Dissertations / Theses on the topic 'Nanodiamonds – Synthesis'

The absence of a cheap and easily scalable synthesis technique for nitrogen-vacancy (NV) centers enriched nanodiamonds (NDs) is a critical factor for the development of devices based on this very peculiar nanoparticle. Indeed, the combination between the unique NV fluorescence properties and NDs characteristics allow to obtain a tool having quantum sensing capabilities, with nanometric spatial resolution, which is able to operate in a wide range of temperature, pressures and in harsh chemical conditions. NVenriched NDs applications in nanothermometry, nanomagnetometry and in bio-imaging have already been reported. However, most of the standard fluorescent NDs production techniques present common drawbacks: poor control in NDs size distribution and in nitrogen concentration, as well as the need of post-synthesis process to clean the NDs surface from impurities and to increase the NV density. In this thesis, an alternative method for fluorescent NDs synthesis based on pulsed laser ablation (PLA) of graphite is demonstrated. After the introductory chapters on NV-centers physics and NDs properties (Chapter 2 and 3), the demonstration that PLA is a viable route for synthesis of NDs is given in Chapter 4. In particular, PLA of graphite and of diamond-like carbon is performed in water. Here, a thermodynamic model taking into account the peculiar physical processes occurring during PLA is developed to explain NDs formation. Then, synthesis of NV-enriched NDs is demonstrated through PLA of graphite in a nitrogen atmosphere (Chapter 5) and in liquid nitrogen (Chapter 6). In both chapters, the thermodynamic model is adapted to explain diamond phase formation in a gaseous environment and in a cryogenic liquid. Furthermore, NV centers optical properties are fully characterized with optically detected magnetic resonance (ODMR) spectroscopy. Finally, in Chapter 7, fluorescent NDs are produced by laser ablation of N-doped graphite in water. This particular target is then used for a quantitative comparison between the other fluorescent NDs laser-synthesis, with the aim of establishing in which condition the highest NV-center formation efficiency is achieved.

