ガラスのようなポリマーの表面移動性の直接的定量測定法
1Department of Physics and Astronomy and Guelph-Waterloo Physics Institute, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada.
Science (New York, N.Y.)
|March 1, 2014
まとめ
薄いポリマーフィルムはユニークなダイナミクスを発揮します. ガラスの移行温度 (Tg) の下では,表面層のみが流れ,この発見は効果的にモデル化され,ナノリトグラフィーのようなアプリケーションにとって極めて重要です.
科学分野:
- ポリマー物理学 ポリマー物理学
- マテリアルサイエンス 材料科学
- 表面科学とは,地表科学である.
背景:
- 薄いポリマーフィルムは,その塊状態と比較して明確なダイナミックな行動を示します.
- 玻璃化温度 (Tg) 近くのポリマーの移動性を理解することは,材料の応用において極めて重要です.
研究 の 目的:
- ステップフィルム幾何学を用いてTg以上および以下の薄ポリマー薄膜の移動性を調査する.
- フィルム全体の流れと表面局所化された流れを区別するために.
- サブTg表面移動のためのモデルを開発し,検証する.
主な方法:
- 基板上にステップポリマーフィルムの製造.
- Tg. 近くを含む様々な温度帯のフィルムダイナミクスの実験的観測.
- 表面の流れに焦点を当てた分析的な薄膜モデルの開発.
主要な成果:
- Tg以上では,ポリマーフィルム全体が流れを示します.
- Tg以下では,流れは表面に近い領域に限定され,インターフェイスエネルギーによって駆動されます.
- 分析モデルは,Tg下流動の動作を正確に予測します.
- 全体のフィルムから表面局所化された流れへの移行は,大部分のTg.の近くで起こります.
結論:
- この研究では,最小限の閉じ込めと基板効果で薄ポリマー膜の表面の移動性を定量化しています.
- この発見は,ガラスのリオロジーに対する正確な制御を提供し,ナノリトグラフィーやその他の高度なアプリケーションに有益です.
さらに関連する動画
11:34Controlled Synthesis and Fluorescence Tracking of Highly Uniform PolyN-isopropylacrylamide Microgels
Published on: September 8, 2016
9.6K
06:55Synthesis of Cyclic Polymers and Characterization of Their Diffusive Motion in the Melt State at the Single Molecule Level
Published on: September 26, 2016
7.6K
関連する概念動画
01:10Polymers: Molecular Weight Distribution
4.0K
For any given polymer, the weight average molecular weight (Mw) is higher than, if not equal to, the number average molecular weight (Mn). The only situation in which the weight average molecular weight and the number average molecular weight are equal is when a polymer consists only of chains with equal molecular weight. However, this never happens in a synthetic polymer, since it is difficult to control the polymerization process up to a molecular level with accuracy to a hundred percent.
4.0K
01:08Molecular Weight of Step-Growth Polymers
2.1K
Step growth polymerization involves bi or multifunctional monomers. Bifunctional monomers react to form linear step growth polymers, whereas multifunctional monomers react to form non-linear or branched polymers.
As the step-growth polymerization involves step-wise condensation of monomers, the molecular weight also builds up eventually. Consequently, high molecular weight polymers are obtained at the late stages of the polymerization, where 99% of monomers have been consumed.
The extent of the...
As the step-growth polymerization involves step-wise condensation of monomers, the molecular weight also builds up eventually. Consequently, high molecular weight polymers are obtained at the late stages of the polymerization, where 99% of monomers have been consumed.
The extent of the...
2.1K
02:57Surface Tension, Capillary Action, and Viscosity
28.6K
Surface Tension
The various IMFs between identical molecules of a substance are examples of cohesive forces. The molecules within a liquid are surrounded by other molecules and are attracted equally in all directions by the cohesive forces within the liquid. However, the molecules on the surface of a liquid are attracted only by about one-half as many molecules. Because of the unbalanced molecular attractions on the surface molecules, liquids contract to form a shape that minimizes the number...
The various IMFs between identical molecules of a substance are examples of cohesive forces. The molecules within a liquid are surrounded by other molecules and are attracted equally in all directions by the cohesive forces within the liquid. However, the molecules on the surface of a liquid are attracted only by about one-half as many molecules. Because of the unbalanced molecular attractions on the surface molecules, liquids contract to form a shape that minimizes the number...
28.6K