CuO nanowhiskers: preparation,structure features,properties, and applications

This paper presents the results of a detailed study of the structure of nanowhiskers (NWs) of copper oxide formed in the process of thermal oxidation. It is shown that NWs have a bi- or poly-crystalline structure with a growth direction [110]. It is noted that the formation of NWs is facilitated by the cooperation of internal stresses with the defective structure of the underlying coating, and they grow owing to surface diffusion of copper cations from the depth of the coating to the top of the whisker. It is established that NWs have a good sorption and photocatalytic ability that will allow their use in the chemical industry, including the areas of catalysis and photocatalysis.     

ZnO薄膜的制备方法、性质和应用

介绍了宽禁带半导体ZnO薄膜的制备工艺、主要性质和器件应用等几方面内容.ZnO薄膜的制备方法大致分为物理法和化学法.前者主要包括溅射、脉冲激光沉积和分子束外延等;后者则涵盖化学气相沉积、喷雾热解和溶胶-凝胶法等.从晶体结构、光学及电学等角度概述了ZnO薄膜的主要性质.与这些性质相联系的器件应用有太阳能电池、发光器件和紫外探测器等.对器件应用领域中存在的一些问题及其解决思路作了探讨.     

类金刚石膜的性能、制备与应用(一)

类金刚石（DLC）膜是一种含有大量sp^3的亚稳态非晶碳薄膜。本文简要地介绍了DLC膜的形成原理、制备方法、发展现状，及其在机械、电子、光学、声学、生物医学等领域的应用与存在的问题。     

类金刚石膜的性能、制备与应用(二)

类金刚石（DLC）膜是一种含有大量sp^3的亚稳态非晶碳薄膜。本文简要地介绍了DLC膜的形成原理、制备方法、发展现状,及其在机械、电子、光学、声学、生物医学等领域的应用与存在的问题。     

Biphasic calcium phosphate bioceramics: preparation, properties and applications

Biphasic calcium phosphate (BCP) bioceramics belong to a group of bone substitute biomaterials that consist of an intimate mixture of hydroxyapatite (HA), Ca₁₀(PO₄)₆(OH)₂, and beta-tricalcium phosphate (-TCP), Ca₃(PO₄)₂, of varying HA/-TCP ratios. BCP is obtained when a synthetic or biologic calcium-deficient apatite is sintered at temperatures at and above 700 °C. Calcium deficiency depends on the method of preparation (precipitation, hydrolysis or mechanical mixture) including reaction pH and temperature. The HA/-TCP ratio is determined by the calcium deficiency of the unsintered apatite (the higher the deficiency, the lower the ratio) and the sintering temperature. Properties of BCP bioceramics relating to their medical applications include: macroporosity, microporosity, compressive strength, bioreactivity (associated with formation of carbonate hydroxyapatite on ceramic surfaces in vitro and in vivo), dissolution, and osteoconductivity. Due to the preferential dissolution of the -TCP component, the bioreactivity is inversely proportional to the HA/-TCP ratio. Hence, the bioreactivity of BCP bioceramics can be controled by manipulating the composition (HA/-TCP ratio) and/or the crystallinity of the BCP. Currently, BCP bioceramics is recommended for use as an alternative or additive to autogeneous bone for orthopedic and dental applications. It is available in the form of particulates, blocks, customized designs for specific applications and as an injectible biomaterial in a polymer carrier. BCP ceramic can be used also as grit-blasting abrasive for grit-blasting to modify implant substrate surfaces. Exploratory studies demonstrate the potential uses of BCP ceramic as scaffold for tissue engineering, drug delivery system and carrier of growth factors.     

