Dissertations / Theses on the topic 'Nano-particle'
To see the other types of publications on this topic, follow the link: Nano-particle.
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 dissertations / theses for your research on the topic 'Nano-particle.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse dissertations / theses on a wide variety of disciplines and organise your bibliography correctly.
1
Davoodi, Amir. "Modification of Water Uptake Capacity of Wood Using Colloidal Solution by Impregnation Technique." Thesis, Université d'Ottawa / University of Ottawa, 2020. http://hdl.handle.net/10393/41172.
Full textAbstract:
Hygroscopic properties are important characteristics of a material that is used in building
construction. Wood is an anisotropic, heterogeneous and hygroscopic material. Given the
cellular structure of wood as well as capillary action in the Lumina, the level of water uptake
in wood is significant.
Such amount of water uptake makes the wood susceptible to dimensional instabilities, causes
alterations in the mechanical properties, and potential for degradation of the material. Various
approaches have been investigated to modify the hydrophilic nature of lignocellulosic
materials, including surface modifications using silane treatments, acetylation, wax etc.
Although these surface modifications can decrease the rate of water uptake by the materials,
the amount of water uptake at saturation remains unchanged. In fact, the lumen diameter is so
small that the rise of liquid, even with a hydrophobic surface, can still occur. Therefore, the
only way to halt the water uptake driven by capillary action in lignocellulosic materials is to
apply a uniform cover on the material surface in addition to filling the lumen with dense
material.
In the current research project, the vascular structure of softwood (Spruce) is obstructed by
silica nanoparticles using the impregnation technique as one of the advanced methods to
reduce the water absorption capacity in wood. This process can form a thin film of
nanoparticles on solid objects with complex geometries. In addition, the technique can fill up
the cavities and voids of porous materials and prevent the capillary action inside the Lumina.
In this method, the wood specimen is dipped into the solution, silica 40 (wt. %) colloidal
solution. Then the solvent is evaporated which results in the formation of nanoparticles in
the form of thin films or particulates. The former may change the moisture absorption on the
surface and the later reduces the capillarity of the vascular system. This project aims to find
the optimal impregnation condition to minimize the water uptake capacity of wood in order to
increase wood physical and mechanical stabilities.
Three immersing times (i.e. short, medium, and long) were used to coat wooden samples with
the silica colloidal solution. The samples were conditioned in wet environments with specificiii
relative time and then their weight as percentage change were examined. To investigate the
capability of the method to obstruct the vascular structure of the wood samples, the
characteristic process was done in the next step by some common tests such as X-ray
Diffraction (XRD), Scanning Electron Microscope (SEM), Water Contact Angle (WCA), etc.
The results from the experiments show that dip-coating the wood samples with silica
nanoparticle colloidal solution had effect on the amount of water absorption, but significant
levels of reduction in water attraction was achieved with considering the other effective
parameters such as duration of each set, the number of sets that are conducted, and
impregnation in vacuumed condition. More research is needed to quantify the benefits of using
nanoparticle in these applications.
2
Peng, Suili. "Nano/micro particle-based functional composites and applications /." View abstract or full-text, 2007. http://library.ust.hk/cgi/db/thesis.pl?NSNT%202007%20PENG.
Full text
3
Al-Zangana, Shakhawan. "Nano- and micro-particle doped liquid crystal phases." Thesis, University of Manchester, 2017. https://www.research.manchester.ac.uk/portal/en/theses/nano-and-microparticle-doped-liquid-crystal-phases(31dbb051-7d9c-4780-bda0-d58773846de0).html.
Full textAbstract:
This thesis presents the investigation of the liquid crystal (LC) - particle suspensions. Particles from nano- to micro-size, spherical to two-dimensional shapes, with different functionality are dispersed into nematic and smectic phases. The aim is to create ordered nanoparticle (NP) assemblies and thereby modify the common properties of the liquid crystal, such as dielectric anisotropy and electro-optical, revealing any interaction between particles and LC properties. It is found that for concentrations (>0.5vol%), the ferroelectric NPs have increased the sensitivity of the nematic liquid crystal to the electric field through electro-optical responses, which is seen by an enhancement in the dielectric anisotropy. This could be induced by the coupling of the electrical dipole moments in the spherical NPs with the LC director field. The electro-optical properties of the chiral smectic (SmC*) phase (tilt angle Θ, switching time τ_s and spontaneous polarisation P_s) are found to be independent of the concentration and sizes of the doped NPs. The relaxation frequency f_R of the Goldstone mode is faster in the ferroelectric NPs suspensions of 2.0vol% compared to the paraelectric NPs. In the graphene oxide (GO) - nematic LC (5CB) suspensions, the small GO sizes of mean size 560 nm are more easily dispersible than larger flakes of 2.8 micro metre mean size. As the GO concentration is increased, each of the threshold voltage and splay elastic constant dramatically increases, reaching saturation at ≈1.0wt%. The field driven switching-on time is practically not affected, while the purely elastically driven switching-off time is strongly sped-up. Interestingly, thermotropic and lyotropic LC phases are exhibited in the GO-5CB suspensions when heating the thermotropic liquid crystal into its isotropic phase. The isotropic phase of 5CB acts as a solvent for the GO particles, forming a lyotropic nematic phase with largely reduced birefringence. It is found that the nematic to isotropic phase transition is shifted toward higher temperature for the GO-5CB system compared to the BaTiO3-5CB system. Dispersions of different sizes of GO flakes are prepared in isotropic and nematic fluid media. The dielectric relaxation behaviour of GO-dispersions was examined for a wide temperature range (25-60 ℃) and frequency range (100 Hz-2 MHz). The mixtures containing GO flakes were found to exhibit varying dielectric relaxation processes, depending on the size of the flakes and the elastic properties of the dispersant fluid. The relaxation frequencies in the isotropic media were lower compared to the nematic medium. Relaxation frequencies (~10 kHz) are observed in the GO-isotropic media, which are reduced as the size of the GO flakes are decreased, are anticipated to be inherited from GO flakes. However, the fast relaxations (~100 kHz) that are observed in the nematic suspensions could imply strongly slowed down molecular relaxation modes of the nematogenic molecules. Finally, the phase diagram of lyotropic LC as a function of the lateral dimensions of the GO flakes, their concentration, geometrical confinement configuration and solvent polarity was investigated. Polarising optical microscopy was used to determine isotropic-biphasic-nematic phase evolution. The confinement volume and geometry of the sample relative to the GO size are shown to be vital to the observation of the lyotropic phase. GO LCs have the potential for a range of applications from display technologies to conductive fibres. The confinement related LC phase transition is critical toward their applications. It is also found that the stability of the LC phase is higher for the solvent of higher dielectric constant.
4
Rodrigues, Melissa. "Preventing nano and micro wear-particle induced inflammation." Thesis, Cardiff University, 2018. http://orca.cf.ac.uk/114163/.
Full textAbstract:
Aseptic loosening, as a consequence of an extended inflammatory reaction induced by wear particles, remains the most common complication of total joint replacement (TJR), representing a major problem for the long-term success and survival of prostheses. Despite it is high incidence, in the last decade any therapeutic approach has been found to treat or avoid aseptic loosening, leaving revision as the only effective treatment for this condition. The local delivery of anti-inflammatory drugs to modulate wear-induced inflammation has been regarded as a potential therapeutic approach to avoid aseptic loosening. In this work, an anti-inflammatory drug-eluting implant model system was developed and characterised. The model system was obtained by attaching DEX to functionalised-TiO2 particles, through different synthetic routes: i) by covalently binding DEX to carboxyl-functionalised particles (amino or mercapto routes) or ii) by coating amino-functionalised particles using Layerby- Layer (LbL) technique. The chemical and physical properties of DEXloaded functionalised TiO2 particles have been determined and the release profiles investigated. Depending on the synthetic route, the DEX release period can vary from hours (amino, mercapto routes) to 3 weeks (LbL route). The model system was then tested for its cytotoxic and anti-inflammatory properties in a rapid and reproducible in vitro mouse macrophage-like cellular model, by utilizing murine RAW 264.7 cells. In this model lipopolysaccharide (LPS) was utilized to activate the Raw macrophages, resulting in the secretion of pro-inflammatory cytokines, including nitric oxide (NO) and tumour necrosis factor alpha (TNF-α), the suppression of which was utilized to investigate the anti-inflammatory effect of DEX released from functionalised-TiO2 particles. In vitro studies showed that DEX decreased LPS-induced NO and TNF-α production at non-cytotoxic concentrations, where DEX released from LbL particles showed the most effective suppression of inflammation for at least 2 weeks. Collectively, these findings show that the model system developed can be a potential therapeutic approach to avoid wear-debris induced aseptic loosening of TJR.
