Dissertations / Theses on the topic 'NanoLED'

Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 2007.
Includes bibliographical references (p. 68-70).
The crude oil supply crisis the world is facing today along with the disastrous global warming caused primarily as a result the green house gases, has heightened the need for an eco-friendly and renewable energy technology. Solar cells, with their ability to convert the free and gigantic energy supply of the sun into electricity, are one such attractive choice. In this thesis, a study of the use of new technologies for enhanced solar cell performance based on conversion efficiency is carried out by first understanding the mechanism of selected major solar cell types, followed by an analysis of external or internal factors that affect their performance. One new technology under investigation to boost solar cell efficiency is the introduction of nanorod/wire structures into existing designs. This report discusses this approach in detail, highlighting beneficial characteristics offered and also looking into the structure realization through advanced nanostructure processing techniques. Finally, having a complete technology background at hand, various potential markets for new solar cell technologies are examined.
by Bertha Tan.
M.Eng.

The remarkable characteristics of Ti02 are widely used, from everyday life applications (pigments, food/cosmetics additives) to more specialised systems, including photovoltaics and structural composites. Use in polymers is substantial (25% of all Ti02 produced), but most applications and research focus on commercial powders. A new generation of Ti02 nanoparticles has emerged, based on very small, single-crystals, with well-defined morphology and phase. A limited number of papers report the use of this new nanoscale Ti02 in polymer nanocomposites, and indicate improved properties. Although the synthesis of anisotropic nanoparticles (e. g. nanorods) has been well-reported, use in polymer nanocomposites remains largely unreported. This thesis broadly covers three topics: (1) synthesis of Ti02 nanorods using different sol-gel routes in presence of structure directing agents, (2) modification of the nanorod surface chemistry in order to control dispersion and surface properties and (3) fabrication of titania nanorod-polymer composites. Singlecrystal anatase nanorods were produced with variable aspect ratio (3-12), depending on the specific structure directing agent (SDA) used during synthesis. Due to organic functionalisation at the nanorod surface, nanorods could be well dispersed in chloroform. A new procedure, based on the self-cleaning ability of Ti02 under UV, was developed for removal of organics from the nanorod surface, without compromising the nanorod morphology, crystallinity or dispersibility. This powerful tool can be used to change the surface character of the nanorods to generate aqueous TNR dispersions. Stable dispersions were achieved using quaternary ammonium hydroxides to modify the surface electrostatically and sterically. Once dispersed individually, the surface can be further modified by sol-gel chemistry. Composite work involved blending both organic and water-soluble polymers with nanorod dispersions in chloroform and water, respectively, to produce composite films of exceptional optical transparency, even for nanorod loadings up to 30 wt%. The films possess very strong, wavelength-tuneable UV absorbance, which could be used in UV filters and optical limiting. The presence of SDAs or dispersants at the nanorodpolymer interface hinders strong adhesion, as evidenced by marginally lower tensile strength and thermal stability of the nanocomposites. The photo-stability of the nanorod composites is comparable to that of the pure polymer and better than that of composites with commercial equiaxed TiO2 nanoparticles.

L'acide hyaluronique est un polysaccharide fortement hydraté. Grâce à sa présence naturelle dans le corps humain et aux nombreuses possibilités de modifications chimiques de ce polysaccharide, l'acide hyaluronique est un bon candidat pour la conception de transporteurs de principes actifs. Dans cette thèse, nous avons synthétisé différents types de dérivés du HA en milieu aqueux. Ceux-ci comprennent les dérivés alkylés du HA, HA-cyclodextrine conjugués et des copolymères «hybrides» composés de HA et d'un copolymère thermosensible de l'éthylène glycol.Basé sur la capacité d'accueillir des molécules hydrophobes paclitaxel dans leurs hydrophobes "nanocavités", nous avons ensuite montré la formation de multicouches de polyélectrolytes de capsules à partir de ces dérivés du HA. L'insertion des molécules paclitaxel dans la paroi des capsules a été réalisée par pré-complexation avec les dérivés du HA en solution, et ensuite déposition ces PTX-polyélectrolytes avec le poly(L-lysine) selon la technique de couche par couche.Dans les deux cas, les capsules chargées de PTX ont été trouvés qu'elles permettent de réduire la viabilité et la prolifération des cellules cancéreuses. Ces multicouches ouvrent de nouvelles voies vers des applications en nanomédecine, comme systèmes transporteurs de médicaments hydrophobes. L'acide hyaluronique modifié par maleimide a été réagit avec poly(diethyleneglycolmethacrylate - oligoethyleneglycolmethacrylate (poly(DEGMA-co-OEGMA)) modifié par thiol afin d'obtenir le copolymère «hybrides» thermosensible. La valeur de la LCST de ce copolymère de HA est autour de 35 °C en déterminant par les mesures du point de trouble des solutions. Au-dessus de cette température, le HA-poly(DEGMA-co-OEGMA) conduit à la formation des nanogels avec la capacité d'encapsuler des molécules hydrophobes dans leur domaine hydrophobe.Les nanogels chargés en PTX ont montré une cytotoxicité plus élevée avec des cellules du cancer surexprimant le récepteur CD44. Ces résultats suggèrent que ces nanogels thermosensible pourraient s'avérer être des candidats intéressants pour la libration thérapeutique dans le traitement de cancer
Hyaluronic acid is a highly hydrated polysaccharide of great biological interest. It can be easily chemically modified, resulting in many kinds of functional polysaccharide derivatives. In this thesis, we have synthesized different types of HA derivatives in aqueous media. These comprise alkylated HA derivatives, HA-cyclodextrin conjugates, and hybrid copolymers made of HA and of a thermosensitive ethylene glycol copolymer. Based on the ability of alkylated HA and cyclodextrin grafted HA to accomodate hydrophobic molecules paclitaxel into their hydrophobic “nanocavities”, we then demonstrated the formation of polyelectrolyte multilayer capsules based on these HA derivatives. The loading of PTX in the nanoshell was achieved by first complexing PTX with HA derivatives in solution and then, depositing these PTX-containing polyelectrolytes alternately with poly(L-lysine) according to the layer-by-layer technique. In the two cases, the PTX loaded capsules were found to decrease the viability and proliferation of MDA MB 231 breast cancer cells, while unloaded capsules did not impact cell viability. Due to these promising results, these hydrophobic polysaccharide nanoshells open new avenues for applications of hydrophobic drug-carrier systems in nanomedicine.Thiol modified poly(diethyleneglycolmethacrylate - oligoethyleneglycolmethacrylate (poly(DEGMA-co-OEGMA)) was reacted with a HA-maleimide conjugate to obtain HA- poly(DEGMA-co-OEGMA). The LCST value of this HA-copolymer was determined to be around 35°C via turbidity measurements. At the body temperature, HA-copolymer was thus shown to self-assemble into nanogels with the ability to encapsulate hydrophobic molecules into their hydrophobic domain. . In vitro cell culture studies showed that with incorporating the hydrophobic anti-cancer drug paclitaxel, the nanogels exhibited high efficiency and selectivity in the eradication of CD44 positive human ovarian cancer cells. These results suggest that these temperature-triggered nanogels hold great potential for the delivery of chemotherapeutics in anti-cancer therapy

This thesis investigated the potential of multiple stimuli-responsive nanogels as carriers in topical drug administration, with a view to developing a multi-responsive topical delivery system. Firstly, temperature-responsive N-isopropylacrylamide (NIPAM) was co-polymerised with a butyl acrylate monomer to yield poly(NIPAM-co- BA), which was loaded with a model permeant, methotrexate. An in vitro study of the loaded nanogel showed that it was capable of delivering methotrexate across the epidermis in levels that significantly reduce the biosynthesis of prostaglandin E2 (PGE2), a key inflammation mediator. Moreover, reduced lag time and enhanced delivery by the addition of sodium carbonate to the nanogel were observed. However, Western blotting for cyclooxygenase-2 (COX-2) in ex vivo skin, found the nanogel to be pro-inflammatory thus the observed reduced level of PGE2 was due to the enhanced delivery of methotrexate, which overwhelmed the inflammatory effect produced by the nanogel. Next, a temperature- and pH-responsive polyNIPAM copolymerised with acrylic acid known as poly(NIPAM-co-AAc) (5%) nanogel was synthesised. An in vitro migration study demonstrated that particles of the poly(NIPAM-co-AAc)(5%) were capable of penetrating the porcine skin and migrating across the epidermis, as shown by the presence of the particulates in the diffusion cell receptor phases. Furthermore, the nanogels were shown to enhance the delivery of loaded drugs across the epidermis in comparison to saturated solutions of the corresponding drugs. Western blotting for COX-2 demonstrated that the nanogel did not induce significant inflammatory reactions post-topical application, suggesting its compatibility with skin. A preliminary investigation examined a single-compartment system comprised of poly(NIPAM-co-AAc) (5%) nanogel and pH modulator-containing liposome, designed to remain stable until its application onto the skin. However, the composite system proved unsuccessful, primarily due to the liposome instability. Overall, this novel smart topical drug delivery system is within reach, provided the pH modulator-loaded liposome can be adequately stabilised.

