Demonstration of nano-size and morphology effect on a coordination polymer nanorystal

2021 Fiscal Year Final Research Report

• Project/Area Number: 19K05186
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 28010:Nanometer-scale chemistry-related
• Research Institution: Kochi University of Technology
• Principal Investigator: OHTANI Masataka 高知工科大学, 環境理工学群, 准教授 (20585004)
• Project Period (FY): 2019-04-01 – 2022-03-31
• Keywords: 配位高分子 / 金属有機構造体 / ナノ結晶 / 相転移 / 固体発光 / 単結晶 / 電子顕微鏡

Outline of Final Research Achievements

We demonstrated that unprecedented property changes appear in PCP/MOF crystals by regulating their crystal size and shape in nanometer scale. Particularly, we found that PCP/MOF crystals, which have been conventionally considered to exhibit thermally stable crystalline phase, undergo an unprecedented thermal crystal phase transition by nanosizing their crystal size. The nanosizing of PCP/MOF crystals also has a remarkable effect on the physical properties of molecules encapsulated in the pore of PCP/MOF crystals. Fluorescent dye-incorporated PCP/MOF nanocrystals, in which fluorescent dyes were encapsulated as guest molecules, showed high quantum yields of fluorescence emission even in the solid state. Furthermore, the fluorescence resonance energy transfer efficiency between an encapsulated fluorescent dye and an adsorbed dye on the nanocrystal surface was also remarkably affected by the nanosizing of the host PCP/MOF crystals.

Free Research Field

ナノ材料化学

Academic Significance and Societal Importance of the Research Achievements

本研究で得られた成果は、PCP/MOF結晶のナノサイズ化に伴う物性の変化を様々な物理化学的な考察から実証するとともに、「精密に結晶サイズ・外形が制御された配位高分子（PCP/MOF）の結晶は、固有の物理的・化学的性質を示すか？」という学術的な問いに対して、前例のない有用な知見を与えている。また、学術的な意義とともに、PCP/MOF結晶の溶融・ガラス転移などの基本的な熱的な物理特性の制御は、新材料としての成形加工性において重要であり、応用的な側面からも今後の発展が期待される成果が得られたと確信している。