5
Zuo, Koucheng. "The mechanical behaviour of nano-particle modified thermoplastics." Thesis, Imperial College London, 2010. http://hdl.handle.net/10044/1/10667.
Full textAbstract:
Hybrids made up of polymers and nano-particles have received great interest both in academia and industry. The uniformly dispersed nano-sized particles create a large interfacial area per unit volume and could result in a remarkable improvement in thermal and mechanical properties when compared with virgin polymer or conventional micron-sized particle modified composites. This thesis presents and discusses the effects of adding rigid nano-sized ZnO particles into four thermoplastic systems at 23 °C and 80 °C. The matrix materials include two styrene acrylonitrile (SAN) copolymers, polymethyl methacrylate (PMMA) and polyamide 6 (PA 6). Three types of ZnO particles were used as fillers, denoted A, B and C. The ZnO-A and ZnO-B are cylindrical, while the ZnO-C particles are spherical. The microstructures and the thermal and fracture behaviour of the resulting systems under quasi-static and fatigue loadings were investigated using various techniques. The microstructure studies showed that ZnO nano-particles could be uniformly dispersed into the matrices up to about 0.30% by volume fraction, above which they tended to cluster into agglomerates. The addition of ZnO nano-particles had only a marginal effect on the glass transition temperature and yield stress of the modified thermoplastics. A notable increase in Young’s modulus was observed when the nano-particles were well bonded with the matrices. Remarkable improvements in toughness and fatigue threshold were also observed for some ZnO modified thermoplastic systems. However, the toughness decreased at relatively high concentrations of reinforcement. Microscopy studies showed that debonding of the nano-particles and subsequent plastic void growth in the matrix and multiple crazing initiated by the nano-particles were the main toughening mechanisms identified. At high volume fractions, the ZnO agglomerates acted as stress concentration sites, and the voids nucleated at lower stress levels, which led to a reduction in the toughness of the modified composites.
6
Srinivasan, Ganesh. "Numerical Simulation of Nano-scale to Micro-scale Particle Growth in Condensation Particle Counter." University of Cincinnati / OhioLINK, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1204577130.
Full text
7
Olk, Phillip. "Optical Properties of Individual Nano-Sized Gold Particle Pairs." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2008. http://nbn-resolving.de/urn:nbn:de:bsz:14-ds-1218612352686-00553.
Full textAbstract:
This thesis examines and exploits the optical properties of pairs of MNPs. Pairs of MNPs offer two further parameters not existent at single MNPs, which both affect the local optical fields in their vicinity: the distance between them, and their relative orientation with respect to the polarisation of the excitation light. These properties are subject of three chapters: One section examines the distance-dependent and orientation-sensitive scattering cross section (SCS) of two equally sized MNPs. Both near- and far-field interactions affect the spectral position and spectral width of the SCS. Far-field coupling affects the SCS even in such a way that a two-particle system may show both a blue- and redshifted SCS, depending only on the distance between the two MNPs. The maximum distance for this effect is the coherence length of the illumination source – a fact of importance for SCS-based experiments using laser sources. Another part of this thesis examines the near-field between two MNPs and the dependence of the locally enhanced field on the relative particle orientation with respect to the polarisation of the excitation light. To attain a figure of merit, the intensity of fluorescence light from dye molecules in the surrounding medium was measured at various directions of polarisation. The field enhancement was turned into fluorescence enhancement, even providing a means for sensing the presence of very small MNPs of 12 nm in diameter. In order to quantify the near-field experimentally, a different technique is devised in a third section of this thesis – scanning particle-enhanced Raman microscopy (SPRM). This device comprises a scanning probe carrying an MNP which in turn is coated with a molecule of known Raman signature. By manoeuvring this outfit MNP into the vicinity of an illuminated second MNP and by measuring the Raman signal intensity, a spatial mapping of the field enhancement was possibleDiese Dissertation untersucht und nutzt die optischen Eigenschaften von Paaren von Metall-Nanopartikeln (MNP). MNP-Paare bieten gegenüber einzelnen MNP zwei weitere Parameter, welche beide auf das optische Nahfeld der zwei MNPs wirken: zum Einen der Abstand der zwei MNPs zueinander, zum Anderen die relative Ausrichtung des Paares bezüglich der Polarisation des anregenden Lichts. Diese Eigenschaften sind Thema der Arbeit: Ein Abschnitt untersucht den abstands- und orientierungsabhängigen Streuquerschnitt (SQS) zweier gleichgroßer MNPs. Die spektrale Position und die Breite des SQS wird von Wechselwirkungen sowohl im Nah- als auch im Fernfeld beeinflusst. Der Einfluß der Fernfeld-Wechselwirkung geht so weit, daß ein Zwei-MNP-System sowohl einen blau- als auch einen rotverschobenen SQS haben kann – dies hängt lediglich vom Abstand der zwei MNPs ab. Die Reichweite dieser Fernfeld-Wechselwirkung wird durch die Kohärenzlänge der Beleuchtungsquelle bestimmt – eine wichtige Tatsache für SQS-Untersuchungen, welche Laserquellen verwenden. Ein weiterer Teil der Dissertation untersucht das Nahfeld zwischen zwei MNPs. Insbesondere wird dargestellt, inwieweit die Überhöhung des Nahfelds von der Orientierung des Partikelpaares bezüglich der Polarisation des Anregungslichts abhängt. Um den Effekt quantifizieren zu können, wurde die Intensität der Fluoreszenz des umgebenden Mediums für verschiedene Polarisationsrichtungen gemessen. Die lokale Feldverstärkung konnte in eine Fluoreszenzverstärkung gewandelt werden, mit deren Hilfe sich sogar die Anwesenheit sehr kleiner MNPs von nur 12 nm Durchmesser nachweisen ließ. Wie Nahfeld-Intensitäten experimentell quantifiziert werden können, stellt ein dritter Abschnitt dieser Dissertation vor – per MNP-verstärkter Raman-Rastersonden-Mikroskopie. Diese Technik besteht aus einer Rastersonde, welcher ein MNP anheftet, welches wiederum mit einem Molekül bekannter Ramansignatur überzogen ist. Indem solch eine Sonde in die unmittelbare Nähe eines zweiten, beleuchteten MNPs gebracht wurde und dabei die Intensität des Raman-Signals aufgezeichnet wurde, ließ sich die räumliche Verteilung der Ramanverstärkung vermessen
8
Lee, Jin Ho. "The fracture behaviour of nano-particle toughened epoxy adhesives." Thesis, Imperial College London, 2006. http://hdl.handle.net/10044/1/11435.
Full text
9
Joo, Sung Chul. "Adhesion mechanisms of nano-particle silver to electronics packaging materials." Diss., Atlanta, Ga. : Georgia Institute of Technology, 2009. http://hdl.handle.net/1853/31730.
Full text
10
Eroglu, Esra. "Synthesis And Characterization Of New Conducting Polymer- Nano Particle Composites." Master's thesis, METU, 2013. http://etd.lib.metu.edu.tr/upload/12615631/index.pdf.
Full textAbstract:
In this study, conjugated monomers containing fluorene units2-(9,9-dihexyl-2-(thiophen-2-yl)-9H-fluoren-7-yl)thiophene (TFT) and 5-(9,9-dihexyl-2-(2,3-dihydrothieno[3,4-b][1,4]dioxin-5-yl)-9H-fluoren-7-yl)-2,3dihydrothieno[3,4b ][1,4] dioxine (EFE) were synthesized on the basis of donor-acceptor-donor approach and their electrochemical polymerization were achieved via potential cycling. Optical and electrochemical properties of their corresponding polymers, poly(2-(9,9-dihexyl-2-(thiophen-2-yl)-9H-fluoren-7-yl)thiophene) PTFT, and poly(5-(9,9-dihexyl-2-(2,3-dihydrothieno[3,4-b][1,4]dioxin-5-yl)-9H-fluoren-7-yl)-2,3dihydrothieno[3,4b ][1,4] dioxine) PEFE, were investigated and it was found that polymer films exhibited quasi-reversible redox behavior (Epox= 1.10 V for PTFT, Epox = 0.70 V and 1.00 V for PEFE) accompanied with a reversible electrochromic behavior, yellow to dark green for PTFT, yellow to parliament blue for PEFE. Their band gap values (Eg) were found to be 2.36 eV and 2.26 eV for PTFT and PEFE, respectively. Furthermore, gold nanoparticles (AuNP) were prepared and their interaction with polymer films, PTFT and PEFE, were investigated using spectroscopic techniques. The fluorescence properties of the polymers and their composites, prepared by the interaction of AuNP with polymers, were also investigated.