In this study, samples of nanoscale structures of nickel (Ni) nanorods were prepared using the glancing angle deposition (GLAD) technique. Annealing was done using a split- top tube furnace at high vacuum chamber pressure. The pre-melting of the nanorods was maintained at 500 °C for 30 minutes in all the samples. Using the samples with 90 minutes of GLAD time, the annealing behavior of the nanorods was studied at 300 °C, 400 °C, 500 °C and 600 °C. The nanorods were then imaged using scanning electron microscopy. Using X-ray diffraction, the crystalline microstructures of the nanorods were studied. It was found that with increasing annealing temperatures, the intensity of peaks for both Ni (111) and Ni (200) increased, which indicates that better crystals were formed. The results indicate that re-crystallization occurs after annealing, leading to the formation of larger grain sizes compared to as-deposited grain sizes. Annealing substantially changed the structure of the nanorods, leading to different smoother, more connected crystal structures for the annealed nanorods compared to as-deposited ones.

The thesis focuses on marketing launch of the premium tobacco product. Defining tobacco product marketing regulation, it also specifies Czech tobacco market (incl. competition, price segments, etc.) together with consumer profiles as well as company brand portfolio. Brand strategy, its vision, authorship and brand positioning are included as well. The practical part is dedidacted to each of marketing plan essential elements: SWOT analysis, marketing objectives and strategy, action plan and overall evaluation including recommendation for future activities.

Plasmonic metamaterials have customized linear and nonlinear optical properties. This thesis investigates the properties of an anisotropic plasmonic metamaterial, consisting of aligned, interacting gold nanorods, to perform ultrafast light modulation, exploiting the intrinsic Kerr nonlinearity of gold. This e ect is based on an illumination-intensity-dependent change in the gold's permittivity, which takes place on ultrafast timescales and induces the intensity-dependent change of the metamaterial's re ection and transmission. A comprehensive theoretical and numerical analysis of the linear and nonlinear response of various con gurations of the metamaterial is performed and compared to experimental results. A new family of hyperbolic waveguided modes above the e ective plasma frequency, enabled by spatial dispersion, is identi ed. The strong nonlinear response and the dynamic modulation capabilities associated with the excitation of the waveguided modes is investigated. The presence of strong electron temperature gradients in the nanorods induced by a control light is shown to determine a stronger nonlinear modulation and to in uence the dynamic response, leading to subpicosecond time recovery components of the nonlinearity. Weak and strong coupling between molecular excitons and the metamaterial's modes can be achieved using core-shell nanorod geometries. The coherent interaction of molecular J-aggregates with coreshell nanorod arrays is analyzed in both the weak and strong coupling regimes. Subpicosecond components of the modulation are determined in the strong coupling conditions. The design of the optical response of the gold nanorod and core-shell metamaterials is studied through the near- to mid- Infrared, key spectral regions for molecular ngerprinting in chemical sensing and absorption spectroscopy. The applicability limits of the analytic approaches using the quasi-static and e ective medium approximations is tested. The results show great potential of the plasmonic nanorod metamaterial for ultrafast nonlinear optics in free-space and integrated applications, in a broad spectral range.

Les nanogels sont des macromolécules ramifiées solubles possédant une structure en réseau et de dimensions inférieures à 100 nm. La méthodologie récente de la copolymérisation radicalaire réticulante contrôlée permet d'accéder à de telles architectures polymères tout en contrôlant finement leur structure interne. Nous présentons dans ce travail: (i) l'étude préalable de systèmes modèles, permettant de dégager les conditions nécessaires à la synthèse de nanogels; (ii) l'application à la synthèse de nanogels hydrophiles valorisables de poly(alcool vinylique) et de poly(N-vinylpyrrolidone); (iii) une modélisation cinétique permettant de rendre compte des tendances observées expérimentalement et de prévoir les grandeurs caractéristiques de produits synthétisés par cette méthodologie
Abstract

Thesis advisor: Dunwei Wang
When their electrodes are made of nanomaterials or materials with nanoscale features, devices for energy conversion and energy storage often exhibit new and improved properties. One of the main challenges in material science, however, is to synthesize these nanomaterials with designed functionality in a predictable way. This thesis presents our successes in synthesizing TiSi₂ nanostructures with various complexities using a chemical vapor deposition (CVD) method. Attention has been given to understanding the chemistry guiding the growth. The governing factor was found to be the surface energy differences between various crystal planes of orthorhombic TiSi₂ (C54 and C49). This understanding has allowed us to control the growth morphologies and to obtain one-dimensional (1D) nanowires, two-dimensional (2D) nanonets and three-dimensional (3D) complexes with rational designs by tuning the chemical reactions between precursors. Among all these morphologies, the 2D nanonet, which is micrometers wide and long but only approximately 15 nm thick, has attracted great interest because it is connected by simple nanostructures with single-crystalline junctions. It offers better mechanical strength and superior charge transport while preserving unique properties associated with the small-dimension nanostructure, which opens up the opportunity to use it for various energy related applications. In this thesis we focus on its applications in lithium ion batteries. With a unique heteronanostructure consisting of 2D TiSi₂ nanonets and active material coating, we demonstrate the performances of both anode and cathode of lithium ion batteries can be highly improved. For anode, Si nanoparticles are deposited as the coating and at a charge/discharge rate of 8400 mA/g, we measure specific capacities >1000 mAh/g with only an average of 0.1% decay per cycle over 100 cycles. For cathode, V₂O₅ is employed as an example. The TiSi₂/V₂O₅ nanostructures exhibit a specific capacityof 350 mAh/g, a power rate up to 14.5 kW/kg, and 78.7% capacity retention after 9800 cycles. In addition, TiSi₂ nanonet itself is found to be a good anode material due to the special layer-structure of C49 crystals
Thesis (PhD) — Boston College, 2012
Submitted to: Boston College. Graduate School of Arts and Sciences
Discipline: Chemistry

Kyoto University (京都大学)
0048
新制・課程博士
博士(工学)
甲第11235号
工博第2446号
新制||工||1328(附属図書館)
22844
UT51-2004-U440
京都大学大学院工学研究科合成・生物化学専攻
(主査)教授 青山 安宏, 教授 森 泰生, 教授 木村 俊作
学位規則第4条第1項該当

Les réseaux bidimensionnels de nanofils (NFs) d’oxyde de zinc (ZnO) aléatoirement orientés, ou nanonets (pour « nanowire networks »), constituent des nanostructures innovantes et prometteuses pour de nombreuses applications. L’objectif de cette thèse est de développer des nanonets de ZnO en vue d’applications à la détection de molécules biologiques ou gazeuses, en particulier de l’ADN, ceci selon une procédure bas coût et industrialisable. Dans ce but, il est essentiel de bien maitriser les différentes étapes d’élaboration qui sont : (i) le dépôt de couches minces de germination de ZnO sur des substrats de silicium par voie sol-gel, (ii) la croissance de NFs de ZnO sur ces couches de germination par synthèse hydrothermale, et (iii) l’assemblage par filtration sous vide de ces NFs en nanonets de ZnO. Des études approfondies de chacun de ces procédés ont donc été menées. Ces travaux ont permis d’élaborer des couches minces, des NFs et des nanonets de ZnO reproductibles et homogènes dont les propriétés morphologiques sont précisément contrôlées sur une large gamme. Deux protocoles de biofonctionnalisation des nanonets avec de l’ADN ont ensuite été développés et ont abouti à des résultats encourageants mais restant à optimiser. Les nanonets ont également été intégrés au sein de dispositifs fonctionnels et les premières caractérisations électriques ont fourni des résultats prometteurs. A terme, ce travail ouvre la voie à l’intégration collective de NFs de ZnO qui permettrait la réalisation d’une nouvelle génération de capteurs (de biomolécules, de gaz…) à la fois portables, rapides et très sensibles
Two-dimensional randomly oriented zinc oxide (ZnO) nanowire (NW) networks, or nanonets, represent innovative and promising nanostructures for numerous applications. The objective of this thesis is to develop ZnO nanonets for the detection of biological or gaseous molecules, in particular DNA, by using a low cost and scalable procedure. To this end, it is essential to control the different elaboration steps which are: (i) the deposition of ZnO seed layer films on silicon substrates by sol-gel approach, (ii) the growth of ZnO NWs on these seed layer films by hydrothermal synthesis, and (iii) the assembly of these NWs into ZnO nanonets by vacuum filtration. In-depth studies of each of these processes were thus carried out. This work enabled to elaborate reproducible and homogenous ZnO thin films, NWs and nanonets whose morphological properties are precisely controlled over a wide range. Two DNA biofunctionnalization protocols were then developed for the nanonets and led to encouraging results which need however to be further optimized. The nanonets were also integrated into functional devices and the first electrical characterizations provided promising results. In the longer term, this work opens the way to the collective integration of ZnO NWs which would enable the development of a new generation of portable, fast and ultra-sensitive (bio- or gas-) sensors

