Dissertations / Theses on the topic 'Lignin nanoparticle'

Lignin is one of the main components of wood and plants that acts as a kind of glue providing mechanical strength. It is a main polymer component composed from three phenolic structures, i.e. p-hydroxyphenyl (H), guaiacyl (G) and syringyl (S) units. It currently draws a lot of attention due to its eco-friendly. Recently, it has been shown that it is possible to produce lignin nanoparticles, small spherical particle that are composed out of lignin, that could possibly be used to replace the hazardous silver nanoparticles that are today used frequently in numerous applications. Lignin nanoparticles could potenitally also be used as functional coatings, as well as biologically degradable adhesives and float switches. Five samples, of nanoparticles, were investigated in this study. The first contained pure lignin nanoparticles, the second pure silver nanoparticles, and the three remaining samples contained lignin-coated silver nanoparticles, extracted from acetone, tetrahydrofuran (THF), and dimetylformamid (DMF) solvents. All samples were characterized using spectroscopic methods, e.g. infrared- and dark-field imaging, as well as UV-Vis-, fluorescence-, and Raman spectroscopy. In this thesis it was shown that lignin-coated silver nanoparticles exhibit surface plasmon resonance which induces a heat effect upon infrared irradiation. To identify the phenolic structures of lignin, UV-Vis spectroscopy was used. It was found that the spectra of the samples exhibited several intense bands. The objective of the UV-Vis spectroscopy was to examine the absorbance characteristics of the lignin-coated silver nanoparticles. Possible surface plasmon resonance wavelengths were determined, and two of the phenolic structures were identified. In this study, Raman spectroscopy was used to define characteristic bands of the samples. This was done to investigate if the lignin nanoparticles have the same characteristics as bulk lignin. Raman spectroscopy provide structural information of lignin. Furthermore, p-hydroxyphenyl, guaiacyl and syringyl structures could be identified with an excitation wavelength of 532nm. A comparison of the spectra of the lignin-containing samples indicated the the Raman features of the specimens were similar meanwhile almost no signs of silver were present, which might show that the particles were fully covered with lignin. Main lignin bands were identified and assigned. The fluorescent properties of the nanoparticles were investigated by obtaining emission spectra for blue-, green- and UV light excitation. The spectra were deconvoluted into their Gaussian components. Emission spectra were obtained for blue-, green- and UV light excitation. It was found that the fluorescence, after UV light exposure, increased with time of exposure. Dark-field microscopy was used to generate light scattering images of the particles. As a result, optical images with different colors (white, yellow, blue and red) could be revealed. The color information, that is related to the size of the particles, was used to estimate ratios of the different particle sizes. The lignin-coated silver nanoparticles, extracted from acetone, exhibited a strong surface plasmon resonance effect, which could be due to the absorbance at 463nm. The lignin-coated silver nanoparticles, extracted from DMF, exhibited a medium surface plasmon resonance effect, which could be due to the absorbance at 362nm. The lignin-coated silver nanoparticles, extracted from the THF solvent, exhibited a weak surface plasmon resonance effect, which could be due to the absorption at 379-380nm. The pure lignin- and silver nanoparticles merely showed bulk heating but no surface plasmon resonance effect could be detected.
Lignin är en av huvudbeståndsdelarna av trä och plantor som fungerar likt ett lim som ger mekanisk styrka. Lignin är en biopolymer, som består av tre fenylgrupper: p-hydroxifenyl (H), guaiacyl (G) och syringyl (S). På senaste tid har det visat sig att det är möjligt att tillverka lignin nanopartiklar, det är små sfäriska partiklar som är helt gjorda av lignin, som skulle kunna ersätta de miljöfarliga silver nanopartiklarna som i nuläget används i många olika tillämpningar. Lignin nanopartiklar kan potentiellt också användas som funktionella ytbeläggningar, såväl som biologiskt nedbrytbara lim och flottörer. Fem prover, av nanopartiklar, undersöktes i denna studie. Det första provet innehöll lignin nanopartiklar, det andra silver nanopartiklarna, och de tre återstående proverna innehöll ligninbelagda silver nanopartiklar, extraherade från aceton, tetrahydrofuran (THF) och dimetylformamid (DMF). Alla prover karakteriserades med hjälp av spektroskopiska metoder: infraröd- och mörkfältavbildning, liksom UV-Vis-, fluorescens- och Ramanspektroskopi. I denna avhandling visades att ligninbelagda silver nanopartiklar uppvisar ytplasmonsresonans, vilket inducerar en värmeeffekt vid infraröd bestrålning. För att identifiera ligninets fenylgrupper användes UV-Vis-spektroskopi. Det visade sig att spektra från proverna uppvisade flera intensiva band. Målet med UV-Vis-spektroskopin var att undersöka absorptionsegenskaperna hos de ligninbelagda silvernanopartiklarna. Möjliga ytplasmonresonansvåglängder bestämdes och två av fenylgrupperna identifierades. I denna studie användes Ramansspektroskopi för att definiera karakteristiska band för proverna. Detta gjordes för att undersöka om lignin nanopartiklarna har samma egenskaper som bulk lignin. Ramanspektroskopi ger information om ligninets struktur. Vidare identigierades p-hydroxifenyl-, guaiacyl- och syringylstrukturerna med en excitationsvåglängd på 532nm. En jämförelse av spektra för de lignininnehållande proverna indikerade att provernas Raman-kännetecken var liknande medan nästan inga tecken på silver fanns, vilket kan visa att partiklarna var täckta med lignin. Huvudsakliga ligninband kunde identifieras. Fluorescensegenskaperna, hos nanopartiklarna, undersöktes genom de erhållna emissionspektra efter exponering av blå-, grön- och UV-ljus. De erhållna spektra dekonvoluterades till dess gaussiska komponenter. Det visade sig att fluorescensen, efter exponering av UV-ljus, ökade med exponeringstiden. Mörkfältmikroskopi användes för att generera bilder på partiklarna. De resulterade i bilder med olika färger (vitt, gult, blått och rött) som motsvarade olika partikelstorlekar och geometrier. På så sätt kunde färhållandena mellan de olika partikelstorlekarna uppskattas. De ligninbelagda silver-nanopartiklarna, extraherade från aceton-lösningen, uppvisade en stark ytplasmonresonanseffekt, vilket kan bero på absorptionen (från absorptionsspektrat) vid 463nm. De ligninbelagda silver-nanopartiklarna, extraherade från DMF-lösningen, uppvisade en medelstark ytplasmonresonanseffekt, vilket kan bero på absorptionen vid 362nm. De ligninbelagda silver-nanopartiklarna, extraherade från THF-lösningen, uppvisade en svag ytplasmonresonanseffekt, vilket kan bero på absorptionen vid 379-380nm. De rena lignin- och silver-nanopartiklarna uppvisade endast uppvärmning men ingen ytplasmonresonanseffekt.

Manufatti in gomma trovano una gran varietà di impieghi tecnologicamente rilevanti. Le proprietà meccaniche della gomma di per sé non sono soddisfacenti per le applicazioni desiderate quindi i miglioramenti necessari sono comunemente ottenuti tramite vulcanizzazione e addizione di filler rinforzanti nella matrice elastomerica. Il filler rinforzante più comune è il nero fumo il cui uso è tuttavia associato a problemi per la salute e l’ambiente. Per questa ragione molti produttori di pneumatici stanno concentrando i propri sforzi per la sostituzione del nero fumo con alternative più sostenibili. Le loro ambizioni includono l’incremento di materiali rinnovabili e la simultanea riduzione di composti derivanti da carbonfossile nella formulazione di pneumatici, contemporaneamente preservando o migliorando le proprietà meccaniche. In questo contesto il presente progetto di ricerca si è concentrato sullo sviluppo di filler rinforzanti sostenibili per compositi elastomerici in alternativa alle tecnologie legate all’industria del petrolio, con una particolare attenzione alla lignina. Nonostante la sua disponibilità a livello industriale, la complessità strutturale della lignina ha impedito la sua conversione in prodotti ad alto valore aggiunto e la progettazione razionale di materiali funzionali. Questo materiale può essere considerato una valida alternativa al nerofumo nei compositi elastomerici per le sue proprietà chimico-fisiche, le proprietà meccaniche, l’attività antiossidante e la stabilità termica. La sua combinazione con una matrice elastomerica comporta la necessità di superare la scarsa compatibilità tra i due materiali associata alla polarità della lignina che dà luogo a forti interazioni con se stessa. È stato necessario modificare la lignina per migliorare il numero e la qualità delle sue interazioni con la gomma al fine di ottenere un rinforzo meccanico della stessa. Per assicurare il rinforzo desiderato si sono esplorate e due strategie. La prima si è focalizzata sulla funzionalizzazione dei gruppi ossidrili della lignina, puntando alla formazione di legami covalenti tra la lignina stessa e la matrice gommosa durante la vulcanizzazione. È stata messa a punto una procedura innovativa per l’esterificazione meccanochimica della lignina che ha consentito di eseguire la reazione allo stato solido, avvantaggiandosi dell’energia meccanica per indurre trasformazioni chimiche, evitando l’uso di solventi organici, limitando le procedure di workup e riducendo la produzione di rifiuti rispetto alle strategie di sintesi in soluzione. Il secondo approccio è consistito nella formulazione di nanoparticelle di lignina (LNP) che sono note esibire proprietà uniche a causa del loro alto rapporto tra area superficiale e volume. Studi analitici riguardo frazioni estratte con solventi organiche hanno guidato la scelta di specifiche frazione di lignina per lo sviluppo di nanoparticelle con caratteristiche peculiari. La procedura innovativa sviluppata ha permesso di valorizzare tutto la lignina kraft di partenza in maniera efficiente. È stato possibile produrre LNP con una provata stabilità dimensionale in un ampio intervallo di pH (4,5-12) , valori ai quali normalmente la lignina si aggrega o dissolve. Lo stesso approccio ha consentito di preparare LNP specificamente funzionalizzate in maniera covalente alla superficie, un risultato mai ottenuto in letteratura al meglio delle nostre conoscenze. La messa appunto e lo scale up di queste procedure hanno permesso la formulazione di compositi elastomerici, seguito dalla valutazione delle proprietà dinamomeccaniche di una varietà di compositi che includevano lignina modificata. I risultati intriganti si sono dimostrati promettenti per lo sviluppo di compositi elastomerici tecnologicamente competitivi contenenti materiali rinnovabili.
Rubber products are commonly employed in a wide variety of industries including tire manufacturing, packaging, engineering and construction. The mechanical performances of rubber itself are unsatisfactory for the desired applications so the necessary improvements are commonly obtained by vulcanization and addition of reinforcing fillers in the elastomeric matrix. The most popular reinforcing filler is carbon black whose use is however associated with health and environmental concerns. For this reason, many tire manufacturers are concentrating their efforts in replacing carbon black with more sustainable alternatives. Their ambitions include the increment of renewable materials and the simultaneous reduction of fossil-based compounds in tire formulations, while preserving pr improving mechanical performances. In this frame, the present research project dealt with the development of sustainable reinforcing fillers for rubber compounds in alternative to fossil-based technologies with a particular focus on lignin. Despite its availability at industrial scale, the structural complexity of lignin has hampered its conversion into value-added products and the rational design of functional materials. However, the concerns about toxicity and environmental concerns related to the use of fossil-based materials are eliciting investigations regarding the use of renewable resources, included lignin. This material could be considered as a valuable alternative to carbon black in rubber compounds due to its good physical chemical and mechanical properties, antioxidant activity and thermal stability. However, its combination with an elastomeric matrix requires overcoming the poor compatibility between the two materials related to the polarity of lignin which results into strong self-interactions. So, it was necessary to modify lignin in order to improve the number and quality of its interaction with rubber resulting in a reinforcing effect. To ensure the desired reinforcement, two strategies were explored in the present project. The former dealt with the functionalisation of lignin hydroxyl groups ensuring the formation of covalent bonds between lignin and the rubber matrix during vulcanization. The procedure consisted in the mechanochemical esterification of lignin, allowing running reactions in the solid state, taking advantage of mechanical energy to trigger chemical transformations, avoiding organic solvents, limiting work-up procedures and reducing wastes with respect to wet chemistry syntheses. The latter consisted in the formulation of lignin into nanoparticles (LNPs)which are acknowledged to exhibit unique properties due to their high surface to volume ratio. Analytical investigations about solvent-extracted fractions guided the choice of specific lignin fractions for the development of LNPs with peculiar features. The innovative procedure allowed valorising the whole starting kraft lignin in a material efficient manner. It was possible to produce LNPs which proved dimensionally stable in a broad pH range 4.5-12.0 where lignin normally aggregates or dissolves The same approach allowed preparing LNPs with a surface-specific covalent functionalisation, an achievement never attempted in literature, to the best of our knowledge. The setup and scaleup of those procedures allowed for the formulation of innovative rubber compounds followed by the assessment of their dynamic-mechanical properties. The intriguing results proved promising for the development of technologically valuable and competitive rubber compounds including renewable materials.