11
Guo, Wei. "Laser Micro/Nano Scale Surface Patterning by Particle Lens Array." Thesis, University of Manchester, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.508543.
Full text
12
Pahalawatta, Kapila Kithsiri. "Image histogram features for nano-scale particle detection and classification." Thesis, University of Canterbury. Computer Science and Software Engineering, 2015. http://hdl.handle.net/10092/10866.
Full textAbstract:
This research proposes a method to detect and classify the smoke particles of common household fires by analysing the image histogram features of smoke particles generated by Rayleigh scattered light. This research was motivated by the failure of commercially available photoelectric smoke detectors to detect smoke particles less than 100 nm in diameter, such as those in polyurethane (in furniture) fires, and the occurrence of false positives such as those caused by steam.
Seven different types of particles (pinewood smoke, polyurethane smoke, steam, kerosene smoke, cotton wool smoke, cooking oil smoke and a test Smoke) were selected and exposed to a continuous spectrum of light in a closed particle chamber. A significant improvement over the common photoelectric smoke detectors was demonstrated by successfully detecting and classifying all test particles using colour histograms. As Rayleigh theory suggested, comparing the intensities of scattered light of different wavelengths is the best method to classify different sized particles. Existing histogram comparison methods based on histogram bin values failed to evaluate a relationship between the scattered intensities of individual red, green and blue laser beams with different sized particles due to the uneven particles movements inside the chamber.
The current study proposes a new method to classify these nano-scale particles using the particle density independent intensity histograms feature; Maximum Value Index. When a Rayleigh scatter (particles that have the diameter which is less than one tenth of the incident wavelength) is exposed to a light with different wavelengths, the intensities of scattered light of each wavelength is unique according to the particle size and hence, a single unique maximum value index in the image intensity histogram can be detected.
Each captured image in the video frame sequence was divided into its red, green and blue planes (single R, G, B channel arrays) and the particles were isolated using a modified frame difference method. Mean and the standard deviation of the Maximum Value Index of intensity histograms over predefined number of frames (N) were used to differentiate different types of particles. The proposed classification algorithm successfully classified all the monotype particles with 100% accuracy when N ≥ 100. As expected, the classifier failed to distinguish wood smoke from other monotype particles due to the rapid variation of the maximum value index of the intensity histograms of the consecutive images of the image sequence since wood smoke is itself a complex composition of many monotype particles such as water vapour and resin smoke. The results suggest that the proposed algorithm may enable a smoke detector to be safer by detecting a wider range of fires and reduce false alarms such as those caused by steam.
13
Venkata, Pradeep Kumar Garudadri. "SURFACE WAVE SCATTERING FROM METALLIC NANO PARTICLES: THEORETICAL FRAMEWORK AND NUMERICAL ANALYSIS." Lexington, Ky. : [University of Kentucky Libraries], 2006. http://lib.uky.edu/ETD/ukymeen2006t00408/Thesis%5FPGV%5FFinal%5Fn.pdf.
Full textAbstract:
Thesis (M.S.)--University of Kentucky, 2006.Title from document title page (viewed on June 1, 2006). Document formatted into pages; contains ix, 94 p. : ill. (some col.). Includes abstract and vita. Includes bibliographical references (p. 91-93).
14
Williams, Kaan Owen. "Modelling electrical transport in nano-particle composites using 3D network analysis." Thesis, University of British Columbia, 2014. http://hdl.handle.net/2429/46120.
Full textAbstract:
Conductive composites consist of a conductive filler dispersed within an insulating matrix. These composite materials have been known for many years and are regularly produced experimentally and commercially for a variety of applications. Novel techniques are now being found for creating composites that exhibit conductivity with less conductive filler material than classical physics suggests is sufficient if the particles are uniformly distributed. Several parties have offered physical explanations for the characteristics of their composites by incorporating a blend of classical and quantum physics but few attempts have been made to compare explanations or develop any mechanism to simulate the physics. The model presented in the present work incorporates first principles physics and semi-empirical theory to account for the distribution of particles within a composite and calculate resultant conductivity using three dimensional network analysis. Results from several model iterations are presented and they are compared with published experimental results. The model demonstrates that a random distribution of spherical particles smaller than 200 nm at 3% loading, given realistic wave function decay rates and reasonable tunnelling barrier heights, cannot explain experimentally observed conductivities in these composite materials. The final model, using a Voronoi tessellation approach, duplicates the behaviour trend of the composites being simulated and illustrates some gaps in the present material science knowledge of conductive composites.
15
Lam, Eric W. (Eric Wing-Jing). "Mechanical property characterization of metal nano-particle films for MEMS devices." Thesis, Massachusetts Institute of Technology, 2012. http://hdl.handle.net/1721.1/78451.
Full textAbstract:
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2012.Cataloged from PDF version of thesis.
Includes bibliographical references (p. 79-83).
Printing-based fabrication methods have emerged as a promising alternative to conventional lithographic processes in a number of applications. These methods are being exploited in display manufacturing, flexible electronics, and more recently MEMS. Unlike applications in printed electronics, MEMS devices require comparatively thick layers, typically on the order of microns. In the micron-thickness regime, nanoparticle-based inks are the preferred means for material delivery, in large part due to the ability to deliver high solids content. However, sintered nanoparticle films possess unique morphology and hence different properties when compared to bulk material or materials deposited through other methods and are dependent on the processing conditions. As such, careful characterization of the film's properties is critical to successful adoption of this technology. A detailed methodology to identify the process-mechanical property of metal nanoparticle-based films was developed using silver nanoparticles as the case study. Silver nanoparticle-based cantilevers and films were fabricated through inkjet printing and conventional microfabrication techniques. These structures were mechanically characterized by beam deflection analysis and nanoindentation to map Young's moduli versus the processing conditions. The results were coupled with sintering and powder metallurgy models to explain the data. For silver-based nanoparticle films, it was determined that the process and mechanical property have a power law relationship with the ratio of the sintering temperature and the melting point of bulk silver. This relationship enables prediction of mechanical properties and provides guidance for optimization of sintering conditions towards a desired mechanical property. The specific results reported include: i) process flows to fabricate nanoparticle-based microstructures, ii) detailed methodology to map film features and properties versus processing conditions, and iii) an empirical model explaining the data and enabling prediction of the resultant properties. While this methodology was shown to determine the process-mechanical property relationship for silver nanoparticle-based films, it should be generally applicable to other metal nanoparticle-based films and lays the groundwork for characterizing this class of materials.
by Eric Wing-Jing Lam.
Ph.D.
16
Fowley, Colin Paul. "Nano/micro particle conjugates for use in photodynamic and sonodynamic therapy." Thesis, Ulster University, 2013. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.692835.
Full textAbstract:
Photodynamic therapy (PDT) has been used as a clinical treatment since the early 1990s and utilizes a photosensitising drug (PS), molecular oxygen and light of a specific wavelength, (usually visible light below 700nm) to generate singlet oxygen and other reactive oxygen species which are highly cytotoxic. Originally used as a treatment for superficial skin cancer it is now emerging as a treatment for other forms of cancer such as head, neck, lung and prostate cancers. There are however, several limitations which have prevented PDT obtaining wide spread clinical use. For example currently approved PS drugs absorb light in the visible region limiting tissue depth penetration to a few mm rendering the treatment unsuitable for deep seated tumours. Secondly, PS molecules also tend to be hydrophobic and can aggregate in aqueous solutions, leading to a reduction in singlet oxygen production. The focus of this PhD seeks to take advantage of the photophysical properties of conventional cadmium selenide quantum dots (QDs) (chapter 3) and the relatively new carbon based nano material known as carbon quantum dots (CQDs) (chapter 4), to address some of the difficulties currently faced with the use of conventional PS drugs in PDT. This strategy shall involve the synthesis, in vitro and in vivo evaluation of suitable nano-particlePS conjugates. In addition to the synthesis of conjugates for PDT implications, microbubblesensitiser conjugates were also developed for use in sonodynamic therapy (SDT). SDT refers to the ultrasound dependent cytotoxic effect of certain compounds (sonosensitisers). Ultrasound having far superior tissue dept penetration than light, overcoming the major limitation of poor tissue depth penetration observed in PDT. However there are still some undesirable characteristics associated with SDT. The accumulation of sonosensitisers in healthy tissue has been one such drawback, as sonosentisers (SS) are generally also PS this can lead to photosensitivity of the skin. In order to achieve a greater degree of selectivity the use of microbubble-SS conjugates was investigated (chapter 5). Lipid based microbubbles (MBs) are currently approved for use as contrast agents in diagnostic ultrasound applications and have also been investigated as potential drug / gene delivery vehicles. In chapter 5 Rose Bengal, a well known SS, was covalently attached to the surface of a lipid coated MB. The overall objective of this strategy was to investigate the potential of this MB-SS conjugate as a therapeutic for highly targeted, minimally invasive treatment of deep seated tumours.
