy storage applications. The electrochemical studies of hollow MoSx nanomaterials in aqueous electrolytes provide insight into the reaction mechanisms of aqueous energy storage systems and push forward the development of metal sulfides for aqueous energy storage applications.

No description available.

No description available.

No description available.