2006 Fiscal Year Final Research Report Summary
Nucleation Mechanism of Organic Compound Crystals and Crystallization for Production of Nano-Medicine
| Project/Area Number |
17560664
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Properties in chemical engineering process/Transfer operation/Unit operation
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| Research Institution | Osaka City University |
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Principal Investigator |
OOSHIMA Hiroshi Osaka City University, Graduate School of Engineering, Professor, 大学院工学研究科, 教授 (20112526)
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| Co-Investigator(Kenkyū-buntansha) |
IGARASHI Koichi Osaka City University, Graduate School of Engineering, Research Associate, 大学院工学研究科, 助手 (70315977)
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| Project Period (FY) |
2005 – 2006
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| Keywords | Nucleation of crystals / Crystal size distribution / Crystal polymorphs / Irradiation of microwave / Crystallization of organic compounds / Nano-medicine / Solution structure / Anti-solvent crystallization |
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| Research Abstract |
1. In order to elucidate mechanism of crystal nucleation of organic compounds, the relationship between crystallization of polymorphs of an organic compound BPPI(C16H12C12F3N302) and the solution structure was investigated. The B02 form of BPPI crystals was precipitated from a methanol solution and the B01 form appeared from an ethanol solution. We compared crystal structures of those polymorphs with each solution structures determined by NMR analysis for solution. As a result, it was found that the conformation of BPPI molecules in each solution was similar to that of BPPI molecules forming each polymorph. The structure of molecular aggregates formed in each solution before nucleation was also similar to each crystal structure. However the structure of molecular aggregates was not completely the same as the corresponding crystal structure. This suggests that nucleation requires structure-transformation of molecular aggregates from a certain random structure to a crystal structure, namely the structure-transformation step should be the nucleation. We also obtained a result suggesting a novel concept about nucleation, that is the propagation of nucleation in solution.
2. We showed that the irradiation of microwave during crystallization suppresses nucleation even under a high super-saturation. The controlled suppression of nucleation must play an important role for production of crystals with small size and a narrow size distribution.
3. We developed a novel continuous crystallizer with a mL-scale for production of micro crystals and production of an unstable polymorph. We could operate this crystallizer at a mean residence time of sub-second without clogging of crystals.
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