17
Kagarise, Christopher D. "Rheological Characterization and Modeling of Micro- and Nano-Scale Particle Suspensions." The Ohio State University, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=osu1259699454.
Full text
18
Amin, Mohammad Mehdi, Bijan Bina, Amir Masood Samani Majd, and Hamidreza Pourzamani. "Survey of Recycled Nano Magnetic Particle in Benzene Removal from Aqueous Solution." Thesis, Sumy State University, 2013. http://essuir.sumdu.edu.ua/handle/123456789/35596.
Full textAbstract:
The removal of benzene, a hazardous monoaromatic compound, from aqueous solution by recycled nano
magnetic particle (NM) Fe3O4 in batch condition was evaluated. Regeneration studies verified that the
benzene adsorbed by the NM could be easily desorbed by temperature. So that the benzene removal
efficiency was 98.7 % for raw NM, 97.8 % for first recycled NM and 97.4 percent for second recycled NM. It
is expected that the Fe3O4 nanoparticles with fine grain size (20-30 nm) will be used as one of effective,
convenient and low-costing methods for removal and recovery of benzene from water and wastewater.
When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/35596
19
Caldwell, Mary Kathryn. "Characterization of Epoxy-hybrid nano-particle Resins for ambient cure VARTM Processes." NCSU, 2007. http://www.lib.ncsu.edu/theses/available/etd-04232007-163012/.
Full textAbstract:
This thesis presents the mechanical characterization of fire resistant epoxy-hybrid resin systems suitable for ambient cure VARTM processes. Several new epoxy-hybrid nano-particle resins were developed and tested for use in large scale composite structures. Based on the viscosity, Tg, and cure time requirements twelve of these resins systems were pre-selected for mechanical testing. Neat resin castings were tested in tension to determine the elastic modulus, tensile strength and maximum elongation. From these results, six of the resin systems were further cast in unidirectional glass fiber laminates. Transverse tension and short beam shear testing was performed on all laminates to determine the mechanical properties of the glass/epoxy systems. Two of the epoxy-hybrid resin systems showed promising behaviors, having a higher transverse modulus and ultimate strength than the original benchmark vinyl-ester resin. Additionally, fiber Bragg grating sensors were embedded in one benchmark vinyl-ester laminate and one epoxy-hybrid laminate during the cure cycle. Taking advantage of both the extrinsic and intrinsic properties of these sensors, residual strains, temperature changes, and degree of cure of the resin were monitored. In addition to having a higher modulus of elasticity and ultimate strength, these new epoxy-hybrid nano-particle resin laminates showed minimal temperature increases during cure and smaller residual strains than the comparable vinyl-ester resin laminates.
20
Madden, Aaron. "Scalable Nano Particle Production of Low Bioavailability Pharmaceuticals for Augmented Aqueous Solubility." Honors in the Major Thesis, University of Central Florida, 2014. http://digital.library.ucf.edu/cdm/ref/collection/ETH/id/1614.
Full textAbstract:
The billion dollar pharmaceutical research and development pipeline suffers greatly from high attrition rates of novel therapeutic compounds within pre-clinical and clinical trials. Poor bioavailability in many new drugs, originating in the various methodologies of high throughput screening, may explain part of these growing failure rates. One interpretation of this phenomenon relies on bioavailability's correlation with aqueous solubility; much modern processing allows chemicals to fully develop without touching water, yielding upwards of 90% of new chemical entities practically insoluble in aqueous media. Thus, one approach to alleviating bioavailability and potentially clinical attrition rates necessitates augmented aqueous solubility. The amorphous nanoparticle presents the largest boost in aqueous solubility of a chemical through processing alone. In this contribution, we propose electrospray as a novel, competitive candidate to produce pharmaceutical amorphous nanoparticles with the intent of augmenting solubility. Electrospray represents an idyllic nominee for three reasons: repeatability, flexibility, and scalability. Electrospray offers low batch to batch variation with less than 30% relative standard deviation between various droplets. This triumphs over the several orders of magnitude in variation in pneumatic sprays. Electrospray's flexibility draws from its ability to attain diameters over several orders of magnitude, ranging from hundreds of microns to several nanometers; in this contribution droplets are produced between 500 nm and 1[micro]m. Finally, electrospray displays scalability to any industrial requirement; though a single nozzle operates at mere microliters per hour, a single multiplexed array of emitters may increase this throughput by several orders of magnitude. This exploration, utilizing Indomethacin as a model low solubility chemical, verifies electrospray as a compatible processing tool for the pharmaceutical industry. Scanning electron microscopy coupled with the image analysis software ImageJ gleans the size and shape of emitted (and dried) particles. Amorphicity verification of particles employs grazing angle x-ray diffraction. Finally, ultraviolet and visual spectrum spectroscopy evaluates the solubility advantage of particles.B.S.M.E.
Bachelors
Mechanical and Aerospace Engineering
Engineering and Computer Science
Mechanical Engineering
21
Liu, Liyu. "Design and fabrication of microfluidic/microelectronic devices from nano particle based composites /." View abstract or full-text, 2008. http://library.ust.hk/cgi/db/thesis.pl?NSNT%202008%20LIU.
Full text
22
Pandit, Viraj Sadanand. "Nano-Particle Removal from Surface of Materials Used in EUV Mask Fabrication." Diss., The University of Arizona, 2006. http://hdl.handle.net/10150/194270.
Full textAbstract:
With device scaling, the current optical lithography technique is reaching its technological limit to print small features. Extreme Ultra-Violet (EUV) lithography has shown promise to print extremely thin lines reliably and cost-effectively. Many challenges remain before introducing EUV to large scale manufacturing. The main challenge addressed in this study is particle removal from EUV mask surfaces (CrON1, CrON2, and fused silica) and thermal oxide (SiO₂). Effective pre-clean procedures were developed for each surface. As chemical cleaning methods fail to meet SEMATECH criteria, addition of megasonic energy to EUV mask cleaning baths is seen as a promising cleaning methodology. As the requirement to print fine lines needs to be met, all materials used in EUV mask fabrication either absorb the incident EUV wavelength light or reflect it. Therefore, the masks used in the industry will be reflective instead of the conventional transmissive masks. Also, for the same reason, no protective pellicle can be used leading to all the surfaces unprotected from particle contamination. To avoid the detrimental effect of the particle contamination, a cleaning study for nano-particle removal was performed. A dark field microscope was utilized to study the removal of gold nano-particles from surfaces. The cleaning procedures utilized H₂SO₄ and NH₄OH chemistries with and without megasonic irradiation. The cleaning variables were bath concentration, temperature, and megasonic power. The contamination variables were the gold nanoparticles charge and size, from 40nm to 100nm. For 100 nm negatively charged gold nano-particles deposited on a CrON1 surface, a 1:10 H₂SO₄:DI bath at boiling temperature (101°C) without megasonics gave high particle removal efficiency (PRE) values as did a 1:10 H₂SO₄:DI bath at 35°C with 100W megasonics. Comparison of removal of poly diallyl-dimethyl ammonium chloride (PDAC) coated and uncoated gold nano-particles deposited on a CrON1 surface using dilute H₂SO₄ baths indicated that the coated, positively charged nano-particles were more difficult to remove. PRE trends for different baths indicate surface dissolution (shown to be thermodynamically favorable) as the particle removal mechanism. However, experimental etch rates indicated minimal surface etching in a 10 minute bath. Increased surface roughness indicated possible local galvanic corrosion at particle sites. Low surface etching results meet SEMATECH requirements. During the fused silica surface cleaning study, particle charge (negative) and size (100 nm) of the contamination source and cleaning bath chemistry (NH₄OH) were kept constant. Low PREs were obtained at room temperature for all NH₄OH bath concentrations; however, high PREs were obtained at an elevated temperature (78°C) without megasonics and at room temperature in more dilute chemistries with megasonic power applied. Similar PRE trends were demonstrated for thermal SiO₂ surfaces. The experimental etch rates of the thermal SiO₂ agree with published values.
23
Yu, Hao. "Processing Routes for Aluminum based Nano-Composites." Digital WPI, 2010. https://digitalcommons.wpi.edu/etd-theses/367.