Macroscopic carbon nanotube assemblies: preparation, properties, and potential applications

As classical 1D nanoscale structures, carbon nanotubes (CNTs) possess remarkable mechanical, electrical, thermal, and optical properties. In the past several years, considerable attention has been paid to the use of CNTs as building blocks for novel high-performance materials. In this way, the production of macroscopic architectures based on assembled CNTs with controlled orientation and configurations is an important step towards their application. So far, various forms of macroscale CNT assemblies have been produced, such as 1D CNT fibers, 2D CNT films/sheets, and 3D aligned CNT arrays or foams. These macroarchitectures, depending on the manner in which they are assembled, display a variety of fascinating features that cannot be achieved using conventional materials. This review provides an overview of various macroscopic CNT assemblies, with a focus on their preparation and mechanical properties as well as their potential applications in practical fields.     

Fluorescent-magnetic hybrid nanostructures: preparation, properties, and applications in biology

Research on nanocomposite materials aims at developing nanoscale composites with innovative optical, chemical, and magnetic properties, all combined in one single nanostructure. In this scenario, nanostructures which show simultaneously fluorescent and magnetic features are of particular interest for pharmaceutical and biomedical applications. In this review, we will focus our attention on magnetic-fluorescent nanocomposite based on colloidal iron oxide nanocrystals combined with different classes of fluorophores which can be either organic dyes, such as fluoresceins, cyanines, porphyrins, or colloidal quantum dots. We will give an overview of the preparation methods of the magnetic-fluorescent nanocomposites that are now available and we will outline the most significant in vitro studies of such nanocomposites on living cells. Some examples of their applications in biology and medicine will also be discussed.     

MWCNT reinforced Polyamide-6,6 films: preparation,characterization and properties

Composite films of Polyamide-6,6 (PA66) and multi-walled carbon nanotubes (MWCNTs) were prepared by a combination of solution casting followed by compression molding techniques. Both unfunctionalized (u-MWCNTs) and functionalized nanotubes (f-MWCNTs) were used in this study. The functionalization involved direct solvent-free amination of MWCNTs with hexamethylenediamine. Thermogravimetric analysis was used to observe the changes in the nanotubes upon functionalization and morphological features of the resulting composite films were studied using scanning electron microscopy, transmission electron microscopy, and atomic force microscopy. The crystallinity changes by incorporation of the u-MWCNTs and f-MWCNTs in the PA66 matrix were studied by wide angle X-ray scattering and differential scanning calorimetry. The f-MWCNT/PA66 film showed an improvement of ∼43% in maximum tensile stress (MTS) and ∼32% in Young’s modulus over pristine PA66 film, while at a similar loading of 0.5 wt%, the f-MWCNT/PA66 film showed ∼15% increase in MTS and ∼16% increase in modulus over the u-MWCNT/PA66 film. Dynamic mechanical analysis indicated significant difference in the small-strain mechanical properties between the MWCNT-filled and unfilled PA66 at the very low MWNT loadings that were tested and supported the tensile results. The water absorption trend of the composite films showed dramatic improvement over the neat film.     

Luminescent CdTe and CdSe semiconductor nanocrystals: preparation, optical properties and applications

The novel optical and electrical properties of luminescent semiconductor nanocrystals are appealing for ultrasensitive multiplexing and multicolor applications in a variety of fields, such as biotechnology, nanoscale electronics, and opto-electronics. Luminescent CdSe and CdTe nanocrystals are archetypes for this dynamic research area and have gained interest from diverse research communities. In this review, we first describe the advances in preparation of size- and shape-controlled CdSe and CdTe semiconductor nanocrystals with the organometallic approach. This article gives particular focus to water soluble nanocrystals due to the increasing interest of using semiconductor nanocrystals for biological applications. Post-synthetic methods to obtain water solubility, the direct synthesis routes in aqueous medium, and the strategies to improve the photoluminescence efficiency in both organic and aqueous phase are discussed. The shape evolution in aqueous medium via self-organization of preformed nanoparticles is a versatile and powerful method for production of nanocrystals with different geometries, and some recent advances in this field are presented with a qualitative discussion on the mechanism. Some examples of CdSe and CdTe nanocrystals that have been applied successfully to problems in biosensing and bioimaging are introduced, which may profoundly impact biological and biomedical research. Finally we present the research on the use of luminescent semiconductor nanocrystals for construction of light emitting diodes, solar cells, and chemical sensors, which demonstrate that they are promising building blocks for next generation electronics.     

