| Budget Amount *help |
¥3,300,000 (Direct Cost: ¥3,300,000)
Fiscal Year 2000: ¥600,000 (Direct Cost: ¥600,000)
Fiscal Year 1999: ¥2,700,000 (Direct Cost: ¥2,700,000)
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| Research Abstract |
In order to synthesize discotic microgel with poly (4-vinyl pyridine) core and polystyrene shell by crosslinking of discotic poly (4-vinyl pyridine) microdomains with 1, 4-diiodobutane, blend films of poly (styrene-block-4-vinyl pyridine) and 3, N-pentadecylphenol were prepared. Morphology of the microphase separation of blend films was investigated by transmission electron microscopy and small angle X-rey scattering with varying molecular weight of block copolymer, molar content of poly (4-vinyl pyridine) in the block copolymers and blend ratio of the 3, N-pentadecyl phenol to the block copolymer. Formation of hydrogen bonding between phenol group and pyridine group was confirmed by FT-IR.Three blend films formed lamellar within cylinder structure and the thickness of the lamellar phases was 3.72 nm. Then, the microphase separated films were crosslinked with 1, 4-diiodobutane. After the crosslinking, the films were dispersed in chloroform that is good solvent for all sequences. Extern
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al size and shape of the microgels were determined by scanning electron microscopy and transmission electron microscopy with a shadowing technique. It was found that these microgels were discotic and the ranges of their thickness and external diameters were from 2.5 to 5 nm and 20 to 40 nm. From surface tension measurements of the microgels, it was concluded that the microgels were not completely covered with polystyrene shell. Finally, aggregation behavior of the microgels was investigated by transmission electron microscopy. Chloroform, dimethylformamide and tetrahydrofurane were used as the cast solvents. Tetrahydrofurane was a selective solvent that was a good solvent for polystyrene shell and non solvent for poly (4-vinyl pyridine) core. For any type of the microgels, microgels did not aggregate in chloroform. However, all microgels formed aggregates in dimethylformamide even though it was a good solvent. In tetrahydrofrane, the tendency of the aggregation of the microgel was governed by no the volume fraction of core but the molecular weight of the shell chains. Less
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