| 세션명 | Korea-Taiwan Joint Symposium: Functional Polymers for Future Applications (English) |
|---|---|
| 발표장 | 제7회장 (103) |
| 논문코드 | 1L7-5 |
| 발표일 | 2018-10-11 |
| 발표시간 | 15:30-16:00 |
| 논문제목 | Effects of Cross-linking density of UV Irradiated Polystyrene Chains on Domain Orientation and Spatial Order of Block Copolymer Nanodomains |
| 발표자 | Ya-Sen Sun |
| 발표자 소속 | National Central University |
| 저자 | Ya-Sen Sun†, Song-Hao Wu, Wei-Chen Yang |
| 소속 | National Central University |
| 논문초록 | 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. |
THE POLYMER SOCIETY OF KOREA