Full textAbstract:
The term "Metal Matrix Nano-Composites (MMNCs)" broadly refers to a composite system that is based on metal or alloy substrate, combined with metallic or non-metallic nano-scale reinforcements. The main advantages of MMNCs include excellent mechanical performance, feasible to be used at elevated temperatures, good wear resistance, low creep rate, etc. In the recent past, MMNCs have been extensively studied, especially the method of fabrication as the processing of such composites is quite a challenge. Though a variety of processing methods have been explored and studied over the years, none have emerged as the optimum-processing route. The major issue that needs to be addressed is the tendency of nano-sized particles to cluster and also the challenge as to how to disperse them in the bulk melt. This work explored the feasibility of utilizing Lorentz forces to address both of these critical issues: clustering and dispersion. The work was carried out both theoretically as well as with accompanying validation experiments. The results indicate that Lorentz Forces may be viable and should be considered in the processing of MMNCs.
24
Ahmad, Zakiah. "Nano-and micro-particle filled epoxy-based adhesives for in-situ timber bonding." Thesis, University of Bath, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.478940.
Full text
25
Tang, Chin Hang. "Transport of light in metal nano-particle chains using a multiple scattering approach /." View abstract or full-text, 2008. http://library.ust.hk/cgi/db/thesis.pl?PHYS%202008%20TANG.
Full text
26
Islam, Mohammad Saidul. "Three-dimensional modelling of particulate deposition in the human respiratory tract." Thesis, Queensland University of Technology, 2018. https://eprints.qut.edu.au/115472/1/115472_9028200_mohammad_saidul_islam_thesis.pdf.
Full textAbstract:
This study is the first-ever approach to simulate particulate matter transport and deposition in the terminal bronchioles of the 17-generation, whole lung model by considering a possible entire branching pattern. The anatomically explicit, digital 17-generation conduit model is generated from the high-resolution CT data. A comprehensive size- and shape-specific particle transport and deposition study is performed for different physical conditions and finds a new deposition pattern for a realistic anatomical model. The present findings would potentially help the targeted drug delivery system design and increase the efficiency of the drug delivery to the specific positions in the pulmonary airways.
27
Qasim, Hasan, and hasanqasim05@gmail com. "Optical spectroscopy characterization of nano-scale photonic structures." RMIT University. Science Engineering and Technology, 2008. http://adt.lib.rmit.edu.au/adt/public/adt-VIT20080829.162734.
Full textAbstract:
Current micro-scale electronics technology has been approaching rapidly towards its technological limit. This has shifted the focus towards nano-scale technology in recent years. More and more researchers around the globe are working in pursuit of bringing nano-scale technology into mainstream. The research carried out here is a small step towards a similar goal. The remarkable optical properties exhibited by certain nano-scale structures are in stark contrast to their bulk form and this provides the basis for this research. Two kinds of nanostructures are developed and investigated for their optical properties. One of these is nanofibers processed from a polymer known as polyaniline (PANI). The focus of this study is to investigate its optical and conductive properties under different conditions of doping environments, temperature and polymerization conditions. Optical characterization technique such as UV-Visible spectroscopy is developed to carry out the investigation. The developed nanofibers have been demonstrated to possess optical and conductive properties to be dependent on doping variables. Study of these optical properties could prove very useful in the development of electrochromic devices and gas sensors. Later in the research, UV-Visible spectroscopy has been improved into a low cost Raman spectroscopy setup which is validated by experimentation carried out on some samples. The second type of nano-structure developed and investigated, is an array of nanoparticles of noble metals such as gold and silver. Such an array is shown to exhibit a phenomenon called plasmon resonance effect when excited by light. UV-Visible spectroscopy technique is utilized to investigate this effect for metal nano-arrays. A biologically nano-structured surface (wing of an insect called cicada) is used as the substrate for the fabrication of metal array. A serious attempt has also been made to do 'Surface Enhanced Raman Spectroscopy (SERS)', making use of the metal nano-array developed. This technique improves the raman lines intensities of certain less sensitive samples such as thiophenol, which are known to give weak raman lines. This is carried out by adsorbing the sample on the metal nano-array.
28
Boudhan, Rachid. "Performance of pulse-jet bag filter regarding particle removal for nano-waste incineration conditions." Thesis, Ecole nationale supérieure Mines-Télécom Atlantique Bretagne Pays de la Loire, 2017. http://www.theses.fr/2017IMTA0022/document.
Full textAbstract:
Les performances de filtration d’un filtre à manche vis-à-vis de particules submicroniques et nanométriques ont été évaluées à l’échelle du laboratoire durant plusieurs cycles de colmatage/décolmatage. La distribution granulométrique des particules (aérosol de combustion) était représentative de celle rencontrée en incinération de nano-déchets en sortie de chambre de combustion à l’échelle du laboratoire. Le filtre à manche opérait en conditions réalistes, représentatives de celles rencontrées dans les lignes de traitement des fumées d’incinération de déchets en termes de température, humidité, vitesse de filtration, présence de réactifs et conditions de décolmatage. Le flux d’air et le filtre à manche étaient chauffés à 150°C, la teneur en eau était de 10-12% (soit 3% d’humidité relative HR), et la vitesse de filtration était fixée à 1,9 cm.s⁻¹. Un mélange de particules de taille submicronique de charbon actif et de bicarbonate de sodium, utilisées dans les lignes de traitement des fumées d’incinération pour l’abattement des dioxines/furanes et des gaz acides, était généré simultanément avec l’aérosol de combustion. L’étude s’est centrée sur les performances de filtration au début de la durée de vie du filtre à manche, avant stabilisation de la perte de charge résiduelle du filtre résultant des précédents cycles de filtration. La perte de charge maximale du filtre était fixée à 150 Pa pour tous les cycles de filtration avant décolmatage par rétro-soufflage à air comprimé. Les performances du filtre à manche ont été évaluées en termes d’évolution de sa perte de charge et de son efficacité de collecte (totale et fractionnelle) au cours des cycles de colmatage/décolmatage. De plus, des études expérimentales et théoriques ont été menées afin d’étudier l’influence de divers paramètres sur les performances de filtration du filtre en configuration manche ou plane, tels que l’humidité de l’air (3% HR versus 0% HR à 150°C), la température (150°C versus 24°C), la vitesse de filtration (1,9 cm.s⁻¹ versus 1,4 cm.s⁻¹) et l’influence de l’injection de réactifs. Les principaux résultats de cette étude sont : (i) importante efficacité de capture des particules du filtre à manche en conditions représentatives des lignes de traitement des fumées d’incinération : efficacité minimale de collecte de 98,5% mesurée pour des particules de taille 74 ± 15 nm (diamètre de mobilité électrique), (ii) influence du gâteau résiduel de particules au début de chaque cycle de filtration sur les performances de traitement, (iii) influence significative de l’humidité de l’air sur la structure du gâteau de particules probablement due à l’augmentation des forces d’adhésion entre les particules en présence d’humidité (150°C – 3% HR soit environ 100 g d’eau par kg d’air sec) ; augmentation plus rapide de la perte de charge du filtre à manche en présence d’humidité (150°C – 3% HR) qu’en conditions d’air sec (150°C – 0% HR)Filtration performance of a pulse-jet bag filter was evaluated at the laboratory-scale regarding submicronic particles with a nanosized fraction during clogging/unclogging cycles. The particle size distribution was representative to those encountered at the outlet of a nano-waste incineration device at laboratory-scale. The bag filter was operated in conditions as similar as possible to those found in flue gas treatment of waste incineration plants, in terms of temperature, humidity, filtration velocity, injection of sorbent reagents and unclogging conditions. The air flow and the bag filter were heated to 150°C, the water content was maintained in the air flow in the range of 10-12% (3% of relative humidity RH), and filtration velocity throughout the bag filter was fixed at 1.9 cm.s⁻¹. A mixture of submicronic suspended particles of activated carbon and sodium bicarbonate, both used in flue gas treatment systems mainly for the removal of dioxins/furans and acid gases, was generated simultaneously with the aerosol representative of combustion emissions.The study focused on the filtration performance at the beginning of the bag filter’s lifetime filter for the 11 first clogging-unclogging cycles before stabilizing the residual pressure drop reached after pulse-jet unclogging. The maximum pressure drop was set at 150 Pa for all filtration cycles. Once the maximum pressure drop was reached, the filter was unclogged using the pulse-jet system. The performance of the bag filter was evaluated in terms of the evolution of pressure drop, fractional and total particle collection efficiencies, during the clogging/unclogging cycles.Moreover, an experimental and theoretical study was carried out on the influence of different parameters on the filtration performance of bag filter and flat filter, such as influence of humidity (3% RH versus 0% RH at 150°C), temperature (150°C versus 24°C), filtration velocity (1.9 cm.s⁻¹ versus 1.4 cm.s⁻¹) and the influence of the injection of sorbent reagents.The main results of this study are: (i) high collection efficiency of the bag filter in representative conditions of flue gas treatment of waste incineration: minimun particle collection efficiency of 98.5% for particle diameter of 74 ± 15 nm (electrical mobility diameter), (ii) influence of residual particle cake at the beginning of the filtration cycles on the bag filter performance, (iii) significant influence of humidity on the porosity of the particle cake due to the capillary condensation of water between the particles in presence of humidity (150°C - 3% RH i.e. almost 100 g of water per kg of dry air). Faster increase of bag filter pressure drop in presence of humidiy (150°C - 3% RH) as compared to the dry conditions (150°C - 0% RH)
29
Motskin, Michael. "Hydroxyapatite nano and microparticles : correlation of particle properties with cytotoxicity, uptake and bio-persistence." Thesis, University of Cambridge, 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.609493.
