METHOD FOR USING A STATIC ELECTRIC FIELD TO INDUCE

专利名称：METHOD FOR USING A STATIC ELECTRIC FIELD TO INDUCE CRYSTALLIZATION AND
TO CONTROL CRYSTAL FORM
发明人：GARETZ, BRUCE, A.,MYERSON, ALLAN,
S.,ARNOLD, STEPHEN,ABER, JANICE, E.
申请号：US2006013324
申请日：20060411
公开号：WO2006124152A3
公开日：
20070104
专利内容由知识产权出版社提供
摘要：Applying a strong static DC electric field to supersaturated aqueous glycine solutions resulted in the nucleation of the Y polymorph attributed to the electric-field induced orientation of the highly polar glycine molecules in large preexisting solute clusters, helping them organize into a crystalline structure. A method to induce crystallization and to prepare polymorphs and/or morphologies of materials by using a static electric field to cause nucleation and crystal growth to occur in a supersaturated solution in such a way as to obtain a crystal structure that would not normally appear without the use of the static electric field. Aqueous glycine solutions were prepared by combining solid glycine and water. Supersaturated solutions were generated by heating the tubes to 62- 640C and holding them at that temperature in an ultrasonicator overnight. Once the glycine was completely dissolved, the solutions were slowly cooled to room temperature. A chamber was constructed consisting of two brass electrodes separated by a 5 mm insulating gap, with a hole drilled down through the center, parallel to the gap-electrode interface, with a diameter large enough to accommodate the test
tube. A DC voltage was applied across the electrodes; large enough to produce electric fields in the range of 400,000 to 800,000 V/m. Tests tubes containing the aged solutions were placed in the high-voltage chamber. Exposure of the aged solutions to fields of 600,000 V/m resulted in crystallization typically within 30-90 min. The onset of nucleation was observed visually by the formation of a needle-shaped crystallite.
申请人：POLYTECHNIC UNIVERSITY,GARETZ, BRUCE, A.,MYERSON, ALLAN, S.,ARNOLD, STEPHEN,ABER, JANICE, E.
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