Semiconducting transparent thin films: their properties and applications

The present state of the art of transparent, electrically conducting films, with special reference to In₂O₃, SnO₂ and Cd₂SnO₄, has been reviewed. Various production techniques currently in use, and typical parameters used in the processes have been discussed in detail. Electrical and optical properties of these films have been reported as a function of various parameters, e.g. substrate temperature, doping, oxygen pressure, etc. Finally, the applications of these films in research and industry have been discussed in detail.     

Review Composite and multilayer ferroelectric thin films: processing, properties and applications

This paper reviews recent developments in processing, properties and applications of composite and multilayer ferroelectric thin films. Methods such as physical vapor deposition, chemical vapor deposition and sol-gel, for the processing of composite and multilayer ferroelectric films are described. Among the techniques reviewed for the fabrication of multilayer ferroelectric films, molecular beam epitaxy and atomic layer metal-organic chemical vapor deposition are the most suitable techniques for the deposition of superlattices with atomically sharp interface. As an efficient and quick way, pulsed-laser deposition has been widely used for the preparation of ferroelectric multilayers and heterostructures. Superior dielectric properties have been reported for sol-gel-derived micrometer-thick ceramic/ceramic composite ferroelectric films. Properties of multilayer ferroelectric films vary as a function of periodicity, which can be exploited for the development of various electronic devices. Enhanced characteristics of composite and multilayer films with selected examples from recent literature and the origin of enhancement are discussed and summarized. Finally, applications of the materials for the development of various electronic devices are also presented.     

Glow discharge optical emission spectroscopy for accurate and well resolved analysis of coatings and thin films

In the last years, glow discharge optical emission spectrometry (GDOES) gained more and more acceptance in the analysis of functional coatings. GDOES thereby represents an interesting alternative to common depth profiling techniques like AES and SIMS, based on its unique combination of high erosion rates and erosion depths, sensitivity, analysis of nonconductive layers and easy quantification even for light elements such as C, N, O and H. Starting with the fundamentals of GDOES, a short overview on new developments in instrument design for accurate and well resolved thin film analyses is presented.The article focuses on the analytical capabilities of glow discharge optical emission spectrometry in the analysis of metallic coatings and thin films. Results illustrating the high depth resolution, confirmation of stoichiometry, the detection of light elements in coatings as well as contamination on the surface or interfaces will be demonstrated by measurements of: a multilayer system Cr/Ti on silicon, interface contamination on silicon during deposition of aluminum, Al₂O₃-nanoparticle containing conversion coatings on zinc for corrosion resistance, Ti₃SiC₂ MAX-phase coatings by pulsed laser deposition and hydrogen detection in a V/Fe multilayer system. The selected examples illustrate that GDOES can be successfully adopted as an analytical tool in the development of new materials and coatings. A discussion of the results as well as of the limitations of GDOES is presented.     

Synthesis of TiC via polymeric titanates: the preparation of fibres and thin films

Polymerization of titanium isopropoxide via its transesterification with o-xylene-,-diacetate enables the formation of a polymeric titanate that can be thermally converted into carbon-deficient TiC after inert atmosphere pyrolysis at 800 °C. The physical and rheological properties of this polymeric titanate allow for the production of crystalline TiC fibres and thin films. The synthesis of this polymeric precursor and the structural transformations leading to the formation of TiC are discussed.     

氟化类金刚石膜结构、性能及应用

氟化类金刚石膜是基于传统类金刚石膜的基础上发展起来的一种改性材料,该膜具有许多良好的性能,包括疏水性能、电学性能、光学性能、机械性能、热稳定性以及生物相容性,因此引起了人们的极大关注.本文介绍了氟化类金刚石膜的结构、性能、应用领域和发展趋势.     