There is a growing global energy demand and the society is forced to shift towards renewable energy sources due to the depletion of fossil fuels. Lignocellulosic biomass is a renewable resource available in vast amounts and could therefore have the potential to become a primary source for fuel production. Lignin, as a substantial part of the biomass, is underutilized due to its complex structure which can limit the potential of applying lignin towards value- adding products. However, one way to promote lignin valorization is to produce lignin nanoparticles (LNPs) that are considered valuable in the biomedical field. The aim of this report was to investigate if different botanical origins will affect the properties of LNPs, such as size, polydispersity index, 𝜁-potential and morphology. LNPs from Miscanthus sinensis grass lignin, obtained by the organosolv process, was successfully produced via solvent exchange and compared with LNPs from spruce organosolv lignin. The experimental part resulted in Miscanthus LNPs ranging from 133.7 to 377.4 nm, where a higher initial concentration yielded larger particles, and the average ζ- potential was -38.7 mV. This work has shown that the botanical origin will affect both size and shape of LNPs produced with the same method. Miscanthus LNPs were larger in size and ellipsoidal in shape compared to the spherical spruce LNPs. The lignin concentration influenced the particle size for both origins and the difference in LNP size became more significant as the concentration increased. However, to only explore two different types of plant origins is not sufficient enough to reach a general conclusion. Also, there are many influential steps from plant origin to LNP and to reach a more generalized conclusion, it is arguable that there is a necessity to explore and determine both the applied pulping method, the process to isolate the lignin and the method used to produce the LNPs.
Det globala energibehovet ökar och samhället tvingas därmed att växla till förnybara resurser eftersom de fossila bränslena kan ta slut. Biomassa är en förnybar resurs som finns tillgänglig i stora mängder och kan därför bli en potentiell primär energikälla. Lignin, som är en väsentlig del av biomassan, används inte i lika stor utsträckning på grund av dess komplexa struktur. Komplexiteten begränsar därför användandet av lignin i värdeskapande produkter. Men en väg för att ta tillvara på lignins värdefulla egenskaper kan vara framställandet av nanopartiklar (NP), vilket öppnar upp för användning av lignin inom det biomedicinska fältet. Syftet med den här rapporten är att undersöka om lignin från olika botaniska ursprung påverkar nanopartiklarnas egenskaper, som exempelvis storlek, polydispersitet, 𝜁-potential och morfologi. NP av lignin från gräsarten Miscanthus sinensis framställdes genom solvent exchange och jämfördes sedan med NP från granlignin. Både miscanthus- och granligninet var isolerat genom organosolvprocessen. Den experimentella delen av arbetet visade att NP from miscanthuslignin gav partiklar inom intervallet 133.7 to 377.4 nm, där högre koncentration gav större partiklar, och medelvärdet för 𝜁-potentialen var -38.7 mV. Resultatet från arbetet visade att det botaniskt ursprunget påverkar både storleken och formen på NP av lignin som framställts med samma metod. NP från miscanthuslignin var större och hade en mer elliptisk form, i jämförelse med de mer sfäriska partiklarna från granlignin. Ligninkoncentrationen påverkade partikelstorleken för båda typerna av lignin, dessutom blev skillnaden i partikelstorlek större när koncentrationen ökade. Däremot var det svårt att dra någon generell slutsats genom att bara undersöka två olika ursprung. Eftersom det finns flera steg i processen från växters ursprung till NP av lignin som kan påverka partiklarnas egenskaper kan det vara nödvändigt att utforska både den tillämpade massaprocessen, isoleringsmetoden och metoden som används för att framställa NP av lignin.

Lignin is one of the most common biopolymers in the world. Together with cellulose andhemicellulose it constitutes the fibers in the wood. It has a high molecular weight due to its complexstructure consisting of crossed-linked phenolic monomers and is concatenated with different types ofcarbon and ether bonds.In pulping processes, lignin is extracted in large quantities and used on site to produce energy for milloperations but is also removed as a waste product. This enables a product with high resources andaccessibility due to lignin's diverse properties. Therefore, lignin has the potential to be utilized inhigher value applications such as polymer materials, as well as a source of platform chemicals. Atpresent, the value applications of lignin are promising as additives for different kinds of productssuch as emulsifiers and especially as biofuel due to lignin's high carbon content.New technologies for development for utilization lignin are emerging for different kinds ofapplications due to lignin’s biocompatibility. The possibilities of lignin combined with existingresearch of nanotechnology gives opportunities to improve biomedical applications. By designinglignin derived nanoparticles with incorporated magnetic materials, the NPs obtainsuperparamagnetic properties which can be utilized for target drug delivery. This could be promisingagainst intractable cancer such as pancreatic cancer.This report presents a protocol for developing magnetic lignin nanoparticles from the lowestmolecular weight kraft lignin fractions of eucalyptus (hardwood) and spruce (softwood). By a methodof self-assembly, particles with a doughnut and core-shell morphology, as indicated by SEM and TEM,were yielded with a 10-50μL content of water-stabilized magnetite. The particle size distribution andzeta potential were determined by DLS and the possibility of the particles being suitable forbiomedical applications was discussed.

La volonté croissante de diminuer l’empreinte écologique des matières plastiques favorise le développement de polymères et d’additifs issus de ressources renouvelables afin de limiter leur impact environnemental. Les retardateurs de flamme sont une famille d’additifs qui jouent un rôle crucial dans de nombreux domaines d’application où le risque d’incendie est avéré. Cette étude vise donc à développer de nouveaux systèmes retardateurs de flamme à partir de composés issus de la biomasse afin d’améliorer le comportement au feu d’un polymère bio-sourcé, l’acide polylactique (PLA). La lignine et la cellulose ont été choisies comme composés de base. Des procédés adaptés ont permis de transformer ces composés à l’état nanoparticulaire, puis ils ont été fonctionnalisés avec des produits phosphorés ou alors mélangés avec du polyphosphate d’ammonium, et incorporés dans l’acide polylactique au mélangeur interne. La stabilité thermique, l’inflammabilité et le comportement au feu des composites ainsi obtenus ont été étudiés. Les résultats obtenus avec certains systèmes sont prometteurs
The growing desire to reduce the ecological footprint of plastic materials promotes the development of polymers and additives from renewable resources in order to limit their environmental impact. Flame retardants represent an important family of additives that play a crucial role in many fields where fire hazard is encountered. Thus this study aims at developing new flame retardant systems from biomass compounds to improve the fire behavior of polylactide (PLA), a bio-based polymer. Lignin and cellulose were chosen as pristine compounds. These compounds have been transformed into nanoparticles with adapted processes. Then, they were functionalized with phosphorous moieties or mixed with ammonium polyphosphate, and incorporated into polylactide with in internal mixer. Thermal, flammability and fire properties of these compounds were evaluated. The results obtained with some systems are promising

