کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
231929 1427459 2008 11 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Ways of manipulating the polymorphism of glycine during supercritical fluid crystallisation
موضوعات مرتبط
مهندسی و علوم پایه مهندسی شیمی مهندسی شیمی (عمومی)
پیش نمایش صفحه اول مقاله
Ways of manipulating the polymorphism of glycine during supercritical fluid crystallisation
چکیده انگلیسی

The precipitation of glycine from aqueous solution was studied using a mixture of supercritical carbon dioxide and ethanol as drying medium and as anti-solvent. Glycine, which has three polymorphs, was precipitated by a direct spraying process using a coaxial nozzle under high pressure. By simple manipulation of the solute concentration, the process could be tuned to selectively precipitate either pure α or β-glycine, as determined by X-ray powder diffraction. When decreasing the solute concentration or increasing the ethanol fraction in the system, the precipitation of the metastable β-glycine was preferred over the precipitation of α-glycine. Modelling of the mass transfer around a drop showed that the ethanol fraction inside the drop can reach significant values, and that the evaporation occurs in less than a second, leaving little space for recrystallisation. Even though the crystal growth rate was extreme (up to 800 μm/s), the product was crystalline.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: The Journal of Supercritical Fluids - Volume 44, Issue 3, April 2008, Pages 422–432
نویسندگان
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