کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
10378077 | 880749 | 2005 | 6 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Characterisation of the protolytic properties of synthetic carbonate free fluorapatite
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
مهندسی شیمی
شیمی کلوئیدی و سطحی
پیش نمایش صفحه اول مقاله
![عکس صفحه اول مقاله: Characterisation of the protolytic properties of synthetic carbonate free fluorapatite Characterisation of the protolytic properties of synthetic carbonate free fluorapatite](/preview/png/10378077.png)
چکیده انگلیسی
The acid/base surface properties of carbonate free fluorapatite (Ca5(PO4)3F) have been characterised using high precision potentiometric titrations and surface complex modelling. Synthetic carbonate free fluorapatite was prepared and characterised by SEM, XRD, FT-IR and FT-Raman. The specific surface area was determined to be 17.7±1.2m2gâ1 with BET (N2 adsorption). The titrations were performed at 25±0.2â°C, within the pH range 5.7-10.8, in 0.10 and 0.50 molâdmâ3 NaNO3 ionic media. Experimental data were interpreted using the constant capacitance model and the software FITEQL 4.0. The surface equilibria: S1OH â S1Oâ + H+âlgβâ110s (int),S2OH â S2Oâ + H+âlgβâ101s (int) well describes the surface characteristics of synthetic fluorapatite. The equilibrium constants obtained were: lgβâ110s(int)=â6.33±0.05 and lgβâ101s(int)=â8.82±0.06 at I=0.10moldmâ3. At the ionic strength 0.50 molâdmâ3, the equilibrium constants were slightly shifted to: lgβâ110s(int)=â6.43±0.05 and lgβâ101s(int)=â8.93±0.06. The number of active surface sites, Ns, was calculated from titration data and was found to be 2.95 and 2.34 sitesânmâ2 for the ionic strengths 0.10 and 0.50 molâdmâ3, respectively. pHPZC or the IEP was found to be 5.7 from Z-potential measurements.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Colloid and Interface Science - Volume 285, Issue 1, 1 May 2005, Pages 206-211
Journal: Journal of Colloid and Interface Science - Volume 285, Issue 1, 1 May 2005, Pages 206-211
نویسندگان
Mathias Jarlbring, Lars Gunneriusson, Willis Forsling,