Manipulating light by controlling surface plasmons on metals is being discussed as a means for bridging the size gap between micrometer-sized photonic circuits and nanometer-sized integrated electronics. Plasmonic waveguides based on metal nanoparticles are of particular interest for circumventing the diffraction limit, thereby enabling high-speed communication over short-range distances in miniaturized micro-components. However, scalable, inexpensive fine-tuning of particle assemblies remains a challenge and near-field probing is required to reveal plasmonic interactions. In this thesis, self-assembled waveguides should be produced on DNA scaffolds. DNA origami is an extremely versatile and robust self-assembly method which allows scalable production of nanostructures with a fine control of assemblies at the nanoscale. To form the plasmonic waveguides, six-helix bundle DNA origami nanotubes are used as templates for attachment of highly monodisperse and monocrystalline gold nanoparticles with an inter-particle distance of 1-2 nm. In the first part of this thesis, the effects of parameters which are involved in assembly reactions are systematically investigated. The assembly yield and binding occupancy of the gold nanoparticles are determined by an automated, high-throughput image analysis of electron micrographs of the formed complexes. As a result, unprecedented binding site occupancy and assembly yield are achieved with the optimized synthesis protocol. In addition, waveguides with different sizes of gold nanoparticles and different inter-particle distances, quantum dots attachments to the waveguides and multimerization of the waveguides are successfully realized. In the second part of this thesis, direct observation of energy transport through a self-assembled waveguide towards a fluorescent nanodiamond is demonstrated. High-resolution, near-field mapping of the waveguides are studied by electron energy loss spectroscopy and cathodoluminescence imaging spectroscopy. The experimental and simulation results reveal that energy propagation through the waveguides is enabled by coupled surface plasmon modes. These surface plasmon modes are probed at high spatial and spectral resolutions. The scalable self-assembly approach presented here will enable the construction of complex, sub diffraction plasmonic devices for applications in high-speed optical data transmission, quantum information technology, and sensing
Die Manipulation des Lichts durch die Kontrolle von Oberflächenplasmonen auf metallischen Oberflächen und Nanopartikeln gilt als vielversprechende Methode zur Überbrückung der Größen-Lücke zwischen Mikrometer-großen photonischen und nanometer-großen elektronischen Schaltkreisen. Plasmonische Wellenleiter basierend auf metallischen Nanopartikeln sind vom besonderen Interesse, da sie die Umgehung des Beugungslimits und somit eine Hochgeschwindigkeitskommunikation über kurze Distanzen in immer kleiner werdenden Schaltkreisen ermöglichen könnten. Allerdings ist die skalierbare und kostengünstige Anordnung von Partikeln eine große Herausforderung und es werden Nahfelduntersuchungen benötigt um plasmonische Interaktionen detektieren zu können. Das Ziel dieser Arbeit ist die Selbstassemblierung von multi-partikel Wellenleitern auf DNA Gerüsten. Die Verwendung von DNA-Origami bietet eine äußerst vielseitige Plattform zur skalierbaren Herstellung von Nanostrukturen mittels Selbstassemblierung und ermöglicht eine präzise Kontrolle der Anordnungen im Nanobereich. Für den Aufbau der plasmonischen Wellenleiter werden DNA-Origami Nanoröhren, bestehend aus sechs Helices als Templat für die Anbindung von monodispersen und monokristallinen Goldnanopartikeln mit einem interpartikulären Abstand von 1-2 nm verwendet. Im ersten Abschnitt dieser Arbeit werden die beeinflussenden Faktoren dieser Assemblierungsreaktion systematisch untersucht. Die Ausbeute der assemblierten Strukturen und die Besetzung der Bindungsstellen werden durch eine automatisierte und effiziente Bildanalyse von Elektronenmikroskopieaufnahmen ausgewertet. Durch die Entwicklung eines optimierten Syntheseprotokolls werden bisher unerreichte Assemblierungsausbeuten ermöglicht. Zusätzlich erfolgen die experimentelle Realisierung von Strukturen mit verschieden großen Goldnanopartikeln und unterschiedlichen interpartikulären Abständen, sowie die Anbindung von Quantenpunkten an die Wellenleiter und eine Verknüpfung der assemblierten Strukturen. Der zweite Abschnitt dieser Dissertation befasst sich mit der Untersuchung des Energietransports in selbstassemblierten Wellenleitern über einen fluoreszierenden Nanodiamanten. Dazu erfolgen hochaufgelöste Nahfeldmessungen der Wellenleiter mittels Elektronenenergieverlustspektroskopie und Kathodolumineszenz-mikroskopie. Die experimentellen Ergebnisse und zusätzlich durchgeführte Simulationen bestätigen eine durch gekoppelte Oberflächenplasmonenmoden induzierte Weitergabe der Energie innerhalb des Wellenleiters. Diese Oberflächenplasmonenmoden werden bei hoher räumlicher und spektraler Auflösung untersucht. Das hier umgesetzte Konzept der Selbstassemblierung wird den Aufbau komplexer plasmonischer Geräte für Anwendungen im Bereich der optischen Hochgeschwindigkeitsdatenübertragung, der Quanteninformations-technolgie und der Sensorik ermöglichen

High-energy ball milling was studied for the ex situ strengthening of aluminum (Al) with nanodiamond (ND). Al-ND metal matrix composite powders with 5 wt% and 10 wt% nanodiamond were synthesized by high-energy ball milling of the blended component powders. Stearic acid was used as a process control agent to minimize agglomeration of the powders upon milling. A uniform distribution of the ND reinforcement was successfully obtained after milling the powders for a period of ten hours with a ball-to-powder ratio of 30:1 in a SPEX 8000M ball mill. Composition and properties of the Al-ND composite was studied using energy dispersive spectrometry (EDS) mapping, scanning electron microscopy (SEM), X-ray diffraction (XRD), optical microscopy, and nanoindentation techniques.