Arrays of free-standing metallic nanorods are promising candidates for sensors, switches and spectroscopy. They have structure sizes much smaller than the wavelength of visible light, feature a long-axis surface plasmonic resonance (LSPR) and show metamaterial-like properties. This thesis provides a detailed investigation of their linear optical properties and highlights some nonlinear optical aspects. By means of graded structures having a tunable LSPR and three different theoretical models -- a numerical multiple-multipole method (MMP) model, a semi-analytic collective surface plasmon (CSP) model and an analytic dipolar interaction model (DIM) -- the optical properties were analyzed. Using the DIM, the experimentally observed blueshift of the LSPR in comparison to a single nanorod is confirmed and a physical explanation is provided. The LSPR strongly depends on the angle of incidence and the rod diameter. However, for a varying length the changes are small with the long-axis mode showing a lower energy limit. The detailed arrangement of the nanorods and the azimuthal angle of the incoming light plays only a minor role for small nanorod separations. Similarly, the dependence on the metal is the same as for single particles, whereas the sensitivity to the surrounding dielectric is much stronger than in the single-particle case. For longer nanorods made of silver, angle-dependent higher-order modes are observed and reproduced using MMP. The CSP model is applied and Fabry-Pérot-like oscillations of the CSPs are found. The propagating nature of these modes leads to the discovery that the p component of the transmitted light experiences a phase jump and to the observation of polarization conversion inside the structures. Negative refraction is found in nanorod arrays; it is revealed that a negative energy flux occurs only within a bandwidth given by the LSPR of a single nanorod and the array resonance. For smaller wavelengths, the in-plane component of the Poynting vector reverses, leading to an (extraordinary) positive flux. At the LSPR itself, the flux parallel to the surface is found to be zero. The negative refraction is also exploited to mimic a nanolens with structure parameters that are infact technical realizable. In the visible regime the nanolens shows a NA of 1.06 and superlens-like features such as identical rotation and linear translation of image and object. The nonlinear measurements on graded structures are conducted using femtosecond pump-probe spectroscopy resulting in kinetics showing either an increased transmission or absorption with signal changes of up to 40%. By converting them to transient spectra and by comparison with the literature, electron distribution changes at the Fermi edge and hot electrons/phonons are identified as the main reasons for the changes. Probing at the inflection points of the LSPR reveals ultrafast signals. Using transient spectra they are traced back to a short blueshift of the LSPR
Strukturen aus frei stehenden metallischen Nanostäbchen versprechen interessante An­wendungen als Sensoren, Schalter und in der Spektroskopie. Da ihre Strukturgrößen kleiner als die Wellenlänge des sichtbaren Lichtes sind, besitzen sie eine langachsige Oberflächen­plasmonenresonanz (LSPR) und weisen metamaterialartige Eigenschaften auf. In dieser Dissertation werden die linearen und nichtlinearen optischen Eigenschaften solcher Struk­turen im Detail untersucht. Mit Hilfe von Gradientenstrukturen, die eine durchstimmbare LSPR besitzen, und dreier theoretischer Modelle – eines numerischen Modells basierend auf der Methode der mul­tiplen Multipole (MMP), eines semianalytischen Modells kollektiver Oberflächenplasmonen (CSP) sowie eines analytischen dipolaren Interaktionsmodells (DIMs) – werden die op­tischen Eigenschaften analysiert. Unter Verwendung des DIMs wird die experimentell beobachtete Blauverschiebung der LSPR im Vergleich zur Resonanz eines Einzelstäbchens bestätigt und eine physikalische Erklärung dafür geliefert. Die LSPR ist stark vom Einfallswinkel und vom Stäbchendurch­messer abhängig. Im Unterschied dazu sind die Änderungen bei einer Längenvariation klein, wobei die langachsige Mode ein unteres Energielimit aufweist. Weiterhin haben die genaue Anordnung der Stäbchen und der azimutale Winkel des einfallenden Lichtes nur einen untergeordneten Einfluss. Die Abhängigkeit vom verwendeten Metall ist analog zu einem Einzelstäbchen, während die Empfindlichkeit in Bezug auf das Umgebungsmedium wesentlich stärker ist. Längere Nanostäbchen aus Silber zeigen winkelabhängige Moden höherer Ordnung, welche mittels MMP reproduziert werden können. Das CSP-Modell wird ebenfalls darauf ange­wendet, wobei Fabry-Pérot-artige Oszillationen der CSPs entdeckt werden. Die propa­gierende Natur der CSPs führt zur Entdeckung eines Phasensprungs der p‑Komponente des transmittierten Lichtes sowie zur Beobachtung von Polarisationskonversion in den Strukturen. Nanostäbchen-Arrays weisen außerdem negative Brechung auf. Es wird gezeigt, dass ein negativer Energiefluss nur in dem Wellenlängenbereich zwischen der LSPR der Einzelstäb­chen und der Arrayresonanz auftritt. Für kleinere Wellenlängen kehrt sich die in der Ebene befindende Poynting-Vektor-Komponente um, was zu einer (außerordentlichen) positiven Brechung führt. An der LSPR selbst ist der zur Strukturebene parallele Fluss Null. Die negative Brechung wird ferner ausgenutzt, um eine Nanolinse mit realistischen Struktur­parametern zu simulieren. Im sichtbaren Bereich zeigt sie eine NA von 1,06 und super­linsenartige Eigenschaften, wie eine identische Rotation und eine lineare Translation von Bild und Objekt. Die nichtlinearen Messungen an Gradientenstrukturen werden mittels Femtosekunden-Pump-Probe-Spektroskopie durchgeführt und liefern Kinetiken, welche entweder eine ver­stärkte Transmission oder eine verstärkte Absorption mit Signalstärken von bis zu 40% aufweisen. Durch Konvertierung in transiente Spektren und Vergleich mit der Literatur werden eine veränderte Elektronverteilung an der Fermi-Kante und heiße Elektronen/Pho­nonen als Ursache für die Änderungen gefunden. Das Abtasten mit dem Probe-Puls an den Wendepunkten der Resonanz offenbart ultraschnelle Signale. Mit Hilfe der transienten Spektren wird dies auf eine kurzzeitige Blauverschiebung der LSPR zurückgeführt

A new class of promising drug carriers based on collagen mimetic peptides assembled into triple helical peptide (THP) is described. The peptides fold into a triple helical conformation forming high aspect ratio, rigid rod nanoparticles. The fluorescein tag is used to visualize cellular uptake. Incorporation of the non-viral cell-penetrating vector (RRG)₂ and R₆ into the sequence does not alter its helical conformation, allowing efficient delivery of peptide carrier to the nucleus. The delivery is not effective for non-helical peptides. THP is stable against enzymatic degradation, as studied in human serum. Because of its size and shape, the THP nanoparticle carrier, a rigid rod with 1.5 nm diameters and adjustable length between 7.5 and 10 nm, has the potential to be efficiently delivered to tumor cells via the Enhanced Permeation and Retention (EPR) effect. The ease of replacement of hydroxyproline with lysine during the synthesis of the peptide allows for simple drug conjugation to the carrier.

Gold nanorod solutions absorb light strongly at specific wavelengths, due to plasmon resonances. The wavelength of peak absorption shifts depending on the refractive index of the solvent, which makes them ideal for optical biosensors. However, in solution multiple resonances are present because the nanorod orientation is random. Here, an attempt at developing a technique for creating an aligned nanorod sample is presented. A solution of gold nanorods suspended in liquid polymer was cured while exposed to an electric field. The samples were imaged using a near-field scanning optical microscope, which showed different morphologies for samples exposed to the field and aggregation for those that were not. Optical measurements confirm this, showing increased absorption in the aligned samples while the aggregated nanorods show reduced plasmon resonance [1].
Les solutions de nanobâtonnets d'or absorbent considérablement la lumière à certaines longueurs d'onde grâce à la résonance plasmonique. La longueur d'onde correspondant au pic d'absorption change selon l'indice de réfraction du solvant ce qui les rend idéals pour la conception de biocapteurs. Cependant, l'orientation des nanobâtonnets d'or est aléatoire en solution ce qui crée plusieurs résonances. Une technique potentielle pour la réalisation de rangs de nanobâtonnets d'or alignés est présentée dans cette thèse. Une solution de nanobâtonnets d'or en suspension dans un polymère liquide est polymérisée alors qu'elle est exposée à un champ électrique. Les échantillons sont photographiés à l'aide d'un microscope optique en champ proche et ces photographies démontrent que les nanobâtonnets d'or sont alignés dans les échantillons qui ont été exposés au champ électrique alors qu'ils sont agrégés dans les échantillons qui n'ont pas été exposés au champ électrique. Ces résultats sont aussi confirmés par des mesures optiques: une plus grande absorption est observée avec les échantillons dont les nanobâtonnets d'or sont alignés alors que la résonance plasmonique est réduite lorsque les nanobâtonnets d'or sont agrégés [1].

"“One-dimensional” nanostructures like nanotubes and nanorods hold great potential for a wide variety of applications. In particular, one-dimensional nanostructures may be able to provide many significant advantages over traditional spherical particles for drug delivery applications. Recent studies have shown that long, filamentous particles circulate longer within the body than spherical particles, giving them more time to reach the target area and deliver their payload more efficiently. In addition, studies investigating the diffusion of drugs through nanochannels have shown that the drug diffusion profiles can be controlled by varying the nanochannel diameter when the drug diameter and nanochannel diameter are close in size. The combination of increased circulation time and controllable drug release profiles give onedimensional nanostructure great potential for future drug release applications. To fully realize this potential, a simple, low cost, and versatile fabrication method for one-dimensional nanostructures needs to be developed and exploited. The objective of this work is to demonstrate the versatility of template-assisted nanofabrication methods by fabricating a variety of unique protein and polymer one-dimensional nanostructures. This demonstration includes the adaptation of two different template-assisted methods, namely layer-by-layer assembly and template wetting, to fabricate glucose oxidase nanocapsules with both ends sealed, segmented polystyrene and poly(methyl methacrylate) nanorods, and poly(L-lactide)-poly(methyl methacrylate) core-shell nanowires with adjustable shell layer thicknesses. The unique nanostructure morphologies that were achieved using our novel fabrication methods will open the arena for future research focused on process control and optimization for specific applications."

