Extraction of biological apatite from cow bone at different calcination temperatures: a comparative study

The purpose of this study is to extract natural hydroxyapatite (HAP) from cow bone. The hydrothermal method followed by calcination treatment at different temperatures is used in this current research. Cow bone has the potential for producing hydroxyapatite, a chief component present in bone and teeth of vertebrates. HAP is an excellent material used in bone restoration and tissue regeneration. Characterizations of the cow bone natural HAP powder were done by X-ray diffraction (XRD) and Thermogravimetric analysis (TGA). TGA data revealed that biological apatite is thermally stable at 1100ºC. XRD data showed that the extracted HAP is, highly crystalline and hexagonal crystal structure having a crystallite size in the range of 10-83 nm. The extracted HAP material is found to be thermally stable up to 1300ºC

Effect of Sintering on Hydroxyapatite/Sodium Alginate Properties

In the present work, a precipitation method was used to prepare a nanocomposite powders consisting of hydroxyapatite and sodium alginate by varying the composition of sodium alginate. The characterization of powder are analyzed by using Scanning Electron Microscopy (SEM) and X-ray diffraction (XRD). SEM is used to identify the morphology and agglomeration of powder while, XRD analysis is used to identify the phase of samples with an increase in the composition of sodium alginate up to 10%. Green samples were prepared and sintered at temperature 1000ËšC and 1100ËšC and the sintered samples are studied based on their phase stability, density and Vickers hardness .The result indicates that there is no secondary phase change happen in this XRD result. The density of HA/SA are increasing relative to hardness for composition ratio 99.5/0.5%. The maximum density were attained by 99.5/0.5% (HA/SA) at 2.12g/cm3 and 2.16g/cm3 for 1000ËšC and 1100ËšC respectively while, the maximum hardness were also attained by 99.5/0.5% for temperature 1000°C and 1100°C at 0.53GPa and 0.62GPa respectively. FESEM images of pure hydroxyapatite are fully disbursed in sodium alginate and the particles size are in agglomerate conditions.Â

Characteristics and Preliminary Study of Ceramic Concretes

One of the most adaptable and frequently used building materials in the world is concrete. It is flexible in terms of size and shape, sturdy, long-lasting, low-maintenance, fireproof, and easy to use. However, further research is needed to increase the durability and sustainability of this material since concrete technology is still in developing industry. Therefore, it's crucial to comprehend how microstructure and characteristics interact in terms of how they affect concrete's strength, dimensional stability, and durability. The findings of this research are crucial in identifying the properties and characteristics of the ceramic concrete used for bridge construction or others. Advanced research to ascertain the hardness and physical qualities and features of ceramic concrete material is required. Thus, it will help to produce a reliable data for engineer to refer for their future works or project. To ascertain its hardness and physical characteristics, research has been conducted on ceramic concrete for several types of grades. In the current study, the ceramic concrete was tested through the physical and Vickers-hardness tests. The X-Ray Diffraction (XRD) and Scanning Electron Microscopy (SEM) on samples were performed to observe the phases and morphology of the ceramic concrete, respectively. For results of physical testing, the density and water absorption correlate to each other by the denser of the sample, the lower of water absorption and the porosity level of the ceramic concrete. Based on the Vickers micro hardness test, it can be seen that longer curing days affected the hardness, where the concretes of grade 30 and 40 at 28 curing days had better hardness value. Next, Scanning Electron Microscopy (SEM) on samples shown almost same microstructure, while the dominant phase of all ceramic concrete grades was SiO2 by the XRD analysis. In summary, better properties of ceramic concretes were indicated at 28 curing days for both grades of ceramic concretes