This work focuses on improving the quality of carbon-based core-shell materials for high performance liquid chromatography (HPLC) via the characterization of the core materials, and also the development of chromatographic methods (separations) for them. In the early part of this work, I applied organic synthesis to make uniform, spherical poly(divinylbenzene) (PDVB) microspheres, and then carbonized them to prepare carbon core materials for core-shell particle synthesis. Here, I studied in detail the surface and material properties of these particles with multiple instruments, which allowed me to describe the physical and chemical changes that took place during each treatment. The uniform, spherical carbon core materials greatly improved the efficiency of the previously developed carbon-based core-shell HPLC columns from ca. 70,000 plates per meter (N/m) to ca. 110,000 N/m for various alkyl benzenes. Later, I focused on generating application notes to showcase these mixed-mode HPLC columns. Here, liquid chromatography mass spectrometry (LC-MS) was used for the detection of analytes that lack chromophores for UV detection. In this dissertation, Chapter 1 contains a historical background and theory of HPLC along with a review of the use of carbon-based core-shell materials for elevated pH and temperature applications. Chapter 2 describes the improvement of the efficiency of carbon-based materials for HPLC using carbonized PDVB microspheres as the carbon core material. Chapter 3 is a study on the characterization of carbonized PDVB microspheres with multiple instruments. Chapter 4 describes the separation of cannabinoids using three types of carbon-based mixed-mode HPLC columns. Chapter 5 consists of (i) guidelines for the retention mechanism of the core-shell particles that have been commercialized for chromatography by Diamond Analytics, a US Synthetic Company in Orem, Utah, and (ii) application notes for these columns. Finally, Chapter 6 discusses possible future work.

Nanodiamonds (NDs) are the most biocompatible member of the carbon nanofamily which are widely researched for diagnostic and therapeutic applications. Unlike other carbon nanomaterials, the surface of NDs is innately reactive, hence capable of conjugating various chemical moieties for targeted actions. This work focuses on utilizing the surface reactivity of NDs for gene therapeutics and addressing the challenges associated with its application in the biological environment. Pristine carboxylated NDs were functionalized with basic amino acids (lysine and lysyl-histidine) through covalent conjugation via a three carbon chain linker. Amino acid functionalized NDs were characterized by infrared spectroscopy, thermogravimetry and size and zeta potential measurements. Lysine conjugation was evident through a marked change in the zeta potential of ND dispersion from negative to a high positive value (-54.6 mV to +26.3 mV). The thermogram of lysine functionalized NDs (Lys-NDs) revealed a significant weight loss from 150ᵒC to 700ᵒC confirming the functionalization through loss of amino acid conjugates from the surface and total loading was calculated as 1.97 mmols/g. Lys-NDs also showed optimum binding with pDNA and siRNA at weight ratios of 1:1 and 1:20 (pDNA/siRNA:ND), respectively. Functionalization of NDs with lysine contributed to limiting aggregation and enhancing the colloidal stability of ND dispersions in biological milieu. The aqueous dispersion of lys-NDs showed minimum sedimentation and remained stable over a period of 25 days. Average sizes under 100 nm and zeta potentials higher than +20 mV indicate a preservation of the cationic surface throughout the testing period. Moreover, size distributions and zeta potentials changed significantly upon incubation of lys-NDs with blood serum suggesting an interaction with biomolecules, mainly proteins and a possible formation of a protein corona. Cellular internalization of bare lys-NDs and their diamoplexes (i.e. complexes of NDs with nucleic acids) was assessed through scanning transmission X-ray microscopy and flow cytometry. Functional efficiency of lysine NDs was determined by flow cytometry monitoring the GFP knockdown through anti-GFP siRNA delivery. Results reveal a promising GFP knockdown of ~17% upon treating the cells with NDs/siRNA diamoplexes at a ratio of 20:1. Subsequent analyses regarding the effect of NDs to prevent cellular proliferation and to cause cellular apoptosis confirmed that they are innately biocompatible at a wide range of concentrations. Unlike lysine NDs, lysyl-histidine functionalization was limited and the surface loading of this conjugate on NDs was very low. Therefore, they were unable to bind pDNA and siRNA even at high weight ratios and hence demand design modifications. Overall this work demonstrates a novel approach of functionalizing NDs with basic amino acids capable of enhancing colloidal stability and delivering of therapeutic genes into mammalian cells. It represents an important step in the development of safe and efficient gene therapy for inherited and acquired diseases.