Cette thèse présente les résultats théoriques et expérimentaux de l’interaction entre une onde plane et une monocouche de particules sub-microniques sphériques/non sphériques transparentes au champ optique. Un renforcement local du champ optique sous la particule peut être observé, menant à la formation d’une concentration d’énergie appelée «nanojet photonique». Une étude théorique de la répartition du champ électromagnétique sous les microparticules et le choix des conditions optimales, nous a permis d’exploiter ce nanojet comme un outil de micro-nano-structuration. Dans le cadre de cette thèse, une structuration périodique 2D d’un matériau photosensible à base de TiO2 déposé sur divers substrats a été effectuée par la technique de photolithographie colloïdale. En utilisant ce matériau, cette approche permet en une seule étape de conduire à une couche fonctionnelle, stable mécaniquement et chimiquement. Enfin, cette thèse présente quelques pistes d’exploitation et de perspectives de l’utilisation du phénomène de concentration d’une onde incidente par les microparticules. Plus précisément, cette microstructuration peut être utilisée pour des fonctions de piégeage optique, pour de la croissance localisée de matériaux fonctionnels ou encore pour augmenter l’activité de photocatalyse de couches actives
This PhD thesis presents the theoretical and experimental results of the interaction between a plane wave and a monolayer of spherical / non-spherical submicron particles that are transparent to the optical field. Local amplification of the optical field under the particle can be observed. This amplification of electromagnetic field is called "photonic nanojet". A theoretical study of nanojet under the microparticles and the choice of optimal conditions, allowed us to exploit this nanojet as a micro-nano-structuring tool. A 2D periodic structuring of a TiO2-based photosensitive material deposited on various substrates was carried out by the colloidal photolithography technique. By using this TiO2-based photosensitive material, this approach makes possible in a single step to produce a functional layer. Finally, this thesis presents some opportunities to exploit the phenomenon of concentration of an incident wave by the microparticles. More precisely, this microstructuration can be used for optical trapping functions, for the localized growth of functional materials or for increasing the photocatalytic activity of active layers

This thesis focused on the fabrication and characterisation of an adaptable plasmonic platform consisting of a regular array of vertically aligned gold nanorods, supported on a gold substrate. The research aimed to understand the optical properties of the array, with particular emphasis on determining the coupling effects between the plasmonic nanorods. Characterisation was performed, both in the near and far-field, by means of optical spectroscopy, finite element modelling (FEM) and electron energy loss spectroscopy (EELS). The work subsequently aimed to use the knowledge gained from characterisation to optimise the absorption of visible light and enhancement of the electric-fields surrounding the plasmonic nanoparticles by controlling the geometrical factors of the array. Lastly, the nanorod arrays were then utilised for photocatalytic applications following their coating in a semiconductor material. During this research, gold nanorod arrays were successfully fabricated by means of electrodeposition in anodic aluminium oxide (AAO) membranes, with accurate control over the geometrical factors. UV-Vis measurements revealed that coupling within the array resulted in the higher wavelength longitudinal mode of the nanorods blue-shifting considerably to occur within the visible spectrum. For short aspect ratio (AR) nanorods, this mode overlapped with that of the transverse mode, however for longer ARs the mode could be tuned throughout the visible spectrum. This was in agreement with FEM results, however, it was additionally revealed that strongly coupled nanorod arrays undergo a redistribution in their electric field from localisation at the end of the nanorods, to one within the middle or base of the nanorods for unsupported and supported arrays respectively. It was further found that the presence of the substrate led to the nanorods coupling with their substrate image leading to greatly red-shifted resonances. Through experimental EELS measurements it was confirmed that this red-shift is due to coupling with the substrate, in addition to further analysing the particle coupling effects for both dimers, and larger arrays of nanorods. It was found that for dimers with strong coupling the longitudinal mode splits into both a bright mode with symmetrically aligned dipoles, and a dark mode with anti-symmetrically aligned dipoles, thereby agreeing with plasmon hybridisation theory. Furthermore, as the number of particles within the array increases, the modes split to form hybridised bright and dark modes consisting of elements of each. An initial attempt at photocatalysis was also performed based on the degradation of methylene blue by injection of hot-electrons into TiO2. No significant increase in activity was found, attributed to the semiconductor layer completely covering the nanorods thereby not allowing available sites for the oxidation reaction to replenish lost electrons in the metal.

The time-dependent wettability of nickel nanorod arrays was studied by measuring their water contact angles as a function of "aging" time in air. The nickel nanorod arrays were deposited on silicon substrates by DC magnetron sputtering using an oblique angle of 85° with respect to the substrate normal. By changing the deposition time from 10 to 90 min., the diameter, height, and separation of the nanorods were varied. The water contact angles of each sample were then periodically measured from a minimum aging time of 30 min. after deposition and exposure to air, up to a maximum aging time of three months. The initial water contact angles for all samples were approximately equal to 8o, indicating that the nickel nanorod arrays were initially superhydrophilic. As the samples aged in air, however, they all showed increasing contact angles as a function of time that were nonlinear with different rates. The results can be grouped into two categories: thinner samples with shorter deposition times (10 to 55 min) demonstrated faster rates of increase in contact angle, and thicker samples with longer deposition times (60 and 90 min.) showed slower rates. The increase in contact angle with time indicates that the Ni nanorods become more hydrophobic with aging time in air. Surface chemical analysis demonstrates that this increase in hydrophobicity may be due to oxidization and hydrocarbon contamination, which depend on the nanorod morphology. X-ray photoelectron spectroscopy results indicate that thinner samples (10-55 min. deposition time) have more adsorbed carbon as compared to thicker samples (60 and 90 min.). It appears that the reactivity of the Ni nanorods with air ambient is enhanced for shorter, smaller-diameter nanorods.

Les semiconducteurs III-N, incluant le GaN, l’AlN, l’InN et leurs alliages, font l’objet d’un intérêt grandissant pour le développement de dispositifs optoélectroniques. Leur gap direct dont l’énergie est comprise entre l’UV profond et l’IR (de 6,14 à 0,64 eV) permet d’exploiter une large gamme du spectre et ainsi viser de nombreuses applications. Depuis la réalisation des premières LEDs bleues à base de puits quantiques InGaN/GaN, ayant donné lieu au prix Nobel de physique de 2014, l’alliage InGaN est particulièrement étudié pour le développement des LEDs visibles. La fabrication des matériaux III-N par épitaxie fait cependant face à de nombreuses difficultés, incluant le large désaccord de maille entre les différents matériaux III-N, ainsi qu’avec les substrats disponibles. Les défauts structuraux générés par les contraintes d’épitaxie, diminuant drastiquement l’efficacité des dispositifs opto-électroniques, font ainsi partie des obstacles majeurs quant au développement des LEDs III-N.Facilitant la relaxation latérale des contraintes d’épitaxie grâce à leur facteur de forme, les nanofils semiconducteurs sont largement étudiés pour la réalisation d’hétérostructures axiales d’excellente qualité structurale. La thèse présentée ici s’intéresse ainsi à l’épitaxie de nano et microfils III-N pour la réalisation de structures LEDs visibles. En particulier, nous chercherons à optimiser l’efficacité des LEDs à haute teneur en In (environ 35%In) pour l’émission dans la gamme rouge. L’épitaxie par jet moléculaire assistée par plasma (PA-MBE) est une technique particulièrement adaptée pour cette étude car elle permet de générer des nanofils à base d’InGaN/GaN dont la composition en In peut varier entre 0 et 100%. Afin de contrôler le diamètre et l’espacement des fils tout en s’affranchissant des inhomogénéités des nanofils auto-nucléés, nous choisissons d’effectuer une reprise d’épitaxie PA-MBE sur des pseudo-substrats réalisés par croissance sélective. Ces pseudo-substrats, contenant des nano et microfils ordonnés de GaN d’orientation [0001], nous permettent d’ouvrir une étude approfondie sur les mécanismes de croissance du GaN et de l’InGaN en fonction des dimensions des fils.L’optimisation d’un dispositif nécessite dans un premier temps de bien maîtriser les mécanismes de croissance intervenant lors de l’homoépitaxie du GaN ou lors de l’hétéroépitaxie de l’InGaN sur les fils GaN. Une première étude sur le mécanisme d’élongation des fils GaN a mis en évidence une nucléation préférentielle en périphérie de la surface supérieure des fils des nouvelles couches atomiques, ainsi que la formation de différents plans cristallins au sommet des fils selon les conditions de croissance. Sachant que l’incorporation de l’In est sensible à l’orientation de croissance, le contrôle des plans cristallins formés constitue une étape clef à la préparation de surface pour l’épitaxie de la zone active de la LED. Contrairement aux structures LEDs MBE à base d’InGaN semi-polaire présentées dans la littérature, nous choisissons l’orientation [0001] permettant de garantir une unique composition d’InGaN par fils pour la réalisation de LEDs monochromatiques. De plus, l’élargissement du sommet du fils GaN permet d’éliminer une source de court-circuit et d’améliorer l’homogénéité fil à fil avant l’épitaxie de l’InGaN. Les analyses optiques, microscopiques et chimiques ont montré que la réalisation de super-réseaux de morphologie pyramidale permettait de réduire la quantité de défauts non-radiatifs dans la zone active et d’augmenter l’intensité de la luminescence. De plus ces structures permettent d’augmenter la surface d’injection électrique dans la zone active, améliorant l’efficacité de la LED. Enfin, l’électroluminescence des LEDs réalisées dans cette thèse couvre une grande gamme du spectre visible (450-610 nm)
III-N semi-conductors, including GaN, AlN, InN and their alloys, are now firmly established as a current solution for solid state lighting and related applications due to their direct band gaps ranging from deep UV to IR (6,14 eV to 0,64 eV). Since the realization of InGaN/GaN quantum wells based blue LEDs, rewarded by the 2014 Nobel Prize in physics, InGaN based visible LEDs have emerged as a prime candidate for lighting applications. However, one of the main challenges for the fabrication of III-N based devices is the large lattice mismatch between the III-N epilayers and the available substrates. Consequently, a high density of extended defects is induced by plastic relaxation, drastically decreasing the LEDs’ efficiency.Semiconductor nanowires are intensely studied for the realization of high efficacity axial heterostructures, due to the greatly eased elastic strain relaxation resulting from their large aspect ratio. With the aim of realizing red emitting InGaN based LEDs and overcome the green gap issue, this PhD work is mainly focused on the growth of InGaN/GaN nanowires and micro-columns with high In content (approximately 35%In). The growth is achieved by using plasma-assisted molecular beam epitaxy (PA-MBE) on [0001]-oriented GaN wires templates, ranging in diameter from nanowires to micro-columns to provide a better understanding of these key parameters.Optimization of such devices requires an extensive understanding of GaN and InGaN growth on top of GaN wires. Firstly, GaN nanowires elongation mechanism was shown to be governed by peripheral nucleation. Depending on GaN growth conditions, the top crystallographic planes are tuned from semi-polar planes to c-planes, making possible a surface preparation for the growth of InGaN active region of LED devices. As a new approach, we propose in this work to perform the InGaN growth on a Ga-polar [0001] GaN top surface, in contrast to the InGaN grown on semi-polar facets reported in literature. Taking into account the In incorporation efficacity with respect to the growth orientation, the InGaN epitaxy on a [0001] top facet guarantees a unique InGaN composition on each wire for the realization of monochromatic LEDs. Moreover, the enlargement of GaN wires toward the top was shown to eliminate a parasitic short-circuit and reduce the wire diameters variability. The replacement of the InGaN section by a pyramidal InGaN/GaN superlattice was observed to reduce non-radiative recombinations and increase the InGaN luminescence intensity. Additionally, these structures increase the surface of current injection in the active region of the LEDs, improving their efficiency. Finally, electroluminescence from LEDs realized during this PhD is covering a large range of visible spectrum from 450 nm to 610 nm

