Electrospinning of polycarbonate with solvent mixtures of THF (Tetrahydrofuran) and DMF (Dimethylformamide) has been performed. The effect of various process parameters like voltage, concentration, flow rate and distance has been investigated to yield uniform polycarbonate nanofibers with minimal bead densities. The temperature and humidity have also been carefully monitored for all the runs. The Design of Experiment (DOE) has been conducted with the help of Minitab software to find the most significant parameter for obtaining uniform beadless nanofibers. These uniform nanofibers can then be used in future work to produce TiO2 nanotubes.

A novel nano-ceramic material, called HSA-CERCANAM®, which has a very high surface area with a nanopore network has been developed. HSA-CERCANAM® can be casted in various shapes and forms resulting in a monolithic piece that has surface area as high as 80–100 m2/g. The surface area and the nanopore network of HSA-CERCANAM® remains stable at temperatures as high as 1000°C. Furthermore, the unique nature of HSA-CERCANAM® allows it to be casted on and around features, either sacrificial or permanent. Using sacrificial features, microchannels can be incorporated internally into the monolithic HSA-CERCANAM® piece in a simple, one-step process. Further, this monolithic ceramic component, which has an intrinsically high surface area and a nanopore network, can be infiltrated with a desired catalyst. This could offer clear technological advantages over currently available microreactors. The surface area, porosity, catalyst type and infiltration levels are some of the ways in which tailored microstructures can be realized in components such as mixers, heat exchangers, extractors, filters or reaction chambers thereby leading to highly efficient, multi-functional ceramic micro-devices.

A chemical gas sensor with a novel pad pattern applicable to NH3, NO2, and H2 gas was developed based on single-walled carbon nanotube ropes. In this pattern named BCE (Barricade confronting electrode), several electrodes were located at the circumference of a sample and each pair of electrode tips was designed to confront to each other with a narrow interval. Several single-walled carbon nanotubes were shifted to the interval by the centrifugal force generated through the rapid rotation of a sample equipped on the spinner. Our device showed improved performance for NO2, NH3, and H2 gases compared with others in references.

The effects of DC and AC magnetic fields on grain growth in electrodeposited nanocrystalline nickel were studied. Magnetic annealing was conducted at 573K in the ferromagnetic temperature region and at 693K in the paramagnetic temperature region. Both DC and AC magnetic annealing could enhance the grain growth and produced a homogeneous grain structure at 573K. On the other hand, AC magnetic annealing shortened the incubation time for the late stage abnormal grain growth at 693K in the paramagnetic temperature region, while DC magnetic field could not affect the incubation time.

New process for the preparation of Fe-Pt nanowires has been developed through anodic oxidation and electro deposition technique. Aluminum thin film sputtered on ITO thin film on a glass surface was decomposed into alumina by anodic oxidation technique. The anodic alumina layer possessed nanometer size pore array standing on the glass surface. The barrier layer at the bottom of nanopores was removed by acid etching to attain DC field smooth electro deposition. Fe-Pt components were introduced into nanopores of anodic alumina by electro deposition. The magnetization of Fe-Pt nanowires was investigated. The magnetization perpendicular to the glass surface was very strong and the in-plane magnetization was very small, indicating that the magnetic Fe-Pt nanowires could be potentially applied to ultra high density magnetic recording. The density of the nanowires was estimated to be about 1T bits /inch2.

The results of x-ray study and electrical measurements are brought together in order to understand a difference in performance and failures of solid electrolyte capacitors made of sintered tantalum and niobium sub-micron powders. It is shown that bulk Ta and Nb exhibit different abilities for the formation and decomposition of oxygen solid solution during manufacturing steps which may be critical for stability of metal/oxide interface of capacitor.

Gold nanoclusters dispersed in single crystal TiO2 (110) have been formed by 2MeV Au2+ implantation to an ion fluence of 1×1017 cm-2 at 300 K and 975 K followed by annealing at 1275 K for 10 hours. The morphological features, size and crystallographic orientation of the Au nanoclusters with respect to the TiO2 matrix have been investigated using conventional transmission electron microscopy and electron diffractions. In particular, the interface structure between the Au nanoclusters and TiO2 was investigated. Atomic structural model of interface between Au and TiO2 was established based on high-resolution transmission electron microscopy (HRTEM) imaging and HRTEM image simulations. Two types of orientation relationship can be identified, Au<110>//TiO2[001] and Au{111}//TiO2(200), and Au<110>//TiO2[001] and Au{111}//TiO2(110). Au clusters are faceted along Au{112}and Au{111} or Au{220} and Au{002} planes. The precipitated Au clusters show extensive (111) twins. These orientation relationships are the same for Au clusters grown on TiO2(110) surface, indicating that lowering interfacial energy to be a governing factor for setting the orientation relationship.