Full text
30
Chiang, Yi-Ting, and 江宜庭. "Nano-particle gel." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/79334273360214582619.
Full textAbstract:
碩士國立中央大學
化學工程與材料工程研究所
98
In general, nano-particles can be suspended in solution due to Brownian motion. Although van der Waals attractions between particles may lead to aggregation, they are not strong enough to form particle network. Typically, upon the addition of polymers, particle gel can be formed by depletion forces. In this work, we show that silicon carbide (SiC) particles are able to form nanoparticle gel in polar solvent ethylene glycol (EG) by the addition of hydrogen-bond forming surfactants. When the surfactant dodecylamine (DDA) is added, the SiC/EG system changes from uniform nano-particle suspension to sediment in the presence of clear solution. According to the rheological measurements, the storage modulus is greater than the loss modulus, i.e., G’ > G’’. That is, upon DDA addition, the sediment displays gel-like behavior. As two SiC particles covered with DDA are nearly in contact, hydrogen bonds can be formed between the primary amine head groups (-NH2) and thus result in interparticle attraction. On the basis of the same mechanism, we show that the addition of dodecanic acid, that possesses the same carbon chain length but different head group (-COOH) from DDA, can lead to the formation of nano-particle gel as well. In addition to the nano-particle gel induced by the addition of hydrogen-bond forming surfactants, we also observe the formation of nano-particle gel in surfactant-free solvent. The examples include SiC nano-particles in decane, ZnO nano-particles in EG, and ZrO2 nano-particles in water or EG. The possible mechanism responsible for particle gel induced by solvent is proposed.
31
Lin, Wei-Te, and 林偉德. "Fabrication of metallic nano particle." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/56077224348399764548.
Full text
32
Ro, Shih-Hung, and 羅世宏. "Nano Particle Fe2O3-TiO2 Aerogel Catalyst." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/63773766813185136302.
Full textAbstract:
碩士國立雲林科技大學
工業化學與災害防治研究所
93
The purpose of study was to develop nanostructured Fe2O3-TiO2 aerogels and investigate their catalytic and structural properties. The materials were synthesized by the sol-gel method followed by the supercritical drying. Their particle shapeswere identified as a function of oxide composition by high-resolution transmission electron microscopy (HRTEM) and field emission scanning electron microscopy (FESEM), and the size was in the range of 10-30 nm. The X-ray diffraction showed that Pseudobrookite was formed when an amount of iron oxide was incorporated into the titania matrix. The reaction of methanol oxidation was carried out in a fixed bed flow reactor. When Fe was added, Lewis acid strength was greater than those of pure Fe2O3 and TiO2. The selectivity to dimethyl ether was related to the presence of Lewis centers Fe3+ and Ti4+. Lattice oxygen participated in the oxidation reaction, and the reaction on the Fe-Ti aerogel catalyst was resolved as a successive pathway CH3OH → CH3OCH3→CO2.
33
Pei-Lun, Chien, and 簡培倫. "Synthesize and application of Fe3O4 nano particle." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/09666095080904376094.
Full textAbstract:
碩士中國文化大學
材料科學與奈米科技研究所
94
In this dissertation, the study of synthesize and application of Fe3O4 nano particle the main purpose, divide the application into three following parts. In the first part, nanometer-sized magnetic materials have attracted the attention of many researchers, because magnetic nanoparticles exhibit unusual chemical and physical properties such as superparamagnetism and quantum tunneling of magnetization. A number of techniques, both chemical and physical, have been used to make magnetic particles. In this dissertation, ferrite nanoparticles [magnetite (Fe3O4)] were prepared using a simple chemical coprecipitation method. Oleic acid was added to protect nanoparticles from aggregation. The characteristics of nano-magnetic Fe3O4 particles were determined by various techniques, such as transmission electron microscopy (TEM), X-ray diffraction (XRD) and X-ray absorption near edge structure spectroscopy (XANES) and X-ray magnetic circular dichroism (XMCD) In the second part, A method for manufacturing ferrous ferric oxide powder is disclosed, The method includes mixing ferrous ferric oxide powder with a coupling agent having a silane functional group in an organic solution for improving its quality. The ferrous ferric oxide powder with improved surface quality manufactured by the present invention can be dispersed and mixed steadily and uniformly in a nonpolur solvent . In addition to that, it has longer dispersion time and is hardly to precipitate, so it has relatively high production value and can be widely used in manufacturing all kinds of ferrous ferric oxide - containing stealth paint. In the third part, we study the preparation and properties of bio-compatible magnetic nanoparticles for immunoassay detection. The magnetite (Fe3O4) nanoparticles were prepared by a chemical co-precipitation method and dextran is selected as the surfactant to suspend the nanoparticles. Suspended particles associated with avidin followed by biotin were qualitatively analyzed by enzyme-linked immunosorbent assay (ELISA) method. We found further the ethylenediamine blocked activated residual groups efficiently, hence enhancing the attachment of biotin for probing the avidin.
34
Wang, Ching-Yao, and 王鏡堯. "Optical properties of single nano-diamond particle." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/74314513571188498985.
Full textAbstract:
碩士國立東華大學
應用物理研究所
95
Since the technology of the synthetic diamond begins to develop, synthetic nano-diamond has already applied to a lot of field, especially in the biomedical field, it has very high using value. Common quantum dot we known is often made by toxic metallic element, and the main components of nano-diamond is carbon element, so it has high compatibility but without toxicity for human body or organism. And, it can be bond with a lot of biological members to the surface of nano-diamond (For instance: Protein, DNA, etc.). Putting the nano-diamond particles which link with biological members into cell and collecting the unique optics characteristic of nano-diamond, it can become a useful biological mark. This thesis will introduce how to make use of a series of technology to observe the optics properties of single nano-diamond particle, the technology includes using electron beam to make a suitable coordinates for orientation of single nano-diamond particle and using a good method to disperse the nano-diamond powder. Finally, using the confocal microscope with excellent optics analysis ability and good laser focus ability obtain micro-Raman and micro-PL spectrum of single nano-diamond. I will make a comparison between the spectrums of single nano-diamond particle, nature diamond and nano-diamond cluster to deduce whether the single nano-diamond particle has special optics nature.
35
Wu, Wei-Zhe, and 伍緯哲. "Modified nano-particle induce Macromolecular phase separation." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/45907915719640573806.
Full text
36
Lin, Yi-Xian, and 林宜賢. "Nano-Particle Self-Assembly and DNA Structural Characterization." Thesis, 2002. http://ndltd.ncl.edu.tw/handle/77789041571479214060.
