Recent Patents on Materials Science - Volume 1, Issue 3, 2008

Transition metal carbides have properties similar to platinum group metals and their synthesis procedure have been the subject of recent patents. This paper deals with the synthesis of Mo2C from the propane carburization of silica supported MoS2. BET surface area was strongly favoured by increased temperature and H2:C3H8 ratio but to a lesser extent by carburization time. Based on statistical analysis, optimum conditions were identified as H2:C3H8 = 1, temperature at 973 K for a period of 1 hour. Surface area also decreased almost hyperbolically with Mo loading. FTIR analysis suggests the presence of co-ordinatively adsorbed NH3 molecules implicating the existence of weak Lewis acid centres with an optimum concentration at about 12% Mo content. The solid-state reaction kinetics was investigated by thermogravimetry. The carburization appeared to follow a 2nd order kinetics but characterised by a low activation energy of 16 kJ mol-1 indicative of a diffusional solid-solid rate controlling step involving interstitial substitution of carbon with sulphur atoms in the Mo matrix.

Cyanoacrylates are solvent free adhesives that cure rapidly when pressed into a thin film between two surfaces. Their ease availability and use in various formulations made them attractive to manufacturers a wide variety of medical devices. Unfortunately, earlier generations of cyanoacrylates had several limitations, such as poor thermal resistance and peel strength. Subsequent developments in cyanoacrylate technology have greatly expanded the performance of these adhesives. This rubber-toughened, surface-insensitive, thermally resistant cyanoacrylate offers advantages over earlier toughened products which has been recently patented. /P>

Within the last decades thin film technology has advanced considerably and plays a key role in several industrial fields. The interest in developing high quality thin films with specific properties has drastically increased due to the rapidly growing needs in applications such as magnetism, semiconductor technology, microelectronics, optical films and microdevices. In the field of nanotechnology thin film deposition plays an important role as well and in certain cases deposition of layers of materials atom by atom is required. Therefore extended research is performed around the world in order to optimize the wide variety of the thin film deposition techniques. This paper focuses on the most common and important techniques used nowadays, which are briefly described, and on presenting a review of the latest developments in this field. Relevant patents are presented and discussed.

Calcium phosphate is a main component of skeletal minerals and its nano material is suggested as an ideal candidate for bone graft in hard tissue engineering due to the superior biocompatibility and bioactivity. The preparation and application of nano calcium phosphate is an important topic in nowadays materials science and some nanoparticles have been already used clinically for various purposes. The current review will discuss recently reported patents and relevant literatures on fabrication of nano calcium phosphates and the improvements of the materials properties including biocompatibility, bioactivity, biofunctionality and mechanical strength, as well as the applications of nano calcium phosphates in biomedicine.

Current status and technology developments of patented sealing glass and glass-ceramics used for solid oxide fuel cells (SOFC) are reviewed. The sealing materials containing mainly silicates and borates are selected to meet several thermal and mechanical requirements relating to the stringent needs of selected solid electrolyte and the reductionoxidation conditions in long-term aspects. Several critical properties, for instance, coefficient of thermal expansion, glass transition, gas leakage, and the strength of patented glass systems are discussed in respect to the trends of SOFC development in near future.

Inhibitors are employed predominantly for corrosion control in closed systems, as a cost-efficiently alternative to the use of high corrosion-resistant materials. Due to the environmental requirements that are currently imposed on the development of cleaner inhibitors, vegetal tannins, a class of natural, non-toxic, biodegradable organic compounds that can be obtained at reduced cost has been proposed. This review relates recent uses of several vegetal tannins in corrosion protection, particularly as corrosion inhibitors of iron and steel in acidic and near neutral media. Several methods of inhibition efficiency evaluations along with their action mechanisms are discussed. The present review presents some important patents in the development of vegetal tannins in corrosion protection of iron and steel.

This paper reviews research on patents of intermetallic matrix composites synthesized methods, such as casting, powder metallurgy, self-propagating high-temperature synthesis, spark plasma sintering, directional solidification and chemical reacting. The present status and applications in various fields as well as the prospects of intermetallic compounds are presented too. It's indicated that in order to enlarge the applications areas, people should intensify not only the investigation of theories but also the research on preparation methods and processes which influence the structure and performance of materials. At the same time, a further study for optimizing the processing parameters is required to improve the property of materials. Future directions in this field have been suggested.

The controlled development of texture in polycrystalline materials is a topic of recent interest in ceramic processing, since it allows improved tailoring of piezoelectric properties. One promising route for controlled texture development is templated grain growth (TGG). The TGG process is dependent on the formation of oriented particles by in situ reaction precursor particles with aligned shape anisotropy templates. It has been shown that ferroelectric/piezoelectric ceramics with a high degree of texture along the polar direction exhibit a good performance. However, how to get the excellent performance with high texture, how to synthesize the plate like template suitable for the ceramics, many issues remain to be overcome for these texture ceramics fabricated by TGG. This article reviews the current literature and patent base of TGG technique of Bismuth Sodium Titanate Bi0.5Na0.5TiO3 (abbreviated as BNT) based ceramic materials which is one group of promising lead free material to replace the widely used lead based perovskite materials.

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