Precise analyses of short-time relaxation at asymmetric polystyrene interface in terms of molecular weight by time-resolved neutron reflectivity measurements

Daisuke Kawaguchi, Andrew Nelson, Yuichi Masubuchi, Jaroslaw P. Majewski, Naoya Torikai, Norifumi L. Yamada, A. R. Siti Sarah, Atsushi Takano, Yushu Matsushita

研究成果: Contribution to journalArticle査読

13 被引用数 (Scopus)

抄録

The short-time mutual diffusion at an interface of linear polystyrene/linear deuterated polystyrene with different molecular weights was examined by time-resolved neutron reflectivity (TR-NR) measurements. The model scattering length density (b/V) profiles obtained by solving a partial differential equation for the diffusion process, using the segmental diffusion coefficients as the only fitting parameter were used to analyze the TR-NR data. In short-time diffusion, the asymmetric (b/V) profiles derived from a segmental relaxation model were able to model the data much better than those obtained by center-of-mass diffusion based on reptation model and by a simple error function. These analyses clearly indicate that even if the molecular weights of both components are larger than the critical molecular weight for entanglement, the initial interfacial broadening of bilayer films with different molecular weight proceeds with asymmetric mobility being proportional to N-1. Time dependence of the interfacial positions, u(t), was extracted from the (b/V) profiles. The exponent of α in u(t) ∼ tα reflects the asymmetric mobility of the components. This analysis also gave the time dependence of mutual diffusion coefficients, D. The D value gradually decreases with increasing time and reaches a constant value.

本文言語英語
ページ(範囲)9424-9433
ページ数10
ジャーナルMacromolecules
44
23
DOI
出版ステータス出版済み - 12 13 2011
外部発表はい

All Science Journal Classification (ASJC) codes

  • 有機化学
  • ポリマーおよびプラスチック
  • 無機化学
  • 材料化学

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