Currently there is a large boost in developing photonic technologies for computing as they promise high speed and low energy consumption. Nanoscale light sources might play a key role for such photonic integrated circuits, which may replace electronic chips one day. Recent experimental implementations include nanolasers, which typically require complex nanostructures for lasing operation, e.g. realized via photonic crystals, metallo-dielectric or plasmonic cavities. Here alternatives to nanolasers are studied - nanolight-emitting diodes (nanoLEDs). The main advantages are that these do not require high quality factor cavities needed to reach a lasing threshold, thus making nanoLEDs less sensitive to fabrication imperfections. By engineering nanoLEDs using nanocavities, the spontaneous emission rate can be increased substantially as compared with the bulk material as described by the Purcell effect. NanoLEDs using cavities smaller than the emitted wavelength, show great potential due to their unique features such as ultra-small footprint, high-speed modulation and unprecedent low energies budget. In this thesis, the optical properties of a dielectric encapsulated semiconductor AlGaAs/GaAs/AlGaAs nanopillars with or without a metal cavity will be investigated, both theoretically and experimentally. The theoretical part includes the analysis of metallo-dielectric micro- and nanopillar structures using 3D-FDTD simulations and the study of the radiative recombination taking the Purcell effect into account. The optical characterization includes the study of the emission properties using micro-photoluminescence and time-resolved photoluminescence techniques. From these results, the expected internal quantum efficiency (IQE) values are analyzed and the potential of these structures for the design of efficient nanoLED sources is discussed. The results are discussed in the perspective of the development of highly efficient nanoLEDs at room-temperature for future integrated photonics circuits.

碩士
國立成功大學
航空太空工程學系碩博士班
93
QUANTUM BUBBLE NANOJET STRUCTURES Student : Tsung-Hsien Lin Advisor : Huei-Huang Chiu ABSTRACT Quantum mechanical simulations of particles ejected from two slits of nanoscales reveal complex evolutionary structure of: quantum bubble, stretched-splitting bubbles, multi-branch nanojets and ultimately, two primary jets, in the order of increasing quantum Reynolds number, defined by the ratio of the inertia force to the quantum force induced by quantum potential. Major quantum mechanical processes involved in formation and their transition of the quantum bubbles and jets are: high harmonic wave excitation, wave propagation, intersection, interference and tunneling, each of which affects the dynamics, configurations and structures of the bubbles and jets. Transverse and axial distributions of velocities, interference fringes and particle paths in jets are also examined and dynamic mechanisms attributed by the quantum potential force discussed. The dynamic and structural complexities of nanojets and bubbles lend themselves to potential applications for nanodevices: mass spectrometer, imaging, sensors, lithography and nanotubes.

碩士
國立臺灣師範大學
物理學系
98
In this study, solar cells consisting of ordered p-i-n junction silicon nanorod matrix array with different lengths, diameters and period were fabricated. The advantages of p-i-n nanorod structures were low reflection and high surface to volume ratio compared to planar silicon thin films. Moreover, we designed hexagonal arrays to get sufficiently dense array to gain more number of p-i-n junction. The direct electrical pathways provided by the nanorod ensure the rapid collection of carriers generated throughout the device limited primarily by the surface area of the nanrods array. And devices deposit the ITO film would supply a shorter carrier diffusion length to enhance the photocurrent. Finally, we present that the p-i-n nanorod of matrix and hexagonal array structure solar cell actually improve the power conversion efficiency up to 10%, and had an excellent antireflection performance of optical. After depositing the ITO film, it enhances the nanorod devices photocurrent value 18.24% (the highest).

