Surface fractal dimensions and textural properties of mesoporous alkaline-earth hydroxyapatites

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• 作者：J. Vilchis-Granados^a ; ^b ; F. Granados-Correa^a ; ^{francisco.granados@inin.gob.mx} ; C.E. Barrera-Dí ; az^b
• 关键词：Alkaline-earth hydroxyapatites ; Surface fractal dimension ; Hydroxyl groups ; Textural properties ; XRD ; FTIR
• 刊名：Applied Surface Science
• 出版年：2013
• 出版时间：15 August, 2013
• 年：2013
• 卷：279
• 期：Complete
• 页码：97-102
• 全文大小：1233 K

文摘

This work examines the surface fractal dimensions (D_f) and textural properties of three different alkaline-earth hydroxyapatites. Calcium, strontium and barium hydroxyapatite compounds were successfully synthesized via chemical precipitation method and characterized using X-ray diffraction, scanning electron microscopy, energy dispersive X-ray spectrometry, Fourier transform infrared spectroscopy, and N₂-physisorption measurements. Surface fractal dimensions were determined using single N₂-adsorption/desorption isotherms method to quantify the irregular surface of as-prepared compounds. The obtained materials were also characterized through their surface hydroxyl group content, determined by the mass titration method. It was found that the D_f values for the three materials covered the range of 0.77 ¡À 0.04-2.33 ¡À 0.11; these results indicated that the materials tend to have smooth surfaces, except the irregular surface of barium hydroxyapatite. Moreover, regarding the synthesized calcium hydroxyapatite exhibited better textural properties compared with the synthesized strontium and barium hydroxyapatites for adsorbent purposes. However, barium hydroxyapatite shows irregular surface, indicating a high population of active sites across the surface, in comparison with the others studied hydroxyapatites. Finally, the results showed a linear correlation between the surface hydroxyl group content at the external surface of materials and their surface fractal dimensions.