We investigated formation processes of a porous anodic alumina film on a p-type silicon (Si) substrate using infrared absorption spectroscopy in the multiple internal reflection geometry (MIR-IRAS). We observed drastic IR spectral changes when porous anodic alumina film approached interfaces between an aluminum (Al) layer and a Si substrate. The intensity of the IR absorption peaks due to water (H2O) molecules and silicon oxides (SiO2) increased simultaneously with a spike of anodic current density. The IR spectral changes indicated that the penetration of electrolytes brought about inhomogeneous oxidation of a Si substrate surface. We observed that the arrangement of the SiO2 nanodots closely reflected that of pores of a porous anodic alumina film. IR absorption peaks due to porous anodic alumina finally disappeared. The formation of SiO2 nanodots on a Si substrate promoted penetration of electrolytes to peel the porous anodic alumina film off it.

Vanadium dioxide nanorods (B phase) have been synthesized, for the first time, using cetyltrimethylammonium bromide (CTAB) as structure-directing template in hydrothermal condition. Morphology and structure of the sample were characterized by XRD, SEM, HRTEM, XPS, TG-DTA and redox titration. The results show that the products are VO2 (B) nanorods and they are 1∼2 μm in length. HRTEM micrographs reveal that they indeed form bundles of agglomerated smaller filaments with diameters ranging from 20 to 40 nm. This filament-like shape in the nanoscale dimension leads to the exposure of a large fraction of the atoms to the surface. Thus, these materials are promising candidates for the development of new functionalized materials. TG investigation shows that there are a weight loss of 2.21 % between 250∼400 °C corresponding to removal of the organic residuals and a weight gain at about 430 °C corresponding to oxidation of vanadium with low oxidation state. The simplicity of hydrothermal process, cheapness, and availability of raw materials are advantages favoring the scaling-up of nanorods.

Formation of hierarchical macropores and mesopores in ethylene-bridged polysilsesquioxane sol-gel systems via concurrent sol-gel transition and phase separation induced by the incorporation of supramolecular templats has been investigated. A series of poly(ethylene-glycol)-poly(propyleneglycol)- poly(ethyleneglycol) triblock copolymers, EOPOEOs, have been employed as supramolecular templates, while 1,2-bis(trimethoxysilyl)ethane was used as a polysilsesquioxane source. Successful combination of templated mesopores and well-defined macropores due to phase-separation has been found in the system with EOPOEOs having 70 PO units and respective 20 EO units. Although similar macroporous morphology has been obtained for all the EOPOEOs with EO chain longer or shorter than 20 units, the optimum composition for the co-continuous macropores and that for templated mesopores deviated from each other, resulting in the failure of producing hierarchical macropores and mesopores.

A new liquid crystalline nanoparticle has been synthesized by the reaction of a cyanobiphenyl derivative with polyhedral oligomeric silsesquioxane (POSS®*). Two POSS nanoparticles, liquid crystalline POSS (LC POSS 3) and a non-LC isooctyl POSS (OPOSS), were then compounded at 2.5 wt % into thermotropic polyester liquid crystalline polymers (LCPs) poly(hexamethylene 4,4'-bibenzoate), poly(diethylene glycol 4,4'-bibenzoate) as well as a frustrated LCP 45:55 poly(ethylene terephthalate-co-4,4'-bibenzoate). These polymers are currently being studied for potential use in high performance fibers and high barrier packaging materials. A comprehensive study of LCP/LC POSS 3 nanocomposites will focus on any changes in the thermal and mechanical properties of the LCPs with increasing LC POSS 3 concentration. It will be determined how incorporation of LC POSS 3 affects the liquid crystalline phases of an amorphous and crystalline LCP. Of special interest is the incorporation of LC POSS 3 into a frustrated LCP. It is proposed that the LC POSS 3 might help to unfrustrate the LCP.

Conventional material synthesis procedures rely on the intrinsic chemical behaviours (e.g., different hydrolysis rates of the reactants in solution phase reactions or different vapour pressure or thermal stability in the gas phase reactions) of the different components, which make the material properties susceptible to inaccuracies due to an increased number of process variables. As a consequence, phase separation and element segregation are present at the nanometer scale, although the global stoichiometry of the product may correspond to the desired composition. In this context, the use of well-defined molecular precursors is a promising approach to grow extended solid-state structures from atomic constituents.

