Recent Patents on Materials Science - Volume 2, Issue 3, 2009

Proteinous bioplastics have received renewed interest over the last decade due to an awareness of the environmental impact of conventional plastics. In the second half of the previous century, further development of proteinous bioplastics was overshadowed by the fast growth in synthetic polymer technology. Today, proteins are considered a sustainable source for producing biodegradable alternatives to conventional plastics. Proteins are complex hetero-polymers, offering a number of different functional side groups capable of forming strong intermolecular bonds. Denaturing, cross-linking and plasticization are the most important aspects of protein processing. Typically, proteins and plasticizers are blended prior to thermo-processing, during which a highly viscous melt should be formed. The softening temperature of proteins is often above their decomposition temperatures, thereby making processability dependant on the type and amount of plasticizer. Generally, increasing the amount of plasticizer will lower the softening temperature and viscosity of the blend. Extrusion is particularly suitable for processing proteins, but excessive aggregation should be avoided by judicial use of chemicals, such as denaturants, plasticizers and reducing agents. Current technology described in recent patents mostly involves chemical modification of protein structures, incorporation of novel plasticizers and developing new process and specialized equipment. These are discussed further in the text.

Aromatic polyamides are high performance materials with superior thermal and mechanical properties which make them extremely useful for advanced technologies. These polymers can be transformed into high-tensile strength synthetic fibers and into flame and cut-resistant materials that have technological applications in the field of coatings and fillers in the aerospace and armaments industry, in asbestos substitutes, electrical insulation, bullet-proof body armor, industrial filters, and sports fabrics, among others. This article sets out to review the existing literature and recent patent claims that describe the design, the preparation and the applications of wholly aromatic polyamides, semiaromatic polyamides and poly(amide imide)s.

Expanded metal has been widely used around the world. This paper is aimed at presenting latest advances in the use of expanded metal in engineering. Currently, expanded metal is mainly used in the construction industry as furniture, fences or protection purposes. Hundreds of patents can be found in the literature regarding possible applications for expanded metal. These applications fall into four main areas: furniture, construction, biomechanics, and energy absorption systems. When expanding the metal, the material undergoes slits and stretching modifying the mechanical properties of the base metal, hence enhancing the material strength. Additionally, there is a reduction of the weight per unit of area, which is an asset when designing lightweight structures. Waste material from the manufacturing process is almost none, since the base metal is cut and stretched to the final form. Recently, expanded metal sheets are used in architecture to create modern, efficient and elegant buildings that are also energy-efficient, open and transparent. The relevant patents on expanded metals are discussed.

In this article, both carbon nanotubes (CNTs) adsorption capability of dioxins and ability of CNTs to carry catalysts which are used for destructing dioxins are reviewed. It is suggested that CNTs are superior adsorbents for dioxins as compared to traditional adsorbing materials. And the TiO2 coating layer, which is the base of the active phase (oxides of vanadium (V), tungsten (W), molybdenum (Mo), niobium (Nb) and tantalum (Ta)) for destructing dioxins, can form successfully on surfaces of CNTs. Further researches aimed at developing a technology to synthesize nanocomposite that uses CNTs to support efficient catalysts for destructing dioxins are recommended. The relevant patents are discussed.

Since the early studies of Hall and Petch, it is a well known fact that fine grain sized materials have better mechanical properties, namely strength, hardness and toughness. However, conventional processing techniques have never been able to produce ultrafine grained metals and alloys, i.e., these methods can not achieve fine grain size beyond some limits around a few micrometers. More recently, the development of new processes comprising severe plastic deformation has demonstrated some capability of producing ultrafine grained, or even nanostructured, materials with better mechanical properties, opening a wide landscape of opportunities for applications in many industrial fields. In this work, new technological developments on the processing of nanostructured metallic materials by severe plastic deformation methods are described, focusing on an analysis of patents registered in the last years on this subject, complemented by available information collected on articles published about this theme.

In contradiction to the theoretical prediction, the characteristics of the quantum dots are thermally unstable in the relatively high temperature regime. This article briefly summaries the temperature behavior of the self-assembled quantum dots in the In(Ga)As/GaAs system, as experimentally observed in both the time-integrated and time-resolved photoluminescence measurements on thermal anomalies, thermal quenching, relaxation- and radiative-lifetime of the quantum dots. In addition, the efforts made in the relevant patterns to reduce the T sensitivity of the semiconductor lasers based on the quantum dots are described. The article gives a brief review on the recent relevant patents.

Full text available