Tese de doutoramento em Biomedical Engineering
Self-assembled nanogels made of hydrophobized mannan or pullulan were obtained using a versatile, simple, reproducible and low-cost method. In a first reaction pullulan or mannan were modified with hydroxyethyl methacrylate or vinyl methacrylate, further modified in the second reaction with 1-hexadecanethiol. The resultant amphiphilic material self-assembles in water via the hydrophobic interaction among alkyl chains, originating the nanogel. Structural features, size, shape, surface charge and stability of the nanogels were studied using hydrogen nuclear magnetic resonance, cryo-field emission scanning electron microscopy and dynamic light scattering. Above the critical micellar concentration (cmc), evaluated by fluorescence spectroscopy with Nile red and pyrene, spherical polydisperse nanogels reveal long-term colloidal stability in aqueous medium up to six months, with a nearly neutral negative surface charge and mean hydrodynamic diameter in the nanoscale range, depending on the polymer degree of substitution. Nanogel based on vinyl methacrylated mannan was selected for further characterization among others because its synthesis is much easier, cheaper and less time consuming, its cmc and size are smaller, it is less polydisperse, and more stable at pH 3–8, in salt or urea solutions being consequently more suitable for biological applications. Proteins (bovine serum albumin or ovalbumin) and hydrophobic drugs (curcumin) are spontaneously incorporated in the mannan nanogel, being stabilized by the hydrophobic domains randomly distributed within the nanogel, opening the possibility for the development of applications as potential delivery systems for therapeutic molecules. No cytotoxicity is detected up to about 0.4 mg/mL of mannan nanogel in mouse embryo fibroblast cell line 3T3 and mouse bone marrow-derived macrophages (BMDM) using cell proliferation, lactate dehydrogenase and Live/Dead assays. Comet assay, under the tested conditions, reveals no DNA damage in fibroblasts, which seems to occur in the case of BMDM. The internalization kinetics, uptake mechanisms and intracellular trafficking pathways of mannan nanogel in mouse BMDM was assessed by flow cytometry and confocal laser scanning microscopy, using fluorescently conjugated nanogel. A time-, concentration- and energy-dependent uptake profile of the mannan nanogel is observed. Inhibition analysis unraveled mannose receptor-mediated phagocytosis and clathrin-mediated endocytosis to be involved in nanogel uptake. The mannan nanogel is also visualized in the cytosol suggesting that a fraction was able to escape from the endolysosomal system. The protein corona formed in human plasma around mannan nanogel was characterized by mass spectrometry after size exclusion chromatography or centrifugation followed by sodium dodecyl sulphate polyacrylamide gel electrophoresis. It consists of a very specific set of proteins, apolipoproteins B-100, A-I and E and human serum albumin, slowly formed following a dynamic protein exchange process. The mannan nanogel does not affect blood coagulation, does not induce complement activation and retards the fibril formation of both Alzheimer’s disease-associated amyloid β peptide and haemodialysis-associated amyloidosis β2 microglobulin, as was assessed by fluorometric thrombin generation assay, Western blot, and continuous thioflavin T fluorescence assay, respectively. Mannan nanogel has potential immunological adjuvant activity, as evaluated on the specific immune response to ovalbumin in intradermally immunized BALB/c mice. Elicited ovalbumin-specific antibodies were predominantly of IgG1 subclass indicating a T helper 2-type bias. Physicochemical characteristics, loading ability of biological agents, cytocompatibility and uptake of mannan nanogel by mouse BMDM, biosafety and biocompatibility studied at molecular level, and adjuvant activity are pronounced hints of the potential applicability of this nanosystem for macrophages targeted delivery of vaccines or drugs, acting as promising nanomedicines, always with the key goal of preventing and/or treating diseases
Nanogéis poliméricos auto-organizados foram obtidos a partir de manano e pululano hidrofobicamente modificados por um método versátil, simples, reprodutível e económico. Numa primeira reação, manano ou pululano foram enxertados com hidroxietil metacrilato ou vinil metacrilato, que por sua vez foram substituídos numa segunda reação com 1- hexadecanetiol. O material anfifílico resultante auto-organiza-se em água através da associação das cadeias alquílicas hidrofóbicas, originando o nanogel. As características estruturais, o tamanho, a forma, a carga de superfície e a estabilidade dos nanogéis foram estudados por espectroscopia de ressonância magnética nuclear 1H, microscopia crio-eletrónica de varrimento e dispersão dinâmica de luz. Acima da concentração micelar critica (cmc), avaliada por espectroscopia de fluorescência usando o vermelho de Nilo e o pireno, os nanogéis esféricos polidispersos revelam longa estabilidade coloidal em meios aquosos até seis meses, com carga de superfície negativa praticamente neutra, e diâmetro médio num intervalo nanométrico, cujo valor depende do grau de substituição do polímero. Dos nanogéis produzidos, o nanogel baseado em manano enxertado com vinil metacrilato foi selecionado para uma caracterização mais aprofundada porque a sua síntese é mais fácil, económica e rápida, a cmc e o tamanho são menores, é menos polidisperso e mais estável no intervalo de pH 3–8 bem como na presença de sal e ureia, sendo consequentemente mais apropriado para aplicações biológicas. Proteínas (albumina sérica bovina ou ovalbumina) e drogas hidrofóbicas (curcumina) são incorporadas espontaneamente no nanogel de manano, sendo estabilizados nos domínios hidrofóbicos aleatoriamente distribuídos no interior do nanogel, abrindo perspetivas para o desenvolvimento de aplicações em sistemas de libertação de moléculas terapêuticas. Nenhuma citotoxicidade é detetada com o nanogel de manano até 0.4 mg/mL na linha celular de fibroblastos de embrião de ratinho 3T3 e nos macrófagos derivados da medula óssea de ratinho usando ensaios de proliferação celular, lactato desidrogenase e “Live/Dead”. O ensaio cometa nas condições testadas, não revela dano no ADN dos fibroblastos, que possivelmente ocorre, no entanto, no caso dos macrófagos. A cinética de internalização, os mecanismos de internalização e as vias de tráfego intracelular do nanogel de manano nos macrófagos derivados da medula óssea de ratinho foram avaliados por citometria de fluxo e microscopia de confocal de varrimento laser, usando o nanogel conjugado com um fluorocromo. O perfil de internalização do nanogel é dependente do tempo, da concentração e de energia. A análise com inibidores revelou que a fagocitose mediada pelo receptor da manose e a endocitose mediada por clatrina estão envolvidos na internalização do nanogel. O nanogel de manano é também visualizado no citosol sugerindo que uma fração é capaz de escapar do sistema endolisossomal. A corona de proteínas formada no plasma humano em redor do nanogel de manano foi caracterizada por espectrometria de massa, após cromatografia de exclusão por tamanho ou centrifugação, seguidas de eletroforese em gel de poliacrilamida na presença de dodecil sulfato de sódio. A corona consiste num conjunto específico de proteínas, apoliproteínas B-100, A-I e E e albumina sérica humana, que se forma após um lento e dinâmico processo de troca de proteínas. O nanogel de manano não afeta a coagulação do sangue, não induz ativação do complemento e retarda a formação de fibras do péptido β amiloide associado à doença de Alzheimer e de β2 microglobulina na amiloidose associada à hemodiálise, como foi avaliado por teste fluorimétrico de geração de trombina, Western blot e análise continua da fluorescência de tioflavina T, respectivamente. O nanogel de manano tem potencial atividade adjuvante, avaliada na resposta imune específica para ovalbumina em ratinhos BALB/c imunizados por via intradérmica. Os anticorpos específicos para ovalbumina induzidos foram predominantemente da subclasse IgG1, o que indica uma propensão para induzir uma resposta mediada por células “T helper” tipo 2. As características físico-químicas, a capacidade de incorporação de agentes biológicos, a citocompatibilidade e a internalização do nanogel de manano por macrófagos derivados da medula óssea de ratinho, a biossegurança e biocompatibilidade estudadas a nível molecular, e a atividade adjuvante deixam entrever a potencial aplicação deste nanosistema na libertação direcionada a macrófagos, quer de vacinas quer de fármacos, atuando como promissores nanomedicamentos, sempre com o objetivo chave de prevenir e/ou tratar doenças.

This dissertation consists of two topics. One is a "Multi-pass Fiber Optic Surface Plasmon Resonance Sensor (SPR)" and the other is a "Nano-metallic Surface Plasmon Lens." Since both topics involved surface plasmon, the title of this dissertation is named "Surface plasmon coupled sensor and nanolens." For a multi-pass fiber optic SPR sensor, a fiber optic 4-pass SPR sensor coupled with a field-assist capability for detecting an extremely low concentration of charged particles is first demonstrated. The multipass feature increases the sensitivity by a factor equal to the number of passes. The field-assist feature forces charged particles/molecules to the SPR surface, increasing the sensitivity by an additional factor of about 100. Overall, the sensitivity exceeds the one-pass SPR device by a factor of about 400. A 10 pM concentration of 47 nm diameter polystyrene (PS) latex beads and 1 ?M concentration of salt dissolved in DI water were detected within a few seconds by the combined system. The equivalent index resolution for atomic size corresponding to ionized chlorine in salt is 10-8. This technique offers the potential for sensitive and fast detection of biomolecules in a solution. Secondly, a 44-pass fiber optic surface plasmon resonance (SPR) sensor coupled with a field-assist capability for measurement of refractive index change due to positive and negative ions is shown. The field-assist feature forces ions to the SPR surface, causing the SPR signal response to change which reflects a decrease or increase in refractive index depending on whether positive or negative ions are being attracted to the surface. This technique offers the potential for the sensitive detection of cations and anions in a solution. For a nano-metallic surface plasmon lens, we analyze the transmission of a normally incident plane wave through an Ag/dielectric layered concentric ring structure using finite difference time domain (FDTD) analysis. The dependency of the transmission efficiency on the refractive index in slit is studied. The numerical analysis indicates that the focusing beyond diffraction limit is found even at the extended focal length comparable to the distance of 7" from the exit plane using a circularly polarized coherent plane wave, ?=405 nm. Especially, compared to an Ag-only structure, the Ag/ LiNbO3 structure amplifies the transmission power by a factor of 6. Therefore, this Ag/dielectric layered lens has the potential for significantly higher resolution imaging and optical data storage.

碩士
國立中正大學
化學所
96
Magnetic nanomaterial recently has been attracted great attention owing to their potential applications in magnetic recording devices and medical diagnoses. FePt nanoparticles provide unique unaxial crystalline anisotropy magnetic properties. The magnetic properties change drastically with particle size. Several researchers work on magnetic behavior of the small size symmetrical FePt nanoparticles between 2~15 nm. Here we report a chemical synthesis of FePt nanorods via thermal decomposition method. We had slightly modified the reference materials of the FePt nanoparticles. The mixture of Fe(CO)5 and HDA were first loaded in a 100 mL reaction flask and the flask was connected with a reflux column in a nitrogen glove box. After the addition of 20 mL o-xylene to this reactor, the solution was stirred at 142℃ for 3 hr to fabricate 8 nm Fe nanoparticles. The heat source was then removed, and the reaction mixture was cooled to room temperature. The solution mixture of Pt(acac)2, co-stabilizer CTAB and o-xylene was transferred to the flask containing the freshly synthesized Fe nanoparticles. The mixture was heated to boiling for 12 hr leads to the formation of the FePt nanorods with average length of 50 nm and average width of 2 nm. We also observed possible growth mechanism by tuning reaction time and reaction concentration. Morphologies were obtained with transmission electron microscope (JEOL JEM-2010 High-Resolution). Elemental analysis was performed on both energy dispersive spectroscopy (INCA 300) attached to the JEOL JEM-2010 High-Resolution TEM and flame atomic absorption spectrometer (Perkin-Elmer AA 3110) to determine the chemical composition of the samples. Powder X-ray diffraction (Shimadzu XRD-6000) data were collected on a diffractometer using Cu K?radiation. Magnetic properties were measured by using vibrating sample magnetometer (DMS 1660).

博士
國立清華大學
化學工程學系
98
Recently, with the progress of nanomachining, nanosized devices have been developed. In addition to nano-scale experimental investigation, molecular dynamic simulation is a powerful tool to study nano-scale processes under different operating conditions. Although continuum mechanics is well accepted in describing the dynamics of process at the macro-scale, continuum modelling is not applicable when nano-scale or molecular-level physics becomes dominant. This study develops a simulation method to study the jet process at nano-scale. The elementary works of this study are as following. First, we analyze the conformational dynamics and entanglement phenomenon of polymer chains during glass transition. Second, the rheology of polymer thin film under various shear conditions is simulated. Furthermore, the application of parallel algorithm is included in this simulation method. Based on the development of the simulation method in nano-scale, we will analyze the process of nanojet with various compressing velocities, pushing periods and solid-liquid wettability surfaces. Results that illustrate various features are presented to aid in the comprehension of the nanojet processes.

