Preparation and characterisation of fluorapatite whiskers

Abstract

Fluorapatite (FAp) whiskers were prepared by using Molten Salt Synthesis (MSS) technique. β-tricalcium phosphate (TCP) and various fluorine salts, along with potassium sulphate as a flux salt were used as starting materials for preparing FAp whiskers. Effects of flux to powder weight ratio, temperature and soaking time on the morphology were studied. The optimum temperature to obtain FAp whiskers was found to be 1175°C. The phase purity of the prepared FAp whiskers were confirmed by powder X-ray diffraction and FTIR spectra, and the whiskers were further characterized by laser Raman spectra, chemical analysis and DTA/TGA thermal analysis. The morphology of the FAp whiskers were investigated by scanning electron microscope (SEM) analysis.

Preparation of calcium sulfate whiskers using waste calcium chloride by reactive crystallization

“…As promising reinforcement materials, inorganic whiskers have attracted considerable interests of scientists and engineers since they exhibit high strength and stiffness, and are nearly free from internal defects such as dislocations owing to their small diameter [1][2][3][4][5][6][7][8]. There are various prospective inorganic whiskers that can be used to reinforce the composite materials, such as silicon carbide (SiC) [9], calcium carbonate [10], potassium titanate (K 2 Ti 6 O 13 ) [2], aluminum borate (Al 18 B 4 O 13 ) [11], titanium boride (TiBw) [12] and calcium sulphate (CaSO 4 ) whiskers [13]. They are reckoned as more effective reinforcements than traditional fibers, such as carbon fiber and glass fiber.…”