2013 Fiscal Year Final Research Report
Direct observation of crystallization behavior of isolated polymer chains by atomic force microscopy
| Project/Area Number |
24655091
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| Research Category |
Grant-in-Aid for Challenging Exploratory Research
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| Allocation Type | Single-year Grants |
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| Research Field |
Polymer chemistry
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| Research Institution | Yamagata University |
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Principal Investigator |
KUMAKI Jiro 山形大学, 理工学研究科, 教授 (00500290)
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| Project Period (FY) |
2012-04-01 – 2014-03-31
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| Keywords | 走査プローブ顕微鏡 / 高分子結晶 / 高分子構造・物性 |
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| Research Abstract |
We successfully visualized crystallization behavior of a single isolated polymer chain at a molecular level by atomic force microscopy (AFM). Previously, we found that isotactic poly(methyl methacrylate) (it-PMMA) formed two-dimensional folded chain crystals upon compression of its Langmuir monolayer, and the molecular images of the crystals were clearly visualized by AFM. In the present study, a high-molecular-weight it-PMMA was diluted in a monolayer of an it-PMMA oligomer which cannot crystallize due to the low molecular weight. At a low surface pressure, isolated amorphous chains of the high-molecular-weight it-PMMA solubilized in the oligomer monolayer were observed. On compression, the isolated chains converted to crystals composed of the single chain. Detailed AFM observations of the crystals indicated that the crystalline nuclei preferably formed at the ends of the chains, and the size of the nuclei was almost independent on the molecular weight of the it-PMMA.
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