Lignin valorization is a key component of the total utilization of biomass in the biorefinery industry. Lignin has seen some use in several different applications, but a breakthrough is still yet to happen, and there is still a need to find more areas where lignin can be used as an alternative feedstock or as the main component. Lignin nanoparticles (LNPs) could be an alternative route towards lignin valorization offering many areas of application. However, research around LNPs still has to overcome many challenges, primarily related to the complex structure of lignin, with composition and structure of lignin depending on its botanical origin and on the pulping process used to isolate the lignin from other components in biomass. This study investigates how spruce lignin originating from Kraft and Organosolv pulping will affect the properties of lignin nanoparticles. Particles from organosolv spruce lignin were prepared using a solvent exchange method with acetone/water as solvent and water as antisolvent. This resulted in spherical LNPs with hollow centers, sizes ranging from 104.6- 270.3 depending on initial lignin concentration and average zeta-potential of -35mV. Comparing Organosolv LPN’s with Kraft LNPs produced with the same experimental procedure, reviled that Organosolv LNPs were larger in and had lower absolute zeta potential, presumably due to the kraft lignin having higher phenolic-OH content. Furthermore, a larger comparison is made with LNPs from previous studies which indicated that LNP properties are further dependant Mw of lignin raw material, phenolic-OH content, and the method applied to produce the particles. In conclusion, this study proves that the pulping process used to isolate lining will affect the properties of NPs. But to strengthen and generalize this conclusion beyond the limitations of this study, more experimental data are needed, to further investigate the relationship between LNP properties and the properties of lignin raw material.
En av utmaningarna för framtidens bioraffinaderier är att fullständigt utnyttja samtliga komponenter av råvaran. Historiskt sett har cellulosa varit den mest värdefulla komponenten av biomassan medan lignin har klassats som en biprodukt och har därför primärt bränts som bränsle vid framställning av pappersmassa. Även om lignin produceras på industriell skala saknas idag värdeskapande applikationsområden där lignin kan utnyttjas ur ett ekonomiskt hållbart perspektiv. Ett alternativ till valorisering av lignin är att använda det som råmaterial för framställande av nanopartiklar , vilket är ett relativ nytt område med stor potential framförallt inom biomedicin. Dock kvarstår en del utmaningar i forskningen runt lignin nanopartiklar. Framförallt relaterat till lignins komplexa och inhomogena struktur, som varierar beroende på botaniskt ursprung och vilken typ av massaframställningsprocess som används för att isolera ligninet från biomassan. Den här studien undersöker hur granlignin från två olika massaframställningsprocesser, Organosolv- och Kraftprocessen, påverkar egenskaper hos NP av lignin. Under den experimentella delen av arbetet framställdes NP från Organosolv granlignin, vilket resulterade i sfäriska och ihåliga partiklar som varierade i storlek mellan 104.5–270.3 nm, beroende på den initiala lignin koncentrationen, samt en genomsnittlig zeta potential kring -35 mV. Egenskaperna hos Organosolv nanopartiklarna som jämfördes med nanopartiklar av Kraflignin som producerats med samma metod. Slutsatsen drogs att organosolv partiklar var större och hade lägre absolut zeta-potential. Vilket troligtvis kan förklaras med den betydligt högre halten av fenoliska-OH enheter i Kraft ligninet. En bredare jämförelse med tidigare studier som producerat olika lignin nanopartiklar visar dessutom att molekylvikten, fenolisk-OH halt och produktionsmetoden, är bidragande faktorer till lignin nanopartiklars egenskaper. Sammanfattnings visar den här studien att den massaframställningsprocess som används för att isolera lignin kommer påverka egenskaperna hos lignin nanopartiklar. Men för att kunna generalisera och stärka slutsatsen krävs dock utökad experimentella, för att vidare undersöka hur lignin nanopartiklars egenskaper beror på egenskaperna hos ligninet som använts för att producera partiklarna.

La lignine est un des polymères naturels les plus abondants et le seul constituant de la biomasse basé sur des unités aromatiques et, à ce titre, représente une ressource renouvelable prometteuse pour la production durable de molécules organiques plus complexes. Les travaux de cette thèse portent sur le développement de matériaux catalytiques capables de transformer sélectivement la lignine en molécules fonctionnelles de base, hautement oxygénées, et l'étude de leur mise en oeuvre en condition alcaline oxydante en utilisant le peroxyde d'hydrogène comme donneur d'oxygène. Différentes familles de matériaux hybrides de type SBA-15 à base de titane, Au/titane, Ag/titane et Fe(TAML) ont tout d'abord été synthétisées et entièrement caractérisées. Des études catalytiques comparatives ont ensuite été réalisées afin d'évaluer leurs performances en termes de degré de dépolymérisation et distribution de produits. Le catalyseur présentant le plus fort potentiel, le matériau TiO2 supporté sur SBA-15, a ensuite été soumis à des études de réactivité plus poussées afin d'optimiser les différents paramètres réactionnels (température, temps de réaction et quantité d'oxydant) permettant d'atteindre en présence d'un excès d'oxydant jusqu'à 90 %pds de conversion de la lignine et à 80°C un rendement en bio-huile de 50%pds constituée principalement d'acides carboxyliques et molécules aromatiques potentiellement valorisables
Lignin is one of the most abundant natural polymers and the only biomass constituent based on aromatic units and as such represents a promising renewable resource for the sustainable production of complex organic molecules. This dissertation reports on the development of catalytic materials capable of selectively transform lignin into basic functional molecules with high oxygen content and the study of their performance under alkaline oxidative conditions, using hydrogen peroxide as oxygen donner. Different families of hybrid materials based on the SBA-15 scaffold were first synthesized by incorporation of titanium, Au/titanium, Ag/titanium and Fe-TAML and completely characterized. Comparative catalytic studies were then accomplished in order to evaluate their performance in terms of degree of depolymerization and product distribution. The catalyst with the highest potential, the TiO2 based SBA-15 material, was then submitted to further reactivity studies in order to optimize the different reaction parameters (temperature, reaction time and quantity of oxidant). In the presence of an excess of oxidant, conversions up to 90 wt. % were obtained, whereas a temperature of 80 °C allowed to obtain a yield in bio-oil of 50 wt. %, which is mainly composed of carboxylic acids and aromatic molecules with potential to be further valorized

La surexploitation des ressources de la planète est aujourd’hui une problématique de premier ordre, et fait du remplacement des sources non renouvelables, d'énergie et de matières premières, l’un des défis majeurs du XXIe siècle. Dans cet objectif, les lignines, par leur disponibilité et leur biocompatibilité, apparaissent comme l’une des alternatives aux ressources fossiles. C’est dans ce contexte que le Laboratoire PEIRENE a décidé de mener ce travail de thèse portant sur le développement de nouveaux matériaux photosensibles à base de lignines modifiées. Dans ce but, trois lignines d’origines différentes ont été acétylées. Leur étude par spectroscopie RPE a révélé que le blocage de leurs fonctions antioxydantes augmente considérablement la quantité d’espèces réactives de l’oxygène qu’elles sont capables de générer sous irradiation lumineuse, permettant ainsi d’envisager l’utilisation de ce biopolymère modifié dans de nombreux domaines tels que le traitement photodynamique antimicrobien. Afin de les rendre hydrodispersibles et d’élargir ainsi leur champ d’applications, ces matériaux aux propriétés prometteuses ont été mis sous forme de nanoparticules puis, leur comportement photosensible a été lui aussi évalué par spectroscopie RPE. Il a ainsi été démontré qu’une fois dispersées dans l’eau sous la forme de nanoparticules, les lignines acétylées étaient toujours capables de produire de l’oxygène singulet sous irradiation lumineuse. Cette activité, qui n’a pas encore été reportée dans la littérature à notre connaissance, reste cependant assez restreinte et nécessite donc d’être améliorée. Afin d’élargir le domaine du spectre solaire permettant leur activation, un photosensibilisateur a par ailleurs été associé à ces nano-objets par encapsulation et par greffage covalent. L’ensemble des résultats découlant de ces travaux permettent d’envisager le développement de systèmes à base de nanoparticules de lignines acétylées dans de nombreux domaines, notamment pharmaceutique et phytosanitaire
The overexploitation of the planet's resources is nowadays a major problem and makes the replacement of non-renewable sources of energy and raw materials, one of the major challenges of the XXIe century. For this purpose, lignins, by their availability and their biocompatibility, appear as one of the alternatives to fossil resourcesIn this context, the PEIRENE Laboratory decided to carry out this PhD work on the development of new photosensitive materials based on modified lignins. For this purpose, three lignins from different origin were acetylated. Their study by EPR spectroscopy revealed that blocking their antioxidant functions considerably increases the quantity of reactive oxygen species they are able to generate under light irradiation. Thus it is possible to envisage the use of this modified biopolymer in many areas such as antimicrobial photodynamic therapy. In order to make them water-dispersible and thus to widen their field of applications, these materials with promising properties were put in the form of nanoparticles. Their photosensitive behavior has been also valuated by EPR spectroscopy. It has been demonstrated that once dispersed in water in the form of nanoparticles, the acetylated lignins were still capable of producing singlet oxygen under light irradiation. This activity, which has not yet been reported in the literature to our knowledge, however, remains quite limited and therefore needs to be improved. In order to widen the range of the solar spectrum allowing their activation, a photosensitizer has also been associated with these nano-objects by encapsulation and covalent grafting. The results of these studies make possible to envisage the development of systems based on acetylated lignins nanoparticles in in many field, in particular pharmaceutical and phytosanitary

This Master’s thesis deals with isolating carbon nanoparticles from South Moravian lignite using "green" – environmentally friendly methods. This method consists of mechanical-chemical-thermal stressing of lignite using ultrasound, hydrogen peroxide and high temperatures. This work aims to develop recommendations on coal as a source of carbon nanoparticles and based on these recommendations, to design procedures for isolating nanoparticles from South Moravian lignite using environmentally friendly methods. The identified procedures were designed to meet carbon-based particles with an oxidized surface. From the results we can deduct that it is possible to use South Moravian lignite for the preparation of carbon nanoparticles. However, it will be necessary to modify the process further and also to optimize the purification of the obtained particles.

Cellulose nanowhisker (CNW) prepared by acid hydrolysis of softwood Kraft pulp was incorporated as nanofiller in rigid polyurethane (PU) foam synthesis. The density, morphology, chemical structure, mechanical properties and thermal behavior of the products were characterized. The nanocomposites exhibited better performance especially at high CNW¡¯s content which was probably due to the high specific strength and aspect ratio of CNW, the hydrogen bonding and crosslinking between CNW and polymer matrix, a higher crosslinking density compared to the control, and the function of CNW as an insulator and mass transfer insulator. Lignin polyol was synthesized through oxypropylation and used for rigid PU foam preparation. The density, morphology, chemical structure, compressive property and thermal behavior of the product were characterized. Lingin-based rigid PU foam showed improved compressive property compared to its commercial counterpart. Ethanol organosolv lignin-based PU showed a slightly stronger compressive property than Kraft lignin-based PU. The enhancement was primarily attributed to the rigid phenolic structure and the high hydroxyl functionality of lignin. Lignin-based PU generated more char than common PUs which was possibly related to the better flame retardant property. This study provided an alternative way to valorize the two most abundant biopolymers and resulted in relatively environmentally benign rigid PU nanocomposite foam.

