The covalent immobilization of crude lipases within silica-based macroporous frameworks have been performed by combining sol-gel process, concentrated direct emulsion, lyotropic mesophase and post-synthesis functionalizations. The as-synthesized open cell hybrid monoliths exhibit high macroscopic porosity, around 90 %, providing interconnected scaffold while reducing the diffusion low kinetic issue. The entrapment of enzymes in such foams deals with a high stability over esterification and transesterification batch process catalysis.

Titania (TiO2) was modified by codoping of Fe3+ and Ta5+ to absorb visible light. The codoped titania [(Fe,Ta)xTi1–xO2, 0 ≤ x ≤ 1] were prepared by a solid state reaction or by the polymer complex method. With increased codoping, the optical absorption spectra are red-shifted and the color ranges from white to brown via yellow. Also, the codoped titania (0 < x ≤ 0.05) possesses photocatalytic activity for organic decomposition under visible light irradiation. The codoped titania (x = 0.01) with yellow color shows the highest activity among the codoped titania (0 ≤ x ≤ 1) and a higher activity than the 1% Fe3+-doped TiO2 with orange brown color.

A novel technology for stretchable electronics is presented which can be used for the realization of wearable textile electronics and biomedical implants. It consists of rigid or flexible component islands interconnected with stretchable meander-shaped copper conductors embedded in a stretchable polymer, e.g. PDMS. The technology uses standard PCB manufacturing steps and liquid injection molding techniques to achieve a robust and reliable product. Due to the stretchable feature of the device, conductors and component islands should be able to withstand a certain degree of stress to guarantee the functionality of the system. Although the copper conductors are meander-shaped in order to minimize the local plastic strain, the lifetime of the system is still limited by the occurrence of crack propagation through the copper, compromising the connectivity between the functional islands. In order to improve the lifetime of the conductors, the most important feature of the presented technology is the use of spin-on polyimide as a mechanical support for the stretchable interconnections and the functional flexible islands. In this way, every stretchable copper connection is supported by a 20μm layer of polyimide being shaped in the same manner as the above laying conductor. The grouped SMD components and straight copper tracks on the functional islands are also supported by a complete 20 μm polyimide layer. By use of the polyimide, the reliability of the stretchable interconnections, the straight interconnections on the flexible islands and the transitions between the stretchable and non-stretchable parts is improved. This approach results in a significant increase of the lifetime of the stretchable interconnections as it is doubled. In this contribution, the different process steps and materials of the technology will be highlighted. Initial reliability results will be discussed and the realization of some functional demonstrators containing a whole range of different components will further illustrate the feasibility of this technology. The advantages and disadvantages in terms of processability, cost and mechanical strength of the photo-definable polyimide will be covered.

We have prepared 100 periodic nano-layers of SiO2/AgSiO2 with Au layer deposited on both sides as metal contacts. The deposited multi-layer films have a periodic structure consisting of alternating layers where each layer is 3.3 nm thick. The purpose of this research is to tailor the figure of merit of the thermoelectric materials generated from the nanolayers of nanocrystals of Ag with SiO2 as host and as buffer layer using a combination of co-deposition and MeV ions bombardment taking advantage of energy deposited in the MeV ion track to nucleate nanoclusters. The electrical and thermal properties of the nanolayered structures were studied before and after 5 MeV Si ions bombardment at various fluences to form nanocrystals. In addition to thermoelectric properties, some optical properties of the SiO2/SiO2+Ag multi-layer superlattice films have been studied.

The fraction of soluble and insoluble fiber was determinate by AOAC International official method for dietary fiber in four varieties of Bamboo called Guadua Angustifolia Kunth. The elastic modulus of the four bamboo varieties was determined using an universal machine INSTROM 4401 based on the ASTM standard method D-143. Finally, the fiber content and the mechanical behavior were correlated using the Pearson coefficient calculated by statistical package STATGRAPHICS 5.1 The fiber content is the main factor responsible for the bamboo mechanical properties. The results show that the all fiber content into the bamboo culms is related with the mechanical behavior. These results confirm that the Guadua Bamboo is a natural composite material with aligned fibers embedded in a matrix formed by soluble fiber.

In this paper we present the results of the studies on proton conduction in composites polyantimonic acid (PAA)-potassium dihydrophosphate (KDP) obtained by precipitation technique as well as mechanical mixing. The highest conductivity (~10-2 Sm/sm at 300 K) is achieved in the precipitated samples with volume fraction of KDP close to f = 13 %. The results of X-ray diffraction showed the absence of reflections from KDP for the samples with f < 20% and slight change in the intensities of odd and even reflections from PAA, which is explained by the ion exchange between the phases through the interface. These indicate that conduction is occurred through the interface regions of the composite. The value of interface conductivity is estimated from the dependence of the composite conductivity on the volume fraction of KDP based according to the model by Uvarov et al. This gives σs ≈ 5 Sm/sm, however the equation derived in this model doesn't represent the experimental data properly. Probably the maximum of the dependence simply corresponds to the percolation through the interface's continuous cluster – it is close to the classical percolation threshold.