Full textAbstract:
碩士國立成功大學
機械工程學系碩博士班
90
DNA is the basic unit which contains gene in cells and controls the human body’s health and gene change. Therefore, one can detect diseases and identify gene by effectively screening DNA base. With the new advent in new medicine and identification of the blood relationship, faster and simpler DNA screening methods are urgently needed. There are several problems in traditional dyeing and fluorescence in DNA screening method that include (1) the precision of fabrication is difficult to control, (2) the screening process is too complex, and (3) cost is too high. These problems limit new developments in gene engineering. Therefore, it is very important to find a new DNA screening method that is simple to operate and cost effective. Some experts combine nanoparticles with probe DNA and screen DNA by different colors between the dispersal and aggregation of nanoparticles. This new approach has many advantages such as fast structure identification, clear colorimetry, fine selectivity, and less experiment equipment. Since the aggregation of the self-assembly of DNA nanoparticles is too complex, it is difficult to describe the process. Even now there is no suitable theories and experiments to prove its practicality. In order to increase the accuracy of the DNA screening system, the characterization of optical properties of the self-assembly of nanoparticles has become more and more important. To solve the aforementioned problem, this paper will explores and studies the self-assembly of nanoparticles and the associated optical properties that can be applied to detect human’s diseases. First, the energy approximation to the self-assembled of DNA nanoparticles is established and the employment of this approximation to analyze the physical rules of DNA self-assembly nanoparticles in micro-viewpoint is provided. Secondly, the nanopartcles polarization technique is used to establish theoretic optical structures and to forecast the optical spectrum of DNA nanoparticles. The results of self-assembly energy approximation and the complete diagnostic rules for DNA structural characterization are presented. The methods that were used to differentiate DNA complementary and measure DNA base number for diagnosing the diseases about DNA base mutation are introduced. Finally, the suggestions to improve the sensitivity of self-assembly of optical nanoparticles in DNA screening system are proposed and implemented. Good agreements between the computed solutions and existing data obtained from the literature indicate that the proposed theory and the modeling procedure is theoretically sound and practically applicable for computing the optical spectrum of self-assembled DNA nanoparticles screening system. Based on the results obtained from examples presented in the paper, one can realize that the proposed methods can differentiate DNA complementary and also measure DNA base number to diagnose the disease about DNA base mutation. Furthermore, the computed results are accurate enough for diagnosing the disease. The proposed error adjustment scheme for improving DNA screening process can actually promote the sensitivity for identification of the structures of self-assembled optical nanoparticles in DNA screening system.
37
Lo, Tan, and 羅丹. "Nano Gold Particle Enhanced Organic Light Emitting Diode." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/8hctbh.
Full textAbstract:
碩士國立清華大學
材料科學工程學系
104
Organic light emitting diode (OLED) can be applied to high quality displays and solid-state lightings due to its self-luminous, low-power consumption, wide-viewing angle, lightness, thinness and flexibility. However, to make products more energy-efficient and with longer lifetime, high efficiency OLED research and development are critical. Besides developing new materials or changing device structures, modification can also be achieved by using additive elements. In this study, we incorporated gold nanoparticles into OLEDs, which notably improved the efficacy and the maximum brightness of green and blue devices. For example, the efficacy at 1,000 cd/m2 increases 24.8% (29.0→36.2 lm/W) and 35.0% (6.0→8.1 lm/W) while the max brightness increases 29.3% (21,500→27,800 cd/m2) and 24.3% (7,800→9,700 cd/m2) for green and blue device. These improvements may be attributed to the current density enhancement due to the incorporation of gold nanoparticles that strengthen the carrier injection. In addition, the use of nanoparticles has following advantages: (1) It is added in non-emissive layer, thus it can be applied to either phosphorescence or fluorescence devices with different colors. (2) Its wet-processable characteristic provides competitive potential for low cost and large area production.
38
Tsai, Hung-Hsin, and 蔡宏欣. "Synthesis of Nano / Submicron Silica / Polymer Complex Particle." Thesis, 2002. http://ndltd.ncl.edu.tw/handle/68933033955507080663.
Full textAbstract:
碩士國立臺灣大學
材料科學與工程學研究所
90
ABSTRACT This work is to prepare nanosize / submicro silica / polymer complex particles . First, we prepare nanosize silica particle from the reaction of hydrolysis of TEOS ( tetraethoxysilane) followed by a condensation reaction . Then, the surface of silica particles are treated with two kinds of silane with different functional groups, C=C and —NH2. On the surface of particles containing group of C=C , further polymerization reaction of Styrene are carried out via the technique of soapless emulsion polymerization. Polymers form over the surface of silica particles. The resulted complex particles are of core-shell structure or strawberry-like structure. On the other hand, the silica particles containing group of —NH2 will go on several steps of reactions to generate radicals on the particle surface, and initiate a following polymerization reaction of MMA in a solution system. Polymers are grafted onto the silica surface and we obtain complex particles as well. A series of nanosize silica particles and submicron complex particles are prepared under different reaction conditions or through different polymerization processes. The size distribution, morphology, grafting ratio and properties of complex particles are tested and discussed. Keywords：nanosize/submicron complex particle ,silica, TEOS(tetraethoxysilane), MMA(methyl methacrylate) , Styrene , emulsion polymerization .
39
Feng, Chi-Kai, and 馮祺凱. "Study of Nano-Particle By Coherent Electron Diffraction." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/58553321844555334440.
Full textAbstract:
碩士國立清華大學
工程與系統科學系
95
The coherent diffractive imaging (CDI) technique offers a promising path toward characterization of the individual non-periodic and near-periodic isolated nanostructures at the atomic resolution. In this aberration-free microscopy, the complex exit surface wave function can be recovered from the over-sampled far-field diffraction pattern using iterative algorithms. We have recorded the image and diffraction pattern of the individual MgO nano-particle with a size of about 24nm with a crystallographic orientation [001] along the incident electron beam. The FEG-TEM (JEOL 2010F) was operated at 200keV accelerating voltage in the nano-area electron diffraction regime. For the reconstruction we utilized the phase-retrieval algorithm with dynamically defined support. The result is in agreement with the TEM image of the particle.
40
Hsieh, Tzu-Wen, and 謝子文. "Analyses of Characteristics of Nano-Particle Scattering Layers." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/53181664852217962433.
Full textAbstract:
碩士國立臺灣大學
電子工程學研究所
100
In recent years, nano-particle scattering films are widely used in organic light-emitting devices (OLEDs) to enhance the optical out-coupling efficiency. How to design nano-particle diffuser films for better performance is the main topic of this thesis. We first introduce the Optical Theorem in the electromagnetic theory, and then describe the scattering parameters, their physical meanings, and their association with the design of nano-particle scattering films. Mie theory gives the analytic solution of a plane wave incident on a single sphere. The scattering characteristics of a single sphere can be learned by writing a simulation program to implement this model. However, it is not sufficient for obtaining the overall scattering properties of a diffuser film composed of many particles. So we further introduce the Generalized Multi-Particle Mie-Solution, which is a numerical expansion method based on Mie Theory, and strictly obey the Maxwell equations. By implementing this model into computer programs, we can calculate the scattering properties of a variety of combinations of nano-particles.
41
Chen, Huang-Nan, and 陳皇男. "Inter-particle interaction''s effect on thermal critical fluctuation of In nano-particle." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/23621550699447360781.
Full textAbstract:
碩士國立中央大學
物理研究所
99
Indium nanoparticles (NPs) are fabricated by employing the thermal evaporation method. The mean particle diameter is determined to be 10.6 nm by XRD and AFM. In our study, the packing fraction of the nanoparticle compact is varied to investigate the effects of inter-particle interaction on the superconducting parameters of the extremely space-restricted Sn particles. Through AC magnetic susceptibility measurements, we observed that the critical fluctuation of the order superconducting parameter is evidently revealed, when the particles are loosely packed. Interparticle particle interaction suppresses the critical fluctuation so that the thermal behavior of the magnetic susceptibility can be described using London expression that ignores the critical behavior. A spontaneous magnetization is observed below TC. We propose that not only s-wave but also p-wave pairings appear in the present 10.6 nm In particles.
42
Chen, Shan-Chien, and 陳善儉. "Multimode Tapered Fiber Sensor Modified With Nano-gold particle." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/33621002093647084434.
Full textAbstract:
碩士國立中正大學
物理所
97
A fiber biosensor modified by nano-gold particles is made according to the localized surface plasma resonance theorem. The nano-gold particles enhances the sensitivity of the sensor measuring the refractive index (RI) by absorbing and scattering the evanescent wave on the interface between the core and the liquid to be tested. Different research teams have used different approaches to achieve the same goal. In this study, we pursue our goal by modification of the fiber with nano-gold particles. This fiber is either tapered or non-tapered in advance. Note that taper of the fiber may result in the variations of numerical aperture of the fiber, normalized frequency, and the path of propagating light. In the practice of this work, we use an arc discharge system to pull and taper a multimode fiber (core: 400 μm and cladding: 430 μm, both in diameter) or simply remove the cladding. Afterwards, we modify the fiber with spherical nano-gold particles with a diameter of 15 nm. Consequently, when we measure refractive indices of different liquids with this tailored fiber, the light intensity variation with the refractive indices is enlarged. When pull and taper of the abovementioned fiber yield diameters of 300 μm and 200 μm, the latter shows a better sensitivity that the former. Besides, they are both superior to the uniform fiber which is not tapered. Keyword：nano-gold particle, refractive index, tapered fiber, evanescent wave and localized surface plasma resonance.