Les nanoparticules d'oxyde de fer sont utilisées dans plusieurs domaines notamment en Biomédecine comme agents théranostiques en Cancérologie et aussi comme agents de contraste en Imagerie par Résonance Magnétique. Avec l'augmentation de la production et de l'utilisation de ces NPs de fer, il y a une évidente augmentation de l'exposition humaine et environnementale à ces NPs, et qui peut présenter un risque. Le sujet de ma thèse porte sur l'étude de l’impact physiopathologique et de la toxicité des nanoparticules de fer (NPs de fer) en utilisant un modèle cellulaire de neuroblastome et un modèle d'étude animal, le rat Wistar. L’objectif des travaux de recherche de la partie in vitro est d’évaluer les effets cytotoxiques et génotoxiques ainsi que les effets sur l’expression des protéines cellulaires suite à l’exposition des cellules SH-SY5Y à des concentrations croissantes des NPs de fer. Nous avons montré que les NPs de fer induisent des perturbations cellulaires d’une manière dépendante de la taille et de la concentration. L'analyse protéomique suivie par l'annotation des gènes avec l’ontologie et l'analyse des voies de signalisation a mis en évidence les effets des NPs de fer sur le cytosquelette, l'apoptose et le développement du cancer. Les objectifs de nos travaux de recherche réalisés in vivo consistent à étudier les effets physiopathologiques des NPs de fer administrées par trois voies différentes, intraveineuse, intranasale et orale, à savoir leur impact sur le comportement émotionnel et cognitif ainsi que sur l’homéostasie des neurotransmetteurs et des éléments traces. Les résultats ont montré que les NPs de fer n’induisent pas de modification concernant l’anxiété, la locomotion, l’apprentissage et la mémoire chez le rat quelle que soit la voie d’administration. Cependant, ces NPs provoquent une perturbation des niveaux des catécholamines et des éléments traces au niveau cérébral. Les effets les plus marqués ont été observés suite à l’instillation intranasale des NPs et se manifestent par une diminution de taux du fer sérique, la thrombocytose et la présence des foyers inflammatoires au niveau hépatique. L’analyse comparative des trois voies d’administration a montré que la voie intraveineuse est la moins toxique. Enfin, l’étude protéomique des protéomes du cerveau, du foie et du poumon a permis d’évaluer la toxicité des NPs de fer au niveau protéique et moléculaire. Les résultats obtenus présentent un support important pour l’estimation et la compréhension des effets potentiellement adverses de ces NPs qui présentent une certaine toxicité non négligeable de point de vue moléculaire et physiopathologique. Ainsi, leur utilisation dans le domaine biomédicale doit être prise avec beaucoup de précaution pour éviter au maximum tout risque lié à leur exposition afin d’améliorer leur biocompatibilité et ainsi augmenter leurs avantages
Iron Oxide Nanoparticles (IONPs) are used in several fields notably in Biomedicine as theranostic agents in Oncology and also as contrast agents in Magnetic Resonance Imaging. With the increase in the production and use of IONPs, there is a clear increase in human and environmental exposure to these NPs, which may pose a risk. The subject of my thesis is the study of the physiopathological impact and toxicity of iron oxide nanoparticles using a cell model of neuroblastoma and an animal study model, the Wistar rat. The aim of the research work of the in vitro part is to evaluate the cytotoxic and genotoxic effects as well as the effects on the expression of cellular proteins following the exposure of SH-SY5Y cells to increasing concentrations of iron NPs. We have shown that iron NPs induce cellular perturbations in a size and concentration dependent manner. Proteomic analysis followed by ontological gene annotation and signaling pathway analysis revealed the effects of IONPs on cytoskeleton, apoptosis and cancer development. The aims of our research carried out in vivo are to investigate the pathophysiological effects of iron NPs administered by three different routes, intravenous, intranasal and oral, also their impact on emotional and cognitive behavior as well as neurotransmitter and trace element homeostasis. The results showed that IONPs do not induce any changes in anxiety, locomotion, learning and memory in rats regardless of the administration route. However, these NPs cause a disruption of catecholamine and trace element levels in the brain. The most marked effects have been observed following intranasal instillation of NPs and are manifested by a decrease in serum iron levels, thrombocytosis and the presence of inflammatory foci in the liver. The comparative analysis of the three routes of administration showed that the intravenous route is the least toxic. Finally, the proteomic study of the proteomes of the brain, liver and lung has made it possible to evaluate the toxicity of the NPs of iron at the protein and molecular level. The obtained results provide an important support for the estimation and understanding of potentially adverse effects of these NPs, which have a certain toxicity that is not negligible from a molecular and physiopathological point of view. Thus, great care must be taken regarding their use in the biomedical field to minimize any risk related to IONP exposure in order to improve their biocompatibility and thus increase their benefits

Anisotropic plasmonic noble metallic nanoparticles (APMNs) have received enormous attention due to their distinct geometric features and fascinating physicochemical properties. Owing in large part to their tailored localized surface plasmon resonance (LSPR) and the intensive electromagnetic field at the sharp corners and edges, APMNs are exceptionally well suited for biomedical applications such as biosensing, bioimaging, diagnostics and therapeutics. Although a rich variety of surfactant-assisted colloidal routes have been developed to prepare well-defined APMNs, biomedical applications necessitate tedious and rigorous purification processes for the complete removal of toxic surfactants. In this dissertation, we aim to develop generic bioenabled green synthetic methodologies towards APMNs. By applying a series of thermodynamic, kinetic and seed quality control, a series of APMNs with varied morphologies such as branched nanostars and triangular nanoprisms have been successfully prepared. We first presented the preparation of gold nanostars (Au NSTs) through a two-step approach utilizing a common Good's buffer, HEPES, as a weak reducing agent. Single crystalline Au NSTs with tunable branches up to 30 nm in length were produced and the halide ions rather than the ionic strength played a significant roles on the length of the branches of Au NSTs. Then consensus sequence tetratricopetide repeat (CTPR) proteins with increasing number of repeats were used as model proteins to probe the effects of concentration as well as the protein shape on the morphology and resulting physicochemical properties of plasmonic gold nanoparticles. Since the underlying growth mechanism for the biomimetic synthesis of APMNs remains elusive and controversial, the other objective is to elucidate the molecular interactions between inorganic species and biopolymers during the course of NP evolution. Fluorescent quenching and 2D NMR experiments have confirmed the moderate binding affinity of CTPR to the Au(0) and Au(III). We observed that the initial complexation step between gold ions and CTPR3 is ionic strength dependent. Furthermore, we also found that NPs preferentially interact with the negatively charged face of CTPR3 as observed in 2D NMR. Knowledge of binding behavior between biospecies and metal ions/NPs will facilitate rational deign of proteins for biomimetic synthesis of metallic NPs. A modified seed-mediated synthetic strategy was also developed for the growth of silver nanoprisms with low shape polydispersity, narrow size distribution and tailored plasmonic absorbance. During the seed nucleation step, CTPR proteins are utilized as potent stabilizers to facilitate the formation of planar-twinned Ag seeds. Ag nanoprisms were produced in high yield in a growth solution containing ascorbic acid and CTPR-stabilized Ag seeds. From the time-course UV-Vis and transmission electron microscopy (TEM) studies, we postulate that the growth mechanism is the combination of facet selective lateral growth and thermodynamically driven Ostwald ripening. By incorporation of seeded growth and biomimetic synthesis, gold nanotriangles (Au NTs) with tunable edge length were synthesized via a green chemical route in the presence of the designed CTPR protein, halide anions (Br⁻) and CTPR-stabilized Ag seeds. The well-defined morphologies, tailored plasmonic absorbance from visible-light to the near infrared (NIR) region, colloidal stability and biocompatibility are attributed to the synergistic action of CTPR, halide ions, and CTPR-stabilized Ag seeds. We also ascertained that a vast array of biosustainable materials including negatively charged lignin and cellulose derivatives can serve as both a potent stabilizers and an efficient nanocrystal modifiers to regulate the growth of well-defined Ag nanoprisms using a one-pot or seeded growth strategy. The influential effects of reactants and additives including the concentration of sodium lignosulfonate, H2O2 and NaBH4 were studied in great detail. It implies that appropriate physicochemical properties rather than the specific binding sequence of biomaterials are critical for the shaped-controlled growth of Ag NTs and new synthetic paradigms could be proposed based on these findings. Last but not the least, we have demonstrated the resulting APMNs, particularly, Au NSTs and Ag NTs exhibit remarkable colloidal stability, enhanced SERS performance, making them promising materials for biosensing and photothermal therapy. Since the Ag nanoprisms are susceptible to morphological deformation in the presence of strong oxidant, they also hold great potential for the colorimetric sensing of oxidative metal cation species such as Fe3+, Cr3+, etc.
Ph. D.

This research focuses on promoting nickel-based catalysts by visible-light illuminated gold and palladium nanoparticles in fine organic synthesis. Using lignin model compound cleavage as the model reaction, the performance of three distinct systems, in-situ formed Ni(OH)2 on ZrO2 supported Au NPs, non-plasmonic NiPd alloy NPs supported on ZrO2 and the mechanical mixture of ZrO2 supported Au NPs and Ni NPs are investigated. Ultra-low palladium loading on sodium titanate sheets for Heck cross-coupling reaction under visible light is also studied. This research has provided innovative findings in new photocatalyst design and application.