Review on advances in porous Al composites and the possible way forward

Porous aluminum (Al) composites are lightweight and high-strength materials composing of Al as a matrix material with some strengthening reinforcements and pore-forming agents that result in the formation of new material with superior physical properties and energy absorption capacities. This work gives an overview of the porous Al-foams developed thus far, including the foaming agents and space holders, their properties, production techniques, and applications. First, it deliberates the foaming agents and space holders responsible for the foaming and formation of pores in the composites followed by the mechanical properties of the foams. Al has huge potential for applications that require lightweight, high-strength, and high-energy absorption capacity materials, especially in structural construction and automobile manufacturing. Although Al-foams have been successfully used in automobiles for crashworthiness, lightweight structure, and other functional applications, the development of Al foams with enhanced characteristics and properties has limitations. This review discusses various reinforcements used for improving the characteristics of Al-foams. This review also provides an overview of various commercial foams and their contribution to several applications. Finally, it attempts to reveal impediments in foam production with suggested solutions for overcoming the problems in this area

Binding agent for biodegradable compression molded rice straw filled rice bran packaging products

Rice bran (RB) has been used as a natural fibre in polyolefin which results in lower mechanical properties and low interfacial adhesion that need a coupling agent or binder at higher loading. Rice bran (RB) and rice straw (RS) which both is low cost materials were developed in the processing of biodegradable packaging by using compression moulding technique. Glycerol, rice starch and polyvinyl acetate (PVAc) have been used as binding agent in this study where their physical (mechanical, chemical, and thermal) properties were studied base on the percentage of binding agent used in RB/RS. Rice starch and PVAc increased the tearing strength and tensile strength of RB/RS. This was continued by fracture surface analysis using inverted microscopy where RS is clearly visible of phase separated without binding agent as compared to RS with binding agent. Although rice starch and PVAc exhibited good mechanical properties, but they showed poor water resistance because of high in hydrophilic molecular structure. Starch influenced the rapid thermal degradation of RB/RS. By incorporation of PVAc in RB/RS, thermal stability property is increased

Mechanochemical synthesis of sodium doped hydroxyapatite powder

Bioactive hydroxyapatite (HA) with nanosized spherical shape has been synthesized through mechanochemical synthesis of calcium hydroxide and diammonium hydrogen phosphate. Sodium ion has been doped into HA by using sodium hydroxide precursor in a dry mixture of Ca(OH)2 and (NH3)2HPO4. Both Na-free HA and Na-doped HA (1% - 9%) are characterized by X-ray diffraction and Fourier transform infrared analyses. Reduction of the peak intensity and adsorption bands is observed with increasing Na+ concentration in the Na-doped HA structure. Increasing Na+ content expands the lattice parameters and unit cell volume of HA, while the crystallite size and degree of crystallinity decrease with increasing Na+ level. A mixture of rods and spheres are found in the Na+ doped HA. Characterization of the obtained powder suggests that Na doped HA has a potential to be used in clinical applications

Mechanochemical synthesis of hydroxyapatite nanopowder: Effects of rotation speed and milling time on powder properties

Mechanochemical synthesis of two or more different precursors is a simple method to prepare metallic alloys, polymer and ceramic composite materials. This mechanical reaction based synthesis also has been employed to produce hydroxyapatite (HA) powder for bone implant application. In this present study, we employed mechanochemical method to synthesize hydroxyapatite nanopowder from dry mixture of calcium hydroxide (Ca (OH)2) and di-ammonium hydrogen phosphate [(NH4)2HPO4] powders. The effect of mechanochemical process on powder properties was investigated. Three rotation speeds of 170 rpm (M1), 270 rpm (M2) and 370 rpm (M3) were chose with 15 hours milling time respectively. The milling time at 370 rpm (M3) was extended to 30 hours (T1) and 60 hours (T2). Characterization of nanopowders were accomplished by Fourier transform infrared (FTIR), X-ray diffraction (XRD), nanosizer analysis, field emission scanning electron microscope (FESEM) and transmission electron microscope (TEM). Rotation speed and milling time affected the obtained powders with nanocrystallite HA structure. The narrow peaks appeared with the incremental of crystallite size (9 – 21 nm) and crystallinity (21-59%) when the rotation speed was increased to 370 rpm (M3). However, particle size distribution (322-192 nm) was decreased with the rotation speed. Morphological evaluation indicated that the average particle size of resultant powder which consists of agglomerate crystals and irregular shapes reached about 17 - 36 nm. The as synthesized nanopowder showed that 370 rpm at 15 hours of milling is the suitable parameter to be applied for hydroxyapatite nanopowder synthesis in mechanochemical method