43
Chiang, Chin-Yeh, and 江菁燁. "Investigate of nano-particle/tube TiO2 composite polymer electrolyte." Thesis, 2003. http://ndltd.ncl.edu.tw/handle/09965377798185218068.
Full textAbstract:
碩士國立中央大學
化學研究所
91
Nano composite polymer electrolytes are one of the effective approaches to enhance ionic conductivity, mechanical stability and better interfacial contact with electrodes ( i.e., Li metal ) in secondary batteries and other ionic devices. Ion conduction enhancement is higher when filler nano particles in smaller dimensions with high specific surface area. The strong Lewis base characteristics of nano inorganic oxide particles facilitate salt disassociation and physical cross-link with polymer chain improves the mechanical strength. The formation of TiO2 nano-particle and nano-tube were confirmed with XRD、TEM、XPS、TGA. The XPS results are consistent with structure that the fluorine atoms in PVDF and oxygen atoms in inorganic oxide TiO2 are coordinate with the dissociated Li+ ions through acid-base reactions. As evident from SEM micrograph, contents of lithium salt and TiO2 with different scale will affect polymer crystallinity. When polymer electrolyte is swollen with organic solvent, the overall ion conductivity would be governed by the dissociation of salt, and ion mobility governed by the polymer and the plasticizer dielectric constant and the viscosity. On a separate studies of PEO, nano-tube TiO2 surface groups provide cross-link centers for the PEO segments and also for the anions, which reduces the polymer reorganization with higher degree of amorphous in composite electrolytes. Nano-tube TiO2 surface groups also facilitated more complete salt dissociation. Conduction path is established on the nano-tube TiO2 where the charge transport achieved by replacing the nearby vacancy ( the “hole” ) hopping in sequential manner.
44
Cherkasova, Anna S. "Thermal conductivity enhancement in micro- and nano-particle suspensions." 2009. http://hdl.rutgers.edu/1782.2/rucore10001600001.ETD.000051795.
Full text
45
Lin, Cheng-Chun, and 林正鈞. "Effects of Copper(II) oxide nano particle on magnatization." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/73442636040026593218.
Full textAbstract:
碩士國立中央大學
物理學系
102
Use the gas condensation method to produce three nano-particle samples. Put samples in the X-ray diffraction machine to detect the profiles. Through the Find it software to find out the components in the samples, and use the GSAS software to fit these profiles. Then, we can get the component’s mass percentage. We can determine the nano-particles’s size by common volume function and intergral breadth method. Then, we can compare the GSAS’s result and the size by common volume function to surmise whether the nano-particle is core-shell model or not ? Take these three nano-particle samples to Nanotechnology Research Center in the National Dong Wha University to determine the magnetic. The experiments are determining the magnetization at different applied magnetic fields and temperatures. Use these datas to realize there are paramagnetic and antiferromagnetic properties in the nano-particles. Use the function to fit the M-H curve, and we will get the saturation 〖(M〗_s)、magnetic moment 〖(μ〗_p) and antiferromagnetic susceptibility〖 (χ〗_AFM) variables. Then, I will surmise these three variables and the components’ relationship.
46
Lin, You-Rong, and 林佑容. "Remote Control of Autophagy by Iron oxide Nano Particle." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/3xt6qs.
Full textAbstract:
碩士國立交通大學
生醫工程研究所
107
Magnetic iron oxide nanoparticle is a nanomaterial which processes many desirable chemical and optical properties. It has been used in a wide range of biomedical applications. Then, autophagy plays a key role in human health and disease. Many autophagy regulators are developed for immunotherapy. Here we described a non-invasive and controllable autophagy response system by regulating of magnetic nanoparticles(size: 52.13 ± 7.0 nm), the nanoparticles were first delivered into autophagosomes or lysosomes inside cells, then further applied with a non-invasive magnetic field for the forming of vesicles accumulation. This non-invasive technique can regulate the level of autophagy and immune response by different time condition or different magnitude of magnet field. Also, we have established the autophagy response triggered by magnetic nanoparticle and the magnetic field device in A20 cells(B cell lymphocyte cells) and CT26 cells(mouse colon cancer cells). We hope this method can be potentially applied to the treatment of cancer and autoimmune diseases in the future.
47
Tasy, Ryh-Shin, and 蔡日新. "Preparation and Properties of Polyimide/Nano-Gold Particle Composite Materials." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/5nhbnq.
Full textAbstract:
碩士中原大學
化學研究所
93
Abstract This thesis is mainly focused on the preparation and property studies of nanocomposite materials, which containing the dispersed phase of nano-scale gold particles and polyimide (PI) matrix. First of all, the nano-scale gold particles were generated through processing the reduction reactions of HAuCl4 compound by citrate. Subsequently, suitable amount of as-prepared gold nanoparticles were homogeneously added into the poly(amic acid) solution through the direct solution dispersion technique, followed by casting the as-mixing solutions on inorganic glass substrate and then treated by heated up to 300�aC to complete the thermal imidization reactions of PI, yielding the polyimide-gold nanocomposite materials. The as-prepared nanocomposite materials were then characterized by FTIR, XRD and TEM. Effect of material composition on the gas permeability, thermal stability, mechanical strength, thermal transport, surface wettability were investigated based on the studies of gas permeability analyzer (TGA), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), hot disk (HD) and contact-angle measurement, respectively.
48
CHUNG, WEI CHIH, and 莊偉智. "Fabrication of periodic nano-particle structure by using interference method." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/15744712648426189637.
Full textAbstract:
碩士國立嘉義大學
光電暨固態電子研究所
95
In this work, a periodic structure of gold nano-particles is fabricated by interference method. The pulse laser is used as writing beam to form a periodic structure of gold nano-particles on a thin gold film. White light source is used to probe the gold periodic structure and the first order diffraction efficiency is measured from 450 to 750 nm in wavelength. The measured result shows that the first order diffraction efficiency was enhanced by the surface plasmon effect of Au nanoparticles. The enhancement was caused by the absorbance of the gold nanoparticles. In addition, a broad absorbance band occurs around 648 nm. This absorbance implied that the surface plasmons on the gold nanoparticles are excited strongly around 648 nm. Therefore, the diffraction efficiency is enhanced within this wavelength region. We are the first one to investigate the surface plasmon effect of gold nanoparticles arranged in a periodic structure.
49
Shiao, Hung, and 蕭宏. "Effect of Silica Nano Particle on Mechanical Behaviors of Nanocomposites." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/11451268003860107223.
Full textAbstract:
碩士國立交通大學
機械工程系所
95
This research aims to investigate silica particle effect on mechanical behaviors of epoxy matrix. Mechanical tests including tensile, flexure and fracture toughness experiments were conducted on the sample with different silica loadings. Moreover, both ductile and brittle epoxy matrix systems were also discussed in this study. The extension of silica dispersion in nanocomposites was determined using Transmission electron microscope (TEM) based on which it reveals that silica exhibits good dispersion within the nanocomposites even though the silica loading is up to 40 wt%. The exfoliated silica particles may play a major role on the improved mechanical properties of nanocomposites especially for fracture toughness as well as the Young’s modulus. The observation on the failure surfaces using a filed emission scanning electron microscopy (SEM) indicates that the interfaces between silica and matrix are well bonded. In addition, the enhanced fracture toughness in the nanocomposites could be due to the rough fracture surfaces caused by the presence of silica particles complicating the crack initiation. The surfaces roughness becomes more severe as the silica particle loadings increase, which can be qualitatively measured using AFM.
50
Chu, Heng-Yi, and 朱恒沂. "Trapping nano-sized particle by waveguide-coupled gold bowtie structure." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/81691549685562177854.
Full textAbstract:
碩士國立交通大學
顯示科技研究所
102
We propose a particle manipulation system by using localized surface plasma resonance excited by a coupling waveguide. The system, featured with advantages such as small footprint and easily being integrated in a chip, is composed of gold bowtie and silicon nitride waveguide. The simulation shows highly concentrated and enhanced field in gap of the bowtie where strong optical trapping force will be established and will be able to trap microscopic particles. We find a bowtie with 5 nm gap at the tips can provide 1389 pN/W force for trapping 20 nm polystyrene particle under excitation at 1.55 μm wavelength. For direct observation in experiment, we use 1 μm polystyrene particle to verify trapping ability of the system. We see the particle transported along the waveguide and finally being trapped stably by the bowtie. We also see release of the particle which swims away after the excitation light source is turned off. In the future, this system can be integrated with other sensing and analyzing systems to realize lab on a chip.