Although studies on the Fe3O4 magnetic particle formation have been markedly advanced by the strenuous efforts of numerous researchers, the preparation and formation of ultrafine Fe3O4 particles with narrow size distribution still remain as an open area due to their broad applications, especially in biomedical fields such as target drug delivery and medical imaging. A new method for the titled template-mediated synthesis of Fe3O4 ultrafine magnetite particles (several tens of nanometers) with narrow size distribution from a polymer matrix has been investigated. Hydrazine hydrate was used as a reducing agent to prepare the poly(itaconic acid-co-acrylic acid) gel-supported iron metallic nanoclusters, which served as nuclei, and were later transferred into ultrafine iron oxide powders in NaOH base solution. The morphology, particle size, structure and magnetic properties, as well as the formation of the particles with narrow size distribution, were investigated by means of transmission electron microscopy, selected area electron diffraction, laser light scattering, wide-angle X-ray diffraction, Fourier-transform infrared spectroscopy, and electron spectroscopy for chemical analysis, as well as magnetic measurements, respectively. It was revealed that the Fe3O4 ultrafine particles prepared from the Fe3+-poly(itaconic acid-co-acrylic acid) complex gel system kept narrow size distribution, which originated from the oxidation and aggregation growth of the primary particles, and the metallic iron nanoclusters would act as “templates” in the later magnetite particles growth stage. This new attempt of template-mineralization of Fe3O4 ultrafine particles in our preparation was proved to be effective for preparing template-mediated ultrafine magnetite particles with narrow size distribution quickly, which could also be used to prepare other kinds of inorganic particles.

This work reports temperature dependent thermal and electrical properties characterization of long (mm size) single-walled carbon nanotube strands. Electrical properties are measured using a 4-probe method. Thermal conductivity and specific heat capacity are determined using an AC driven, self-heating method. Normalized values of resistivity, thermal conductivity, specific heat, thermal diffusivity, and the temperature coefficient of resistance are reported. The trends observed in the temperature dependent properties are comparable with previously published data on multi-walled carbon nanotube strands measured with a similar technique.

Catalytic properties of noble metal catalysts are often caused by their nanostructures. Gold catalysts are typical cases. It is especially interesting that the catalytic property of gold suddenly changes to resemble that of platinum when the mean size of gold dispersed on certain oxides is <2nm. This phenomenon should be owing to the change of the local electronic structure of the gold particle or the interface between the gold and the oxides, however its detail has not been cleared yet. We measured the mean inner potential of gold particles supported on TiO2 using electron holography and HREM, and found that the mean inner potential of gold depend largely on the size of the gold particles. When the size is >5nm, the mean inner potential is the same as the reported values of bulk gold (experimental: 21–23V, calculated: 25–30V). When the size is <5nm, it begins to increase >30V, and it begins to increase suddenly >40V at the size <2nm. It indicates that the electronic structure of the gold particle varies from that of the bulk state as the size of the gold reduces due to the nano-size effect or the interaction at the interface, since the mean inner potential is sensitive to the electronic state of the outer valence electron. On the other hand, the behavior of the platinum catalysts is different from that of gold catalysts. When the size of the platinum particle on the TiO2 support is >1.5nm, the mean inner potential of platinum is the same as that of the bulk (∼25V). In case of the particle with the size <1.5nm, it begins to increase and the increase rate is lower than that of the gold particles with the size <2nm. It is suggested to be due to the difference of the interaction with TiO2.

Miniaturized thin film humidity sensors were fabricated using nanostructured materials deposited by an advanced technique known as glancing angle deposition (GLAD). These sensors exhibited extremely fast desorption response times of less than 40 ms to steplike changes in humidity. Multiple response time measurements for various initial humidities have shown that the sensors maintain their rapid response at all levels of humidity.

Oxygen (18O) diffusivity in sol-gel synthesized nano-crystalline ceria films of average grain size of 3 nm and 7 nm, annealed at 300 °C and 450 °C for one hour respectively is examined by nuclear reaction analysis (NRA). Diffusivity and electrical transport properties measured by a. c. impedance spectroscopy were compared with microcrystalline ceria film of average grain size 38 nm annealed at 900 °C for one hour. Effect of enhanced oxygen diffusion along with reduced ionic transport in nano-crystalline ceria and reduced oxygen diffusion along with enhanced ionic transport in microcrystalline ceria are correlated to long range ordering, grain boundary scattering and defect density. Enhancement in the conductivity with reduction in activation energy from 1 eV to 0.5 eV in the case 4 atom% ytterbium (Yb) doped ceria compared to pure ceria is a result of increased oxygen vacancies taking part in the defect transport.

The subtle electronic properties and large electroactive surface of carbon nanotubes (CNTs) suggest that they have the ability to promote electron-transfer and favor electrocatalytic behavior in electrochemical reactions when they are employed as an electrode. In this paper, CNT-modified gold electrodes for glucose biosensor have been fabricated using multi-walled carbon nanotubes. The CNT-based electrode exhibits a strong and stable amperometric response toward glucose even at a low potential of +0.35 V versus Ag/AgCl in comparison with the glassy carbon-based electrode.

Supercritical fluid extraction (SFE) technique which enables to fabricate mesoporous film at low temperature has been developed. Meso-structure silica films are prepared by sol-gel process based on the self-organization of surfactant templates, and the organic templates are successfully extracted from the films by supercritical CO2 (sc-CO2) modified with hydrogen peroxide at 80 °C and 19.6 MPa. The extraction process is analyzed by X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy of the films. In order to discuss the feasibility of such films obtained at low temperature for electronics applications with low dielectric and low dielectric loss, the mechanical properties and the densities of the films are compared with various silica films prepared by different method.