相关实验视频
Updated: Jun 5, 2026

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Measurement of Aggregate Cohesion by Tissue Surface Tensiometry
Published on: April 8, 2011
粘附:湿头发中的弹性毛囊凝聚
José Bico1, Benoît Roman, Loïc Moulin
1Physique et Mécanique des Milieux Hétérogènes (UMR CNRS 7636), ESPCI, 75231 Paris Cedex 5, France. jbico@pmmh.espci.fr
Nature
|December 14, 2004
概括
潮湿的头发由于毛细血管力和叶片弹性而形成块. 这项研究揭示了一种新的自我组装过程,模仿昆虫结构和粘合剂,对微型设备有影响.
科学领域:
- 物理 物理学 物理
- 材料科学 材料科学 材料科学
- 生物模拟学是一种生物模拟学.
背景情况:
- 头发丝,就像弹性叶片一样,在湿时表现出复杂的行为.
- 了解头发凝结可以为仿生材料和粘合剂的设计提供信息.
- 毛细管力在柔性结构的自我组装中起着重要作用.
研究的目的:
- 为了研究湿头发凝结背后的物理机制.
- 为了建模在湿液中平行弹性叶片的聚合.
- 在等级模式形成中识别毛细血管力和材料弹性之间的相互作用.
主要方法:
- 在一个完全湿透的液体中,将一个平行弹性叶片的模型刷浸入完美湿透的液体中.
- 当刷子被拉出来时,观察状束的聚合.
- 分析毛细血管力和叶片弹性之间的平衡.
主要成果:
- 两对叶片束在从液体中提取时相继聚合.
- 复杂的等级模式出现,由毛细血管力驱动.
- 观察到的现象代表了一种新的毛细管驱动的自我组装或凝聚的新型.
结论:
- 湿头发的凝结是由弹性结构的毛细血管驱动的自我组装解释的.
- 这个过程对理解自然现象 (例如,昆虫) 和技术应用 (例如,粘合剂,微型设备) 有影响.
- 这些发现为灵活的自组装系统中的凝聚带来了新的视角.
相关概念视频
Adhesion
Adhesion occurs when one type of molecule is attracted to a different molecule. Water exhibits adhesive properties in the presence of polar surfaces, such as glass or cellulose in plants. For instance, when water is poured into a glass, the positively charged hydrogen molecules of water are more attracted to the negatively charged oxygen molecules in the silica than to the oxygen in neighboring water molecules.
Capillary action is a result of water’s adhesive tendencies. When a narrow glass...
Capillary action is a result of water’s adhesive tendencies. When a narrow glass...
Cohesion
Cohesion is the attraction between molecules of the same type, such as water molecules. Water molecules have an overall neutral charge but are polar molecule. An oxygen atom in one water molecule has a partial negative charge that can bind to a hydrogen atom with a partial positive charge in a second water molecule, forming a hydrogen bond. Each water molecule can form up to four hydrogen bonds with other water molecules. Hydrogen bonds are responsible for water's cohesive nature.
On a surface,...
On a surface,...
Surface Tension, Capillary Action, and Viscosity
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...
Rise of Liquid in a Capillary Tube
When very thin cylindrical tubes, called capillaries, are dipped in a liquid, the liquid rises or falls in the tube compared to the surrounding liquid. This phenomenon is called capillary action. Capillary action occurs due to the combination of two opposing forces: the cohesive forces of the liquid, which cause it to stick to itself and form a rounded shape, and the adhesive forces between the liquid and the walls of the container, which cause the liquid to be attracted to the container walls.
Surface Tension
Surface tension is defined as the force per unit length (γ) acting along the surface of a liquid. It arises due to strong intermolecular forces of attraction. A molecule located inside the bulk of the liquid is surrounded by other molecules and experiences equal forces in all directions. However, a molecule at the surface experiences unbalanced forces because there are more neighboring molecules below than above. This creates a net inward force that pulls surface molecules toward the interior,...
Capillarity in Fluid
Capillarity describes the movement of liquid in small spaces without external forces acting on it. The capillarity is driven by surface tension and adhesive interactions between the liquid and surrounding solid surfaces. This effect is often seen in narrow tubes, porous materials, and fine particles.
Surface tension is crucial to capillarity. It results from cohesive forces between liquid molecules at the liquid-air boundary, forming a skin that resists external forces. When the capillary tube...
Surface tension is crucial to capillarity. It results from cohesive forces between liquid molecules at the liquid-air boundary, forming a skin that resists external forces. When the capillary tube...

