Nanoferrite Composites: Synthesis, Characterization, and Catalytic Action on Thermal Decomposition of Ammonium Perchlorate

Jalpa A. Vara and Pragnesh N. Dave


Nanoscience is an interdisciplinary field of science which is closely connected with the research of the properties of matters at the atomic, molecular, and macromolecular ranges. ‘Nanotechnology’ denotes the technology that performs at a nanoscale level by controlling the shape and size at nanometer scale for design, production, characterization, and application. Nanotechnology was first described by the renowned physicist Richard Feynman in a meeting held at the American Physical Society, California Institute of Technology in 1959, entitled ‘There’s plenty of room at the bottom: An invitation to enter a new field of physics’. The term ‘nano’ comes from the Greek word ‘nano’ which means ‘dwarf’. One nanometer is designated as lnm and is equal to 10-9 m, which means one nanometer in length is approximately equivalent to the width of 6 carbon atoms or 10 water molecules (Mansoori 2005; Roukes 2009).

Nanomaterials are commonly classified as materials with an average grain size of less than 100 nanometers (Das and Ansari 2009); the materials include nanoparticles, and can are appreciated due to having improved properties like lower weight and higher strength. Nanomaterials comprise a branch involving atomic, molecular, and bulk structures. The novel and increased shape and size under such properties are exposed in comparison to their equivalent bulk materials. Nanomaterials are of attention as, at this range, the unique and relatively different magnetic, electrical, and optical properties emerge. Nanomaterials contain a much larger surface area-to-volume ratio than their bulk materials, which can cause better chemical reactivity and influence their strength. Also, at the nano range, quantum effects can happen to be highly important in determining the properties of materials and qualities, or most important to novel electrical, magnetic, and optical behaviors.

Ferrites are a huge group of oxides with amazing magnetic properties, which have been studied and proven useful throughout the last approximate 50 years (Valenzuela 2005). Ferrites are familiar magnetic nanomaterials effectively studied because of their greater physical properties. The properties of ferrites create a best applicant for technical uses like catalysis, magnetic resonance imaging enhancement, pigments, and sensors (Mathew and Juaug 2007). Mixed ferrites are considered effective for the coming years, owing to their potential utilization. The chemical formula of ferrites has MFe204 in which M can be any divalent metal cations.

Ferrites are fundamentally ferromagnetic oxide substances having high permeability and resistivity, while the diffusion magnetization of ferrite is under partially that of ferromagnetic alloys. The ferrite has benefits as an application due to its high resistivity, high frequency, higher resistance of heat, superior decomposition resistance, and low cost. Although its vast application is as a bulk material, the source of magnetism is a nano range occurrence (Beringer and Heald 1954). The improvement of magnetic nanostructure materials is a topic of concern, and equally for the scientific importance of considering the exclusive functional properties of materials, and for the technological importance in increasing the act of obtaining substances.

Composite solid propellants (CSPs) are the major source of chemical energy in space vehicles and missiles. Ammonium perchlorate (AP) is widely used as an oxidizer in composite solid propellants (Said 1991: Shen et al. 1993; Gao et al. 2001; Nema et al. 2004; Chaturvedi and Dave 2011). It is commonly observed that since catalytic activity is primarily a surface phenomenon, the size reduction of the catalysts increases their catalytic activity (Singh et al. 2009b). The ballistics of a composite propellant can be improved by adding a catalyst such as ferric oxide (Fe203), copper oxide (CuO), copper chromite (Cu0.Cr203), nickel oxide (NiO), etc., which accelerates the rate of decomposition of AP (Said 1991; Shen et al. 1993; Gao et al. 2001; Nema et al. 2004; Chaturvedi and Dave 2011). Recent investigations have shown that nanoparticles of transition metal oxides without any agglomeration can increase the burning rate (Jacobs and Whithead 1969). The efficiency of catalytic action increases more sharply in nanometer-size oxide particles than microscale oxide particles (Boldyrev 2006). The size distribution, morphology, and nanostructure of particles are very important characteristics and affect the kinetics of decomposition of ammonium perchlorate.

< Prev   CONTENTS   Source   Next >