ポリマーガラスの構造的な緩解は,表面,インターフェース,およびその間の部分に起因する
Rodney D Priestley1, Christopher J Ellison, Linda J Broadbelt
1Department of Chemical and Biological Engineering, Northwestern University, Evanston, IL 60208, USA.
Science (New York, N.Y.)
|July 16, 2005
まとめ
ポリマーの構造的緩解は,表面や接点の近くで著しく減速する. この効果は,ポリマーフィルムに100nmを超えて広がり,材料の特性に影響を与えます.
科学分野:
- ポリマーサイエンスの科学
- マテリアルサイエンス 材料科学
- 物理化学 物理化学
背景:
- インタフェース付近のポリマーダイナミクスを理解することは,材料設計において極めて重要です.
- ガラス状の構造的緩和が,ポリマーの長期的性能を左右する.
- 表面とインターフェースの影響は,散発ポリマーの性質を変化させることができます.
研究 の 目的:
- ポリマーの構造的な緩解に対する表面とインターフェースの影響を定量化するために.
- ポリマーフィルム内のこれらの効果の空間的範囲を決定する.
主な方法:
- 多層ポリマーフィルムでの光モニタリングを利用した.
- ポリメチルメタクリlate (PMMA) の構造的緩和率を分析した.
- 自由な表面とシリカ界面でのリラクゼーション速度を大量PMMAと比較した.
主要な成果:
- 構造的な緩解率は,自由な表面では2倍,シリカ界面では15倍減少した.
- シリカ界面で観察されたリラクゼーションのほぼ完全な停止.
- ポリマーフィルムに100nmまで放緩が観察されました.
結論:
- 表面とインターフェースは,ポリマーの構造的緩和を劇的に遅らせます.
- これらの効果は,ガラスの移行温度の変化よりも,ポリマーに深く浸透します.
- ポリマーのダイナミクスにおけるインターフェースによって引き起こされる変化は,大きく,長期に渡るものです.
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