Growth Rate Enhancement Phenomena By Microcrystals And Their Effects On Crystal Quality
| Project/Area Number |
05453098
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
反応・分離工学
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| Research Institution | Tokyo University Of Agriculture & Technology |
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Principal Investigator |
MATSUOKA Masakuni Tokyo University of Agriculture & Technology, Department of Chemical Engineering, Professor, 工学部, 教授 (40016671)
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| Co-Investigator(Kenkyū-buntansha) |
TAKIYAMA Hiroshi Tokyo University of Agriculture & Technology, Department of Chemical Engineering, 工学部, 助手 (40251582)
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| Project Period (FY) |
1993 – 1994
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| Project Status |
Completed (Fiscal Year 1994)
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| Budget Amount *help |
¥7,000,000 (Direct Cost: ¥7,000,000)
Fiscal Year 1994: ¥600,000 (Direct Cost: ¥600,000)
Fiscal Year 1993: ¥6,400,000 (Direct Cost: ¥6,400,000)
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| Keywords | Crystallization / Nucleation / Crystal size distribution / Microcrystals / Growth enhancement / Growth mechanism |
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| Research Abstract |
In industrial crystallizers complicated phenomena such as agglomeration and breakage or attrition caused by collisions between the crystalline particles occur in addition to nucleation and growth of crystals from supersaturated solutions. These phenomena have significant influences on the quality of product crystals which include purity, morphology, size distribution and crystallinity. So far interrelations between nucleation and growth of crystals are unknown so that the present study aims to investigate the effects of nucleation on the growth of crystals experimentally. The main conclusions obtained are as follows.
1.Growth enhancement by microcrystals was observed for aqueous solutions of NaCl and potash alum and for acetone solutions of m-chloronitrobenzene.
2.Supersaturation decrease was observed immediately after the nucleation.
3.Relations were obtained between the number and size of nuclei generated and the enhancement factors.
4.The above mentioned facts lead to a conclusion that the generated nuclei act as the macro growth units which results in the growth rate enhancement.
5.The enhancement effects were 3 times of the normal growth rates at the maximum.
6.The enhancement effects weakened as the nuclei grew.
7.The crystal grown after the enhancement have inclusions of the mother liquor and defects, thus decreased their qualities.
8.The defects are currently under investigation with the corporation of Prof.Sherwood at Strathclyde University, Glasgow by the use of the X-ray topography, and soon will be published after the analysis is over.
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Report
(3 results)
Research Products
(10 results)