碩士
東海大學
化學系
105
The rapid development of nanotechnology , let it have a chance applied to Biology and Medicine. Recently a great potential of nanodiamond (ND) particles as a multimodal imaging/therapy platform has been demonstrated. Nanodiamonds (NDs) play a key role with their excellent physicochemical properties, including high biocompatibility, physical adsorption and photostabilizing activity. To combined with Biomedical Science development of drug delivery systems may be to facilitate the permeation of drugs provide the best use in medical care. In this study, the use of colon cancer and its EGFR mechanism as the goal, the nanodiamonds as a drug carrier. Here be divided into two parts, synthetic antibody-conjugated nanodiamonds and peptide-conjugated nanodiamonds. Use BCA Protein assay、MALDI-TOF MS and FTIR to identified the effect of nanodiamonds as carrier on HT-29 cells. The results show that antibody-conjugated nanodiamonds can also be successfully associated with HT-29 cells with specific binding without loss activity. The inhibition of HT-29 cells exhibited by peptide 3C-conjugated nanodiamonds is also more effective than peptide 3C. The results show that nanodiamonds as a drug carrier, has a certain potential value.

博士
國立暨南國際大學
應用化學系
105
In this work, we have developed a novel synthesis route for the production of titanium (IV) sulfonate-functionalized nanodiamonds (Ti4+-SND) as Ti4+-IMAC (Immobilized metal-ion affinity chromatography)adsorbents for selective enrichment of phosphopeptides. Nanodiamonds were first functionalized with polyarginine via EDC-mediated coupling reaction and then the titanium-sulfonate functionalization was performed by mixing with polystyrene sulfate and TiCl4 solutions. The obtained Ti4+-SNDs were used to specific capture of phosphopeptides from standard protein digests and nonfat milk digests. The results demonstrated that by taking advantage of the strong Ti4+-sulfate chelating effect and high Ti4+ loading amount, the Ti4+-SND show remarkable selectivity (β-casein/BSA = 1:1000), good sensitivity (10 fmol), and high recovery in phosphopeptide analysis. This novel approach for developing and producing IMAC adsorbents was further validated using different metal ions including Zr4+ and Fe3+. Both of the synthesized Zr4+ and Fe3+ IMAC adsorbents show excellent performance in selective enrichment of phosphopetides from complex peptide mixtures. Keywords: Polyarginine、Polystyrene sulfonate、Ti-IMAC、Phosphopeptides

碩士
國立暨南國際大學
應用化學系
102
Recent advances in nanotechnology for biomedical applications have rapidly growing needs for developing multifunctional nanoparticles. Here, one new class of fluorescent nanodiamond(FND) hybrids that process biocompatible, fluorescent and magnetic functionalities is presented. Magnetic iron oxide/Fluorescent nanodiamond (IO/FND) hybrids are prepared from 100 nm FNDs functionalized at the surface with polyarginine brushes to accommodate the 20 nm magnetic IOs, and then coating with a biocompatible Heparin layer. These new FND hybrids exhibit both fluorescent and magnetic properties with a maximum saturation magnetization of 4.35 emu g-1 and far-red fluorescence emission. The fluorescent intensity of FND hybrids is similar to bare FND. MTS assay reveals that FND Hybrids show have extremely low cytotoxicity toward HeLa cells. The FND hybrids are demonstrated with HeLa cell line for in vitro cellular labeling/imaging and magnetic cell manipulation. The fluorescence intensities were increased in a concentration-dependent manner by treatment with FND hybrids in HeLa cells. However, the existence of FND hybrids inside the cells did not alter cellular size distribution. The approach should be widely applicable to incorporate into a variety of biomedical applications such as hyperthermia, long-term magnetic resonance and fluorescence imaging, cell manipulation and separation.