This work focuses on the investigation of plasmonic Gold (Au) and Silver (Ag) nanoparticles (NPs) by using optically induced local thermal dewetting technique and their applications. Firstly, Au and Ag NPs are fabricated by a thermal annealing method using a hot oven. This technique allows obtaining Au and Ag NPs, which are randomly distributed in a large area. The NPs sizes and properties are controlled by annealing conditions, such as annealing temperature and duration. Plasmonic properties of Au and Ag NPs are experimentally characterized and compared with the simulation ones performed by the FDTD method. These large-area Au and Ag NPs are demonstrated to be useful for applications in fluorescence enhancement and random laser. Secondly, we demonstrate a robust way to realize desired plasmonic nanostructures by using a direct laser writing method. This technique bases on optically induced local thermal effect allowing the realization of NPs at a small area, i.e. focusing area. By moving thus the laser spot, any desired plasmonic structure can be realized. The NPs sizes and distributions can be controlled by exposure doses (laser power and exposure time) and moving trajectory of the focusing spot resulting in different reflection or transmission colors. By focusing a continuous-wave laser at 532 nm on Au films having 50 nm thickness, we demonstrated for the first time the direct fabrication of plasmonic nanoholes array. These fabricated structures are demonstrated to be very potential for many applications such as data storage, color nanoprinter, fluorescence enhancement, and plasmonics based random laser
This work focuses on the investigation of plasmonic Gold (Au) and Silver (Ag) nanoparticles (NPs) by using optically induced local thermal dewetting technique and their applications. Firstly, Au and Ag NPs are fabricated by a thermal annealing method using a hot oven. This technique allows obtaining Au and Ag NPs, which are randomly distributed in a large area. The NPs sizes and properties are controlled by annealing conditions, such as annealing temperature and duration. Plasmonic properties of Au and Ag NPs are experimentally characterized and compared with the simulation ones performed by the FDTD method. These large-area Au and Ag NPs are demonstrated to be useful for applications in fluorescence enhancement and random laser. Secondly, we demonstrate a robust way to realize desired plasmonic nanostructures by using a direct laser writing method. This technique bases on optically induced local thermal effect allowing the realization of NPs at a small area, i.e. focusing area. By moving thus the laser spot, any desired plasmonic structure can be realized. The NPs sizes and distributions can be controlled by exposure doses (laser power and exposure time) and moving trajectory of the focusing spot resulting in different reflection or transmission colors. By focusing a continuous-wave laser at 532 nm on Au films having 50 nm thickness, we demonstrated for the first time the direct fabrication of plasmonic nanoholes array. These fabricated structures are demonstrated to be very potential for many applications such as data storage, color nanoprinter, fluorescence enhancement, and plasmonics based random laser

Le recuit photonique est une technologie émergente basée sur la conversion instantanée del’énergie lumineuse absorbée par les nanoparticules (NPs) en chaleur. Dans ces travaux, il estdéployé sur des pistes d’interconnexions imprimées sur support souple par jet de matière, àpartir d’une encre de NPs d’argent (Ø=25nm).Une étude des paramètres du procédé a permis d’établir le lien entre ces derniers (énergie,fréquence) et la résistance carrée (120m!/ ) induite. Celui-ci a été confirmé grâce à unemodélisation thermique multicouches et au développement d’une instrumentation inéditemesurant, toutes les 4μs, les variations de la résistance pendant le recuit photonique (quelquesms). La stabilisation de la résistance corrélée avec les propriétés optiques du film est optimalepour une exposition de 2-3J/cm² induisant un échauffement à environ 200°C.L’analyse de la microstructure des films par diffraction des rayons X met en évidence le lienentre la croissance des cristallites et la résorption des défauts. La minimisation de la résistanceélectrique est corrélée à la croissance du collet entre les nanoparticules par diffusion atomiquede surface. De plus, une meilleure cohésion des NPs améliore la dureté par rapport au recuit àl’étuve.La résistance électrique de contact (200m!) entre les plots d’interconnexion d’une puce ensilicium et les pistes imprimées a été mesurée grâce à un montage dédié de mesure électriqueau nano-indendeur. Les forces à appliquer (300mN par bump)
Photonic sintering is an emerging technology based on the instantaneous conversion ofabsorbed light energy by nanoparticles (NPs) into heat. In this work, it is used oninterconnections printed on flexible substrates by inkjet printing of a metal silver nanoinkwith particle mean diameter of Ø=25nm.A process parameters study has allowed us to link them (energy, frequency) with theinduced sheet resistance (120m!/ ). This has been confirmed through thermal modeling ofthe multilayer system, and also by monitoring the resistance variations in-situ duringphotonic sintering (a few ms) using an innovative characterization tool, allowingmeasurements every 4 μs. The electrical resistance stabilization correlated with the opticalproperties of the film was found to be optimal for an exposition of 2-3J/cm², whichcorresponds to heating up to approximately 200°C.Films microstructure analysis with X-ray diffraction enlightens the link between crystallitescoarsening and defaults density reduction. The minimization of electrical resistivity iscorrelated with neck growth between nanoparticles trigged by surface atomic diffusion.Moreover, a stronger cohesion between NPs improves the mechanical hardness compared toclassical oven curing.The electrical contact resistance (200m!) between a silicon chip interconnection bumpand printed tracks is measured thanks to an in-house setting for electrical measurement withthe nanoindenter. The level of forces to apply (300mN per bump) is optimized and transferredto a thermocompression by industrial equipment. A set of prototypes are fabricated andconfirm the compatibility of these technologies with a future industrial integration

This research focuses on plasmonic materials as photocatalyst in fine organic synthesis under visible light irradiation. It was illustrated that noble metal (silver) nanoparticles performed well as photocatalyst in toluene oxidation reaction, which was not only achieved in mind reaction condition, but also controlled with high selectivity of product. In addition, titanium nitride (TiN) material and transition metal (Pd) nanoparticles both can be applied in the cleavage of lignin models with two different reaction pathway and product selectivity. Finally, the analysis of all the reaction mechanism is significant for the further study of related organic synthesis.

Les lignocelluloses constituent une matière première renouvelable et disponible en grande quantité. L’utilisation de cette ressource végétale à des fins non alimentaires nécessite une meilleure compréhension des évènements sous-tendant l’architecture des parois végétales lignifiées, composante principale des biomasses lignocellulosiques. Devant la complexité des phénomènes impliqués in planta dans la construction des parois lignifiées, nous avons tenté d’approcher les mécanismes de formation des interactions entre les polymères pariétaux au moyen d’approches modèles chimiques. Dans cet objectif, nous avons examiné l’organisation supramoléculaire d’assemblages lignines-hémicelluloses en focalisant notre approche sur l’étude des propriétés associatives entre les xylanes (hémicelluloses majoritaires de graminées) et des modèles chimiques de lignines, DHPs (DeHydrogenative Polymers) lors de la polymérisation des lignines. Au sein des parois lignifiées, les xylanes peuvent être reliés aux lignines par des liaisons covalentes via l’acide férulique (FA) et/ou via la méthylène quinone (MQ). Ce dernier mécanisme a été étudié en synthétisant des DHPs en présence de xylanes non féruloylés. L’analyse du complexe xylane/DHP en chromatographie d’exclusion stérique et spectroscopie RMN a montré que la formation des liaisons covalentes entre les xylanes et les DHPs implique l’arabinose et la MQ. Toutefois la formation des liaisons non covalentes entre ces deux polymères peut influencer et contrôler la formation des associations covalentes. Afin d’examiner l’impact de la densification du milieu sur la réactivité des monomères de lignine, nous avons synthétisé des DHPs à fortes concentrations en présence de teneurs élevées en xylane. Les résultats indiquent que la densification du système a un effet remarquable sur la réactivité du monomère de lignine et par conséquent sur la structure finale des DHP (augmentation des liaisons β-alkyle aryle éther et de la masse molaire). L’impact de l’acide férulique dans l’organisation des assemblages lignine-xylanes a été étudié au cours de la polymérisation des deux principaux monomères de lignine, syringyle (S) et/ou gaïacyle (G) en présence de xylanes féruloylés ou non. Les données obtenues en Diffusion de la Lumière (DL), Chromatographie d’Exclusion Stérique couplée à la Diffusion de Lumière Multi-Angle (CESDLMA), Microscopie Electronique à Transmission (MET) et Diffusion de Neutrons aux Petits Angles (DNPA) ont mis en évidence que la présence de FA et le type de monomère de lignine S et G affectent la morphologie et l’organisation supramoléculaire des nanoparticules DHP-xylanes
Lignocelluloses represent abundant and renewable biomass for which non food use still require an in-depth knowledge of the mechanisms involved in the architecture of lignified plant cell wall as the main lignocellulosic components. Owing to the highly complex mechanisms involved in planta in building the lignified cell walls; we attempted to study wall polymer interactions using chemical model systems. To this end, the supramolecular organization of composites made of xylans (as the main hemicelluloses of grass cell walls) and model lignin (DHP, DeHydrogenative Polymers) were investigated along in vitro polymerisation of lignin. In the lignified cell wall, xylans can be covalently linked to lignin via ferulic acid (FA) and/or via quinone methide (QM). The latter mechanism has been studied during lignin polymerisation in the presence of feruloylated xylan. Size exclusion chromatography (SEC) and NMR analysis of the DHP-xylans complex indicated that arabinose and QM are involved in covalent bonds between xylans and DHP. However, the formation of these linkages can be affected and controlled by non covalent interactions between the two polymers. In order to investigate the impact of the media concentration on the lignin monomer reactivity, highly concentrated DHPs were synthesised in increasing concentrations of xylans. Densification of the system was shown to impact on the monomer reactivity and consequently the DHP structure (increases of β-alkyl aryl ether bonds and of molar mass). The role of FA on xylan-DHP networks was further studied along polymerisation of the main lignin monomers, i. E. Syringyl (S) and guaiacyl (G) in the presence of xylans with different FA levels. DHP-xylan analysis by Light Scattering (LS), Size exclusion chromatography with online multi-angle laser light scattering (SEC-MALLS), Transmission electron microscopy (TEM), and Small Angles Neutron Scattering (SANS) showed that both FA and the type of lignin monomer (S and/or G) have a clear impact on the morphology and supramolecular organization of DHP-xylan nanoparticules