The effect of thermal treatments in oxidizing ambient on the structural and electrical properties of low-energy Si-implanted thin SiO2 layers which previously suffered or not high temperature annealing in inert ambient was investigated. Based on TEM examination, charge trapping evaluation and FN conduction analysis of the resulting Si-NC SiO2 matrices, a model taking into account the healing of excess silicon atoms introduced by implantation and the generation of Si interstitials by oxidation above and below the viscoelastic temperature of SiO2 is proposed.

The idea of making biocompatible multifunctional nanoparticles, combining therapy, imaging and targeting, was aimed at cancer from the start a dozen years ago. This presentation will emphasize targeted theranostic nanoparticles, where “theranostic” literally means combining therapy and diagnostics, but more generally may mean a combination of imaging/visualization with therapy/surgery. Specific examples will cover (1) imaging (MRI, CT and optical methods), (2) therapy (chemo, photodynamic, radiation) and (3) guided surgery (using intra-operative imaging and therapy). Progress on brain and on head and neck cancer will be reported.

The microstructure and crystallization kinetics of electron beam evaporated Si on ZnO:Al coated glass for polycrystalline solar cells was studied by electron backscatter diffraction and optical microscopy at various deposition temperatures. A time dependent analysis of the dynamics of the crystallization allowed for the individual determination of growth and nucleation processes. The nucleation process of Si on ZnO:Al was found to be influenced by a variation of the deposition temperature of the amorphous Si in a critical temperature regime of 200 ˚C to 300 ˚C. The nucleation rate decreased significantly with decreasing deposition temperature, while the activation energy for nucleation increased from 2.9 eV at a deposition temperature of 300 ˚C to 5.1 eV at 200 ˚C, resulting in poly-Si which comprised grains with features sizes of several μm.

A direct synthesis of (001) oriented nanostructured CoPt thin films has been successfully achieved using a 880 J pulsed Dense Plasma Focus (DPF) device operating in a non-optimized focus mode with a low charging voltage of about 8 kV. The (001) oriented fct structured L10 phase nanostructured CoPt thin films have been synthesized directly in as-deposited sample, as verified by XRD results, without any post deposition annealing. The SEM imaging results show that nanostructured CoPt were achieved in non-optimized focus mode with agglomerate/particle size ranging from 10 to 55 nm. Furthermore, the VSM analysis shows that the as-deposited samples in non-optimized focus mode have higher coercivity (due to direct L10 phase) as compared the annealed sample and the as-deposited sample of optimized focus mode operation.

Pd is widely used in producing electrodes to single-walled carbon nanotubes (SWNT). However up to now its ability to form ohmic contacts to SWNTs was not employed in scanning probe microscopy (SPM). Here we present a study of SWNTs with Pd electrodes by SPM using Pd-coated tips. SWNTs were selectively grown on oxidized silicon substrates by low pressure CVD method. Pd electrodes were prepared to SWNTs to fabricate two terminal structures for SWNTs resistance measurements. It is shown that SPM Kelvin mode is a reliable technique for SWNT detection on insulating substrate. Contact potential difference between Pd electrode and SWNT is measured using the Kelvin mode.

In situ investigations of the chemical and mechanical mechanisms during CMP processes require analytical access to the wafer surface while interacting with the slurry and the pad under polishing conditions. In this study me make use of novel, specifically prepared, and self-designed Si wafer called microstructured single reflection elements (mSRE) utilizing the IR transparency of silicon [1]. The mSRE's enable in and ex situ attenuated total reflection (ATR) Fourier transform infrared (FTIR) investigations at the interface between silicon and the ambient with an enhanced usable spectral range. So, a thin silicon oxide layer or the polishing slurry can be investigated in the entire mid and far infrared spectral region. These mSRE wafers were placed at a simple reflection accessory of a FTIR spectrometer and either wet etched by a buffered oxide etch or polished using a CMP equivalent polishing configuration. During CMP the change of typical vibration bands of SiO2 layers and slurry constituents are observed. It was shown that the sensitivity as well as the surface selectivity of the experimental setup enables slurry and thin-film characterisations within the thickness range of monolayers. Surprisingly, the spectral features of the pad have not been observed during the polishing investigations.

Different synthesis procedures of Pt supported on tungstated zirconia catalysts (Pt/WOx-ZrO2) were investigated with the aim to elucidate the different WOx nanostructures developed on the zirconia surface depending on the preparation route. Pt/WOx-ZrO2 catalysts were synthesized by the coprecipitation and impregnation methods and pretreated by various procedures such as different calcinations temperatures or the use of reflux. The catalysts characterization was carried out by X-ray diffraction (XRD), Raman spectroscopy, transmission and scanning electron microscopy (TEM, SEM) and nitrogen physisorption, and the catalytic activity was evaluated in the n-hexane isomerization reaction. The results indicate that the development of active sites for isomerization of n-hexane is enhanced by the stabilization of the WOx nanostructures on the surface of zirconia, before the formation of the WO3 crystallites, and it largely depends on the synthesis method.