碩士
國立暨南國際大學
應用化學系
105
Polycyclic aromatic hydrocarbons (PAHs) are notorious environmental pollutants generated primarily during the incomplete combustion of organic materials. Many PAHs have toxic, mutagenic and/or carcinogenic properties. In this work, polydopamine-coated nanodiamonds (PDA@NDs) were synthesized by in situ polymerization method and applied as a Surface-Assisted Laser Desorption Ionization, SALDI matrix for ultra-sensitive detection of PAHs by MALDI-TOF-MS. PDA@NDs exhibited low matrix background interference and high signal response for a large number of PAHs. Ultra-high sensitive detection of benzo[a]pyrene (BaP) was found to be in the low pictogram region. Furthermore, the PDA@NDs were utilized as a high affinity probe to enrich trace amount of BaP from aqueous solutions and to detect the PAHs in a real PM 2.5 sample. These results demonstrated that PDA@NDs show great potential serving both as MALDI matrix and affinity absorbent in ultra-sensitive detection of PAHs by MADI-TOF MS.

A unique feature of nanoscale carbon materials is the nature of their surfaces and how their surfaces interact with other species. The carbon materials specifically studied here include single-wall carbon nanotubes, nanoscale carbon nitrides, and a brief study of nanodiamonds from meteorite carbon, and related diamond surface chemistry. These nanometer sized carbon materials often possess curved surfaces. These curved surfaces can result in special structure-property relationships, such as a unique resistance to oxidation in the case of the nanotubes. Also the synthesis of nanoscale structures can be governed by surface interactions with the growth substrate, as shall be demonstrated with the carbon nitrides. The final materials obtained after such chemical treatments, should prove useful in applications such as catalysis, gas storage, chromatography, molecular electronics, high-strength composites, batteries and fuel cells, and abrasives.

碩士
國立東華大學
化學系
104
This thesis contains three topics : (1) Total Synthesis of Cajaninstilbene acid. (2) Synthesis of Nanodiamond and drugs conjugates. (3) Conjugation of Nanodiamond and Iressa analogue. First, Total Synthesis of Cajaninstilbene acid. I used cheap trans-crotonic acid as starting martial, through cyclization, and bromination to get the final product, Cajaninstilbene acid. Second, Synthesis of Nanodiamond and drugs conjugates. All-trans-retinoic acid was conjugated with Bovine serum albumin (BSA) and Nanodiamond to evaluate the biological activity. Third, Conjugation of Nanodiamond and Iressa analogue. Iressa was extended the side chain, then conjugated with Nanodiamond.

碩士
國立雲林科技大學
電子與資訊工程研究所
94
Carbon-based materials for electron sources are of great interest due to their low threshold emission fields. These materials include diamond, nano-diamond, amorphous diamond, carbon nanofibers, tetrahedral amorphous carbon (ta-C) films, and random or oriented carbon nanotubes (CNTs). The field emission characteristics of carbon-based materials had been studied extensively, but their gas sensing characteristics deny practical applications. In this dissertation, the different electron field emission characteristics of nanodiamond film deposited onto Si substrate with low work function by a microwave plasma-chemical vapor deposition (MPCVD) reactor will be discussed. Furthermore, the different qualities of nanodiamond films will apply in gas sensing, and utilized there breakdown field to compare the influence on the sensitivity of gas sensing. It was found that field emission properties of nanodiamond film were relative to the thickness of nanodiamond film. It was suggested that good field emission performance proportional to the ratio of ID/IG. It was concluded that the nanodiamond field emitters would be the good candidate to fabricate gas sensor devices with good performance of field emission properties.