碩士
國立交通大學
光電工程學系
100
Indium nitride (InN) with a narrow direct band gap has superior electronic transport properties over other group-III nitrides and it makes InN attractive for applications such as high-frequency electronic devices, near-infrared optoelectronics, and high-efficiency solar cells. With the rapid down-sizing of electronic and photonic device dimensions, understanding of the carrier transportation in nanoscale materials becomes crucial. In this thesis, we report the ultrafast carrier dynamics of vertically aligned InN nanorod arrays grown by molecular-beam epitaxy on Si (111) substrates. We employ ultrafast optical spectroscopy at a wide range of probe wavelengths (800 nm – 1600 nm) to understand the absorption/relaxation process of nanorods with different rod height, diameter, and rod density. The band-filling effect dominant absorption process is observed for nanorods, while the band-gap renormalization effect is dominant in epilayer. Typically, band-gap renormalization is significant in high carrier density and then band-filling dominant absorption in InN nanorods indicates smaller carrier density than in epilayer, due to less efficient absorption limited by the size of nanorods. Polarization-dependent transient reflectivity responses in nanorods shows that carrier lifetimes along parallel and perpendicular directions to the axis of nanorods are different only for small-diameter nanorods, implying that the carrier confinement can occur in the nanorods with the diameter comparable to theirs diffusion length.

碩士
國立清華大學
化學工程學系
91
The inkjet is an important technology and has been widely applied in the industry. That will be a significant contribution to the science and engineering if inkjet can be controlled at Nano-scale. In this work the process of nanojet is carried out by molecular dynamics simulation. The stability of jet formation with different sizes of nozzles and varied driving pressure will be studied. The systems can’t generate stable and continuous jet by using of estimated driving pressure. In this condition, the propane molecules will assemble progressively around the nozzle outlet and become the semi-spheroid. Moreover, the stability of the jet will reduce as the nozzle size decrease. The number of beads inside nozzle presents period fluctuation during the formation of continuous jet. The period is approximately 10 Pico-seconds and amplitude is about 1000 beads. The attractive interactions between propane molecules will from several thin adsorbed propane films on the nozzle outer surface. Moreover, the speed of fluid will increases as the fluid approaches the nozzle exit. As leaving the nozzle, the fluid velocity reduces to 250 m/sec because of the attractive interactions and viscous effect from the propane molecular thin films. Furthermore, The wall slip can be observed inside the nozzle of non-roughness of Nano-scale nozzle surface. The pressure of the system will decrease significantly along the nozzle and become zero at the nozzle exit. The density shows the same tends with pressure behavior, but it will increases gradually when out of nozzle because of evaporative cooling of the jet.

碩士
國立交通大學
應用化學系分子科學碩博士班
100
In this thesis, by using e-beam lithography, dielectrophoresis and focused ion beam techniques, we demonstrate methods to manipulate, align and make electrical contacts with a single Co:ZnO nanorod on metal pads. With this technique, we can measure the entire electric properties for ZnO nanrods doped with various ratio of cobalt. To eliminate the influence of contact resistance and to accurately determine the resistivity of a single nanorod, we devised a four-point-probe contact device. The electrical measurements were analyzed with three different measuring methods to determine the resistivity of the single Co:ZnO nanorod. In order to investigate the activity energy and electron transport properties at low temperatures, temperature dependent resistivity measurements were carried out room temperature to 80K. At high temperature, the electrron transport properties are dominated by thermally activated mechanism. The activity energy is determined to be 33.67~27.26meV. At low temperature, electrons are localized by the impurities and the nearest-neighbor hopping mechanism dominates the carrier transport at low temperature. When the ZnO nanorods were exposed under air for long time, the resistivity of ZnO nanorods was found to increase due to the oxygen absorption on surface.

碩士
國立成功大學
光電科學與工程學系
100
Visible light can propergate with surface Plasmon in structure with metal in nanometer size. This paper mainly discuss light’s propergative behavior and property by Theoretical derivation , Numerical Simulation and references.We based on light’s wave function and dispersion relation to get light’s Chiral mode then get improve and application

碩士
國立雲林科技大學
電子工程系
102
This study develops a density-controlled and seedless pressure growth method for laterally bridged ZnO nanorods from Au electrode for use in metal–semiconductor–metal photodetector fabrication. Firstly, directly grown laterlly ZnO nanorods on the Au electrode. Secondly, Using the different annealing time for Au electrode, the effect of pre-annealing process on suppressing vertical ZnO nanorods is systematically investigated by atomic force microscopy and scanning electron microscopy. The pre-annealing process is demonstrated to have direct influence on controlling vertical/lateral ZnO nanorod density and morphology. Interlaced and density-controlled ZnO nanorods with approximate single-crystalline structure can be directly grown from the side wall of pre-annealed Au electrode fingers without seed-layer. Through pre-annealing process, dark-current can be decreased three orders with an applied voltage of 1 V. Highly dense lateral ZnO nanorod-based photodetectors produce remarkable responsivity of 7.01 × 103 A/W and UV/visible rejection ratio of 281.21. Moreover, high internal photoconductive gain (104–105) exists in the fabricated photodetectors. For a given bandwidth of 10 k Hz and 1 V applied bias, the low-frequency noise spectra obtained from the UV photodetector were caused purely by the 1/f noise. The noise equivalent power of photodetectors with 0, 10, and 20 min pre-annealing periods are estimated to be 3.58 × 10−13, 6.78 × 10−13, and 4.86 × 10−13 W, and correspond to normalized detectivity of 1.85 × 1012, 1.17 × 1012, and 1.99 × 1012 cm Hz0.5 W−1, respectively. Finally, the different pressure with 0, 1, 2 kg/cm2 by grown ZnO nanorod, the photo-current to dark-current ratio can achieved 444.59 at 1V. This result may be attributed to internal photoconductive gain mechanism and high-density bridged ZnO nanorods. Our approach provides a simple and controllable method to fabricate high-performance ultraviolet photodetectors.

碩士
國立臺北科技大學
光電工程系
106
In this study, titanium nitride nanorod arrays with different thicknesses were deposited with glancing angle deposition technique by DC magnetron sputtering and argon-nitrogen mixed gas. Titanium nitride nanorod arrays with different columnar angles and thicknesses were deposited at a flow ratio of argon and nitrogen with ratio of (Ar (sccm): N2 (sccm) = 30:3.5). X-ray Photoelectron Spectroscopy (XPS) and X-ray Diffractometer (XRD) were used to derive the chemical analysis and lattice orientation of TiN nanorod array, respectively. Both p-polarized and s- polarized transmittance and reflectance spectra of each TiN nanorod array at angles of incident from +700 to -700 were measured. The absorption peaks associated with the Longitudinal Plasmon Mode (LPM) and the Transverse Plasmon Mode (TPM) in the p-polarized and s-polarized absorbance spectra were investigated. The absorptions of two modes were compared with a silver nanorod array with similar rod length. The difference between TiN and Ag nanorods array is discussed by analyzing the lattice orientation and intrinsic electromagnetic property of deposited TiN nanorods. The Finite-Difference Time-Domain (FDTD) is also applied to understand the mechanism of plasmonic modes in the TiN nanorods.

碩士
國立虎尾科技大學
光電與材料科技研究所
103
In this study，Zinc oxide nanorods homogeneous production Optoelectronic Devices To research topics，the lithium doped zinc oxide nanorods arrays were synthesized on glass substrate by using the hydrothermal method. Production of P-type zinc oxide nanorods array films before stacking N-type zinc oxide nanorods，Forming a P-N junction Optoelectronics, reducing the lattice mismatch. The main research can be divided into two parts: First , Using RF magnetron sputtering machine on glass substrate by sputtering a layer of aluminum zinc oxide thin film as a seed layer after, Placed configuration zinc nitrate, hexamethylene tetramine mixed with different concentrations of lithium solution after growth, Placed configuration zinc nitrate、 hexamethylene tetramine mixed with different concentrations of lithium solution after growth, The samples were made by rapid thermal annealing，Then Measurement Hall Effect Analyzer 、Secondary lon Mass Spectrometer、Multipurpose X-Ray Thin-Film Diffractometer、photoluminescence、 Field-Emission Scanning Electron Microscope、High-resolution Field-Emission Transmission Electron Microscopy、UV-VIS-NIR Spectrophotometer Discussion of different concentrations of lithium thin film of zinc oxide nanorods array surface structure and topography、(N or P type)、Electrical resistivity、Carrier concentration、Carrier mobility、Optical properties. Second , the p-Type zinc oxide nanorods arrays，Placed a solution of zinc nitrate, hexamethylene tetramine of Growth N-type zinc oxide nanorods，After forming the P-N junction thin film of zinc oxide nanorods array，Coated with silver paste as electrodes and using a solar simulator to measure whether there is rectifying IV characteristics. Keywords: zinc oxide nanorods, optoelectronic components, lithium, hydrothermal method

碩士
國立臺灣科技大學
化學工程系
96
Zinc oxide nanorods (ZNR) on substrate were prepared in this study by chemical bath deposition method. In order to obtain ZNR of high aspect ratio and high photocatalytic activity of ZNR, we added polyethylenimine (PEI) and Ag were added. PEI was used to hinder the lateral growth of the nanorods. All the catalysts prepared in this study were characterized by XRD, SEM, UV-vis, and AA. The photocatalytic activity of ZNR arrays was measured by photobleaching of 10 mg/L methylene blue, in a photo-reactor equipped with a light of 128 W and λmax=300 nm. The efficiency of photoconversion of ZNR was evaluated by 100 W Xe arc lamp illuminating the work-electrode in 1 M KOH solution. As the synthesis time increased from 5 to 20 hours, the results showed that, the length of the ZNR increased from 3.3μm to 12.4μm , the diameter increased from 100 nm to 400 nm, the average aspect ratio was about 34. Adding PEI to the synthesis solution would increase the aspect ratio to 60. For ZNR of 10μm length, the photobleaching activity of ZNR prepared with the addition of PEI is higher than that of zinc oxide nanoparticles film (ZNP). The most active photocatalytic catalyst was prepared by adding PEI in the synthesis solution and with the incorporation of Ag. The same catalyst also had the highest efficiency of photoconversion and incident monochromatic photo-to-current conversion in water splitting reaction.

