Recent Patents on Materials Science - Volume 7, Issue 3, 2014

Fuel cells are the energy conversion devices that can convert the chemical energy of fuel into electrical energy efficiently and, more importantly, in a greener way by utilizing air as an oxidant. Solid polymeric electrolyte membrane is one of the major parts of the fuel cell device, which selectively allows the passage of protons while blocking the flow of electrons through it and makes the device functional. Till date, Nafion® is the most successful candidate in this field but it loses its proton conductivity at elevated temperature due to the loss of water molecules. In addition to the functional requirement of membranes, the durability and stability are also prime concerns for the electrolyte membranes. To develop alternative suitable membranes at lower cost different systems have been investigated time to time as fuel cell membranes. In this review, patents and research articles on various approaches that have been practiced to fabricate the alternative membranes, their characterization, stability, durability, degradation mechanism along with the life cycle estimation will be discussed to acquire a complete overview about the material design and fabrication of a perfect membrane electrode assembly.

The research on the application of multiferroic and magnetoelectric materials has gained momentum recently due to the exciting technological applications offered by the coupling between magnetic and electric order. In this article, an extensive review of patents on the application of multiferroic and magneto electric materials is presented. Beginning with an introduction, a brief idea of the magneto electric effect is given. Followed by the description on the different methods used for the fabrication of multiferroic single crystals and layer structures, the patents which describe the use of multiferroic and magneto electric materials for different applications are surveyed.

Multiferroic materials which display the coexistence of ferromagnetism (FM) and ferroelectric (FE) polarization have drawn considerable attention due to their fundamental physical characteristics and potentially wide applications including tunable microwave devices. In a multiferroic material system, due to the mutual coupling of the ferroelectric and ferromagnetic order, an applied magnetic field can alter the dielectric polarization and an applied electric field can alter the magnetic polarization. This gives an additional degree of freedom to the designer for developing voltage tunable devices. There are some patented technologies which demonstrate the importance and development of multiferroic thin films for voltage tunable devices. This manuscript presents an analysis of the present and future of the mutiferroic materials- based technology for microwave applications. It also gives an extensive summary of recent patents and other relevant articles published in this field.

In the domain of magneto transport properties of materials, giant magnetoimpedance (GMI), is of research interest as it represents a large change of both real and imaginary parts of the impedance under a static magnetic field applied. Understanding of GMI needs the understanding of the micro magnetic characteristics of the materials and its dependence on dynamic magnetism. After early observation of GMI in soft magnetic amorphous wires and ribbons, the reseach has been extended to systems like polycrystals, amorphous alloys, nanocrystalline materials, single crystals and also in different structures like thin films, sandwiched structures, glass-covered microwires etc. giving a large number of papers as well as patents in the last decades. Different system display magnetoimpedance which is effective in different applications; in some, it has already been proposed and tested in laboratory prototypes, and is already on the market. Here, we will discuss the room temperature GMI property of typical polycrystalline manganites. The material preparation, characterization and magnetoimpedance properties are described in detail. The unique scaling behavior of field dependence of magnetoimpedance observed is well described by a phenomenological model.

This manuscript reviews the recent patents and literature on the development of sustainable resource based polymer blends. In recent years, much attention has been focused on the research to replace petroleum-based polymers with renewable resource based materials that exhibit competitive mechanical properties. A great deal of work is focused on polymer blends to understand the mixing dynamics at the molecular level. The modification of polymer blends by using sustainable resource based polymers can not only fulfill our ecological but also our economic and social needs. The compatibility studies of linseed oil and castor oil based epoxy and polyesteramide blends with polyvinyl alcohol (PVOH) are discussed. These blends exhibit miscibility in the concentrated solution phase which can be correlated with their behaviour in the solid phases. The use of such natural plasticizers, with low toxicity and good compatibility with several plastics, resins, rubber and elastomers in substitution of conventional plasticizers, such as phthalates and other synthetic conventional plasticizers holds potential for important applications, in pharmaceutical, biopackaging and medical fields. It is highly significant that rheological measurement which is a dynamic technique gives results about the blend’s characteristics being very similar to those obtained from ultrasonic velocity measurements, a stationary technique. Deeper understanding of their interactions and fundamental physicochemical and biochemical properties is needed in order to enable the design and production of desirable and competitive materials.

Enhancing the optical transmission of ZnO film is an important topic for its application. This work presents the manufacture and potential application of the ZnO materials containing various dopants in recent literatures and patents and then focuses on the comparison of optical properties of Al- and Mo-doped and codoped ZnO films. The films were deposited on quartz glass substrate by a sol-gel process, and characterized by X-ray diffraction, atomic force microscopy, atomic force microscopy, and UV-vis and luminescent spectrophotometries. The Mo-doping was more effective in increasing transmission and widening band gap than the Al-doping, while the codoping was more effective than single dopings. The films also showed strong ultraviolet, violet and bluish violet emission.