L'asthme allergique est une maladie inflammatoire chronique des voies aériennes. Elle se caractérise par le recrutement de cellules inflammatoires incluant les lymphocytes T helper (Th)CD4+ de type 2, producteurs d'interleukine (IL)-4, IL-5 et IL-13, ainsi que les éosinophiles, les mastocytes et les basophiles. La prévalence de l'asthme ne cesse d'augmenter ces dernières décennies et les modifications génétiques ne peuvent être les seules responsables. La pollution atmosphérique, et notamment particulaire, est suspectée de participer à cette tendance à la hausse. Les particules atmosphériques peuvent être classées selon leur diamètre aérodynamique, parmi lesquelles on retrouve les particules ultrafines (< à 100 nm). Ces dernières sont potentiellement plus nocives en raison de leur petite taille qui leur confère la capacité de se déposer profondément dans l'arbre bronchique. Elles sont également capables d'adsorber des molécules telles que les hydrocarbures aromatiques polycycliques. Or, certains de ces hydrocarbures, tels que le benzo(a)pyrène, sont connus pour être nocifs pour la santé et notamment pour l'appareil respiratoire. Nous nous sommes intéressés aux effets d'une exposition aux particules ultrafines liées au benzo(a)pyrène, sur la réponse inflammatoire dans deux modèles expérimentaux d'asthme induits par un allergène. Pour cela, nous avons utilisé un modèle simplifié de particules issues d'un processus industriel, que nous appellerons donc« nanoparticules ».Dans notre premier modèle, une exposition chronique aux nanoparticules de carbone couplées ou non au benzo(a)pyrène, a été réalisée chez des souris C57Bl/6 sensibilisées par voie intranasale à l'allergène Dermatophagoïdes pteronyssinus. Les nanoparticules n'ont eu aucun effet sur le recrutement cellulaire dans le lavage broncho-alvéolaire induit par l'allergène. De manière surprenante, la co-administration des nanoparticules avec l'allergène a diminué l'hyperréactivité bronchique par rapport à l’allergène seul. A l’inverse, au niveau tissulaire, la coexpositionaux nanoparticules couplées au benzo(a)pyrène avec l’allergène induit une forte augmentation de l'expression des cytokines Th2 et du recrutement de cellules inflammatoires dans le tissu pulmonaire par rapport aux souris sensibilisées. De plus, cette co-exposition modifie le type de cellules recrutées par rapport à l'allergène, avec une augmentation du nombre de neutrophiles, de cellules NKT-like, des cellules T CD8+, des monocytes/macrophages Ly6C+ etLy6C-. Ces résultats n'ont pas été retrouvés lors d'une co-exposition de l’allergène avec les nanoparticules non couplées au benzo(a)pyrène.Dans notre deuxième modèle, une exposition aux nanoparticules de carbone, couplées ou non au benzo(a)pyrène, a été réalisée chez des souris C57Bl/6 sensibilisées par voie intranasale avec une faible dose de l'allergène Dermatophagoïdes farinae. Les résultats préliminaires ont montré un effet adjuvant des nanoparticules avec l'allergène sur la production d'immunoglobulines E et sur l'infiltrat inflammatoire dans le lavage broncho-alvéolaire, principalement composé d'éosinophiles. L'expression des cytokines Th2 est également augmentée par la co-administration de l’allergène avec les nanoparticules non couplées au benzo(a)pyrène, mais pas avec celles couplées. La co-exposition aux nanoparticules couplées au benzo(a)pyrène avec l’allergène induit néanmoins l'expression de l'Il-33, une alarmine produite par l'épithélium, également pro-Th2.En conclusion, nos résultats suggèrent que les nanoparticules ont un impact sur l'inflammation chez les souris sensibilisées à l'allergène dans nos deux modèles expérimentaux. Cependant, la dose, la quantité et la nature des allergènes ainsi que des nanoparticules inhalées semblent influencer la réponse induite in vivo
Allergic asthma is a chronic inflammatory disease of the airways. It is characterized by therecruitment of inflammatory cells including CD4+ type 2 helper T-lymphocytes (Th), interleukin(IL)-4, IL-5 and IL-13 producers, eosinophils as well as mast cells and basophils. The prevalenceof asthma has continued to increase in recent decades and genetic changes cannot be solelyresponsible Air pollution, especially particulate matter, is suspected to be part of this rising trend.Atmospheric particles can be classified according to their aerodynamic diameter, includingultrafine particles (< 100 nm). These particles are potentially more harmful because of their smallsize, which gives them the ability to settle deep in the bronchial tree. They are also able to adsorbmolecules such as polycyclic aromatic hydrocarbons. However, some of these hydrocarbons,such as benzo(a)pyrene, are known to be harmful to health and in particular to the respiratorysystem. We investigated the effects of exposure to benzo(a)pyrene-bound ultrafine particles onthe inflammatory response in two experimental models of allergen-induced asthma. For this, weused a simplified model of particles from an industrial process that we call « nanoparticles ».In our first model, chronic exposure to carbon nanoparticles coupled or not to benzo(a)pyrene,was performed in C57Bl/6 mice sensitized intranasally to the allergen Dermatophagoidespteronyssinus. Nanoparticles had no effect on cell recruitment in allergen-inducedbronchoalveolar lavage. Surprisingly, co-administration of nanoparticles with the allergendecreased bronchial hyperreactivity compared to allergen alone. In contrast, we observed aneffect on lung tissue when co-exposed to benzo(a)pyrene-coupled nanoparticles and allergen.Indeed, this co-exposure induced a strong increase in Th2 cytokine expression and cellrecruitment in lung tissue compared to sensitized mice. In addition, this co-exposure modify thetype of cells recruited by the allergen, with an increase in the number of neutrophils, NKT-likecells, CD8+ T cells, Ly6C+ and Ly6C- monocytes/macrophages. These results were not found inco-exposure to nanoparticles not coupled to benzo(a)pyrene.In our second model, exposure to carbon nanoparticles, coupled or not with benzo(a)pyrène, wasperformed in C57Bl/6 mice sensitized intranasally with a low dose of the allergenDermatophagoides farinae. Preliminary results showed an adjuvant effect of nanoparticles withthe allergen on immunoglobulin E production but also on the inflammatory infiltrate in thebroncho-alveolar lavage, mainly composed of eosinophils. The expression of Th2 cytokines isalso increased by the administration of allergen with nanoparticles uncoupled to benzo(a)pyreneand not with benzo(a)pyrene-coupled particles. But, co-exposure of allergen withbenzo(a)pyrene-coupled nanoparticles induces the expression of Il-33, an alarmin produced bythe epithelium, which is also pro-Th2. In conclusion, our results suggest that nanoparticles have an impact on inflammation in allergensensitizedmice in our two experimental models. However, the dose, the amount of allergen andthe nature of the inhaled nanoparticles appear to influence the induced response in vivo

Cette étude porte sur le mode d’action de tensio-actifs macromoléculaires à base d’alcools polyvinyliques (PVA) sur la stabilisation d’émulsions chlorure de vinyle (VCM)/eau utilisées pour la polymérisation en suspension du VCM. Cinq PVA dits primaires (PVA I) de différents degrés d'hydrolyse ( de 73 à 88 %mol) et différents degrés de polymérisation ( de 700 à 2500), ainsi qu’un PVA dit secondaire (PVA II) de 45%mol ont été étudiés sur un large domaine de concentration [0-1000 ppm/eau]. Les tensions interfaciales, ainsi que les tailles et distributions de taille des émulsions ClBu/eau, choisies comme modèle des émulsions VCM/eau, ont été déterminées en fonction du temps. Une technique originale de granulométrie en ligne : la spectroscopie par atténuation d’ultrasons a été mise en place. Les stabilisants les plus efficaces sont les PVA I de faible et . Pour chaque PVA I, une corrélation directe entre diamètre moyen des gouttelettes et tension interfaciale a pu être établie et l’importance de la viscoélasticité de l’interface a été démontrée. Le PVA II, du fait de son plus faible est insoluble dans l’eau. Des particules colloïdales bien définies de PVA II seul ou de combinaisons PVA I/ PVA II ont été préparées par coacervation. Pour une même concentration totale en PVA, ces nanoparticules de diamètre 150-200 nm abaissent davantage la tension interfaciale et les diamètres moyens des gouttelettes d’émulsion, que les PVA I seuls. Une stabilisation particulaire de type Pickering peut donc être envisagée en complément de la stabilisation stérique apportée par les PVA I
This study focuses on the action mechanisms of poly vinyl alcohol-based macromolecular surfactants on the stabilization of vinyl chloride (VCM)/water emulsions used for the suspension polymerization of VCM. Five “primary” PVA (PVA I) with high hydrolysis degrees ( between 73 à 88 %mol) and different polymerization degrees ( between 700 à 2500), as well as one “secondary” PVA (PVA II) with 45%mol, have been studied on a large concentration range [0-1000 ppm/water]. The interfacial tensions and the size distributions of ClBu/water emulsions have been determined as a function of time. An original technique of on-line granulometry: the ultrasound attenuation spectroscopy has been used. The PVA I with low and are the most efficient stabilizers. For each PVA I, a direct correlation between mean diameter of droplets and interfacial tension has been established. Moreover, the importance of the interface viscoelasticity has been demonstrated. Because of their low , PVA II are insoluble in water. Well-defined colloidal particles of PVA II and combinations PVA I/ PVA II have been prepared by coacervation. For a given total PVA concentration, these nanoparticles of diameter 150-200 nm lower more the interfacial tension, and the mean droplet diameters, than PVA I alone. A Pickering stabilization by nanoparticles can be considered, in addition to the steric stabilization provided by PVA I