Manipulating light by controlling surface plasmons on metals is being discussed as a means for bridging the size gap between micrometer-sized photonic circuits and nanometer-sized integrated electronics. Plasmonic waveguides based on metal nanoparticles are of particular interest for circumventing the diffraction limit, thereby enabling high-speed communication over short-range distances in miniaturized micro-components. However, scalable, inexpensive fine-tuning of particle assemblies remains a challenge and near-field probing is required to reveal plasmonic interactions. In this thesis, self-assembled waveguides should be produced on DNA scaffolds. DNA origami is an extremely versatile and robust self-assembly method which allows scalable production of nanostructures with a fine control of assemblies at the nanoscale. To form the plasmonic waveguides, six-helix bundle DNA origami nanotubes are used as templates for attachment of highly monodisperse and monocrystalline gold nanoparticles with an inter-particle distance of 1-2 nm. In the first part of this thesis, the effects of parameters which are involved in assembly reactions are systematically investigated. The assembly yield and binding occupancy of the gold nanoparticles are determined by an automated, high-throughput image analysis of electron micrographs of the formed complexes. As a result, unprecedented binding site occupancy and assembly yield are achieved with the optimized synthesis protocol. In addition, waveguides with different sizes of gold nanoparticles and different inter-particle distances, quantum dots attachments to the waveguides and multimerization of the waveguides are successfully realized. In the second part of this thesis, direct observation of energy transport through a self-assembled waveguide towards a fluorescent nanodiamond is demonstrated. High-resolution, near-field mapping of the waveguides are studied by electron energy loss spectroscopy and cathodoluminescence imaging spectroscopy. The experimental and simulation results reveal that energy propagation through the waveguides is enabled by coupled surface plasmon modes. These surface plasmon modes are probed at high spatial and spectral resolutions. The scalable self-assembly approach presented here will enable the construction of complex, sub diffraction plasmonic devices for applications in high-speed optical data transmission, quantum information technology, and sensing.
Die Manipulation des Lichts durch die Kontrolle von Oberflächenplasmonen auf metallischen Oberflächen und Nanopartikeln gilt als vielversprechende Methode zur Überbrückung der Größen-Lücke zwischen Mikrometer-großen photonischen und nanometer-großen elektronischen Schaltkreisen. Plasmonische Wellenleiter basierend auf metallischen Nanopartikeln sind vom besonderen Interesse, da sie die Umgehung des Beugungslimits und somit eine Hochgeschwindigkeitskommunikation über kurze Distanzen in immer kleiner werdenden Schaltkreisen ermöglichen könnten. Allerdings ist die skalierbare und kostengünstige Anordnung von Partikeln eine große Herausforderung und es werden Nahfelduntersuchungen benötigt um plasmonische Interaktionen detektieren zu können. Das Ziel dieser Arbeit ist die Selbstassemblierung von multi-partikel Wellenleitern auf DNA Gerüsten. Die Verwendung von DNA-Origami bietet eine äußerst vielseitige Plattform zur skalierbaren Herstellung von Nanostrukturen mittels Selbstassemblierung und ermöglicht eine präzise Kontrolle der Anordnungen im Nanobereich. Für den Aufbau der plasmonischen Wellenleiter werden DNA-Origami Nanoröhren, bestehend aus sechs Helices als Templat für die Anbindung von monodispersen und monokristallinen Goldnanopartikeln mit einem interpartikulären Abstand von 1-2 nm verwendet. Im ersten Abschnitt dieser Arbeit werden die beeinflussenden Faktoren dieser Assemblierungsreaktion systematisch untersucht. Die Ausbeute der assemblierten Strukturen und die Besetzung der Bindungsstellen werden durch eine automatisierte und effiziente Bildanalyse von Elektronenmikroskopieaufnahmen ausgewertet. Durch die Entwicklung eines optimierten Syntheseprotokolls werden bisher unerreichte Assemblierungsausbeuten ermöglicht. Zusätzlich erfolgen die experimentelle Realisierung von Strukturen mit verschieden großen Goldnanopartikeln und unterschiedlichen interpartikulären Abständen, sowie die Anbindung von Quantenpunkten an die Wellenleiter und eine Verknüpfung der assemblierten Strukturen. Der zweite Abschnitt dieser Dissertation befasst sich mit der Untersuchung des Energietransports in selbstassemblierten Wellenleitern über einen fluoreszierenden Nanodiamanten. Dazu erfolgen hochaufgelöste Nahfeldmessungen der Wellenleiter mittels Elektronenenergieverlustspektroskopie und Kathodolumineszenz-mikroskopie. Die experimentellen Ergebnisse und zusätzlich durchgeführte Simulationen bestätigen eine durch gekoppelte Oberflächenplasmonenmoden induzierte Weitergabe der Energie innerhalb des Wellenleiters. Diese Oberflächenplasmonenmoden werden bei hoher räumlicher und spektraler Auflösung untersucht. Das hier umgesetzte Konzept der Selbstassemblierung wird den Aufbau komplexer plasmonischer Geräte für Anwendungen im Bereich der optischen Hochgeschwindigkeitsdatenübertragung, der Quanteninformations-technolgie und der Sensorik ermöglichen.