The barrier discharge: basic properties and applications to surface treatment

Barrier discharges (BDs) produce highly non-equilibrium plasmas in a controllable way at atmospheric pressure, and at moderate gas temperature. They provide the effective generation of atoms, radicals and excited species by energetic electrons. In the case of operation in noble gases (or noble gas/halogen gas mixtures), they are sources of an intensive UV and VUV excimer radiation. There are two different modes of BDs. Generally they are operated in the filamentary one. Under special conditions, a diffuse mode can be generated. Their physical properties are discussed, and the main electric parameters, necessary for the controlled BD operation, are listed. Recent results on spatially and temporally resolved spectroscopic investigations by cross-correlation technique are presented. BDs are applied for a long time in the wide field of plasma treatment and layer deposition. An overview on these applications is given. Selected representative examples are outlined in more detail. In particular, the surface treatment by filamentary and diffuse BDs, and the VUV catalyzed deposition of metallic layers are discussed. BDs have a great flexibility with respect to their geometrical shape, working gas mixture and operation parameters. Generally, the scaling-up to large dimensions is of no problem. The possibility to treat or coat surfaces at low gas temperature and pressures close to atmospheric once is an important advantage for their application.     

Effects of discharge power on the structure and electrical properties of plasma polymerized polypyrrole films

We report on the effects of the discharge conditions on the structure and conductivity of the plasma polymerized polypyrrole films. Comparative studies of the infrared spectroscopy, elemental analysis and UV–VIS spectroscopy give information that the some pyrrole rings are remained in the PPPy films prepared with 10, 20 W discharge power, whereas almost all the pyrrole rings are cleaved in the PPPy films prepared with 50, 100 W discharge power and the three-dimensional crosslinked structure seems to have been formed. However, the different in the structure of the polymer backbone of the PPPy films does not crucially affect on the conductivity, the high conductivity is obtained under the wide discharge condition.     

Novel low-molecular-weight hypromellose polymeric films for aqueous film coating applications

The concentration of hypromellose (HPMC) is known to significantly impact the viscosity of coating solutions. The purpose of this study was to determine the viscosity of novel low-molecular-weight (LMW) HPMC products as a function of polymer concentration. The mechanical properties and water vapor permeability of free films prepared from these novel LMW HPMC polymers were also determined and the results were compared with films prepared with conventional HPMC. Solutions of LMW and conventional HPMC 2910 and 2906 containing up to 40% polyethylene glycol (PEG) 400 were prepared and the viscosities were measured using a Brookfield viscometer. Solutions were then cast onto glass plates and stored at 30?C and 50% relative humidity until films were formed. A Chatillon digital force gauge attached to a motorized test stand was used to quantify the mechanical properties of the films, whereas water vapor permeabilities were determined according to the ASTM E96 M-05 water method. As expected, the novel LMW polymer solutions exhibited significantly lower viscosities than the conventional comparators at equivalent polymer concentrations. Film strength of the LMW materials was lower than films prepared from the conventional HPMC solutions, although this effect was not as evident for the HPMC 2906 chemistry. Increasing concentrations of the plasticizer resulted in decreased tensile strength and Young?s modulus and increased elongation as well as increased water vapor permeability, irrespective of polymer type. No statistical difference was found between the tensile strength to Young?s modulus ratios of the F chemistry LMW and conventional HPMC polymer films.     

Chiroptical properties in azobenzene molecule-doped side-chain polymeric films

Thin, intrinsically achiral films of a side-chain polymeric liquid crystal system doped with photochromic azobenzene molecules exhibited dynamic chiroptical properties when irradiated with circularly polarized light (CPL). Photoinduced circular anisotropy was observed in these films with increasing CPL irradiation time. Reversible chiroptical switching was also realized by alternating irradiation with right- and left-CPL. We also monitored photoinduced chirality as a function of excitation wavelength.     

Deposition rate and structural properties of microcrystalline glow discharge Si:H,Cl films

The deposition rate and the structural properties of Si:H, Cl films produced in SiCl₄H₂ glow discharges were studied as functions of the substrate temperature, the gas feed composition and the operating pressure. The experimental results were interpreted on the basis of a discharge equilibrium involving both deposition and etching of the film. A close relationship between the deposition rate and the crystallite size is shown.