碩士
國立中興大學
機械工程學系
92
Abstract Due to the fast development of the nanotechnology, size of material can be made into a relatively small shape. Surface area and volume ratio increasing effects change the physical and chemical characteristics of the material tremendously. Since one-dimensional nano-material has unique nano structure, they are very good in sensor, field-emitter and photoelectric component applications. Indium-Tin Oxide (ITO) is a transparently conductive material with good photoelectric characteristics. It has been widely used as the electrode material of the liquid crystal display and organic LED. In this research, an anodizated aluminum oxide (AAO) based Indium-Tin Oxide (ITO) nano rod array fabrication method is proposed. Firstly, a nano porous oxidized aluminum mold with 70 nm in diameter, 33 μm in height is constructed through electrochemical anodization method. Nickel-cobalt nanorods were grown on the holes of the porous AAO mold by electric-forming. Sodium hydroxide solution was then adopted to remove the aluminum film, resulting in a regular nickel-cobalt nanorod array. The nickel-cobalt nanorod array serves as a mask to further product oxidized indium-tin oxide nanorod array by dry etching.

碩士
國立中正大學
化學研究所
91
Abstrate To targeting an interesting issue related to the catalytical properties, we have fabricated a new type of nanocomposite materials combining 1D and 0D nanoparticles: Au nanorod@ thiolated silica-M, where M = Pt, Pd, and Au. Au nanorods are synthesized by electrochemical methods with an aid of co-surfactants. An thiolated silica shell layer is coated on each Au nanorod and it serves as a substrate for immobilizing foreign 0D nanoparticles. The sol-gel process is employed to prepare the nanometer thick “glue” layer with the precursors of 3-mercaptopropyl- trimethoxy silane (MPTMS). The thickness of the shell can be controlled easily. The embedded 0D nanoparticles are synthesized by first adsorbing Mn+ ions into the thiolated silica layer within the solution phase and then followed by reduction and growth to form immobilized nanoparticles. The particle dimensions, compositions, and crystallinity of the fabricated nanomaterials have been well characterized.

碩士
國立中正大學
化學暨生物化學研究所
105
Following our previous studies in the anisotropic heat release of the gold nanorod coated with non-uniform silica shell (AuNR-nu-SiO2) system based on the observations in the relative photo-induced melting routes of the gold nanorod. Such non-uniform coating means the end-thickness (ET) of silica required to be negligible. The split-melting phenomenon indicates a strong anisotropic heat release in the individual nanoparticle. This thesis explored further evidences for the interfacial bonding effect. Furthermore, the dependence of the split-melting yields on the shell porosity and on the side-thickness (ST) of silica were investigated. First, we design two kinds of interfacial structures between AuNR and silica: one is the chemical bonding (AuNR-SH-nu-SiO2) and the other is physical adsorption (AuNR-CTAB-nu-SiO2). This design likes to prove that difference of thermal conductivity of side-shell will be caused by different interfaces of structure and we expect it will result in different phenomenon. The results show that after the AuNR of AuNR-SH-nu-SiO2 absorbs the light, power of light will transform into heat, resulting in up to 70% melting and no rod-to-two spheres (split-melting). But for AuNR-CTAB-nu-SiO2, there are only 30% melting and found 30% split-melting. We attribute different results to different interface forces. The interaction of the physical adsorption (ca. 9 kcal/mol) is much smaller for the chemical bond (ca. 45 kcal/mol) so that the thermal conductivity is lower and causes the lager difference of temperature between the medium and the end of AuNR so the split-melting is produced. Second, we design two different densities of silica shell of AuNR-CTAB-nu-SiO2 to investigate. The two kinds of densities is known by the total pore volume of BET test, 0.151cm3/g and 0.071 cm3/g, respectively. At lower density, there is 10% split-melting but it is increased to 30% at the higher density. The results demonstrate when the density get higher, the heat is harder to transfer from the side of shell so split-melting will increase. Third, in the AuNR-CTAB-nu-SiO2 system, we made two kinds of side-thicknesses (ST) of shell which are 12 nm and 15 nm, respectively. The researches appear that split-melting would be 30% at the thinner shell and it is increased to 50% at the thicker shell. That means when ST of shell is thicker, the heat is harder to release from side of shell, so that split-melting will be higher. Final, we made AuNRs with different aspect ratios of AuNR-CTAB-nu-SiO2 core-shell nanoparticle. The aspect ratio of AuNR are between 5 and 6. The results indicate when the aspect ratio of AuNR is between 5.2 and 6, there is no difference in split-melting. But, split-melting will decrease when the aspect ratio of AuNR is between 4.9 and 5.2. That means when the aspect ratio of AuNR falls out of range, the heat is easier to release from the end of AuNR, so that split-melting will be lower.

碩士
國立中山大學
物理學系研究所
98
In this article, we report the study of defects between single and bulk GaN nanorods in temperature dependence. High quality of GaN nanorods have been investigated by μ-photoluminescence. Optical properties and surface morphology have been analyzed by a series of measurements, including field-emission electron microscopy (FESEM), and cathodoluminescence (CL). CL data reveal that the intensity of surface state emission is larger than near-band-edge emission at 20K . The 3.21eV peak reveals the structural defect at GaN/Si interface. The surface state emission from bottom is larger than top.

碩士
國立臺灣海洋大學
光電科學研究所
99
In this thesis, surface plasmon resonance (SPR) effects and near field optics properties on a single gold nanorod are investigated by using the three-dimensional finite element method (FEM). Seven patterns of nanorods with different aspect ratio are explored. The scattering crossing sections (SCSs) and the field intensities on a single gold nanorod are calculated under the incident wavelength with p-polarization. Six meaningful results are described as follows: The number of standing waves on the surface of nanorod can be controlled by varying the length and diameter of the nanorod. The SCSs of gold nanorod is sensitive than that of silver one as the rod length L=1μm and rod diameter D = 40nm. An interesting phenomenon is found that the number of node on the surface of nanorod is increased two times as the length of nanorod is increased 500 nm. A red shift can be found in the pattern of separating nanorod with a small gap (30 nm). We found that the separationg nanorod with total rod length L=3μm (from the first nanorod to the last one) and separating rod length d1 = 105nm possesses two time of SCSs than that of a single nanorod with length L=3μm. It can be found four standing waves on the surface of separating nanorod as the wavelength of incident light is λ=900 nm. These results can be prospect for application in nanooptical devises, sensing, and surface-enhanced spectroscopy, due to the effects of strong and tunable plasmon resonance.

碩士
東海大學
環境科學與工程學系
99
In the present study, a microwave-assisted hydrothermal method was used to prepare titanium nonorods (TNRs) and TNR/multi-wall carbon nanotube （TNR/MWCNT） photocatalysts in relatively short time. The composites were characterized by Multi-Function Scanning Electron Microscope （SEM）、Transmission Electron Microsopy（TEM）、X-ray Powder Diffractometer（XRD）、BET surface area、Diffuse Reflectance UV-visible Spectrophotometer（UV-Vis spectrophotometer）、X-ray Photoelectron Spectroscopy（XPS）、X-ray Absorption Spectroscope（XAS）and their photocatalytic activities were tested by photo degradation of methyl blue in water. SEM and TEM micrographs indicated that TNRs had a length of approximately 300 nm with a diameter of about 30 nm and were non-hollowed. XPS spectra strongly indicated the existence of Ti－C bond; TNRs exited in anatase and rutile forms as shown by the results from both XRD and XAS. The BET surface area of the TNRs were 53~ 197 m2/g. TNRs showed a red-shift in UV-Vis absorption that increased with greater MWCNT addition.Under UV light illumination for 3 hours, the greatest photocatalytic activity was observed for the composite catalyst with C/Ti mole ratio of 1：1.

碩士
國立臺北科技大學
光電工程系研究所
99
In this study, optical birefringence of bideposited symmetric nanorod arrays is investigated. A Ta2O5 nanorod array with zigzag structures is fabricated by serial bideposition technique. Each nanorod is composed of several unit sections and each section is composed of symmetrical subsections. From the lateral view, the sectional layer is composed of symmetrical layers ABA. The deposition plane of A is perpendicular to that of B. The equivalent refractive index and phase retardation of multiple units are analyzed and measured using ellipsometry. The result indicates that a bideposited symmetric nanorod array is potentially applied as a waveplate.