Biomimetic Synthesis of Hydroxyapatite in Presence of Imidazole-4,5-dicarboxylic Acid Grafted Chitosan for Removing Chromium(VI)

Abstract

In order to biomimetic synthesize hydroxyapatite similar to natural bone. Hydroxyapatite (HAP) is biomimetic synthesized in simulated body fluid (SBF) by addition of imidazole-4,5-dicarboxylic acid grafted chitosan (IDACS). e effect of molar ratio of chitosan (CS) to imidazole-4,5-dicarboxylic acid (IDA) on preparation of HAP was investigated. e structure, size, and crystal phase of the obtained hydroxyapatite were observed by Fourier transform infrared spectroscopy, X-ray powder diffraction, and scanning electron microscopy. e results show that the molar ratio of CS to IDA is 1 : 3, the temperature is 37.0°C, the aging time is 48 h, the synthesized nanorod-like hydroxyapatite with diameter 20-30 nm, and length ranging from 75 to 120 nm presents excellent phase, which disperses well and is similar to the natural bone of HAP. e obtained HAP can be used to remove chromium(VI) by the orthogonal experiments, and the results indicated that the removal rate can reach 95.66% under the optimum conditions. ese results suggest that the morphology of the obtained HAP is more affected by the material ratio of chitosan to imidazole-4,5-dicarboxylic acid than its structure, and the obtained HAP can effectively remove Cr(VI), which provides a novel method for biomimetic synthesis of other biomaterials and application in the water purification.