Proton dissociation and transfer are investigated with ab initio molecular dynamics (AIMD) simulations of carbon nanotubes (CNT) functionalized with perfluorosulfonic acid (-CF2SO3H) groups with 3 H2O/–SO3H. The CNT systems were constructed both with and without fluorine atoms covalently bound to the inner walls to determine the effects of the presence of fluorine on proton dissociation, hydration, and stabilization. The results of the AIMD trajectories show that decreasing the separation of sulfonic acid groups increases the propensity for proton dissociation. The simulations also revealed that the dissociated proton was preferentially stabilized as a hydrated hydronium (H3O+) cation in the CNT systems with the fluorine. This feature is attributed to the fluorine atoms providing a localized negative charge that promotes hydrogen bonding of the water molecules coordinated to the central hydronium ion. The hydrated H3O+ ion differed from a traditional Eigen cation (H9O4 +) as it donated hydrogen bonds to sulfonate oxygen atoms, as well as water molecules.

In order to study magnetic states in Fe-hydride under pressure, X-ray magnetic circular dichroism (XMCD) at the Fe K-edge has been measured up to 27.5 GPa. As a result, hydrogenation from bcc-Fe to dhcp-FeH occurs within a narrow region of 3.2-3.8 GPa, which is clearly observed by the dichroic profile in dhcp-FeH differing from that in bcc-Fe. Influence of H atoms on Fe 3d and 4p electronic states is discussed using the pressure-dependent XMCD and the first-principles calculation.

Stress corrosion cracking (SCC) in light water reactor components has long been studied from a post mortem perspective, yielding insights into water chemistries and effects on crack propagation. Analysis of a cracked component does not effectively provide information on the corrosion events or on SCC initiation. It is important that microstructures of these early stages be understood because the original surface of the component formed during fabrication is often not the final surface condition that is exposed to reactor water. Pre-service grinding of reactor components and welds is performed for a variety of reasons, from aesthetics to preparation for non-destructive testing. It is this final surface microstructure that often controls SCC initiation. Surface and near-surface characteristics have been investigated in 304SS metal coupons on which controlled grinding was performed. These examinations indicate the extent of subsurface microstructural damage before high-temperature water exposure. Analytical electron microscopy techniques have been used to gain insights into possible surface precursors to corrosion damage and SCC initiation.Nanocrystalline grains were commonly found at the surface in lightly ground to heavily abraded materials within the first ˜0.5-10 ųm along with high dislocation densities, twinning and lath structures.

We report on the size relationship of Au and Au-Pt nanoparticles that were synthesised on silica and anatase phase titania supports. Deposition-precipitation (DP) of metal chlorides with the addition of urea and ammonium hydroxide was used to produce the nanoparticles. The relative particle size relationship of the Au and Au-Pt nano particles (NP's) was investigated, relating the Pt concentration and the support polymorph over a temperature range. It was found, with the use of in-situ variable temperature powder X-ray diffraction (VT-PXRD) and transmission electron microscopy (TEM), that the addition of Pt to the Au system corresponded to a reduction in particle size over a broad temperature range.

We report resistive switching characteristics in Pt/ZnO/Pt devices where ZnO thin film is fabricated at various oxygen conditions. With the increase of oxygen contents in ZnO thin film, the forming voltage is gradually increased while reset and set voltages are almost unchanged. We also investigated the effect of top electrodes on resistive switching of top electrode/ZnO/Pt device. For a Pt/ZnO/Pt device, it exhibits the excellent resistive switching behavior due to high electrical field of the well-defined Schottky barrier. For Al/ZnO/Pt device, little resistive switching phenomena were occurred due to leakage current of the weak Schottky (or Ohmic) contact.

The low thickness stainless steel is widely used in the food and automotive industry and also to manufacture heat exchangers in the transport of fluids, due the stainless characteristics, in these applications the quality control of the pipe is very high, that is why it is important to achieve a strict control of the welding parameters during the manufacturing process. In order to quantify the effect of the travel speed and the hydrogen content in the shielded gas of the welding quality different test were performed with low thickness tubing's welded by GTAW process without filler material. The weld specimens were characterized by optic microscopy and scanning electron microscopy, energy dispersive x-ray spectrometry, and mechanical test like micro hardness and reverse. It was found that when the travel speed increase, a lack of penetration on the welding is observed when the hydrogen content is low, due a lower heat input.

Organosilicate materials with dielectric constants (k) ranging from 3.0 to 2.2 are in production or under development for use as interlayer dielectric materials in advanced interconnect logic technology. The dielectric constant of these materials is lowered through the addition of porosity which lowers the film density, making the patterning of these materials difficult. The etching kinetics and surface roughening of a series of low-k dielectric materials with varying porosity and composition were investigated as a function of ion beam angle in a 7% C4F8/Ar chemistry in an inductively-coupled plasma reactor. A similar set of low-k samples were patterned in a single damascene scheme. With a basic understanding of the etching process, we will show that it is possible to proactively design a low-k material that is optimized for a given patterning. A case study will be used to illustrate this point.