MSc, Faculty of Science, University of the Witswatersrand, 2011
The objective of this project is to understand the details of the electronic transport in low dimensional carbon structures at low temperatures as well as high magnetic fields. The emphasis is on the quasi-2 dimensional thin grain boundary regions of nanodiamond films and one dimensional carbon nanotubes. As such nitrogen “doped” and undoped nanodiamond films were synthesized by the hot filament chemical vapor deposition method (HFCVD). The films were micro-structurally and electrically characterized using several techniques such as Raman spectroscopy, scanning electron microscopy, transmission electron microscopy, atomic force microscopy and magnetoresistance (MR) measurements. The electronic transport properties were compared to the films deposited by microwave plasma enhanced chemical vapour deposition (MWCVD). The conductivity revealed a typical semiconducting and semi-metallic behavior for the HFCVD films depending on the nitrogen percentage in the chamber. The dephasing time of the electronic wave function was found to be weakly temperature dependant i.e. τ T-p with p < 1, a behavior reported in artificial superlattices. These results show potential application of these materials in novel nano-electronic devices. Previously the transport mechanism in nanodiamond films has been attributed to hopping conduction in the grain boundaries which is predominately disordered sp2 phases. Our studies on nanodiamond films have however shown different mechanisms in these films. We observed very little contribution from hopping and pronounced weak localization contributions in nanodiamond films. We thus establish the significance of tunneling transport in nanodiamond films. We also studied the electronic transport in films of metal filled multiwalled carbon nanotubes which show significant contribution from the hopping mechanism and a negative magnetoresistance at low fields that crosses over into positive MR at high magnetic fields.

碩士
國立東華大學
化學系
100
In this thesis presents the use of chemical method to modify the surface of nano-diamond by covalent bond. The functional groups of nano-diamond surface were analyzed by TGA-MS. The functional groups number on the surface of nano-diamond was evaluated by GC-MS. In addition the anticancer drug ─ Iressa, was modified and connect with Paclitaxel. The anti-cancer ability in under investigation.

碩士
國立東華大學
化學系
99
We have developed a method to monitor the degree of functionalization of nanodiamond by subsequent esterification and hydrolysis. The efforts have been taken to increase the degree of functionalization under microwave condition. In the two different attempts of oxidation; by ozone as well as treatment with conc. HNO3; earlier method found to be superior over later. Better degree of functionalization has been observed with alkylation by short side chain over nanodiamond under microwave condition than alkylation with long side chain. Higher cell activeness is evident by paclitaxel modified nanodiamond under microwave condition. We have synthesized structurally similar derivatives 1-20, 1-3 of well-known anticancer drug Iressa. The derivative 1-20 showed higher cytotoxicity than Iressa, on the other hand 1-3 failed. Adopting strategy reported by Trost et al., 2, 2’-bipyridine ligand was modified by introducing phosphine moity to it, but unfortunately all attempts have been failed to isolate ligand 2-30. on the other hand, we also designed the ligand 2-A, which contains functionalities such as amine, amide, triazole group. But it has been proved inefficient to impart an asymmetric induction to the substrates as postulated.