Structure refinements of Pb2+ ion-exchanged apatites by x-ray powder pattern-fitting

ADSORBABILITY OF ALIZARIN RED S ON Fe(III)- AND Pb(II)-TREATED HYDROXYAPATITES IN WATER

“…This material was washed three times with H 2 O and dried at 150˚C overnight in a drying oven, DZ-54 (Yamato Scientific Co., Ltd., Tokyo, Japan) to obtain Fe(III)-treated hydroxyapatites, HAP-300-Fe (Ca 6.27%, P 15.8%, Fe 28.15%, (Ca+Fe)/P = 1.29) and HAP-400-Fe (Ca 4.39%, P 17.76%, Fe 28.51%, (Ca+Fe)/P = 1.08), and Pb(II)-treated hydroxyapatites, HAP-300-Pb (Ca 24.24%, P 7.80%, Pb 27.09%, (Ca+Pb)/P = 2.92) and HAP-400-Pb (Ca 8.41%, P 5.83%, Pb 56.19%, (Ca+Pb)/P = 2.56). Chlorine element was not detected in the Fe(III)-treated apatites, and no strong IR absorptive band for NO 3 -stretching between 1520-1280 cm -1 was detected in Pb(II)-treated hydroxyapatites (referred to FIGURE 7 and the previous report 10 ). Specific surface area (see in Section 3.3) and X-ray diffraction patterns of these product materials (referred to FIGURE 1 as representative XRD patterns, HAP-300-Fe and HAP-300-Pb) were in good accordance with the previous report.…”

“…Hydroxyapatite indicates a unique property, exchange of Ca 2+ and OH -for outer cations [1][2][3][4][5][6][7] and anions. 8,9 In the previous paper, 10 we reported that reaction of heavy metal ions such as Pb 2+ 6 (OH) 2 , HAP-300 (Ca/P=1.68, slightly containing CO 3 ), and Ca-deficient hydroxyapatite Ca 10-x (HPO 4 ) x (PO 4 ) 6-x (OH) 2-x , HAP-400 (Ca/P=1.38), afforded the corresponding metal-treated hydroxyapatites.…”

Structure refinements of lead-substituted calcium hydroxyapatite by X-ray powder fitting

“…The observed deviations from Vegard's law have been attributed to a possible preference of the Pb 2+ ion for site (2) of the apatite structure, on the basis of the cation distribution deduced from the relative intensities of suitable reflections in the powder diffractogram Furthermore, the structure analysis of a sample of Pb9(PO4) 6 prepared by hydrothermal reaction (Hata, Marumo, Iwai & Aoki, 1980) revealed a deficiency of lead in site (1). In contrast, the results of structure refinements of lead-calcium hydroxyapatite solid solutions by an X-ray powder-pattern-fitting method led to a suggestion of random distribution of lead in sites (1) and (2) (Miyake, Suzuki & Ishigaki, 1986). In order to determine the possible site preference of Pb atoms in hydroxyapatite we have refined the crystal structures of hydroxyapatite samples containing 20% (Pb20), 45% (Pb45) and 80% (Pb80) Pb atoms by an X-ray powder-pattern-fitting method (Rietveld method).…”

Efficient destruction of bacteria with Ti(IV) and antibacterial ions in co-substituted hydroxyapatite films

“…It has thermal catalytic and photocatalytic properties [16]. Suzuki coworkers have found that Ca(II) of HAP can be exchanged with various metal ions in aqueous media [17][18][19]. Some studies has been reported that Ag, Cu or Zn ions were incorporated in HAP and showed obvious antimicrobial effect [20,21].…”