M. Tech. (Department of Chemical Engineering, Faculty of Engineering and Technology), Vaal University of Technology
Fenton oxidation is classified into two processes, homogeneous and heterogeneous. Homogeneous Fenton oxidation process, have been shown to be efficient in the degradation of organic pollutants. However, it was shown to have limitations which can be addressed by the heterogeneous Fenton oxidation. Despite the high efficiency of the heterogeneous Fenton oxidation process in the degradation of recalcitrant organic pollutants, the currents synthesis trends of the heterogeneous Fenton catalyst have been proven to be time and energy constraining, since it involves the multi-step were the activated carbon have to be prepared first then co-precipitate the iron oxide on the activated carbon. However, as much as the heterogeneous Fenton catalyst has been proven to have high catalytic activity towards degradation of organic pollutants, these catalysts have some limitations, such limitations include metal ions being leached from the catalyst support into the treated water causing catalyst deactivation and a secondary pollution to the treated water. In this thesis, these catalysts have been applied in the degradation of recalcitrant organic pollutants such as methylene blue and phenols. This study focuses on the single step synthesis of iron oxide nanoparticles supported on activated carbon, were carbonaceous material is impregnated with iron salt then pyrolysed via microwave heating. Microwave power and the amount of iron salt were optimized. The prepared activated carbon-iron oxide composites were applied to the degradation of 2-nitrophenol (2-NP) and methylene blue (MB). Methylene blue was used as a model compound due to the fact that it is easier to monitor the degradation process with UV-Vis as compared to 2-nitrophenol . 2-nitrophenol the additional step for the adjustment of pH is required since nitrophenols are colorless in color at lower pH. The characterization showed that the microwave power and the amount of the iron precursor have an influence on the porosity and surface functional groups of the activated carbon. Further it was vi observed that microwave power and iron precursor influnces the amount of iron oxide formed on the surface of the support. It was also observed that the activated carbon-iron oxide composite have the catalytic effects on the Fenton oxidation process of MB and 2-NP. The parameters such as H2O2, pH, catalyst dose, initial concentration, temperature affect the degradation of both MB and 2-NP. Kinetics studies showed that Fenton is a surface driven reaction since the results fitted the pseudo first order model. The thermodynamics parameters also showed that the reaction is endothermic, spontaneous and is randomized. This implies that the reaction of the degradation of MB and 2-NP is feasible and the catalysts prepared have high catalytic activity. MB and 2-NP were degraded to smaller organic molecules (carboxylic acids). The stability of the catalyst observed to decrease as the number of cycles increased, this is due to the leaching of iron ions from the support material. Hence it was concluded that the activated carbon-iron oxide composite was successfully synthesized and had the high catalytic activity for the degradation of MB and 2-NP.

This Monography was entirely publish in a scientific article: Figueiredo P, Ferro C, Kemell M, Liu Z, Kiriazis A, Lintinen K, et al. Functionalization of carboxylated lignin nanoparticles for targeted and pH-responsive delivery of anticancer drugs. Nanomedicine (Lond) [Internet]. 2017. Available from: http://dx.doi.org/ 10.2217/nnm-2017-0219
Trabalho Final de Mestrado Integrado, Ciências Farmacêuticas, Universidade de Lisboa, Faculdade de Farmácia, 2017
Recently, lignin has been used as a starting material for the development of nanoparticles (NPs) for different purposes, including for biomedical applications. In this study, the carboxylation of the native lignin was carried out towards the modification of carboxylated lignin NP (CLNPs) with a block copolymer made of poly(ethylene glycol) (PEG), poly(histidine) (PHIS) and cell-penetrating peptide (CPP). The success of the conjugation reactions was confirmed by the conversion of the zeta-potential (ζ-potential) values from negative values for the bare CLNPs to positive values after the surface functionalization. The prepared CLNPs showed spherical shape, good size distribution, moderate polydispersity, good stability in physiological media and low cytotoxicity in all the tested cell lines at a concentration up to at least 250 µg/mL, after 24 h of incubation. A poorly water-soluble cytotoxic agent, benzazulene (BZL), was loaded into the CLNPs, improving its release profiles at pH 5.5 and 7.4. Furthermore, the release of BZL was found to be pH-sensitive, with higher release rates at pH 5.5 than at pH 7.4. Consequently, the BZL-loaded CLNPs conjugated with PEG-PHIS-CPP (BZL@CLNPs-PEG-PHIS-CPP) showed an enhanced antiproliferative effect in the different cancer cells (IC50 < 24 µM) compared to a normal endothelial cell line (IC50 ≈ 45 µM) after 24 h incubation, making the CLNPs promising candidates for anticancer therapy.
Recentemente, a lignina tem sido utilizada como matéria-prima para o desenvolvimento de nanopartículas para diferentes fins, incluindo para aplicações biomédicas. Neste estudo, procedeu-se à carboxilação da lignina nativa tendo em vista a modificação de nanopartículas de lignina carboxilada (CLNPs) com um copolímero constituído por poli(etilenoglicol) (PEG) e poli(histidina) (PHIS). A superfície das CLPNs também foi funcionalizada com um Péptido de Penetração Celular (CPP). O sucesso das reações de conjugação foi confirmado pela conversão dos valores negativos do potencial zeta obtido para as CLNPs puras, para valores positivos após a funcionalização da superfície destas nanopartículas. As CLNPs apresentaram forma esférica, boa distribuição de tamanhos, polidispersão moderada, boa estabilidade em meios fisiológicos e baixa citotoxicidade em todas as linhas celulares testadas em concentrações até pelo menos 250 μg/mL, após 24 h de incubação. Um agente citotóxico pouco solúvel em água, benzazulina (BZL), foi encapsulado nas CLNPs, melhorando os seus perfis de libertação a pH 5,5 e 7,4. Além disso, a libertação de BZL foi sensível ao pH, com taxas de libertação mais elevadas a pH 5,5 do que a pH 7,4. Consequentemente, as CLNPs conjugadas com PEG-PHIS-CPP contendo BZL (BZL @ CLNPs-PEG-PHIS-CPP) mostraram um efeito antiproliferativo aumentado nas diferentes células cancerígenas (IC50 <24 μM), em comparação com uma linha celular endotelial normal (IC50 ≈ 45 μM) após 24 h de incubação, o que torna as CLNPs alternativas terapêuticas promissoras para o tratamento do cancro.

Lignin is an undervalued product that does not yet provide economic returns. Finding value-added applications of lignin is needed to achieve economic sustainability. Carbon nanoparticles have great technological and industrial importance because of their enhanced physicochemical, electrical, thermal and mechanical properties. In this work a novel method has been explored to produce carbon nanoparticles from lignin. The objective of this work is to synthesize carbon nanoparticles with high surface area from lignin through the carbonization process. Lignin was dissolved in alkaline solutions with different weight ratios of lignin and potassium hydroxide. An intermediate sublimation process was adopted to reduce agglomeration of particles. The lignin was thermo-stabilized after the sublimation process in oxidizing atmosphere followed by the carbonization process in an inert atmosphere at 700oC using tubular furnace. The increase in glass transition tem-perature during thermo-stabilization process was confirmed by DSC analysis. The con-densation reactions during thermo-stabilization process were confirmed by FTIR analysis. The formation of carbon nanoparticles was confirmed by transmission electron microscopy (TEM) analysis. Carbon nanoparticles with high specific surface area of 42 m2/g were produced. From the DLS particle size distribution it was found that 5 wt% KOH is the optimum concentration for synthesizing carbon nanoparticles from lignin.
Ontario Ministry of Agriculture, Food and Rural Affairs (OMAFRA) New Directions Research Program for funding the project (number SR 225).

A resistência antibacteriana é uma ameaça ao desenvolvimento da medicina moderna, representando um fardo econômico e social nos próximos anos. Esta crise é agravada por um reduzido portfólio de novos medicamentos antibacterianos, devido aos altos custos de investigação e baixa lucratividade. Além disso, o desenvolvimento de novas moléculas específicas não é garantia de que não surja resistência antibacteriana contra qualquer nova molécula, e há uma tendência crescente de buscar alternativas antibacterianas com alvos moleculares inespecíficos. Nesse aspecto, a Quimioterapia Antimicrobiana Fotodinâmica realiza a desinfecção bacteriana por meio do uso de uma molécula fotossensibilizadora que só é ativa sob irradiação de luz, adicionando outro nível de controle ao processo. Neste trabalho, apresentamos um sistema de transporte biopolimérico para moléculas fotossensibilizantes, como nanopartículas de lignina acetilada. A preparação, caracterização física e caracterização fotofísica são discutidas ao longo deste projeto, explorando os efeitos do encapsulamento para o fotossensibilizador. Finalmente, essas nanopartículas foram testadas contra bactérias, descobrindo que eram capazes de erradicá-las de forma eficiente apenas após irradiação de luz, demonstrando baixa toxicidade no escuro e estabilidade ao longo do tempo e exposição à luz. Então, essa formulação para moléculas fotossensibilizantes tem se mostrado uma formulação antibacteriana eficiente, cumprindo seu propósito, ao mesmo tempo em que atua na desinfecção antibacteriana e valoriza um biopolímero altamente abundante.
Antibacterial resistance is a threat to the developments of modern medicine, representing an economic, and social burden in years to come. This crisis is enhanced by a belittled pipeline of novel antibacterial drugs, due to the high research costs and low profitability. Furthermore, the development of new, specific molecules is not guarantee that antibacterial resistance will not arise against any new molecule, and then there is a growing tendency to look for antibacterial alternatives with unspecific molecular targets. In this aspect, Photodynamic Antimicrobial ChemoTherapy achieves bacterial disinfection through the use of a photosensitizing molecule which is only active upon light irradiation, adding another level of control to the process. In this work, we present a biopolymeric delivery system for photosensitizing molecules, as acetylated lignin nanoparticles. The preparation, physical characterization and photophysical characterization are discussed along this project, exploring the effects of the encapsulation towards the photosensitizer. Finally, these nanoparticles were tested against bacteria, finding that they were able to efficiently eradicate them only upon light irradiation, demonstrating low dark toxicity, and stability over time and light exposure. Then, this formulation for photosensitizing molecules has proven to be an efficient antibacterial formulation, fulfilling its purpose, while tackling antibacterial disinfection and valorizing a highly abundant biopolymer.

