An approach for determination of asphaltene crystallite by X-ray diffraction analysis: A case of study
An approach for determination of asphaltene crystallite by X-ray diffraction analysis: A case of study
复制标题
X 射线衍射分析测定沥青质微晶的方法：一个研究案例
DOI：
10.1080/10916466.2017.1336771
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发表时间：
2017
影响因子：
1.5
通讯作者：
F. Trejo
中科院分区：
文献类型：
--
作者：
H. Díaz;J. B. Rojas;C. Leyva;F. Trejo
摘要 沥青质从大气残渣中沉淀出来并分成两部分。其中一份原样保留，第二份在回流下进行洗涤。通过元素分析和 X 射线衍射对两种馏分进行表征。分析衍射图，以便通过解卷积之前的平滑过程获得微晶参数，然后检测多项式函数的局部最大值。在对应于γ、(002)和(10)带的20°、25°和41°附近发现了主峰。 Bragg 和 Scherrer 方程用于确定芳香族层间和脂肪族距离，以及芳香族片的厚度和直径。首先使用校正公式估计主峰的半峰全宽 (FWHM)，因此应用校正程序来改进 FWHM 的初始猜测。使用这种数学方法时，观察到两个分析样品之间微晶参数的差异。
ABSTRACT Asphaltenes were precipitated from atmospheric residue and divided into two fractions. One of them was left as such and the second one was submitted to washing under reflux. Characterization of both fractions was carried out through elemental analysis and X-ray diffraction. Diffractograms were analyzed in order to obtain crystallite parameters by smoothing processes previous to deconvolution and then local maxima of a polynomial function were detected. Major peaks were found at around 20°, 25°, and 41° corresponding to γ, (002) and (10) bands. Bragg and Scherrer equations were used to determine the aromatic interlayer and aliphatic distances, as well as thickness and diameter of aromatic sheets. The full-width at half-maximum (FWHM) of the main peaks was firstly estimated using the corrector formula, and therefore the corrector procedure was applied to improve the initial guesses of FWHM. Differences in crystallite parameters between both analyzed samples were observed when using this mathematical approach.