کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
7692975 | 1496323 | 2011 | 9 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Crystal structure and microstructure of cholesteryl oleyl carbonate
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
شیمی
شیمی (عمومی)
پیش نمایش صفحه اول مقاله
![عکس صفحه اول مقاله: Crystal structure and microstructure of cholesteryl oleyl carbonate Crystal structure and microstructure of cholesteryl oleyl carbonate](/preview/png/7692975.png)
چکیده انگلیسی
The crystal structure as well as the microstructure, i.e., size and strain, of crystallites of cholesteryl oleyl carbonate was determined from X-ray powder diffraction data. The X-ray line broadening was analyzed through the refinement of TCH-pseudo-Voigt function parameters (isotropic effects) and the refinement of multipolar functions, i.e., symmetrized cubic harmonics (anisotropic effects). The crystal structure turns out to be primitive monoclinic, space group Pc, type I monolayer having two molecules per unit cell with parameters: a = 18.921 ± 0.006 Ã
, b = 12.952 ± 0.003 Ã
, c = 9.276 ± 0.002 Ã
and β = 91.32 ± 0.03°. The average size of a well ground specimen of crystallites was 60 nm. The average micro-strain, e.g., 45 Ã 10â4 has been tentatively attributed to fatty chain conformational disorder. The unit cell parameters, including the lamellar thickness, of COC crystal is very closely similar to those of another, structurally similar cholesterol ester, e.g., cholesteryl oleate (CO) crystal, space group P21, type II monolayer. Type I monolayer structure has been established for COC on the basis of the intensity calculations of the XRD profiles of both CO and COC. The dipolar and structural disorder in a 4:1 molar, binary mixture of CO and COC can be accommodated in an induced smectic phase with a lamellar thickness, which is nearly equal to that of pure CO or pure COC.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Chemistry and Physics of Lipids - Volume 164, Issue 1, January 2011, Pages 33-41
Journal: Chemistry and Physics of Lipids - Volume 164, Issue 1, January 2011, Pages 33-41
نویسندگان
Pradip Das, Joyes De,