The properties of electromagnetic waves are known to be modified by interactions with periodic and aperiodic structures. Photonic crystals made of a periodic array of dielectric materials, e.g. colloidal spheres, have been studied intensively in terms of formation of photonic bandgaps, localization of light and control of spontaneous emission. Bandgap engineering is expected to bring a variety of optical device applications such as narrow-band filters and lowthreshold lasers. Another promising way to modify properties of light is by using the discrete and singular photon density of states within self-similar (fractal) structures. Results reviewed here clearly show that the unique optical properties of fractal structures offer large opportunities for designing new optical materials. The present review focuses on recently reported publications & patents on the molding of fluorescence light by photonic crystals and fractal structures respectively as well as their possible applications in future. With this review we want particularly to stimulate more interest in research on optical properties of fractal structures obtainable by different chemical and physical procedures.
This review paper is to give an overview of the recent progress on the development of TiO2 thin film photocatalysts for pollutant removal. Photocatalysis process involves the photoinduced oxidation and reduction reactions in the photocatalyst that has the ability in degrading most organic compounds into carbon dioxide, water and any harmless substances. Upon the exposure of ultraviolet light of wavelength λ < 390nm, the photocatalyst plays its role in degrading any kind of pollutants either in liquid or gaseous phase. One of the most outstanding photocatalysts that has received particular attention in application is titanium dioxide due to its high chemical stability and photocatalytic activity. The development of the photocatalyst in the form of a thin film is due to the impractical use of conventional powder photocatalyst in certain environmental applications. Recent patents of the thin film photocatalyst as well as some environmental applications have also been reviewed. Also included are techniques for modifying thin film characteristics, film deposition methods and variation in types of substrates used for improved photocatalytic properties of the TiO2 thin film.
In this review, recent patents on CO2-absorbent ceramics for high-temperature use and the mechanism of CO2 absorption by these absorbents are introduced. CO2 reduction technology is a large research field at the global level and the number of studies in this field is constantly increasing. The development of CO2 absorbents is included in the technology of CO2 reduction. Lithium complex oxides such as lithium zirconate and lithium silicate, calcium complex oxides, and alkaline earth complex oxides are all candidates for CO2 absorbents at high temperatures in the range of 700° to 1100 °C. These absorbent ceramics are useful for steam reformation of hydrocarbons-such as coal, oil, and natural gasto improve power generation efficiency.
Hollow micro/nanostructures (HM/NS) have attracted increasing attention due to the unique properties and potential applications in chemistry, biotechnology, and materials science. Within these applications, control of HM/NS dimension and shape lends increasing functionality and selectivity. In this paper, zero-dimensional (0D), one-dimensional (1D) and three-dimensional (3D) organized architectures of inorganic, polymer, and inorganic polymer composite HM/NS are presented, with a particular focus on solution-based syntheses. General strategies for synthetic HM/NS are discussed including commonly used template method and template-free method, such as through the Kirkendall effect, Ostwald ripening process, oriented assembly, and sonochemical method. Herein, we mainly discussed some recent patents for template-assisted fabrication of hollow HM/NS. In addition, the applications of HM/NS are introduced.
Jatropha, belonging to the family of Euphorbiace, is a plant of Latin American origin, spreads throughout the arid and semi-arid tropical regions of the world. The oil seed of Jatropha plant is a known feed stock for biodiesel production. The farming community has yet to explore jatropha as an alternate or commercial crop. The government and non governmental institutions/organisations have started the development program for jatropha plantation. Traditionally, jatropha plants have been used as a fence for all agricultural crops. Few reasons for the cultivation of this non food crop are the diminution of fossil fuel reserves, increased green house gas emission and the utilisation of food crops for biofuel production. Due to the technical and economic reasons, the full potential of jatropha plant has not been utilised. In addition to biodiesel production from jatropha seeds, the various parts of jatropha plant can find useful applications in different areas like medicine, polymeric materials, fertiliser, fence, etc. The innovation of value added application for this versatile and potentially useful crop may improve the economic health of the farmers and provide a competitive biodiesel. The present review article discussed the reported research in recent patens and journals on the utilisaton of various parts of jatropha plant for different applications.
Perovskite Pb(ZrxTi1-x)O3 piezoelectric ceramics were widely used. However, these ceramics with lead element cause a serious environmental pollution. In recent years, some countries have required all new electronic products to be lead-free for the environmental protection and human health. As a result, it is necessary to rapidly develop the lead-free piezoelectric ceramics with excellent properties to replace the lead-based ceramics. Over the past few years, considerable attention for the lead-free piezoelectric ceramics has been given to (KxNa1-x)NbO3 (KNN)-based piezoelectric ceramics for their good electrical and environmentally friendly properties. This review will cover patent and paper progress in the field of KNN-based lead-free piezoelectric ceramics achieved during the past few years. Current researches and achievements fully indicated that the KNN-based lead-free piezoelectric ceramics can be commercially produced in the near future.
Although high-entropy alloys were not reported in a scientific journal till 2003, the alloys had been investigated in (Taiwan) National Tsing Hua University in 1995. In more than ten years, the synthesization and application of highentropy alloys have been widely patented. In this paper, we review the recent developments in the technology of highentropy alloys and the patent literature in this area.
Platinum complexes of unsaturated siloxanes are useful as hydrosilation catalysts. In the process of room temperature vulcanized (RTV) silicone rubber, improved hydrosilation results are needed, however, a period of working time is also necessary in practice. Platinum at the zero oxidation state, like Karstedt catalyst is found active in parts per million levels in RTV silicon rubbers. Preferred addition cured silicone is formed by addition of an organohydrogenpolysiloxane (Si-H) across a π-bond to a vinyl-containing organopolysiloxane (C = C). The report reviews the preparation of platinum complexes from Speiers catalyst to Karstedt catalyst both of which are widely used in industry. Patents on the improvement of Karstedt catalyst and papers on the mechanism of hydrosilylation are also presented. The inhibitors for high temperature vulcanized (HTV) silicon rubber are reviewed as well as RTV silicon rubber.