界面曲線の変動から表面張力を決定するための線形回帰ベースの方法
Carrie E Perlman1, Bret A Brandner2, Stephen B Hall2
1Department of Biomedical Engineering, Stevens Institute of Technology, Hoboken, New Jersey 07030, United States.
Langmuir : the ACS journal of surfaces and colloids
|August 20, 2025
まとめ
新しい線形回帰法では,表面活性物質を使用しても,表面張力 (γ) を界面曲線から正確に決定します. このアプローチは,流体界面の表面張力測定を簡素化し,科学的研究のための貴重なツールを提供します.
科学分野:
- 流体力学
- 表面科学
- 物理化学
背景:
- 表面張力 (γ) は,ヤング-ラプレス関係による水圧 (ΔP) によってバランスをとる流体界面にとって決定的なものです.
- 表面活性剤は,界面特性を変化させ, γ 決定の正確な方法を必要とします.
- 表面活性剤が表面張力に及ぼす影響は,既存の方法では完全に考慮できない場合がある.
研究 の 目的:
- 界面の曲線から表面張力 (γ) を決定するための新しい線形回帰ベースの方法を開発する.
- ディパルミトイル・フォスファティディルコリン (DPPC) モノレイヤーのセシール・ドロップとキャプティブ・バブルを用いてこの方法を検証する.
- 軸対称ドロップ形分析のような確立された技術と比較して,新しい方法の精度を評価する.
主な方法:
- ヤング-ラプレス関係 (ΔP = γ (k1 + k2)) と高さによるΔPの線形変数を使用する.
- 異なる高さでの界面曲率 (k1 + k2) を測定するために,静止ドロップとキャプティブバブルの画像を分析する.
- 線形回帰を ΔP (オフセット) と (k1 + k2) のグラフに適用して γ を決定する.
主要な成果:
- インターフェイスの曲線 (k1 + k2) は,ヨング-ラプレス関係と一致して,高さによって線形に変化することが判明した.
- 開発された線形回帰アルゴリズムは,表面張力 (γ) を正確に決定した.
- 軸対称性滴形分析と比較すると,DPPC単層の平均絶対差は0. 30 ± 0. 37 mN/mで,gamma範囲は2〜70 mN/mであった.
結論:
- 新しい線形回帰法は,界面の曲線から表面張力 (γ) を決定するための正確でアクセス可能な手段を提供します.
- この方法は,DPPCのような表面活性物質の存在でも堅実です.
- 基礎となる理論は3Dイメージングに適応し,複雑なインタフェースの幾何学に応用できる可能性がある.
関連する概念動画
01:16Surface Tension and Surface Energy
1.9K
When a paint brush is immersed in water, the bristles wave freely inside the water. When it is taken out, the bristles stick together. The reason behind this effect is surface tension.
Consider a beaker filled with liquid. The bulk molecules in the liquid experience equal attractive forces on all sides with the surrounding molecules. However, the surface molecules experience a net attractive force downward due to the bulk molecules. The surface of the liquid behaves like a stretched membrane,...
Consider a beaker filled with liquid. The bulk molecules in the liquid experience equal attractive forces on all sides with the surrounding molecules. However, the surface molecules experience a net attractive force downward due to the bulk molecules. The surface of the liquid behaves like a stretched membrane,...
1.9K
01:22Surface Tension of Fluid
484
Surface tension is a fundamental property of fluids, occurring at the boundary between a liquid and a gas or between two immiscible liquids. This phenomenon arises from the cohesive forces between molecules at the fluid's surface, creating an effect similar to a stretched elastic membrane. Inside each fluid, molecules are equally attracted in all directions by neighboring molecules, but surface molecules experience a net inward force, resulting in surface tension.
Surface tension varies...
Surface tension varies...
484
02:57Surface Tension, Capillary Action, and Viscosity
29.2K
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...
29.2K
01:04Hydrostatic Pressure Force on a Curved Surface
2.0K
Hydrostatic pressure on curved surfaces is a fundamental concept in fluid mechanics with broad applications in the civil engineering field. When fluid is in contact with a curved surface, as in a reservoir, dam, or storage tank, it exerts pressure that varies in magnitude and direction along the curved surface. To assess the total hydrostatic force exerted by the fluid on a curved structure, engineers typically isolate the fluid volume adjacent to the surface and analyze the forces acting on...
2.0K
01:16Bending of Curved Members - Neutral Surface
237
In curved beams, unlike straight beams, the stress distribution across the cross-section is not uniform due to the beam's curvature. This non-uniformity arises because the neutral axis, where stress is zero, does not align with the centroid of the section. In a curved beam, the strain varies along the section as a function of the distance from the neutral axis.
Consider the curved member described in the previous lesson. According to Hooke's law, which relates stress to strain within...
Consider the curved member described in the previous lesson. According to Hooke's law, which relates stress to strain within...
237
01:13Contact Angle
13.2K
When a solid is dipped inside a liquid, the liquid surface becomes curved near the contact. For some solid–liquid interfaces, the liquid is pulled up along the solid, while for others, the liquid surface is convex or depressed near the solid surface. This phenomenon can be explained using the concept of cohesive and adhesive forces.
The adhesive force is the molecular force between molecules of different materials, that is, between the molecules of the solid and the liquid. The cohesive...
The adhesive force is the molecular force between molecules of different materials, that is, between the molecules of the solid and the liquid. The cohesive...
13.2K