Dissertação de mestrado em Biotechnology
Lignin is one of the most abundant polymers and renewable resource obtained from lignocellulosic biomass. Organosolv is a promising chemical pretreatment that involves the use of organic solvents such as methanol, ethanol or acetone for extracting lignin. Regarding to other pretreatment technologies, organosolv process is able to produce a high purity (low inorganic impurities and sulfur-free) and low molecular weight (Mw) lignin. Due to its aromatic structure, lignin is a promising raw material for the synthesis of different biomaterials. Furthermore, the production of lignin nanoparticles (LNPs) gained prominence due to their biodegradability and bioactive properties. However, the properties of nanoparticles from organosolv lignin (OL) are unclear. For this reason, the objective of this work was the production and characterization of LNPs. For that, LNPs were produced from ethanol organosolv lignin using the nanoprecipitation method. Two types of LNPs were optimized: LNPs 100 nm and LNPs 300 nm, which presented a spherical shape, narrow size distribution and a reduced polydispersity. The thermal stability of these LNPs was improved regarding to raw lignin, and the chemical structure of lignin was not affected when the LNPs were produced. The antimicrobial preliminary tests proved that LNPs with 300 nm presented a bacteriostatic effect on E. coli O157:H7 and Salmonella Typhimurium. Relatively to the antioxidant effect, LNPs presented a lower RSA than raw lignin. However, when increased the time of reaction and the concentration of LNPs, this value was very similar to the raw lignin. Additionally, the LNPs showed a low cytotoxic effect in Caco-2 cell line in a time dependent-manner. Furthermore, the LNPs presented an antioxidant effect against intracellular ROS in a concentration-manner (0.005 and 0.01 mg/mL) These results showed that it was possible to obtain LNPs with good physico-chemical properties and with potential for high value applications such as biomedical, pharmaceutical and food applications.
A lignina é um dos polímeros mais abundantes e um recurso renovável obtido a partir da biomassa lignocelulósica. Organosolv é um pré-tratamento químico promissor que envolve o uso de solventes orgânicos como o metanol, o etanol ou a acetona para a extração da lignina. Em comparação com outras tecnologias de pré-tratamento, o processo organosolv é capaz de produzir uma lignina de alta pureza (baixa impureza inorgânica e livre de enxofre) e de baixo peso molecular (Mw). Devido à sua estrutura aromática, a lignina é uma matéria-prima promissora para a síntese de diferentes biomateriais. Além disso, a produção de nanopartículas de lignina (LNPs) ganhou destaque devido à sua biodegradabilidade e propriedades bioativas. Contudo, as propriedades das nanopartículas produzidas a partir de lignina organossolv não são claras. Por esse motivo, as LNPs foram produzidas a partir da lignina organosolv utilizando o método de nanoprecipitação. Dois tipos de LNPs foram o desenvolvidas: LNPs 100 nm e LNPs 300 nm, que apresentaram uma forma esférica, estreita distribuição de tamanho e uma polidispersividade reduzida. A estabilidade térmica dessas LNPs foi melhorada quando comparada à lignina bruta, e a estrutura química dos LNPs não foi afetada quando estas foram produzidas. Os testes antimicrobianos preliminares comprovam que os LNPs com 300 nm apresentam um efeito bacteriostático nas estirpes bacterianas de E.coli O157:H7 e Salmonella Typhimurium. Relativamente ao efeito antioxidante, as LNPs apresentam uma menor RSA do que a lignina bruta. No entanto, quando aumentamos o tempo de reação e a concentração, esse valor é muito semelhante ao da lignina bruta. Adicionalmente, as LNPs mostraram um baixo efeito de citotoxico na linha celular Caco-2. No entanto este efeito citotoxico aumenta quando aumentamos o tempo de incubação e quando a concentração de LNPs é maior. Além disso, os LNPs apresentam um efeito antioxidante contra as ROS intracelulares, quando a concentração destas LNPs é maior (0.05 e 0.1 mg/mL). Estes resultados mostraram que foi possível obter LNPs com boas propriedades físico-químicas e com potencial para aplicações de alto valor como aplicações biomédicas, farmaceuticas e na indústrial alimentar.

博士
朝陽科技大學
應用化學系生化科技博士班
101
Abstract Dysosma pleiantha (Hance) Woodson, (Berberidaceae) is a herbaceous, rhizomatous perennial, highly prized by the mountain tribes of Taiwan for its medicinal properties. It has long been used as a traditional Chinese medicine for general remedies including treatment of snakebite, condyloma, weakness, lymphadenopathy and tumors. It contains lignans, flavonoids and steroids and these compounds are accumulated abundant in rhizome. These lignans and flavonoids have potential application in anticancer activities. In recent years, natural populations of D. peliantha have declined considerably due to anthropogenic activities such as habitat destruction and over exploitation for medicinal applications. Thus, the present study focused on the quantification of anticancer compounds in D. pleiantha collected from different geographical regions, in vitro callus culture and production of anticancer compounds under the influence of organic additives, isolation, cloning, characterization and expression analysis of lignan biosynthetic pathway genes and anticancer activity of biologically synthesized metal nanoparticles from D. pleiantha rhizome. At first, we have quantified the podophyllotoxin, quercetin and kaempferol in different parts and rhizome of D. pleiantha collected from different geographical regions using RP-HPLC. Initially we have used different mobile phase in various combinations for the simultaneous detection of podophyllotoxin, quercetin and kaempferol. Among the different solvent used, water and methanol in the ratio of 50:50 gave symmetric and high peak area. The quantitative analysis of different parts of D. pleiantha showed that the rhizome was the best source for the extraction of medicinally important podophyllotoxin as compared to other plant parts, whereas both quercetin and kaempferol were mainly distributed in stem, roots and rhizome as compared to leaf and petioles. On the other hand, the rhizome of D. pleiantha collected from different geographical area result showed that the rhizome collected from Hsinchu, Miaoli, Nantou and Yangminshan showed maximum podophyllotoxin accumulation than the rhizome grown in Alishan. In the case of quercetin, Alishan and Miaoli chemotypes possess maximum accumulation than other chemotypes, whereas, kaempferol were abundantly accumulated in all the chemotypes with slightly lower in Hsinchu and Yangminshan. The second major part of the study is focused on in vitro callus culture of D. pleiantha and production of important anticancer compounds such as podophyllotoxin, quercetin and kaempferol. Among the different explants used, the leaf produced 100 % callus frequency and the leaf callus was further investigated for mass multiplication and secondary metabolite content. We found that the callus grown on B5 medium (Gamborg et al., 1968) supplemented with 1 mg/L 2,4-D under dark condition produced maximum biomass of callus. Further, the callus was cultured under different concentration of organic additives. Among the different concentration of various additives used, the leaf callus cultured on B5 medium supplemented peptone (1-4 g/L) is most suitable for the callus biomass induction and production of lignan and flavonoids. The third part of the thesis aims on isolation, cloning, characterization and expression of lignan biosynthetic pathway genes in D. pleiantha. We have successfully isolated two genes namely secoisolariciresinol dehydrogenase (DpSD) and pinoresinol synthase (DpPS) from D. pleiantha using PCR based approach. The expression of DpSD and DpPS genes in different parts of D. pleiantha were analyzed using qRT-PCR. We found that both DpSD and DpPS mRNA accumulates predominantly in rhizome. The fourth part of the study investigates the anti-metasatic activity of biologically synthesized gold nanoparticles on human fibrosarcoma cell line HT- 1080. The biosynthesized gold nanoparticles were confirmed and characterized by ultraviolet–visible spectroscopy, Fourier transform infrared spectroscopy, transmission electron microscopy, and scanning electron microscopy equipped with energy dispersive spectroscopy. The results revealed that aqueous extract of D. pleiantha rhizome has potential to reduce chloroauric ions into gold nanoparticles and the synthesized gold nanoparticles were showed spherical in shape with an average size of 127 nm. Further, we investigated the anti-metastatic activity of biosynthesized gold nanoparticles against human fibrosarcoma cancer cell line HT- 1080. The results showed that the biosynthesized gold nanoparticles were non-toxic to cell proliferation and, also it can inhibit the chemo-attractant cell migration of human fibrosarcoma cancer cell line HT-1080 by interfering the actin polymerization pathway. Final part of the thesis covered anticancer activity of biologically synthesized silver nanoparticles on breast cancer and AGS colon cancer cell lines. In this study, silver nanoparticles were successfully synthesized by a rapid biological synthetic method from aqueous rhizome extract of Dysosma pleiantha. The synthesized Dp- AgNPs were characterized by ultraviolet–visible spectroscopy, Fourier transform infrared spectroscopy, transmission electron microscopy, and scanning electron microscopy equipped with energy dispersive spectroscopy. Further, we tested for its efficiency as a potent cytotoxic agent against breast and colon cancer cell lines. It was observed that the synthesized silver nanoparticles induced concentration dependent inhibition of cell proliferation in both breast and colon cancer cells.

In this work, new heterogeneous catalysts based on mesoporous silica nanoparticles (MSNPs) with different cations of ionic liquids (ILs) covalently bonded to their surface, 1-butyl-3-methylimidazolium ([C4MIM]+), 1-butylpyridinium ([C4Py]+) and tetrabutylammonium ([N4,4,4,4]+), and with the polyoxometalate (POM) derived from phosphomolybdic acid ([H(3-x)PMo12O40]x-) as anions were prepared. Their analogous homogeneous compounds were also prepared for comparison (POM-ILs), [N4,4,4,4]3[PMo12O40], [C4MIM]3[PMo12O40] and [C4Py]3[PMo12O40]. The catalysts were characterized by elemental analysis, in solution (1H and 31P) and solid-state (13C and 31P) NMR spectroscopy, DLS (for the silica nanoparticles), SEM, TEM, EDS, X-ray fluorescence spectroscopy, FTIR spectroscopy and ICP-MS. The homogeneous catalysts were applied in the preliminary oxidation reactions of two lignin model compounds, cinnamyl alcohol and guaiacol, varying the reaction conditions (time, presence of hydrogen peroxide and use of conventional heating or microwave heating). The results obtained were characterized by solution 1H NMR spectroscopy. The oxidation of cinnamyl alcohol seems to be promissory using microwave heating process in comparison to conventional process. All catalysts prepared were also applied in the oxidative desulfurization reactions of a multicomponent model diesel, composed by 1-benzothiophene, dibenzothiophene, 4-methyldibenzothiophene and 4,6-dimethyldibenzothiophene in order to study the performance of each catalyst in the removal of sulfur compounds present in fuels. This part of the study was performed in Faculdade de Ciências from Universidade do Porto, and the catalytic performance was evaluated by gas chromatography. The heterogeneous catalysts had the most promising results, in particular MSNPs-[N4,4,4,4]POM achieving 100% of total desulfurization after only 2 hours. Its recycling ability was evaluated for three consecutive cycles and it was observed an increase of the catalytic efficiency for the second and third cycles reaching the complete desulfurization of the model diesel after just 1h instead of the 2h. The catalysts with cation tetrabutylammonium had the best results in both heterogeneous and homogeneous catalysis in comparison to the other two catalysts. In general, all catalysts tested had interesting results.