| 학회 |
한국고분자학회 |
| 학술대회 |
2018년 가을 (10/10 ~ 10/12, 경주컨벤션센터) |
| 권호 |
43권 2호 |
| 발표분야 |
Korea-Taiwan Joint Symposium: Functional Polymers for Future Applications(영어발표) |
| 제목 |
Effects of Cross-linking density of UV Irradiated Polystyrene Chains on Domain Orientation and Spatial Order of Block Copolymer Nanodomains |
| 초록 |
UV irradiation (UVI) of varied duration caused cross-linking and neutralization of polystyrene homopolymers of molar mass (Mn) from 6 to 290 kg mol-1 on a silicon- oxide surface. A skin layer of a neutral surface of PS was obtained with an optimum oxidation via brief UVI in air (UVIA). UVI in an inert environment (gaseous dinitrogen) (UVIN) stabilized the PS layers via cross-linking and enabled the PS networks to have an effective adhesive contact with the underlying substrate. Thorough examination of domain orientations and spatial orders of block copolymer via grazing-incident small angle X-ray scattering (GISAXS) and atomic force microscopy (AFM), polystyrene-block-poly(methyl methacrylate) (PS-b-PMMA), thin films in a series on the UVI-treated PS layers yielded clear evidence that a dense layer of neutralized PS chains was required for the perpendicular orientation of PS-b-PMMA nanodomains. In particular, in addition to neutralization, two factors -the densities of physical entanglements and of chemical crosslinks- both in UVI-treated PS, should be considered for the perpendicular orientation of nanolamellae and nanocylinders in symmetric and asymmetric PS-b-PMMA thin films. The density of physical entanglement in PS depended intrinsically on Mn of the PS whereas the density of chemical crosslinks was controlled with a varied duration of UVIN. Both neutron and X-ray reflectivity (NR/XRR) results indicate that sufficiently large densities of physical entanglements and chemical crosslinks can prevent PS-b-PMMA chains from penetrating through the neutral skin layer. The total density of physical entanglements and chemical crosslinks required for the perpendicular orientation correlated with the dimensions of the PS-b-PMMA chains. |
| 저자 |
Ya-Sen Sun, Song-Hao Wu, Wei-Chen Yang
|
| 소속 |
National Central Univ. |
| 키워드 |
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| E-Mail |
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